feat(infra): playlist processing saga + generalize fault handling (phase 3)

Adds the PlayList picture-processing lifecycle saga (correlated by PlayListId)
mirroring the track one, and generalizes the failure plumbing:
- Rename the track fault translator to ProcessingSlipFaultConsumer and use a
  generic Workflow.SubjectId variable + ProcessKind; it now emits typed
  Track{Picture,Audio}/PlayListPicture ProcessingFailed events for all slips
- PlayListProcessingStateMachine (+ EF-persisted PlayListProcessingState,
  migration): starts on CreatePlayListResourcesEvent, finalizes on
  PlayListPictureProcessed, and on failure marks the playlist Failed and
  removes the orphaned final picture (PlayListProcessingFailedConsumer +
  MarkPlayListAsFailedActivity)
- UpdatePlayListPictureActivity publishes PlayListPictureProcessed on success
- Picture slip carries SubjectId + PlayListPicture kind + fault subscription

Verified end-to-end in Docker (RabbitMQ + migrated Postgres): both saga
endpoints, the fault translator and cleanup consumers configure, and an
addressing cross-check confirms all 21 activity execute queues the builders
address exist (caught + fixed a kebab mismatch on mark-play-list-as-failed).

Build: 0 warnings, 0 errors.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.claude/launch.json

@@ -1,30 +0,0 @@
-{
-	"version": "0.0.1",
-	"configurations": [
-		{
-			"name": "musify-web",
-			"runtimeExecutable": "npm",
-			"runtimeArgs": ["--prefix", "web-player", "run", "dev"],
-			"port": 3000,
-			"autoPort": true
-		},
-		{
-			"name": "musify-api",
-			"runtimeExecutable": "dotnet",
-			"runtimeArgs": ["run", "--project", "backend/Hosts/Musify.Api"],
-			"port": 5111
-		},
-		{
-			"name": "musify-worker",
-			"runtimeExecutable": "dotnet",
-			"runtimeArgs": ["run", "--project", "backend/Hosts/Musify.Worker"],
-			"port": 5112
-		},
-		{
-			"name": "musify-streaming-gateway",
-			"runtimeExecutable": "dotnet",
-			"runtimeArgs": ["run", "--project", "backend/Hosts/Musify.StreamingGateway"],
-			"port": 8081
-		}
-	]
-}

.gitattributes

@@ -4,13 +4,6 @@
 # Force LF for shell scripts
 *.sh text eol=lf
 
-# Env templates get `cp`-ed straight into deploy/.env / deploy/.env.prod,
-# which containers (e.g. zitadel-init in deploy/compose.yml) parse with
-# plain shell text tools — keep them LF so a Windows checkout can't
-# reintroduce CRLF into a value that then looks non-empty but isn't.
-.env.example text eol=lf
-.env.prod.example text eol=lf
-
 # Treat common binaries as binary
 *.png binary
 *.jpg binary

.gitea/workflows/ci-cd.yml

@@ -1,127 +0,0 @@
-name: CI/CD
-
-on:
-  push:
-    branches: ['**']
-  pull_request:
-    branches: ['**']
-
-concurrency:
-  group: production-deploy
-  cancel-in-progress: false
-
-jobs:
-  backend-tests:
-    name: BackEnd
-    runs-on: ubuntu-latest
-    timeout-minutes: 20
-    defaults:
-      run:
-        working-directory: backend
-    steps:
-      - uses: actions/checkout@v4
-
-      - uses: actions/setup-dotnet@v4
-        with:
-          dotnet-version: '10.0.x'
-
-      - name: Restore
-        run: dotnet restore Musify.slnx
-
-      - name: Build
-        run: dotnet build Musify.slnx --no-restore -c Release
-
-      - name: Test
-        run: dotnet test Musify.slnx --no-build -c Release
-
-  web-player-checks:
-    name: WebPlayer
-    runs-on: ubuntu-latest
-    timeout-minutes: 15
-    defaults:
-      run:
-        working-directory: web-player
-    steps:
-      - uses: actions/checkout@v4
-
-      - uses: actions/setup-node@v4
-        with:
-          node-version: '22'
-          cache: npm
-          cache-dependency-path: web-player/package-lock.json
-
-      - run: npm ci
-
-      - name: Type-check
-        run: npm run check
-
-      - name: Lint
-        run: npm run lint
-
-  # Runs on the production host itself, through the existing self-hosted
-  # Gitea Actions runner (act_runner), which also carries a "production"
-  # label registered in native (non-docker) mode so its steps see the host's
-  # real Docker daemon directly (Docker socket + a bind-mounted deploy
-  # directory — see deploy/README.md for how that runner is set up).
-  #
-  # DEPLOY_PATH is the persistent clone already on that host (the one whose
-  # deploy/.env.prod is filled in and matches SharedServices/.env.prod) —
-  # deploy reuses it instead of a fresh checkout, since .env.prod is
-  # untracked and only lives there.
-  deploy:
-    name: Deploy
-    needs: [backend-tests, web-player-checks]
-    if: github.ref == 'refs/heads/master' && github.event_name == 'push'
-    runs-on: [production]
-    timeout-minutes: 20
-    env:
-      DEPLOY_PATH: /home/ubuntu/deploys/musify
-      COMPOSE: docker compose --env-file deploy/.env.prod -f deploy/compose.yml -f deploy/compose.prod.yml
-    steps:
-      - name: Pull latest master
-        run: |
-          set -euo pipefail
-          git config --global --add safe.directory "$DEPLOY_PATH"
-          cd "$DEPLOY_PATH"
-          git fetch origin master
-          git reset --hard origin/master
-
-      - name: Generate stream-ticket keys
-        run: |
-          set -euo pipefail
-          cd "$DEPLOY_PATH"
-          $COMPOSE run --rm --no-deps keys-init
-
-      # The migrations are baked into the migrator image, so it is rebuilt on
-      # every deploy (plain `up` would reuse the stale image and re-apply the
-      # old migrations). `run --rm` starts wait-for-postgres, blocks until the
-      # migration finishes and propagates its exit code, so a failed migration
-      # aborts the deploy before the new API is started against an old schema.
-      - name: Migrate database
-        run: |
-          set -euo pipefail
-          cd "$DEPLOY_PATH"
-          $COMPOSE build migrate
-          $COMPOSE run --rm migrate
-
-      # Both jobs verify themselves through the public auth./s3. URLs, served
-      # by the shared edge nginx (Infrastructure's edge/), and are idempotent.
-      - name: Create OIDC app and S3 bucket
-        run: |
-          set -euo pipefail
-          cd "$DEPLOY_PATH"
-          $COMPOSE up -d seaweedfs-init zitadel-init
-          for job in musify-seaweedfs-init musify-zitadel-init; do
-            code=$(docker wait "$job")
-            if [ "$code" != "0" ]; then
-              docker logs "$job"
-              echo "$job exited with $code"
-              exit 1
-            fi
-          done
-
-      - name: Build and start apps
-        run: |
-          set -euo pipefail
-          cd "$DEPLOY_PATH"
-          $COMPOSE --profile apps up -d --build api worker gateway web-player

.github/copilot-instructions.md

@@ -0,0 +1,4 @@
+# Copilot Instructions
+
+## Project Guidelines
+- No crear pruebas/tests si el usuario no lo solicita explícitamente; evitar cambios no pedidos.

.gitignore

@@ -7,9 +7,6 @@ obj/
 *.userosscache
 .vs/
 artifacts/
-TestResults/
-*.trx
-*.coverage
 
 # Rider / VS
 .idea/
@@ -18,14 +15,5 @@ TestResults/
 Thumbs.db
 .DS_Store
 
-# Environment files (deploy/.env, deploy/.env.prod, web-player/.env, ...)
-.env
-.env.*
+# Secrets / local
 *.env
-!.env.example
-!.env.prod.example
-
-# Deploy secrets and runtime state
-deploy/keys/
-deploy/secrets/
-deploy/zitadel/.output/

README.md

@@ -1,55 +0,0 @@
-# Musify
-
-A music streaming app. Upload your own tracks, organize them into playlists
-and albums, and stream them back with a web player built around your
-listening habits: auto-generated mixes, a home feed, search, likes, and an
-Explore page for finding something new.
-
-## What it does
-
-- **Upload and organize your own music**: tracks, albums, cover art, artist credits.
-- **Playlists**, likes, and a "recently played" history.
-- **Mixes**, playlists generated automatically from what you actually listen to.
-- **Explore**, genre browsing and search across tracks, albums, playlists and people.
-- **Real streaming**, not just file downloads: seek, queue, shuffle, repeat.
-- **Accounts via OIDC login**, with an optional anonymous listening mode.
-- Light and dark themes, and a layout that works on both desktop and mobile.
-
-## How it's built
-
-**Backend**: .NET 10, split into a REST API, a background worker, and a
-dedicated streaming gateway.
-- Clean architecture (Domain / Application / Infrastructure) with CQRS (Mediator) and `ErrorOr` results.
-- PostgreSQL via EF Core for metadata. RabbitMQ and MassTransit handle async processing (audio transcoding, thumbnails) with saga-based rollback.
-- SeaweedFS (S3-compatible) for file storage. Uploads and downloads go straight between the client and storage, never through the API.
-- ffmpeg for audio transcoding, ImageSharp for thumbnails.
-- A YARP reverse proxy that streams the audio and checks a signed, short-lived ticket on every request.
-- Zitadel for login (OIDC/OAuth2).
-
-**Web client**: SvelteKit 2 on Svelte 5 (runes), TypeScript, Tailwind 4.
-The session lives on the server, so the backend access token never reaches the browser.
-
-**Infrastructure**: Musify's own apps run from Docker Compose (dev and
-production overlays). Postgres, RabbitMQ, SeaweedFS, Zitadel and Jaeger are
-shared infrastructure that lives in a separate `Infrastructure` git
-repository, used by Musify and by other projects that need the same OIDC
-provider and object storage.
-
-## Project layout
-
-```
-backend/      .NET solution: Api, Worker, StreamingGateway, and the shared Domain/Application/Infrastructure
-web-player/   the SvelteKit web client
-deploy/       Docker Compose stacks for dev and production
-docs/         architecture notes, one file per area
-```
-
-Postgres, Zitadel, SeaweedFS, RabbitMQ and Jaeger are not part of this
-layout. They live in the separate `Infrastructure` repository instead.
-
-## Digging deeper
-
-[docs/](docs/README.md) covers how each piece works and why: architecture,
-authentication, storage, streaming, media processing, and the local dev
-setup. [deploy/README.md](deploy/README.md) has the full instructions for
-running the stack, in development or on a production server.

backend/.dockerignore

@@ -1,12 +0,0 @@
-**/bin/
-**/obj/
-**/.vs/
-**/.idea/
-.git/
-.github/
-.agents/
-.claude/
-**/DesignSettings.json
-*.user
-# Test projects: never shipped, no app Dockerfile needs them in its build context.
-Tests/

backend/.editorconfig

@@ -1,79 +0,0 @@
-root = true
-
-[*]
-charset = utf-8
-insert_final_newline = true
-trim_trailing_whitespace = true
-indent_style = space
-
-[*.{csproj,props,targets,slnx,xml}]
-indent_size = 2
-
-[*.json]
-indent_size = 4
-
-[**/Migrations/**.cs]
-generated_code = true
-
-[*.cs]
-indent_size = 4
-
-csharp_style_namespace_declarations = block_scoped:warning
-csharp_using_directive_placement = outside_namespace:warning
-dotnet_sort_system_directives_first = true
-dotnet_separate_import_directive_groups = false
-dotnet_diagnostic.IDE0005.severity = warning
-
-dotnet_style_require_accessibility_modifiers = always:warning
-csharp_style_var_for_built_in_types = true:suggestion
-csharp_style_var_when_type_is_apparent = true:suggestion
-csharp_style_var_elsewhere = true:suggestion
-csharp_prefer_braces = when_multiline:warning
-csharp_style_prefer_primary_constructors = true:suggestion
-csharp_style_expression_bodied_methods = when_on_single_line:suggestion
-dotnet_style_prefer_collection_expression = when_types_loosely_match:suggestion
-
-# Naming. Roslyn applies the first matching rule in file order, so the specific rules come first.
-# Private fields are _camelCase whatever their modifiers (static, readonly, const).
-dotnet_naming_rule.private_fields.symbols = private_fields
-dotnet_naming_rule.private_fields.style = underscore_camel_case
-dotnet_naming_rule.private_fields.severity = warning
-dotnet_naming_symbols.private_fields.applicable_kinds = field
-dotnet_naming_symbols.private_fields.applicable_accessibilities = private
-dotnet_naming_style.underscore_camel_case.capitalization = camel_case
-dotnet_naming_style.underscore_camel_case.required_prefix = _
-
-# Non-private fields (constants, static readonly, etc.) are PascalCase.
-dotnet_naming_rule.other_fields.symbols = other_fields
-dotnet_naming_rule.other_fields.style = pascal_case
-dotnet_naming_rule.other_fields.severity = warning
-dotnet_naming_symbols.other_fields.applicable_kinds = field
-dotnet_naming_symbols.other_fields.applicable_accessibilities = public, internal, protected, protected_internal, private_protected
-dotnet_naming_style.pascal_case.capitalization = pascal_case
-
-dotnet_naming_rule.interfaces.symbols = interfaces
-dotnet_naming_rule.interfaces.style = interface_style
-dotnet_naming_rule.interfaces.severity = warning
-dotnet_naming_symbols.interfaces.applicable_kinds = interface
-dotnet_naming_style.interface_style.capitalization = pascal_case
-dotnet_naming_style.interface_style.required_prefix = I
-
-dotnet_naming_rule.types_and_members.symbols = types_and_members
-dotnet_naming_rule.types_and_members.style = pascal_case
-dotnet_naming_rule.types_and_members.severity = warning
-dotnet_naming_symbols.types_and_members.applicable_kinds = class, struct, enum, delegate, property, method, event
-dotnet_naming_symbols.types_and_members.applicable_accessibilities = *
-
-# CA1848/CA1873 would turn every log call into a [LoggerMessage] source-generated method; CA1716 flags the
-# EF-style IDatabase.Set<T>() and the Musify.Application.Shared namespace, whose names are deliberate.
-dotnet_diagnostic.CA1848.severity = suggestion
-dotnet_diagnostic.CA1873.severity = suggestion
-dotnet_diagnostic.CA1716.severity = suggestion
-# The routing slip builders are stateless services resolved from DI; they stay instance members.
-dotnet_diagnostic.CA1822.severity = suggestion
-
-# Test names follow Method_Scenario_Expected.
-[Tests/**.cs]
-dotnet_diagnostic.CA1707.severity = none
-# xUnit collection fixtures are conventionally named ...Collection.
-dotnet_diagnostic.CA1711.severity = none

backend/CLAUDE.md

@@ -1,58 +0,0 @@
-# Musify: backend
-
-.NET 10 solution (`Musify.slnx`): `Core/` (Domain, Application, Infrastructure), `Hosts/` (Api, Worker, StreamingGateway) and `Tests/`. Architecture and flows are in `../docs/`.
-
-## Commands
-
-Run from `backend/`.
-
-```sh
-dotnet build Musify.slnx            # warnings are errors, including unused usings (IDE0005)
-dotnet test Musify.slnx             # Infrastructure and Api tests need Docker (Testcontainers)
-dotnet format Musify.slnx --verify-no-changes
-```
-
-- Read the totals of `dotnet test` (`total:`, `succeeded:`) before trusting it; don't chain it with `&&` into a commit.
-- EF migrations: `dotnet ef migrations add <Name> --project Core/Musify.Infrastructure --startup-project Core/Musify.Infrastructure` (set `Database__ConnectionString` to any value). A model change needs a migration; the entity model lives in `ModelConfiguration.Apply`, which the in-memory test database reuses.
-- An HTTP contract change (routes, DTOs, responses) needs the web-player schema regenerated (`web-player/src/lib/api/schema.d.ts`, from `/openapi/v1.json`) and `npm run check` clean.
-- A MassTransit message change (events, routing slip arguments, process kinds) means the queues must be drained before deploying; note it in the commit.
-
-## Style
-
-- Block-scoped namespaces (`namespace X { }`; file-scoped `namespace X;` is not allowed), usings outside the namespace and sorted (`.editorconfig` enforces it).
-- Private fields are `_camelCase` whatever their modifiers (including `static readonly` and `const`); non-private constants and static fields, types, methods and properties are PascalCase; interfaces start with `I`; explicit accessibility. Enforced by `.editorconfig` (IDE1006).
-- `ArgumentNullException.ThrowIfNull(x)` without `nameof`.
-- Use `PlayList` (not `Playlist`) in code; configuration POCOs end in `Configuration`; injected services are named after their type (`storageService`).
-- User-facing strings are in English (the web-player owns translation).
-- Trim stored names; normalized columns go through `TextNormalizer.Normalize`.
-- Format ids and numbers with `CultureInfo.InvariantCulture`; put `CancellationToken` last.
-
-## Application layer
-
-- One file per use case, `<Feature>/<UseCase>.cs`, holding the record and its handler; responses go in `Responses/`.
-- Errors come from `AppErrors` (`NotFound`, `Forbidden` = 403 for "not the owner", `Conflict`). `Error.Unauthorized` (401) only means "not signed in". The success value is `Result.Success`; the API maps it to 204.
-- Handlers that cannot fail return plain types. Lists are paginated through `PageRequest` / `ToPaginatedAsync`, ordered with an `Id` tiebreak, and public reads return only `LifeCycleStatus.Active` rows.
-- Owned-entity operations go through `FindOwnedAsync` (non-active entities are not found).
-- No try/catch around `SaveChangesAsync` or `PublishAsync` in handlers: the outbox makes publish + save atomic. Infrastructure either handles an error or lets it propagate; never log and rethrow.
-- List query records keep `int PageNumber, int PageSize`; the API binds them through `PageQuery` and validates them with `PageQueryValidator`.
-
-## API layer
-
-- Routes: `{id:guid}` for the resource, `{trackId:guid}` for sub-resources, `{id:long}` / `{userId:long}` for user ids.
-- Every endpoint returns `IResult` (`Results.Ok` when the handler cannot fail, `ToHttpResult()` otherwise).
-- Validation limits live in `Validators/Limits.cs`; the database column length wins when a limit disagrees with the web-player. Upload allow-lists are in `Validators/Uploads.cs`.
-- `.WithSummary(...)` is sentence case without a trailing period.
-
-## Infrastructure and hosts
-
-- MassTransit routing slips are built from `RoutingSlips.Create` / `AddStep` / `TrackFaults`; activities for the three owner types share generic bases (`MarkLifeCycleActivity<T>`, `DeleteEntityActivity<T>`, `UpdatePicturesActivity<T>`).
-- Recurring work is Hangfire (`RecurringJobsRegistrar`); intervals are in seconds and rounded up to whole minutes.
-- The Worker calls `AddApplication` and validates its service container on build, so any handler dependency must be registered there. Shared config sections in its `appsettings.json` mirror the API's.
-- The StreamingGateway references neither Application nor Infrastructure and keeps its own options.
-
-## Tests
-
-- xUnit v3; pass `TestContext.Current.CancellationToken` to methods that take a token (analyzer xUnit1051).
-- Test names are `Method_Scenario_Expected`.
-- Application tests use the in-memory SQLite `TestDatabase`; Infrastructure and Api tests use Testcontainers (Postgres, SeaweedFS). MassTransit sagas and consumers are tested on the MassTransit test harness.
-- `Infrastructure` exposes its internals to `Musify.Infrastructure.Tests`.

backend/Core/Musify.Application/Albums/AddTracksToAlbum.cs

@@ -1,76 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums
-{
-    public record AddTracksToAlbumCommand(long UserId, Guid AlbumId, IReadOnlyList<Guid> TrackIds)
-        : ICommand<ErrorOr<Success>>;
-
-    public class AddTracksToAlbumCommandHandler(
-        IDatabase database,
-        ILogger<AddTracksToAlbumCommandHandler> logger)
-        : ICommandHandler<AddTracksToAlbumCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(AddTracksToAlbumCommand request, CancellationToken cancellationToken)
-        {
-            var album = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-            if (album.IsError)
-                return album.Errors;
-
-            var requestedIds = request.TrackIds.Distinct().ToList();
-
-            var tracks = await database.Tracks
-                .AsNoTracking()
-                .Where(track => requestedIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active)
-                .Select(track => new { track.Id, track.OwnerUserId })
-                .ToListAsync(cancellationToken);
-
-            var missing = requestedIds.FirstOrDefault(id => tracks.All(track => track.Id != id));
-            if (missing != Guid.Empty)
-                return AppErrors.NotFound("Track", missing);
-
-            var foreign = tracks.FirstOrDefault(track => track.OwnerUserId != request.UserId);
-            if (foreign != null)
-                return AppErrors.Forbidden("Track", foreign.Id);
-
-            var alreadyInAlbum = await database.AlbumHasTracks
-                .AsNoTracking()
-                .Where(link => link.AlbumId == request.AlbumId && requestedIds.Contains(link.TrackId))
-                .Select(link => link.TrackId)
-                .ToListAsync(cancellationToken);
-
-            var toAdd = requestedIds.Where(id => !alreadyInAlbum.Contains(id)).ToList();
-            if (toAdd.Count == 0)
-                return Result.Success;
-
-            var nextTrackNumber = (await database.AlbumHasTracks
-                .Where(link => link.AlbumId == request.AlbumId)
-                .MaxAsync(link => (int?)link.TrackNumber, cancellationToken) ?? 0) + 1;
-
-            foreach (var trackId in toAdd)
-            {
-                await database.AlbumHasTracks.AddAsync(new AlbumHasTrack
-                {
-                    AlbumId = request.AlbumId,
-                    TrackId = trackId,
-                    TrackNumber = nextTrackNumber++
-                }, cancellationToken);
-            }
-
-            var saved = await database.TrySaveChangesAsync(
-                AppErrors.Conflict("Album.ConcurrentChange", "The album changed while adding tracks. Try again."), cancellationToken);
-            if (saved.IsError)
-                return saved;
-
-            logger.LogInformation("Added {Count} tracks to album {AlbumId}", toAdd.Count, request.AlbumId);
-
-            return Result.Success;
-        }
-    }
-}

backend/Core/Musify.Application/Albums/CreateAlbum.cs

@@ -1,104 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Pictures;
-using Musify.Application.Services;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums
-{
-    public record CreateAlbumCommand(
-        long UserId,
-        string Title,
-        string? Description,
-        int? ReleaseYear,
-        Guid PictureIntentId,
-        AlbumType Type = AlbumType.Album,
-        IReadOnlyList<Guid>? TrackIds = null)
-        : ICommand<ErrorOr<AlbumApplicationResponse>>;
-
-    public class CreateAlbumCommandHandler(
-        IEventBus eventBus,
-        IDatabase database,
-        UploadIntentValidator uploadIntentValidator,
-        ILogger<CreateAlbumCommandHandler> logger,
-        AlbumConfiguration albumConfiguration)
-        : ICommandHandler<CreateAlbumCommand, ErrorOr<AlbumApplicationResponse>>
-    {
-        public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(CreateAlbumCommand request, CancellationToken cancellationToken)
-        {
-            var userExists = await database.Users
-                .AsNoTracking()
-                .AnyAsync(user => user.Id == request.UserId, cancellationToken);
-            if (!userExists)
-                return AppErrors.NotFound("User", request.UserId);
-
-            var trackIds = (request.TrackIds ?? []).Distinct().ToList();
-            var tracks = await database.Tracks
-                .AsNoTracking()
-                .Where(track => trackIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active)
-                .Select(track => new { track.Id, track.OwnerUserId, track.IsPublished })
-                .ToListAsync(cancellationToken);
-
-            var missing = trackIds.FirstOrDefault(id => tracks.All(track => track.Id != id));
-            if (missing != Guid.Empty)
-                return AppErrors.NotFound("Track", missing);
-
-            var foreign = tracks.FirstOrDefault(track => track.OwnerUserId != request.UserId);
-            if (foreign != null)
-                return AppErrors.Forbidden("Track", foreign.Id);
-
-            var prepared = await PictureSourceChange.PrepareAsync(
-                uploadIntentValidator, request.PictureIntentId, request.UserId, UploadIntentPurpose.AlbumPicture, albumConfiguration, cancellationToken);
-            if (prepared.IsError)
-                return prepared.Errors;
-
-            var picture = prepared.Value;
-            var title = request.Title.Trim();
-
-            var album = new Album
-            {
-                OwnerUserId = request.UserId,
-                Title = title,
-                NormalizedTitle = TextNormalizer.Normalize(title),
-                Description = request.Description,
-                ReleaseYear = request.ReleaseYear,
-                Type = request.Type,
-                Pictures = picture.Pictures
-            };
-
-            await database.Albums.AddAsync(album, cancellationToken);
-
-            for (var index = 0; index < trackIds.Count; index++)
-            {
-                await database.AlbumHasTracks.AddAsync(
-                    new AlbumHasTrack { AlbumId = album.Id, TrackId = trackIds[index], TrackNumber = index + 1 },
-                    cancellationToken);
-            }
-
-            await eventBus.PublishAsync(
-                new CreateAlbumResourcesEvent(
-                    album.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-                cancellationToken);
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Created album {AlbumId} for user {UserId} with {Count} tracks", album.Id, request.UserId, trackIds.Count);
-
-            var published = tracks.Where(track => track.IsPublished).Select(track => track.Id).ToHashSet();
-            var visibleTrackIds = trackIds.Where(published.Contains).ToList();
-
-            return AlbumApplicationResponse.FromEntity(
-                album,
-                visibleTrackIds.Count,
-                [.. visibleTrackIds.Take(AlbumProjections.CoverTrackCount)]);
-        }
-    }
-}

backend/Core/Musify.Application/Albums/DeleteAlbum.cs

@@ -1,37 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums
-{
-    public record DeleteAlbumCommand(long UserId, Guid AlbumId)
-        : ICommand<ErrorOr<Success>>;
-
-    public class DeleteAlbumCommandHandler(
-        IDatabase database,
-        IEventBus eventBus,
-        ILogger<DeleteAlbumCommandHandler> logger)
-        : ICommandHandler<DeleteAlbumCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(DeleteAlbumCommand request, CancellationToken cancellationToken)
-        {
-            var found = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-            if (found.IsError)
-                return found.Errors;
-
-            var album = found.Value;
-            album.LifeCycleStatus = LifeCycleStatus.Removing;
-
-            await eventBus.PublishAsync(new DeleteAlbumEvent(album.Id, request.UserId), cancellationToken);
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Marked album {AlbumId} as removing", request.AlbumId);
-
-            return Result.Success;
-        }
-    }
-}

backend/Core/Musify.Application/Albums/GetAlbumById.cs

@@ -1,30 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-
-namespace Musify.Application.Albums
-{
-    public record GetAlbumByIdQuery(Guid Id)
-        : IQuery<ErrorOr<AlbumApplicationResponse>>;
-
-    public class GetAlbumByIdQueryHandler(IDatabase database)
-        : IQueryHandler<GetAlbumByIdQuery, ErrorOr<AlbumApplicationResponse>>
-    {
-        public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(GetAlbumByIdQuery request, CancellationToken cancellationToken)
-        {
-            var album = await database.Albums
-                .AsNoTracking()
-                .Active()
-                .Where(a => a.Id == request.Id)
-                .SelectResponse()
-                .SingleOrDefaultAsync(cancellationToken);
-
-            return album == null
-                ? AppErrors.NotFound("Album", request.Id)
-                : album;
-        }
-    }
-}

backend/Core/Musify.Application/Albums/GetAlbumTrackIds.cs

@@ -1,35 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums
-{
-    public record GetAlbumTrackIdsQuery(long UserId, Guid AlbumId)
-        : IQuery<ErrorOr<AlbumTrackIdsResponse>>;
-
-    public class GetAlbumTrackIdsQueryHandler(IDatabase database)
-        : IQueryHandler<GetAlbumTrackIdsQuery, ErrorOr<AlbumTrackIdsResponse>>
-    {
-        public async ValueTask<ErrorOr<AlbumTrackIdsResponse>> Handle(GetAlbumTrackIdsQuery request, CancellationToken cancellationToken)
-        {
-            var found = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-            if (found.IsError)
-                return found.Errors;
-
-            var trackIds = await database.AlbumHasTracks
-                .AsNoTracking()
-                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId
-                    && albumTrack.Track.LifeCycleStatus == LifeCycleStatus.Active)
-                .OrderBy(albumTrack => albumTrack.TrackNumber)
-                .ThenBy(albumTrack => albumTrack.Id)
-                .Select(albumTrack => albumTrack.TrackId)
-                .ToListAsync(cancellationToken);
-
-            return new AlbumTrackIdsResponse(trackIds);
-        }
-    }
-}

backend/Core/Musify.Application/Albums/GetAlbumTracks.cs

@@ -1,39 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Application.Tracks.Responses;
-
-namespace Musify.Application.Albums
-{
-    public record GetAlbumTracksQuery(
-        Guid AlbumId,
-        int PageNumber,
-        int PageSize)
-        : IQuery<ErrorOr<PaginatedResponse<TrackApplicationResponse>>>;
-
-    public class GetAlbumTracksQueryHandler(IDatabase database)
-        : IQueryHandler<GetAlbumTracksQuery, ErrorOr<PaginatedResponse<TrackApplicationResponse>>>
-    {
-        public async ValueTask<ErrorOr<PaginatedResponse<TrackApplicationResponse>>> Handle(GetAlbumTracksQuery request, CancellationToken cancellationToken)
-        {
-            var albumExists = await database.Albums
-                .AsNoTracking()
-                .Active()
-                .AnyAsync(album => album.Id == request.AlbumId, cancellationToken);
-            if (!albumExists)
-                return AppErrors.NotFound("Album", request.AlbumId);
-
-            return await database.AlbumHasTracks
-                .AsNoTracking()
-                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId && albumTrack.Track.LifeCycleStatus == Domain.ValueObjects.LifeCycleStatus.Active && albumTrack.Track.IsPublished)
-                .OrderBy(albumTrack => albumTrack.TrackNumber)
-                .ThenBy(albumTrack => albumTrack.Id)
-                .Select(albumTrack => albumTrack.Track)
-                .SelectResponse()
-                .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Albums/GetAlbums.cs

@@ -1,34 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-
-namespace Musify.Application.Albums
-{
-    public record GetAlbumsQuery(string? Title, int PageNumber, int PageSize)
-        : IQuery<PaginatedResponse<AlbumApplicationResponse>>;
-
-    public class GetAlbumsQueryHandler(IDatabase database)
-        : IQueryHandler<GetAlbumsQuery, PaginatedResponse<AlbumApplicationResponse>>
-    {
-        public async ValueTask<PaginatedResponse<AlbumApplicationResponse>> Handle(GetAlbumsQuery request, CancellationToken cancellationToken)
-        {
-            var albumsQuery = database.Albums
-                .AsNoTracking()
-                .Active();
-
-            if (!string.IsNullOrWhiteSpace(request.Title))
-            {
-                var normalizedTitle = TextNormalizer.Normalize(request.Title);
-                albumsQuery = albumsQuery.Where(album => album.NormalizedTitle.Contains(normalizedTitle));
-            }
-
-            return await albumsQuery
-                .OrderByDescending(album => album.CreatedAt)
-                .ThenBy(album => album.Id)
-                .SelectResponse()
-                .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Albums/GetAlbumsByUserId.cs

@@ -1,34 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-
-namespace Musify.Application.Albums
-{
-    public record GetAlbumsByUserIdQuery(long UserId, int PageNumber, int PageSize)
-        : IQuery<ErrorOr<PaginatedResponse<AlbumApplicationResponse>>>;
-
-    public class GetAlbumsByUserIdQueryHandler(IDatabase database)
-        : IQueryHandler<GetAlbumsByUserIdQuery, ErrorOr<PaginatedResponse<AlbumApplicationResponse>>>
-    {
-        public async ValueTask<ErrorOr<PaginatedResponse<AlbumApplicationResponse>>> Handle(GetAlbumsByUserIdQuery request, CancellationToken cancellationToken)
-        {
-            var userExists = await database.Users
-                .AsNoTracking()
-                .AnyAsync(user => user.Id == request.UserId, cancellationToken);
-            if (!userExists)
-                return AppErrors.NotFound("User", request.UserId);
-
-            return await database.Albums
-                .AsNoTracking()
-                .Active()
-                .Where(album => album.OwnerUserId == request.UserId)
-                .OrderByDescending(album => album.CreatedAt)
-                .ThenBy(album => album.Id)
-                .SelectResponse()
-                .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Albums/GetRecentlyListenedAlbums.cs

@@ -1,53 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Contracts;
-
-namespace Musify.Application.Albums
-{
-    public record GetRecentlyListenedAlbumsQuery(long UserId, int Limit)
-        : IQuery<IReadOnlyList<AlbumApplicationResponse>>;
-
-    public class GetRecentlyListenedAlbumsQueryHandler(IDatabase database)
-        : IQueryHandler<GetRecentlyListenedAlbumsQuery, IReadOnlyList<AlbumApplicationResponse>>
-    {
-        public async ValueTask<IReadOnlyList<AlbumApplicationResponse>> Handle(GetRecentlyListenedAlbumsQuery request, CancellationToken cancellationToken)
-        {
-            var listens = database.ListeningHistories
-                .AsNoTracking()
-                .Where(history => history.UserId == request.UserId && history.IsCounted);
-
-            var ranked = await database.AlbumHasTracks
-                .AsNoTracking()
-                .Where(albumTrack => albumTrack.Album.LifeCycleStatus == Domain.ValueObjects.LifeCycleStatus.Active)
-                .Where(albumTrack => albumTrack.Track.LifeCycleStatus == Domain.ValueObjects.LifeCycleStatus.Active && albumTrack.Track.IsPublished)
-                .Join(
-                    listens,
-                    albumTrack => albumTrack.TrackId,
-                    history => history.TrackId,
-                    (albumTrack, history) => new { albumTrack.AlbumId, history.ListenedAt })
-                .GroupBy(entry => entry.AlbumId)
-                .Select(group => new { AlbumId = group.Key, LastListenedAt = group.Max(entry => entry.ListenedAt) })
-                .OrderByDescending(entry => entry.LastListenedAt)
-                .ThenBy(entry => entry.AlbumId)
-                .Take(request.Limit)
-                .ToListAsync(cancellationToken);
-
-            if (ranked.Count == 0)
-                return [];
-
-            var albumIds = ranked.Select(entry => entry.AlbumId).ToList();
-
-            var albumsById = await database.Albums
-                .AsNoTracking()
-                .Where(album => albumIds.Contains(album.Id))
-                .SelectResponse()
-                .ToDictionaryAsync(album => album.Id, cancellationToken);
-
-            return ranked
-                .Where(entry => albumsById.ContainsKey(entry.AlbumId))
-                .Select(entry => albumsById[entry.AlbumId])
-                .ToList();
-        }
-    }
-}

backend/Core/Musify.Application/Albums/RemoveTrackFromAlbum.cs

@@ -1,46 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-
-namespace Musify.Application.Albums
-{
-    public record RemoveTrackFromAlbumCommand(long UserId, Guid AlbumId, Guid TrackId)
-        : ICommand<ErrorOr<Success>>;
-
-    public class RemoveTrackFromAlbumCommandHandler(
-        IDatabase database,
-        ILogger<RemoveTrackFromAlbumCommandHandler> logger)
-        : ICommandHandler<RemoveTrackFromAlbumCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(RemoveTrackFromAlbumCommand request, CancellationToken cancellationToken)
-        {
-            var album = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-            if (album.IsError)
-                return album.Errors;
-
-            var albumTracks = await database.AlbumHasTracks
-                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId)
-                .OrderBy(albumTrack => albumTrack.TrackNumber)
-                .ToListAsync(cancellationToken);
-
-            var link = albumTracks.SingleOrDefault(albumTrack => albumTrack.TrackId == request.TrackId);
-            if (link == null)
-                return Error.NotFound("Album.TrackNotFound", "Track is not in the album.");
-
-            database.AlbumHasTracks.Remove(link);
-
-            var trackNumber = 1;
-            foreach (var remaining in albumTracks.Where(albumTrack => albumTrack.Id != link.Id))
-                remaining.TrackNumber = trackNumber++;
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Removed track {TrackId} from album {AlbumId}", request.TrackId, request.AlbumId);
-
-            return Result.Success;
-        }
-    }
-}

backend/Core/Musify.Application/Albums/RequestAlbumPictureUpload.cs

@@ -1,25 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Musify.Application.Configuration;
-using Musify.Application.Pictures.Responses;
-using Musify.Application.Services;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums
-{
-    public record RequestAlbumPictureUploadCommand(
-        long UserId,
-        string FileType,
-        string ContentType,
-        long? ExpectedSizeBytes = null)
-        : ICommand<ErrorOr<PictureUploadResponse>>;
-
-    public class RequestAlbumPictureUploadCommandHandler(UploadIntentIssuer issuer, AlbumConfiguration albumConfiguration)
-        : ICommandHandler<RequestAlbumPictureUploadCommand, ErrorOr<PictureUploadResponse>>
-    {
-        public async ValueTask<ErrorOr<PictureUploadResponse>> Handle(RequestAlbumPictureUploadCommand request, CancellationToken cancellationToken) =>
-            await issuer.IssuePictureAsync(
-                request.UserId, UploadIntentPurpose.AlbumPicture, albumConfiguration,
-                request.FileType, request.ContentType, request.ExpectedSizeBytes, cancellationToken);
-    }
-}

backend/Core/Musify.Application/Albums/Responses/AlbumApplicationResponse.cs

@@ -1,44 +0,0 @@
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums.Responses
-{
-    public record AlbumApplicationResponse(
-        Guid Id,
-        string Title,
-        string? Description,
-        int? ReleaseYear,
-        long OwnerUserId,
-        int TrackCount,
-        string? SmallImageKeyName,
-        string? MediumImageKeyName,
-        string? LargeImageKeyName,
-        DateTime CreatedAt,
-        DateTime UpdatedAt,
-        IReadOnlyList<Guid> CoverTrackIds,
-        AlbumType Type)
-    {
-        public const int CoverTrackCount = AlbumProjections.CoverTrackCount;
-
-        public static AlbumApplicationResponse FromEntity(
-            Album album,
-            int trackCount,
-            IReadOnlyList<Guid>? coverTrackIds = null)
-        {
-            return new AlbumApplicationResponse(
-                album.Id,
-                album.Title,
-                album.Description,
-                album.ReleaseYear,
-                album.OwnerUserId,
-                trackCount,
-                album.Pictures?.SmallName,
-                album.Pictures?.MediumName,
-                album.Pictures?.LargeName,
-                album.CreatedAt,
-                album.UpdatedAt,
-                coverTrackIds ?? [],
-                album.Type);
-        }
-    }
-}

backend/Core/Musify.Application/Albums/Responses/AlbumProjections.cs

@@ -1,34 +0,0 @@
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums.Responses
-{
-    public static class AlbumProjections
-    {
-        public const int CoverTrackCount = 4;
-
-        public static IQueryable<Album> Active(this IQueryable<Album> query) =>
-            query.Where(album => album.LifeCycleStatus == LifeCycleStatus.Active);
-
-        public static IQueryable<AlbumApplicationResponse> SelectResponse(this IQueryable<Album> query) =>
-            query.Select(album => new AlbumApplicationResponse(
-                album.Id,
-                album.Title,
-                album.Description,
-                album.ReleaseYear,
-                album.OwnerUserId,
-                album.AlbumTracks.Count(albumTrack => albumTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && albumTrack.Track.IsPublished),
-                album.Pictures!.SmallName,
-                album.Pictures!.MediumName,
-                album.Pictures!.LargeName,
-                album.CreatedAt,
-                album.UpdatedAt,
-                album.AlbumTracks
-                    .Where(albumTrack => albumTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && albumTrack.Track.IsPublished)
-                    .OrderBy(albumTrack => albumTrack.TrackNumber)
-                    .Take(CoverTrackCount)
-                    .Select(albumTrack => albumTrack.TrackId)
-                    .ToList(),
-                album.Type));
-    }
-}

backend/Core/Musify.Application/Albums/Responses/AlbumTrackIdsResponse.cs

@@ -1,4 +0,0 @@
-namespace Musify.Application.Albums.Responses
-{
-    public record AlbumTrackIdsResponse(IReadOnlyList<Guid> TrackIds);
-}

backend/Core/Musify.Application/Albums/UpdateAlbum.cs

@@ -1,52 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums
-{
-    public record UpdateAlbumCommand(
-        long UserId,
-        Guid AlbumId,
-        string Title,
-        string? Description,
-        int? ReleaseYear,
-        AlbumType? Type = null)
-        : ICommand<ErrorOr<AlbumApplicationResponse>>;
-
-    public class UpdateAlbumCommandHandler(
-        IDatabase database,
-        ILogger<UpdateAlbumCommandHandler> logger)
-        : ICommandHandler<UpdateAlbumCommand, ErrorOr<AlbumApplicationResponse>>
-    {
-        public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(UpdateAlbumCommand request, CancellationToken cancellationToken)
-        {
-            var found = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-            if (found.IsError)
-                return found.Errors;
-
-            var album = found.Value;
-            var title = request.Title.Trim();
-
-            album.Title = title;
-            album.NormalizedTitle = TextNormalizer.Normalize(title);
-            album.Description = string.IsNullOrWhiteSpace(request.Description) ? null : request.Description.Trim();
-            album.ReleaseYear = request.ReleaseYear;
-            album.Type = request.Type ?? album.Type;
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Updated album {AlbumId}", album.Id);
-
-            return await database.Albums
-                .AsNoTracking()
-                .Where(a => a.Id == album.Id)
-                .SelectResponse()
-                .SingleAsync(cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Albums/UpdateAlbumPicture.cs

@@ -1,59 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Pictures;
-using Musify.Application.Services;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums
-{
-    public record UpdateAlbumPictureCommand(long UserId, Guid AlbumId, Guid PictureIntentId)
-        : ICommand<ErrorOr<AlbumApplicationResponse>>;
-
-    public class UpdateAlbumPictureCommandHandler(
-        IEventBus eventBus,
-        IDatabase database,
-        UploadIntentValidator uploadIntentValidator,
-        ILogger<UpdateAlbumPictureCommandHandler> logger,
-        AlbumConfiguration albumConfiguration)
-        : ICommandHandler<UpdateAlbumPictureCommand, ErrorOr<AlbumApplicationResponse>>
-    {
-        public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(UpdateAlbumPictureCommand request, CancellationToken cancellationToken)
-        {
-            var found = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-            if (found.IsError)
-                return found.Errors;
-
-            var album = found.Value;
-
-            var prepared = await PictureSourceChange.PrepareAsync(
-                uploadIntentValidator, request.PictureIntentId, request.UserId, UploadIntentPurpose.AlbumPicture, albumConfiguration, cancellationToken);
-            if (prepared.IsError)
-                return prepared.Errors;
-
-            var picture = prepared.Value;
-            album.Pictures = picture.Pictures;
-
-            await eventBus.PublishAsync(
-                new UpdateAlbumPictureSourceEvent(
-                    album.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-                cancellationToken);
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Updated picture of album {AlbumId}", album.Id);
-
-            return await database.Albums
-                .AsNoTracking()
-                .Where(a => a.Id == album.Id)
-                .SelectResponse()
-                .SingleAsync(cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/ApplicationDependencyInjection.cs

@@ -1,29 +0,0 @@
-using Microsoft.Extensions.Configuration;
-using Microsoft.Extensions.DependencyInjection;
-using Musify.Application.Configuration;
-using Musify.Application.Services;
-
-namespace Musify.Application
-{
-    public static class ApplicationDependencyInjection
-    {
-        public static IServiceCollection AddApplication(this IServiceCollection services, IConfiguration configuration)
-        {
-            services.AddMediator();
-            services.AddScoped<UploadIntentValidator>();
-            services.AddScoped<UploadIntentIssuer>();
-            services.AddScoped<TrackStreamIssuer>();
-
-            services.AddValidatedOptions<ApplicationStorageConfiguration>(configuration);
-            services.AddValidatedOptions<PlayListConfiguration>(configuration);
-            services.AddValidatedOptions<AlbumConfiguration>(configuration);
-            services.AddValidatedOptions<TrackConfiguration>(configuration);
-            services.AddValidatedOptions<MixConfiguration>(configuration);
-            services.AddValidatedOptions<StreamGatewayConfiguration>(configuration);
-            services.AddValidatedOptions<UploadIntentConfiguration>(configuration);
-            services.AddValidatedOptions<PlaybackConfiguration>(configuration);
-
-            return services;
-        }
-    }
-}

backend/Core/Musify.Application/Coauthors/GetCoauthorInvitations.cs

@@ -1,35 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Coauthors.Responses;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Coauthors
-{
-    public record GetCoauthorInvitationsQuery(long UserId, int PageNumber, int PageSize)
-        : IQuery<PaginatedResponse<CoauthorInvitationResponse>>;
-
-    public class GetCoauthorInvitationsQueryHandler(IDatabase database)
-        : IQueryHandler<GetCoauthorInvitationsQuery, PaginatedResponse<CoauthorInvitationResponse>>
-    {
-        public async ValueTask<PaginatedResponse<CoauthorInvitationResponse>> Handle(GetCoauthorInvitationsQuery request, CancellationToken cancellationToken)
-        {
-            return await database.TrackCoauthors
-                .AsNoTracking()
-                .Where(coauthor => coauthor.UserId == request.UserId
-                    && coauthor.Status == CoauthorStatus.Pending
-                    && coauthor.Track.LifeCycleStatus == LifeCycleStatus.Active)
-                .OrderByDescending(coauthor => coauthor.InvitedAt)
-                .ThenBy(coauthor => coauthor.Id)
-                .Select(coauthor => new CoauthorInvitationResponse(
-                    coauthor.Id,
-                    coauthor.TrackId,
-                    coauthor.Track.Title,
-                    coauthor.Track.Owner.Name,
-                    coauthor.Track.OwnerUserId,
-                    coauthor.InvitedAt))
-                .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Coauthors/InviteCoauthors.cs

@@ -1,84 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Application.Tracks.Responses;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Coauthors
-{
-    public record InviteCoauthorsCommand(long OwnerId, Guid TrackId, IReadOnlyList<long> UserIds)
-        : ICommand<ErrorOr<IReadOnlyList<TrackCoauthorInviteReference>>>;
-
-    public class InviteCoauthorsCommandHandler(
-        IDatabase database,
-        ILogger<InviteCoauthorsCommandHandler> logger)
-        : ICommandHandler<InviteCoauthorsCommand, ErrorOr<IReadOnlyList<TrackCoauthorInviteReference>>>
-    {
-        public async ValueTask<ErrorOr<IReadOnlyList<TrackCoauthorInviteReference>>> Handle(InviteCoauthorsCommand request, CancellationToken cancellationToken)
-        {
-            var found = await database.Tracks.FindOwnedAsync(request.TrackId, request.OwnerId, cancellationToken);
-            if (found.IsError)
-                return found.Errors;
-
-            var userIds = request.UserIds.Distinct().ToList();
-            if (userIds.Contains(request.OwnerId))
-                return Error.Validation("Coauthor.Self", "You cannot invite yourself as a coauthor.");
-
-            var existingUserIds = await database.Users
-                .AsNoTracking()
-                .Where(user => userIds.Contains(user.Id))
-                .Select(user => user.Id)
-                .ToListAsync(cancellationToken);
-
-            var missing = userIds.Where(id => !existingUserIds.Contains(id)).Select(id => (long?)id).FirstOrDefault();
-            if (missing != null)
-                return AppErrors.NotFound("User", missing.Value);
-
-            var existing = await database.TrackCoauthors
-                .Where(coauthor => coauthor.TrackId == request.TrackId && userIds.Contains(coauthor.UserId))
-                .ToListAsync(cancellationToken);
-
-            var alreadyInvited = existing.FirstOrDefault(coauthor => coauthor.Status != CoauthorStatus.Rejected);
-            if (alreadyInvited != null)
-                return AppErrors.Conflict("Coauthor.AlreadyInvited", $"User {alreadyInvited.UserId} was already invited to this track.");
-
-            var now = DateTime.UtcNow;
-            foreach (var rejected in existing)
-            {
-                rejected.Status = CoauthorStatus.Pending;
-                rejected.InvitedAt = now;
-                rejected.RespondedAt = null;
-            }
-
-            var reinvitedIds = existing.Select(coauthor => coauthor.UserId).ToHashSet();
-            foreach (var userId in userIds.Where(id => !reinvitedIds.Contains(id)))
-            {
-                await database.TrackCoauthors.AddAsync(new TrackCoauthor
-                {
-                    TrackId = request.TrackId,
-                    UserId = userId,
-                    InvitedAt = now
-                }, cancellationToken);
-            }
-
-            var saved = await database.TrySaveChangesAsync(
-                AppErrors.Conflict("Coauthor.AlreadyInvited", "A user was already invited to this track."), cancellationToken);
-            if (saved.IsError)
-                return saved.Errors;
-
-            logger.LogInformation("Owner {OwnerId} invited {Count} coauthors to track {TrackId}", request.OwnerId, userIds.Count, request.TrackId);
-
-            return await database.TrackCoauthors
-                .AsNoTracking()
-                .Where(coauthor => coauthor.TrackId == request.TrackId)
-                .OrderBy(coauthor => coauthor.InvitedAt)
-                .ThenBy(coauthor => coauthor.UserId)
-                .Select(coauthor => new TrackCoauthorInviteReference(coauthor.UserId, coauthor.User.Name, coauthor.Status))
-                .ToListAsync(cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Coauthors/RemoveCoauthor.cs

@@ -1,47 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Coauthors
-{
-    public record RemoveCoauthorCommand(long UserId, Guid TrackId, long CoauthorUserId)
-        : ICommand<ErrorOr<Success>>;
-
-    public class RemoveCoauthorCommandHandler(
-        IDatabase database,
-        ILogger<RemoveCoauthorCommandHandler> logger)
-        : ICommandHandler<RemoveCoauthorCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(RemoveCoauthorCommand request, CancellationToken cancellationToken)
-        {
-            var ownerUserId = await database.Tracks
-                .AsNoTracking()
-                .Where(track => track.Id == request.TrackId && track.LifeCycleStatus == LifeCycleStatus.Active)
-                .Select(track => (long?)track.OwnerUserId)
-                .SingleOrDefaultAsync(cancellationToken);
-
-            if (ownerUserId == null)
-                return AppErrors.NotFound("Track", request.TrackId);
-
-            if (ownerUserId != request.UserId && request.CoauthorUserId != request.UserId)
-                return AppErrors.Forbidden("Track", request.TrackId);
-
-            var coauthor = await database.TrackCoauthors
-                .SingleOrDefaultAsync(c => c.TrackId == request.TrackId && c.UserId == request.CoauthorUserId, cancellationToken);
-            if (coauthor == null)
-                return AppErrors.NotFound("Coauthor", request.CoauthorUserId);
-
-            database.TrackCoauthors.Remove(coauthor);
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("User {UserId} removed coauthor {CoauthorUserId} from track {TrackId}",
-                request.UserId, request.CoauthorUserId, request.TrackId);
-
-            return Result.Success;
-        }
-    }
-}

backend/Core/Musify.Application/Coauthors/RespondToCoauthorInvitation.cs

@@ -1,44 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Coauthors
-{
-    public record RespondToCoauthorInvitationCommand(long UserId, Guid InvitationId, bool Accept)
-        : ICommand<ErrorOr<Success>>;
-
-    public class RespondToCoauthorInvitationCommandHandler(
-        IDatabase database,
-        ILogger<RespondToCoauthorInvitationCommandHandler> logger)
-        : ICommandHandler<RespondToCoauthorInvitationCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(RespondToCoauthorInvitationCommand request, CancellationToken cancellationToken)
-        {
-            var invitation = await database.TrackCoauthors
-                .Include(coauthor => coauthor.Track)
-                .SingleOrDefaultAsync(coauthor => coauthor.Id == request.InvitationId, cancellationToken);
-
-            if (invitation == null || invitation.Track.LifeCycleStatus != LifeCycleStatus.Active)
-                return AppErrors.NotFound("CoauthorInvitation", request.InvitationId);
-
-            if (invitation.UserId != request.UserId)
-                return AppErrors.Forbidden("CoauthorInvitation", request.InvitationId);
-
-            if (invitation.Status != CoauthorStatus.Pending)
-                return AppErrors.Conflict("CoauthorInvitation.NotPending", "The invitation was already answered.");
-
-            invitation.Status = request.Accept ? CoauthorStatus.Accepted : CoauthorStatus.Rejected;
-            invitation.RespondedAt = DateTime.UtcNow;
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("User {UserId} {Action} coauthor invitation {InvitationId}",
-                request.UserId, request.Accept ? "accepted" : "rejected", request.InvitationId);
-
-            return Result.Success;
-        }
-    }
-}

backend/Core/Musify.Application/Coauthors/Responses/CoauthorInvitationResponse.cs

@@ -1,10 +0,0 @@
-namespace Musify.Application.Coauthors.Responses
-{
-    public record CoauthorInvitationResponse(
-        Guid Id,
-        Guid TrackId,
-        string TrackTitle,
-        string? Artist,
-        long OwnerUserId,
-        DateTime InvitedAt);
-}

backend/Core/Musify.Application/Configuration/AlbumConfiguration.cs

@@ -1,15 +0,0 @@
-using System.ComponentModel.DataAnnotations;
-
-namespace Musify.Application.Configuration
-{
-    public class AlbumConfiguration : IConfigurationOptions, IPictureOwnerConfiguration
-    {
-        public static string SectionName => "Album";
-
-        [Required]
-        public PictureRoutes Routes { get; set; } = new() { ParentFolder = "Albums" };
-
-        [Required]
-        public PictureSizes PicturesSizes { get; set; } = new();
-    }
-}

backend/Core/Musify.Application/Configuration/ConfigurationDependencyInjection.cs

@@ -1,30 +0,0 @@
-using Microsoft.Extensions.Configuration;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Options;
-
-namespace Musify.Application.Configuration
-{
-    public static class ConfigurationDependencyInjection
-    {
-        public static IServiceCollection AddValidatedOptions<T>(this IServiceCollection services, IConfiguration configuration)
-            where T : class, IConfigurationOptions =>
-            services.AddValidatedOptions<T>(configuration, T.SectionName);
-
-        public static IServiceCollection AddValidatedOptions<T>(
-            this IServiceCollection services,
-            IConfiguration configuration,
-            string sectionName)
-            where T : class
-        {
-            services
-                .AddOptionsWithValidateOnStart<T>()
-                .Bind(configuration.GetRequiredSection(sectionName))
-                .ValidateDataAnnotations();
-
-            services.AddSingleton(serviceProvider =>
-                serviceProvider.GetRequiredService<IOptions<T>>().Value);
-
-            return services;
-        }
-    }
-}

backend/Core/Musify.Application/Configuration/GetPlaybackPublicConfig.cs

@@ -1,17 +0,0 @@
-using Mediator;
-using Musify.Application.Configuration.Responses;
-
-namespace Musify.Application.Configuration
-{
-
-    public record GetPlaybackPublicConfigQuery : IQuery<PlaybackPublicConfigResponse>;
-
-    public class GetPlaybackPublicConfigQueryHandler(PlaybackConfiguration playbackConfiguration)
-        : IQueryHandler<GetPlaybackPublicConfigQuery, PlaybackPublicConfigResponse>
-    {
-        public ValueTask<PlaybackPublicConfigResponse> Handle(GetPlaybackPublicConfigQuery query, CancellationToken cancellationToken) =>
-            ValueTask.FromResult(new PlaybackPublicConfigResponse(
-                playbackConfiguration.AllowAnonymousListening,
-                playbackConfiguration.AnonymousFragmentSeconds));
-    }
-}

backend/Core/Musify.Application/Configuration/IConfigurationOptions.cs

@@ -1,7 +0,0 @@
-namespace Musify.Application.Configuration
-{
-    public interface IConfigurationOptions
-    {
-        public static abstract string SectionName { get; }
-    }
-}

backend/Core/Musify.Application/Configuration/MixConfiguration.cs

@@ -1,12 +0,0 @@
-using System.ComponentModel.DataAnnotations;
-
-namespace Musify.Application.Configuration
-{
-    public class MixConfiguration : IConfigurationOptions
-    {
-        public static string SectionName => "Mix";
-
-        [Range(4, 100)]
-        public int ItemsPerMix { get; set; } = 12;
-    }
-}

backend/Core/Musify.Application/Configuration/Pictures.cs

@@ -1,91 +0,0 @@
-using System.ComponentModel.DataAnnotations;
-using System.Globalization;
-using Musify.Application.Shared;
-
-namespace Musify.Application.Configuration
-{
-    public enum PictureSize
-    {
-        Small,
-        Medium,
-        Large
-    }
-
-    public class PictureRoutes
-    {
-        [Required]
-        public string UploadsFolder { get; set; } = "uploads";
-
-        [Required]
-        public string ParentFolder { get; set; } = string.Empty;
-
-        [Required]
-        public string OriginalPicturesFolder { get; set; } = "OriginalPictures";
-
-        [Required]
-        public string SmallPicturesFolder { get; set; } = "SmallPictures";
-
-        [Required]
-        public string MediumPicturesFolder { get; set; } = "MediumPictures";
-
-        [Required]
-        public string LargePicturesFolder { get; set; } = "LargePictures";
-
-        public string FolderPath(PictureSize size) => StorageKey.Combine(ParentFolder, size switch
-        {
-            PictureSize.Small => SmallPicturesFolder,
-            PictureSize.Medium => MediumPicturesFolder,
-            PictureSize.Large => LargePicturesFolder,
-            _ => throw new ArgumentOutOfRangeException(nameof(size), size, null)
-        });
-
-        public string BuildPicturePath(PictureSize size, string pictureName) => StorageKey.Combine(FolderPath(size), pictureName);
-
-        public string BuildOriginalPicturePath(long userId, string pictureName) =>
-            StorageKey.Combine(UploadsFolder, userId.ToString(CultureInfo.InvariantCulture), ParentFolder, OriginalPicturesFolder, pictureName);
-
-        public string BuildTempPath(string tempRootPrefix, long userId, string objectName) =>
-            StorageKey.Combine(tempRootPrefix, userId.ToString(CultureInfo.InvariantCulture), ParentFolder, objectName);
-    }
-
-    public class PictureSizes
-    {
-        [Range(1, 1024)]
-        public int SmallWidth { get; set; } = 128;
-
-        [Range(1, 1024)]
-        public int SmallHeight { get; set; } = 128;
-
-        [Range(1, 1024)]
-        public int MediumWidth { get; set; } = 256;
-
-        [Range(1, 1024)]
-        public int MediumHeight { get; set; } = 256;
-
-        [Range(1, 1024)]
-        public int LargeWidth { get; set; } = 512;
-
-        [Range(1, 1024)]
-        public int LargeHeight { get; set; } = 512;
-
-        public ImageSizes ToImageSizes(PictureRoutes routes) => new(
-            new ImageSize(routes.FolderPath(PictureSize.Small), SmallWidth, SmallHeight),
-            new ImageSize(routes.FolderPath(PictureSize.Medium), MediumWidth, MediumHeight),
-            new ImageSize(routes.FolderPath(PictureSize.Large), LargeWidth, LargeHeight));
-    }
-
-    public interface IPictureOwnerConfiguration
-    {
-        public PictureRoutes Routes { get; }
-
-        public PictureSizes PicturesSizes { get; }
-    }
-
-    public static class PictureSizeParser
-    {
-        public static PictureSize Parse(string? value) =>
-            Enum.TryParse<PictureSize>(value, ignoreCase: true, out var size) && Enum.IsDefined(size)
-                ? size
-                : PictureSize.Medium;
-    }
-}

backend/Core/Musify.Application/Configuration/PlayListConfiguration.cs

@@ -1,15 +0,0 @@
-using System.ComponentModel.DataAnnotations;
-
-namespace Musify.Application.Configuration
-{
-    public class PlayListConfiguration : IConfigurationOptions, IPictureOwnerConfiguration
-    {
-        public static string SectionName => "PlayList";
-
-        [Required]
-        public PictureRoutes Routes { get; set; } = new() { ParentFolder = "PlayLists" };
-
-        [Required]
-        public PictureSizes PicturesSizes { get; set; } = new();
-    }
-}

backend/Core/Musify.Application/Configuration/PlaybackConfiguration.cs

@@ -1,18 +0,0 @@
-using System.ComponentModel.DataAnnotations;
-
-namespace Musify.Application.Configuration
-{
-
-    public sealed class PlaybackConfiguration : IConfigurationOptions
-    {
-        public static string SectionName => "Playback";
-
-        public bool AllowAnonymousListening { get; set; }
-
-        [Range(0, 3600)]
-        public int AnonymousFragmentSeconds { get; set; }
-
-        [Range(1, int.MaxValue)]
-        public int EstimatedAudioBytesPerSecond { get; set; } = 16_000;
-    }
-}

backend/Core/Musify.Application/Configuration/Responses/PlaybackPublicConfigResponse.cs

@@ -1,5 +0,0 @@
-namespace Musify.Application.Configuration.Responses
-{
-
-    public record PlaybackPublicConfigResponse(bool AllowAnonymousListening, int AnonymousFragmentSeconds);
-}

backend/Core/Musify.Application/Configuration/TrackConfiguration.cs

@@ -1,57 +0,0 @@
-using System.ComponentModel.DataAnnotations;
-using System.Globalization;
-using Musify.Application.Shared;
-
-namespace Musify.Application.Configuration
-{
-    public class TrackConfiguration : IConfigurationOptions, IPictureOwnerConfiguration
-    {
-        public static string SectionName => "Track";
-
-        [Required]
-        public TrackRoutes Routes { get; set; } = new();
-
-        [Required]
-        public PictureSizes PicturesSizes { get; set; } = new();
-
-        PictureRoutes IPictureOwnerConfiguration.Routes => Routes;
-    }
-
-    public class TrackRoutes : PictureRoutes
-    {
-        public TrackRoutes()
-        {
-            ParentFolder = "Tracks";
-        }
-
-        [Required]
-        public string PresetOriginalPicture { get; set; } = "PresetOriginalPicture.webp";
-
-        [Required]
-        public string PresetSmallPicture { get; set; } = "PresetSmallPicture.webp";
-
-        [Required]
-        public string PresetMediumPicture { get; set; } = "PresetMediumPicture.webp";
-
-        [Required]
-        public string PresetLargePicture { get; set; } = "PresetLargePicture.webp";
-
-        [Required]
-        public string OriginalAudiosFolder { get; set; } = "OriginalAudios";
-
-        [Required]
-        public string ProcessedAudiosFolder { get; set; } = "ProcessedAudios";
-
-        public string PresetSmallPicturePath => StorageKey.Combine(ParentFolder, PresetSmallPicture);
-
-        public string PresetMediumPicturePath => StorageKey.Combine(ParentFolder, PresetMediumPicture);
-
-        public string PresetLargePicturePath => StorageKey.Combine(ParentFolder, PresetLargePicture);
-
-        public string BuildOriginalAudioPath(long userId, string audioName) =>
-            StorageKey.Combine(UploadsFolder, userId.ToString(CultureInfo.InvariantCulture), ParentFolder, OriginalAudiosFolder, audioName);
-
-        public string BuildProcessedAudioPath(string folderName) =>
-            StorageKey.Combine(ParentFolder, ProcessedAudiosFolder, folderName);
-    }
-}

backend/Core/Musify.Application/Contracts/AudioTranscodeResult.cs

@@ -1,4 +0,0 @@
-namespace Musify.Application.Contracts
-{
-    public record AudioTranscodeResult(int StatusCode, TimeSpan Duration);
-}

backend/Core/Musify.Application/Contracts/IAudioTranscoderService.cs

@@ -1,7 +0,0 @@
-namespace Musify.Application.Contracts
-{
-    public interface IAudioTranscoderService
-    {
-        public Task<AudioTranscodeResult> TranscodeToAudioFileAsync(Stream audioStream, string destinationPath, CancellationToken cancellationToken);
-    }
-}

backend/Core/Musify.Application/Contracts/IDatabase.cs

@@ -1,45 +0,0 @@
-using ErrorOr;
-using Microsoft.EntityFrameworkCore;
-using Musify.Domain.Entities;
-
-namespace Musify.Application.Contracts
-{
-    public interface IDatabase
-    {
-        public DbSet<User> Users { get; }
-
-        public DbSet<PlayList> PlayLists { get; }
-
-        public DbSet<Album> Albums { get; }
-
-        public DbSet<AlbumHasTrack> AlbumHasTracks { get; }
-
-        public DbSet<Track> Tracks { get; }
-
-        public DbSet<PlayListHasTrack> PlayListHasTracks { get; }
-
-        public DbSet<Mix> Mixes { get; }
-
-        public DbSet<MixItem> MixItems { get; }
-
-        public DbSet<UploadIntent> UploadIntents { get; }
-
-        public DbSet<ListeningHistory> ListeningHistories { get; }
-
-        public DbSet<TrackLike> TrackLikes { get; }
-
-        public DbSet<TrackTag> TrackTags { get; }
-
-        public DbSet<UserFollow> UserFollows { get; }
-
-        public DbSet<TrackCoauthor> TrackCoauthors { get; }
-
-        public Task<IDatabaseTransaction> BeginTransactionAsync(System.Data.IsolationLevel isolationLevel, CancellationToken cancellationToken);
-
-        public DbSet<TEntity> Set<TEntity>() where TEntity : class;
-
-        public Task<int> SaveChangesAsync(CancellationToken cancellationToken);
-
-        public Task<ErrorOr<Success>> TrySaveChangesAsync(Error onUniqueViolation, CancellationToken cancellationToken);
-    }
-}

backend/Core/Musify.Application/Contracts/IEventBus.cs

@@ -1,7 +0,0 @@
-namespace Musify.Application.Contracts
-{
-    public interface IEventBus
-    {
-        public Task PublishAsync<T>(T message, CancellationToken cancellationToken) where T : class;
-    }
-}

backend/Core/Musify.Application/Contracts/IPictureService.cs

@@ -1,7 +0,0 @@
-namespace Musify.Application.Contracts
-{
-    public interface IPictureService
-    {
-        public Task<Stream> ResizePictureAsWebpAsync(Stream pictureStream, int width, int height, CancellationToken cancellationToken);
-    }
-}

backend/Core/Musify.Application/Contracts/IStorageService.cs

@@ -1,24 +0,0 @@
-namespace Musify.Application.Contracts
-{
-    public interface IStorageService
-    {
-        public Task<Stream?> GetFileAsync(string bucket, string key, CancellationToken cancellationToken);
-
-        public Task<ObjectMetaData?> HeadObjectAsync(string bucket, string key, CancellationToken cancellationToken);
-
-        public Task<string> GetUploadUrlAsync(string bucket, string key, string contentType, TimeSpan expirationTime, bool preventOverwrite = true, CancellationToken cancellationToken = default);
-
-        public Task UploadFileAsync(string filePath, string bucket, string key, CancellationToken cancellationToken);
-
-        public Task UploadFileAsync(Stream sourceStream, string contentType, string bucket, string key, CancellationToken cancellationToken);
-
-        public Task<IReadOnlyList<string>> TransferFilesAsync(string sourceDirectory, string bucket, string route, CancellationToken cancellationToken);
-
-        public Task RemoveFileAsync(string bucket, string key, CancellationToken cancellationToken);
-
-        public Task CopyFileAsync(string sourceBucket, string sourceKey, string destinationBucket, string destinationKey,
-            CancellationToken cancellationToken);
-
-        public IAsyncEnumerable<StorageObject> ListObjectsAsync(string bucket, string prefix, CancellationToken cancellationToken);
-    }
-}

backend/Core/Musify.Application/Events/AlbumPictureProcessed.cs

@@ -1,4 +0,0 @@
-namespace Musify.Application.Events
-{
-    public record AlbumPictureProcessed(Guid AlbumId);
-}

backend/Core/Musify.Application/Events/AlbumPictureProcessingFailed.cs

@@ -1,4 +0,0 @@
-namespace Musify.Application.Events
-{
-    public record AlbumPictureProcessingFailed(Guid AlbumId);
-}

backend/Core/Musify.Application/Events/AlbumProcessingFailed.cs

@@ -1,7 +0,0 @@
-namespace Musify.Application.Events
-{
-    public record AlbumProcessingFailed(
-        Guid AlbumId,
-        string? Bucket,
-        string? PictureKey);
-}

backend/Core/Musify.Application/Events/CreateAlbumResourcesEvent.cs

@@ -1,12 +0,0 @@
-using Musify.Application.Shared;
-
-namespace Musify.Application.Events
-{
-    public record CreateAlbumResourcesEvent(
-        Guid AlbumId,
-        Guid PictureIntentId,
-        string Bucket,
-        string PictureSourceKey,
-        string PictureDestinationKey,
-        ImageSizes Sizes);
-}

backend/Core/Musify.Application/Events/DeleteAlbumEvent.cs

@@ -1,6 +0,0 @@
-namespace Musify.Application.Events
-{
-    public record DeleteAlbumEvent(
-        Guid AlbumId,
-        long UserId);
-}

backend/Core/Musify.Application/Events/UpdateAlbumPictureEvent.cs

@@ -1,10 +0,0 @@
-using Musify.Application.Shared;
-
-namespace Musify.Application.Events
-{
-    public record UpdateAlbumPictureEvent(
-        Guid AlbumId,
-        string Bucket,
-        string SourceKey,
-        ImageSizes Sizes);
-}

backend/Core/Musify.Application/Events/UpdateAlbumPictureSourceEvent.cs

@@ -1,12 +0,0 @@
-using Musify.Application.Shared;
-
-namespace Musify.Application.Events
-{
-    public record UpdateAlbumPictureSourceEvent(
-        Guid AlbumId,
-        Guid PictureIntentId,
-        string Bucket,
-        string PictureSourceKey,
-        string PictureDestinationKey,
-        ImageSizes Sizes);
-}

backend/Core/Musify.Application/Genres/GetAvailableGenres.cs

@@ -1,25 +0,0 @@
-using Mediator;
-using Musify.Application.Genres.Responses;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Genres
-{
-    public record GetAvailableGenresQuery : IQuery<IReadOnlyList<AvailableGenreResponse>>;
-
-    public class GetAvailableGenresQueryHandler
-        : IQueryHandler<GetAvailableGenresQuery, IReadOnlyList<AvailableGenreResponse>>
-    {
-        public ValueTask<IReadOnlyList<AvailableGenreResponse>> Handle(GetAvailableGenresQuery request, CancellationToken cancellationToken)
-        {
-            var all = Enum.GetValues<Genre>().Where(genre => genre != Genre.None).ToArray();
-
-            IReadOnlyList<AvailableGenreResponse> result = all
-                .Select(genre => new AvailableGenreResponse(
-                    genre,
-                    all.Where(other => !GenreCompatibility.AreCompatible(genre, other)).ToList()))
-                .ToList();
-
-            return ValueTask.FromResult(result);
-        }
-    }
-}

backend/Core/Musify.Application/Genres/GetGenres.cs

@@ -1,30 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Genres.Responses;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Genres
-{
-    public record GetGenresQuery : IQuery<IReadOnlyList<GenreResponse>>;
-
-    public class GetGenresQueryHandler(IDatabase database)
-        : IQueryHandler<GetGenresQuery, IReadOnlyList<GenreResponse>>
-    {
-        public async ValueTask<IReadOnlyList<GenreResponse>> Handle(GetGenresQuery request, CancellationToken cancellationToken)
-        {
-            var rows = await database.TrackTags
-                .AsNoTracking()
-                .Where(tag => tag.Track.LifeCycleStatus == LifeCycleStatus.Active && tag.Track.IsPublished)
-                .GroupBy(tag => tag.Tag)
-                .Select(group => new { Genre = group.Key, TrackCount = group.Select(tag => tag.TrackId).Distinct().Count() })
-                .ToListAsync(cancellationToken);
-
-            return rows
-                .OrderByDescending(row => row.TrackCount)
-                .ThenBy(row => row.Genre)
-                .Select(row => new GenreResponse(row.Genre, row.TrackCount))
-                .ToList();
-        }
-    }
-}

backend/Core/Musify.Application/Genres/Responses/AvailableGenreResponse.cs

@@ -1,6 +0,0 @@
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Genres.Responses
-{
-    public record AvailableGenreResponse(Genre Genre, IReadOnlyList<Genre> IncompatibleWith);
-}

backend/Core/Musify.Application/Genres/Responses/GenreResponse.cs

@@ -1,6 +0,0 @@
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Genres.Responses
-{
-    public record GenreResponse(Genre Genre, int TrackCount);
-}

backend/Core/Musify.Application/Likes/GetLikedTracks.cs

@@ -1,31 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Application.Tracks.Responses;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Likes
-{
-    public record GetLikedTracksQuery(
-        long UserId,
-        int PageNumber,
-        int PageSize)
-        : IQuery<PaginatedResponse<TrackApplicationResponse>>;
-
-    public class GetLikedTracksQueryHandler(IDatabase database)
-        : IQueryHandler<GetLikedTracksQuery, PaginatedResponse<TrackApplicationResponse>>
-    {
-        public async ValueTask<PaginatedResponse<TrackApplicationResponse>> Handle(GetLikedTracksQuery request, CancellationToken cancellationToken)
-        {
-            return await database.TrackLikes
-                .AsNoTracking()
-                .Where(like => like.UserId == request.UserId && like.Track.LifeCycleStatus == LifeCycleStatus.Active && like.Track.IsPublished)
-                .OrderByDescending(like => like.CreatedAt)
-                .ThenBy(like => like.Id)
-                .Select(like => like.Track)
-                .SelectResponse()
-                .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Likes/ToggleTrackLike.cs

@@ -1,58 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Likes
-{
-    public record ToggleTrackLikeCommand(long UserId, Guid TrackId)
-        : ICommand<ErrorOr<bool>>;
-
-    public class ToggleTrackLikeCommandHandler(
-        IDatabase database,
-        ILogger<ToggleTrackLikeCommandHandler> logger)
-        : ICommandHandler<ToggleTrackLikeCommand, ErrorOr<bool>>
-    {
-        public async ValueTask<ErrorOr<bool>> Handle(ToggleTrackLikeCommand request, CancellationToken cancellationToken)
-        {
-            var trackExists = await database.Tracks
-                .AsNoTracking()
-                .AnyAsync(t => t.Id == request.TrackId && t.LifeCycleStatus == LifeCycleStatus.Active && t.IsPublished, cancellationToken);
-            if (!trackExists)
-                return AppErrors.NotFound("Track", request.TrackId);
-
-            var existingLike = await database.TrackLikes
-                .SingleOrDefaultAsync(like => like.UserId == request.UserId && like.TrackId == request.TrackId, cancellationToken);
-
-            bool nowLiked;
-            if (existingLike != null)
-            {
-                database.TrackLikes.Remove(existingLike);
-                nowLiked = false;
-            }
-            else
-            {
-                await database.TrackLikes.AddAsync(new TrackLike
-                {
-                    UserId = request.UserId,
-                    TrackId = request.TrackId
-                }, cancellationToken);
-                nowLiked = true;
-            }
-
-            var saved = await database.TrySaveChangesAsync(
-                AppErrors.Conflict("TrackLike.Duplicate", "Track is already liked."), cancellationToken);
-            if (saved.IsError)
-                return true;
-
-            logger.LogInformation("User {UserId} {Action} track {TrackId}",
-                request.UserId, nowLiked ? "liked" : "unliked", request.TrackId);
-
-            return nowLiked;
-        }
-    }
-}

backend/Core/Musify.Application/Mixes/GenerateMixesForUser.cs

@@ -1,131 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Mixes
-{
-    public record GenerateMixesForUserCommand(long UserId)
-        : ICommand;
-
-    public class GenerateMixesForUserCommandHandler(
-        IDatabase database,
-        MixConfiguration mixConfiguration,
-        ILogger<GenerateMixesForUserCommandHandler> logger)
-        : ICommandHandler<GenerateMixesForUserCommand>
-    {
-        private sealed record MixDraft(MixKind Kind, IReadOnlyList<Guid> TrackIds);
-
-        public async ValueTask<Unit> Handle(GenerateMixesForUserCommand request, CancellationToken cancellationToken)
-        {
-            var userId = request.UserId;
-
-            var libraryTrackIds = await database.Tracks
-                .AsNoTracking()
-                .Where(track => track.OwnerUserId == userId && track.LifeCycleStatus == LifeCycleStatus.Active && track.IsPublished)
-                .Select(track => track.Id)
-                .ToListAsync(cancellationToken);
-
-            if (libraryTrackIds.Count == 0)
-            {
-                logger.LogInformation("User {UserId} has no tracks yet, skipping mix generation", userId);
-                return Unit.Value;
-            }
-
-            var historyTrackIds = await database.ListeningHistories
-                .AsNoTracking()
-                .Where(history => history.UserId == userId && history.IsCounted)
-                .Select(history => history.TrackId)
-                .Distinct()
-                .ToListAsync(cancellationToken);
-
-            var historySet = new HashSet<Guid>(historyTrackIds);
-            var unheardTrackIds = libraryTrackIds.Where(id => !historySet.Contains(id)).ToList();
-
-            var drafts = new List<MixDraft>();
-
-            var discovery = Take(Shuffle(unheardTrackIds));
-            if (discovery.Count > 0)
-            {
-                drafts.Add(new MixDraft(MixKind.Discovery, discovery));
-            }
-
-            var daily = Take(Interleave(Shuffle(historyTrackIds), Shuffle(unheardTrackIds)));
-            if (daily.Count > 0)
-            {
-                drafts.Add(new MixDraft(MixKind.Daily, daily));
-            }
-
-            if (drafts.Count == 0)
-            {
-                logger.LogInformation("No candidate songs found for user {UserId}, skipping mix generation", userId);
-                return Unit.Value;
-            }
-
-            await ReplaceMixesAsync(userId, drafts, cancellationToken);
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Generated {Count} mixes for user {UserId}", drafts.Count, userId);
-            return Unit.Value;
-        }
-
-        private List<Guid> Take(IEnumerable<Guid> trackIds) =>
-            [.. trackIds.Take(mixConfiguration.ItemsPerMix)];
-
-        private static List<Guid> Shuffle(IEnumerable<Guid> trackIds) =>
-            [.. trackIds.OrderBy(_ => Guid.NewGuid())];
-
-        private static List<Guid> Interleave(List<Guid> first, List<Guid> second)
-        {
-            var merged = new List<Guid>(first.Count + second.Count);
-            for (var index = 0; index < Math.Max(first.Count, second.Count); index++)
-            {
-                if (index < first.Count)
-                    merged.Add(first[index]);
-                if (index < second.Count)
-                    merged.Add(second[index]);
-            }
-
-            return merged;
-        }
-
-        private async Task ReplaceMixesAsync(long userId, IReadOnlyList<MixDraft> drafts, CancellationToken cancellationToken)
-        {
-            var previousMixes = await database.Mixes
-                .Where(mix => mix.UserId == userId)
-                .ToListAsync(cancellationToken);
-
-            if (previousMixes.Count > 0)
-            {
-                database.Mixes.RemoveRange(previousMixes);
-            }
-
-            for (var position = 0; position < drafts.Count; position++)
-            {
-                var draft = drafts[position];
-                var mix = new Mix
-                {
-                    UserId = userId,
-                    Kind = draft.Kind,
-                    Position = position
-                };
-
-                await database.Mixes.AddAsync(mix, cancellationToken);
-
-                for (var itemPosition = 0; itemPosition < draft.TrackIds.Count; itemPosition++)
-                {
-                    await database.MixItems.AddAsync(new MixItem
-                    {
-                        MixId = mix.Id,
-                        Position = itemPosition,
-                        TrackId = draft.TrackIds[itemPosition]
-                    }, cancellationToken);
-                }
-            }
-        }
-    }
-}

backend/Core/Musify.Application/Mixes/GetMixById.cs

@@ -1,32 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Mixes.Responses;
-using Musify.Application.Shared;
-
-namespace Musify.Application.Mixes
-{
-    public record GetMixByIdQuery(long UserId, Guid MixId)
-        : IQuery<ErrorOr<MixApplicationResponse>>;
-
-    public class GetMixByIdQueryHandler(IDatabase database)
-        : IQueryHandler<GetMixByIdQuery, ErrorOr<MixApplicationResponse>>
-    {
-        public async ValueTask<ErrorOr<MixApplicationResponse>> Handle(GetMixByIdQuery request, CancellationToken cancellationToken)
-        {
-            var mix = await database.Mixes
-                .AsNoTracking()
-                .Include(mix => mix.Items)
-                .SingleOrDefaultAsync(mix => mix.Id == request.MixId && mix.UserId == request.UserId, cancellationToken);
-
-            if (mix == null)
-                return AppErrors.NotFound("Mix", request.MixId);
-
-            var orderedItems = mix.Items.OrderBy(item => item.Position).ToList();
-            var items = await MixItemMapper.ToResponsesAsync(database, orderedItems, cancellationToken);
-
-            return new MixApplicationResponse(mix.Id, mix.Kind, items.Count, items);
-        }
-    }
-}

backend/Core/Musify.Application/Mixes/GetMixesByUserId.cs

@@ -1,57 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Mixes.Responses;
-
-namespace Musify.Application.Mixes
-{
-    public record GetMixesByUserIdQuery(long UserId)
-        : IQuery<IReadOnlyList<MixApplicationResponse>>;
-
-    public class GetMixesByUserIdQueryHandler(IDatabase database)
-        : IQueryHandler<GetMixesByUserIdQuery, IReadOnlyList<MixApplicationResponse>>
-    {
-        public async ValueTask<IReadOnlyList<MixApplicationResponse>> Handle(GetMixesByUserIdQuery request, CancellationToken cancellationToken)
-        {
-            var mixes = await database.Mixes
-                .AsNoTracking()
-                .Where(mix => mix.UserId == request.UserId)
-                .Include(mix => mix.Items)
-                .OrderBy(mix => mix.Position)
-                .ThenBy(mix => mix.Id)
-                .ToListAsync(cancellationToken);
-
-            var orderedItemsByMix = mixes.ToDictionary(
-                mix => mix.Id,
-                mix => mix.Items.OrderBy(item => item.Position).ToList());
-
-            var visibleTrackIds = await MixItemMapper.VisibleTrackIdsAsync(
-                database, orderedItemsByMix.Values.SelectMany(items => items), cancellationToken);
-            var visibleItemsByMix = orderedItemsByMix.ToDictionary(
-                entry => entry.Key,
-                entry => entry.Value.Where(item => visibleTrackIds.Contains(item.TrackId)).ToList());
-
-            var coverItems = visibleItemsByMix.Values
-                .SelectMany(items => items.Take(MixApplicationResponse.CoverItemCount))
-                .ToList();
-            var coverResponses = (await MixItemMapper.ToResponsesAsync(database, coverItems, cancellationToken))
-                .GroupBy(response => response.TrackId)
-                .ToDictionary(group => group.Key, group => group.First());
-
-            var responses = new List<MixApplicationResponse>(mixes.Count);
-            foreach (var mix in mixes)
-            {
-                var orderedItems = visibleItemsByMix[mix.Id];
-                var covers = orderedItems
-                    .Take(MixApplicationResponse.CoverItemCount)
-                    .Where(item => coverResponses.ContainsKey(item.TrackId))
-                    .Select(item => coverResponses[item.TrackId])
-                    .ToList();
-
-                responses.Add(new MixApplicationResponse(mix.Id, mix.Kind, orderedItems.Count, covers));
-            }
-
-            return responses;
-        }
-    }
-}

backend/Core/Musify.Application/Mixes/MixItemMapper.cs

@@ -1,57 +0,0 @@
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Mixes.Responses;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Mixes
-{
-
-    internal static class MixItemMapper
-    {
-        public static async Task<HashSet<Guid>> VisibleTrackIdsAsync(
-            IDatabase database,
-            IEnumerable<MixItem> items,
-            CancellationToken cancellationToken)
-        {
-            var trackIds = items.Select(item => item.TrackId).Distinct().ToList();
-
-            var visible = await database.Tracks
-                .AsNoTracking()
-                .Where(track => trackIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active && track.IsPublished)
-                .Select(track => track.Id)
-                .ToListAsync(cancellationToken);
-
-            return [.. visible];
-        }
-
-        public static async Task<List<MixItemApplicationResponse>> ToResponsesAsync(
-            IDatabase database,
-            IReadOnlyList<MixItem> orderedItems,
-            CancellationToken cancellationToken)
-        {
-            var trackIds = orderedItems.Select(item => item.TrackId).Distinct().ToList();
-
-            var tracksById = await database.Tracks
-                .AsNoTracking()
-                .Include(track => track.Owner)
-                .Where(track => trackIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active && track.IsPublished)
-                .Select(track => new { Track = track, ListensCount = track.ListeningHistories.Count(l => l.IsCounted) })
-                .ToDictionaryAsync(x => x.Track.Id, cancellationToken);
-
-            return orderedItems
-                .Where(item => tracksById.ContainsKey(item.TrackId))
-                .Select(item =>
-                {
-                    var entry = tracksById[item.TrackId];
-                    return new MixItemApplicationResponse(
-                        item.TrackId,
-                        entry.Track.Title,
-                        entry.Track.Owner.Name,
-                        entry.Track.DurationSeconds,
-                        entry.ListensCount);
-                })
-                .ToList();
-        }
-    }
-}

backend/Core/Musify.Application/Mixes/Responses/MixApplicationResponse.cs

@@ -1,13 +0,0 @@
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Mixes.Responses
-{
-    public record MixApplicationResponse(
-        Guid Id,
-        MixKind Kind,
-        int ItemCount,
-        IReadOnlyList<MixItemApplicationResponse> Items)
-    {
-        public const int CoverItemCount = 4;
-    }
-}

backend/Core/Musify.Application/Mixes/Responses/MixItemApplicationResponse.cs

@@ -1,9 +0,0 @@
-namespace Musify.Application.Mixes.Responses
-{
-    public record MixItemApplicationResponse(
-        Guid TrackId,
-        string Title,
-        string? Artist,
-        double DurationSeconds,
-        int ListensCount);
-}

backend/Core/Musify.Application/Pictures/GetCover.cs

@@ -1,101 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using MimeMapping;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Pictures
-{
-    public enum CoverOwner
-    {
-        Track,
-        Album,
-        PlayList
-    }
-
-    public record GetCoverQuery(CoverOwner Owner, Guid Id, PictureSize Size = PictureSize.Medium)
-        : IQuery<ErrorOr<CoverLocation>>;
-
-    public record CoverLocation(string Bucket, string Key, string ContentType);
-
-    public class GetCoverQueryHandler(
-        IDatabase database,
-        ApplicationStorageConfiguration storageConfiguration,
-        TrackConfiguration trackConfiguration,
-        AlbumConfiguration albumConfiguration,
-        PlayListConfiguration playListConfiguration)
-        : IQueryHandler<GetCoverQuery, ErrorOr<CoverLocation>>
-    {
-        private sealed record CoverSource(long OwnerUserId, string? Original, string? Small, string? Medium, string? Large);
-
-        public async ValueTask<ErrorOr<CoverLocation>> Handle(GetCoverQuery request, CancellationToken cancellationToken)
-        {
-            var (source, routes) = request.Owner switch
-            {
-                CoverOwner.Track => await FindTrackSourceAsync(request.Id, cancellationToken),
-                CoverOwner.Album => (await database.Albums.AsNoTracking()
-                    .Where(a => a.Id == request.Id && a.LifeCycleStatus == LifeCycleStatus.Active && a.Pictures != null)
-                    .Select(a => new CoverSource(a.OwnerUserId, a.Pictures!.OriginalName, a.Pictures.SmallName, a.Pictures.MediumName, a.Pictures.LargeName))
-                    .SingleOrDefaultAsync(cancellationToken), albumConfiguration.Routes),
-                _ => (await database.PlayLists.AsNoTracking()
-                    .Where(p => p.Id == request.Id && p.LifeCycleStatus == LifeCycleStatus.Active && p.Pictures != null)
-                    .Select(p => new CoverSource(p.OwnerUserId, p.Pictures!.OriginalName, p.Pictures.SmallName, p.Pictures.MediumName, p.Pictures.LargeName))
-                    .SingleOrDefaultAsync(cancellationToken), playListConfiguration.Routes)
-            };
-
-            var entity = request.Owner.ToString();
-            if (source == null)
-                return AppErrors.NotFound($"{entity}Cover", request.Id);
-
-            var resizedName = request.Size switch
-            {
-                PictureSize.Small => source.Small,
-                PictureSize.Large => source.Large,
-                _ => source.Medium
-            };
-
-            var (name, key) = !string.IsNullOrEmpty(resizedName)
-                ? (resizedName, routes.BuildPicturePath(request.Size, resizedName))
-                : !string.IsNullOrEmpty(source.Original)
-                    ? (source.Original, routes.BuildOriginalPicturePath(source.OwnerUserId, source.Original))
-                    : (null, null);
-
-            if (name == null || key == null)
-                return AppErrors.NotFound($"{entity}Cover", request.Id);
-
-            return new CoverLocation(storageConfiguration.Bucket, key, MimeUtility.GetMimeMapping(name));
-        }
-
-        private async Task<(CoverSource? Source, PictureRoutes Routes)> FindTrackSourceAsync(Guid trackId, CancellationToken cancellationToken)
-        {
-            var track = await database.Tracks.AsNoTracking()
-                .Where(t => t.Id == trackId && t.LifeCycleStatus == LifeCycleStatus.Active)
-                .Select(t => new
-                {
-                    Own = new CoverSource(t.OwnerUserId, t.Pictures.OriginalName, t.Pictures.SmallName, t.Pictures.MediumName, t.Pictures.LargeName),
-                    Album = t.AlbumTracks
-                        .Where(albumTrack => albumTrack.Album.LifeCycleStatus == LifeCycleStatus.Active && albumTrack.Album.Pictures != null)
-                        .OrderBy(albumTrack => albumTrack.AddedAt)
-                        .ThenBy(albumTrack => albumTrack.AlbumId)
-                        .Select(albumTrack => new CoverSource(
-                            albumTrack.Album.OwnerUserId,
-                            albumTrack.Album.Pictures!.OriginalName,
-                            albumTrack.Album.Pictures.SmallName,
-                            albumTrack.Album.Pictures.MediumName,
-                            albumTrack.Album.Pictures.LargeName))
-                        .FirstOrDefault()
-                })
-                .SingleOrDefaultAsync(cancellationToken);
-
-            if (track == null)
-                return (null, trackConfiguration.Routes);
-
-            return string.IsNullOrEmpty(track.Own.Original) && track.Album != null
-                ? (track.Album, albumConfiguration.Routes)
-                : (track.Own, trackConfiguration.Routes);
-        }
-    }
-}

backend/Core/Musify.Application/Pictures/PictureSourceChange.cs

@@ -1,35 +0,0 @@
-using ErrorOr;
-using Musify.Application.Configuration;
-using Musify.Application.Services;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Pictures
-{
-    public sealed record PreparedPicture(UploadIntent Intent, EntityPictures Pictures, string FinalKey, ImageSizes Sizes);
-
-    public static class PictureSourceChange
-    {
-        public static async Task<ErrorOr<PreparedPicture>> PrepareAsync(
-            UploadIntentValidator uploadIntentValidator,
-            Guid intentId,
-            long userId,
-            UploadIntentPurpose purpose,
-            IPictureOwnerConfiguration owner,
-            CancellationToken cancellationToken)
-        {
-            var validation = await uploadIntentValidator.ValidateAndLoadAsync(intentId, userId, purpose, cancellationToken);
-            if (validation.IsError)
-                return validation.Errors;
-
-            var intent = validation.Value;
-
-            return new PreparedPicture(
-                intent,
-                EntityPictures.Pending(intent.ObjectName),
-                owner.Routes.BuildOriginalPicturePath(userId, intent.ObjectName),
-                owner.PicturesSizes.ToImageSizes(owner.Routes));
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/AddAlbumToPlayList.cs

@@ -1,81 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Albums.Responses;
-using Musify.Application.Contracts;
-using Musify.Application.PlayLists.Responses;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists
-{
-    public record AddAlbumToPlayListCommand(long UserId, Guid PlayListId, Guid AlbumId)
-        : ICommand<ErrorOr<AddAlbumToPlayListResponse>>;
-
-    public class AddAlbumToPlayListCommandHandler(
-        IDatabase database,
-        ILogger<AddAlbumToPlayListCommandHandler> logger)
-        : ICommandHandler<AddAlbumToPlayListCommand, ErrorOr<AddAlbumToPlayListResponse>>
-    {
-        public async ValueTask<ErrorOr<AddAlbumToPlayListResponse>> Handle(AddAlbumToPlayListCommand request, CancellationToken cancellationToken)
-        {
-            var playList = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-            if (playList.IsError)
-                return playList.Errors;
-
-            var albumExists = await database.Albums
-                .AsNoTracking()
-                .Active()
-                .AnyAsync(album => album.Id == request.AlbumId, cancellationToken);
-            if (!albumExists)
-                return AppErrors.NotFound("Album", request.AlbumId);
-
-            var albumTrackIds = await database.AlbumHasTracks
-                .AsNoTracking()
-                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId && albumTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && albumTrack.Track.IsPublished)
-                .OrderBy(albumTrack => albumTrack.TrackNumber)
-                .Select(albumTrack => albumTrack.TrackId)
-                .ToListAsync(cancellationToken);
-
-            var playListTracksQuery = database.PlayListHasTracks
-                .Where(link => link.PlayListId == request.PlayListId);
-
-            var existingTrackIds = (await playListTracksQuery
-                .Select(link => link.TrackId)
-                .ToListAsync(cancellationToken)).ToHashSet();
-
-            var newTrackIds = albumTrackIds
-                .Where(trackId => !existingTrackIds.Contains(trackId))
-                .ToList();
-
-            if (newTrackIds.Count == 0)
-                return new AddAlbumToPlayListResponse(0);
-
-            var nextPosition = existingTrackIds.Count > 0
-               ? await playListTracksQuery.MaxAsync(link => link.Position, cancellationToken) + 1
-                : 0;
-
-            foreach (var trackId in newTrackIds)
-            {
-                await database.PlayListHasTracks.AddAsync(new PlayListHasTrack
-                {
-                    PlayListId = request.PlayListId,
-                    TrackId = trackId,
-                    Position = nextPosition++
-                }, cancellationToken);
-            }
-
-            var saved = await database.TrySaveChangesAsync(
-                AppErrors.Conflict("PlayList.ConcurrentChange", "The playlist changed while adding tracks. Try again."), cancellationToken);
-            if (saved.IsError)
-                return saved.Errors;
-
-            logger.LogInformation("Added {Count} tracks from album {AlbumId} to playlist {PlayListId}",
-                newTrackIds.Count, request.AlbumId, request.PlayListId);
-
-            return new AddAlbumToPlayListResponse(newTrackIds.Count);
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/AddTracksToPlayList.cs

@@ -1,75 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists
-{
-    public record AddTracksToPlayListCommand(long UserId, Guid PlayListId, IReadOnlyList<Guid> TrackIds)
-        : ICommand<ErrorOr<Success>>;
-
-    public class AddTracksToPlayListCommandHandler(
-        IDatabase database,
-        ILogger<AddTracksToPlayListCommandHandler> logger)
-        : ICommandHandler<AddTracksToPlayListCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(AddTracksToPlayListCommand request, CancellationToken cancellationToken)
-        {
-            var playList = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-            if (playList.IsError)
-                return playList.Errors;
-
-            var requestedIds = request.TrackIds.Distinct().ToList();
-
-            var existingIds = await database.Tracks
-                .AsNoTracking()
-                .Where(track => requestedIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active && track.IsPublished)
-                .Select(track => track.Id)
-                .ToListAsync(cancellationToken);
-
-            var missing = requestedIds.FirstOrDefault(id => !existingIds.Contains(id));
-            if (missing != Guid.Empty)
-                return AppErrors.NotFound("Track", missing);
-
-            var alreadyInPlayList = await database.PlayListHasTracks
-                .AsNoTracking()
-                .Where(link => link.PlayListId == request.PlayListId && requestedIds.Contains(link.TrackId))
-                .Select(link => link.TrackId)
-                .ToListAsync(cancellationToken);
-
-            var toAdd = requestedIds.Where(id => !alreadyInPlayList.Contains(id)).ToList();
-            if (toAdd.Count == 0)
-                return Result.Success;
-
-            var playListTracksQuery = database.PlayListHasTracks
-                .Where(link => link.PlayListId == request.PlayListId);
-
-            var nextPosition = await playListTracksQuery.AnyAsync(cancellationToken)
-               ? await playListTracksQuery.MaxAsync(link => link.Position, cancellationToken) + 1
-                : 0;
-
-            foreach (var trackId in toAdd)
-            {
-                await database.PlayListHasTracks.AddAsync(new PlayListHasTrack
-                {
-                    PlayListId = request.PlayListId,
-                    TrackId = trackId,
-                    Position = nextPosition++
-                }, cancellationToken);
-            }
-
-            var saved = await database.TrySaveChangesAsync(
-                AppErrors.Conflict("PlayList.ConcurrentChange", "The playlist changed while adding tracks. Try again."), cancellationToken);
-            if (saved.IsError)
-                return saved;
-
-            logger.LogInformation("Added {Count} tracks to playlist {PlayListId}", toAdd.Count, request.PlayListId);
-
-            return Result.Success;
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/CreatePlayList.cs

@@ -1,79 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Pictures;
-using Musify.Application.PlayLists.Responses;
-using Musify.Application.Services;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists
-{
-    public record CreatePlayListCommand(
-        long UserId,
-        string Name,
-        string? Description,
-        Guid? PictureIntentId,
-        PlayListVisibility Visibility = PlayListVisibility.Private)
-        : ICommand<ErrorOr<PlayListApplicationResponse>>;
-
-    public class CreatePlayListCommandHandler(
-        IEventBus eventBus,
-        IDatabase database,
-        UploadIntentValidator uploadIntentValidator,
-        ILogger<CreatePlayListCommandHandler> logger,
-        PlayListConfiguration playListConfiguration)
-        : ICommandHandler<CreatePlayListCommand, ErrorOr<PlayListApplicationResponse>>
-    {
-        public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(CreatePlayListCommand request, CancellationToken cancellationToken)
-        {
-            var userExists = await database.Users
-                .AsNoTracking()
-                .AnyAsync(u => u.Id == request.UserId, cancellationToken);
-            if (!userExists)
-                return AppErrors.NotFound("User", request.UserId);
-
-            PreparedPicture? picture = null;
-            if (request.PictureIntentId.HasValue)
-            {
-                var prepared = await PictureSourceChange.PrepareAsync(
-                    uploadIntentValidator, request.PictureIntentId.Value, request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration, cancellationToken);
-                if (prepared.IsError)
-                    return prepared.Errors;
-
-                picture = prepared.Value;
-            }
-
-            var name = request.Name.Trim();
-            var playList = new PlayList
-            {
-                OwnerUserId = request.UserId,
-                Name = name,
-                NormalizedName = TextNormalizer.Normalize(name),
-                Description = string.IsNullOrWhiteSpace(request.Description) ? null : request.Description.Trim(),
-                Pictures = picture?.Pictures,
-                Visibility = request.Visibility
-            };
-            await database.PlayLists.AddAsync(playList, cancellationToken);
-
-            if (picture != null)
-            {
-                await eventBus.PublishAsync(
-                    new CreatePlayListResourcesEvent(
-                        playList.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-                    cancellationToken);
-            }
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Created playlist {PlayListId} for user {UserId}", playList.Id, request.UserId);
-
-            return PlayListApplicationResponse.FromEntity(playList);
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/DeletePlayList.cs

@@ -1,37 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists
-{
-    public record DeletePlayListCommand(long UserId, Guid PlayListId)
-        : ICommand<ErrorOr<Success>>;
-
-    public class DeletePlayListCommandHandler(
-        IDatabase database,
-        IEventBus eventBus,
-        ILogger<DeletePlayListCommandHandler> logger)
-        : ICommandHandler<DeletePlayListCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(DeletePlayListCommand request, CancellationToken cancellationToken)
-        {
-            var found = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-            if (found.IsError)
-                return found.Errors;
-
-            var playList = found.Value;
-            playList.LifeCycleStatus = LifeCycleStatus.Removing;
-
-            await eventBus.PublishAsync(new DeletePlayListEvent(playList.Id, request.UserId), cancellationToken);
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Marked playlist {PlayListId} as removing", request.PlayListId);
-
-            return Result.Success;
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/GetPlayListTracks.cs

@@ -1,42 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.PlayLists.Responses;
-using Musify.Application.Shared;
-using Musify.Application.Tracks.Responses;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists
-{
-    public record GetPlayListTracksQuery(
-        Guid PlayListId,
-        int PageNumber,
-        int PageSize,
-        long? ViewerId = null)
-        : IQuery<ErrorOr<PaginatedResponse<TrackApplicationResponse>>>;
-
-    public class GetPlayListTracksQueryHandler(IDatabase database)
-        : IQueryHandler<GetPlayListTracksQuery, ErrorOr<PaginatedResponse<TrackApplicationResponse>>>
-    {
-        public async ValueTask<ErrorOr<PaginatedResponse<TrackApplicationResponse>>> Handle(GetPlayListTracksQuery request, CancellationToken cancellationToken)
-        {
-            var playListVisible = await database.PlayLists
-                .AsNoTracking()
-                .Active()
-                .VisibleTo(request.ViewerId)
-                .AnyAsync(playList => playList.Id == request.PlayListId, cancellationToken);
-            if (!playListVisible)
-                return AppErrors.NotFound("PlayList", request.PlayListId);
-
-            return await database.PlayListHasTracks
-                .AsNoTracking()
-                .Where(playListTrack => playListTrack.PlayListId == request.PlayListId && playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && playListTrack.Track.IsPublished)
-                .OrderBy(playListTrack => playListTrack.Position)
-                .ThenBy(playListTrack => playListTrack.Id)
-                .Select(playListTrack => playListTrack.Track)
-                .SelectResponse()
-                .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/GetPlayListsByUserId.cs

@@ -1,41 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.PlayLists.Responses;
-using Musify.Application.Shared;
-
-namespace Musify.Application.PlayLists
-{
-    public record GetPlayListsByUserIdQuery(
-        long UserId,
-        string? Name,
-        int PageNumber,
-        int PageSize,
-        long? ViewerId = null)
-        : IQuery<PaginatedResponse<PlayListApplicationResponse>>;
-
-    public class GetPlayListsByUserIdQueryHandler(IDatabase database)
-        : IQueryHandler<GetPlayListsByUserIdQuery, PaginatedResponse<PlayListApplicationResponse>>
-    {
-        public async ValueTask<PaginatedResponse<PlayListApplicationResponse>> Handle(GetPlayListsByUserIdQuery request, CancellationToken cancellationToken)
-        {
-            var playListsQuery = database.PlayLists
-                .AsNoTracking()
-                .Active()
-                .VisibleTo(request.ViewerId)
-                .Where(playList => playList.OwnerUserId == request.UserId);
-
-            if (!string.IsNullOrWhiteSpace(request.Name))
-            {
-                var normalizedName = TextNormalizer.Normalize(request.Name);
-                playListsQuery = playListsQuery.Where(playList => playList.NormalizedName.Contains(normalizedName));
-            }
-
-            return await playListsQuery
-                .OrderBy(playList => playList.CreatedAt)
-                .ThenBy(playList => playList.Id)
-                .SelectResponse()
-                .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/RemoveTrackFromPlayList.cs

@@ -1,46 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-
-namespace Musify.Application.PlayLists
-{
-    public record RemoveTrackFromPlayListCommand(long UserId, Guid PlayListId, Guid TrackId)
-        : ICommand<ErrorOr<Success>>;
-
-    public class RemoveTrackFromPlayListCommandHandler(
-        IDatabase database,
-        ILogger<RemoveTrackFromPlayListCommandHandler> logger)
-        : ICommandHandler<RemoveTrackFromPlayListCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(RemoveTrackFromPlayListCommand request, CancellationToken cancellationToken)
-        {
-            var playList = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-            if (playList.IsError)
-                return playList.Errors;
-
-            var playListTracks = await database.PlayListHasTracks
-                .Where(plt => plt.PlayListId == request.PlayListId)
-                .OrderBy(plt => plt.Position)
-                .ToListAsync(cancellationToken);
-
-            var link = playListTracks.SingleOrDefault(plt => plt.TrackId == request.TrackId);
-            if (link == null)
-                return Error.NotFound("PlayList.TrackNotFound", "Track is not in the playlist.");
-
-            database.PlayListHasTracks.Remove(link);
-
-            var position = 0;
-            foreach (var remaining in playListTracks.Where(plt => plt.Id != link.Id))
-                remaining.Position = position++;
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Removed track {TrackId} from playlist {PlayListId}", request.TrackId, request.PlayListId);
-
-            return Result.Success;
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/RequestPlayListPictureUpload.cs

@@ -1,25 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Musify.Application.Configuration;
-using Musify.Application.Pictures.Responses;
-using Musify.Application.Services;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists
-{
-    public record RequestPlayListPictureUploadCommand(
-        long UserId,
-        string FileType,
-        string ContentType,
-        long? ExpectedSizeBytes = null)
-        : ICommand<ErrorOr<PictureUploadResponse>>;
-
-    public class RequestPlayListPictureUploadCommandHandler(UploadIntentIssuer issuer, PlayListConfiguration playListConfiguration)
-        : ICommandHandler<RequestPlayListPictureUploadCommand, ErrorOr<PictureUploadResponse>>
-    {
-        public async ValueTask<ErrorOr<PictureUploadResponse>> Handle(RequestPlayListPictureUploadCommand request, CancellationToken cancellationToken) =>
-            await issuer.IssuePictureAsync(
-                request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration,
-                request.FileType, request.ContentType, request.ExpectedSizeBytes, cancellationToken);
-    }
-}

backend/Core/Musify.Application/PlayLists/Responses/AddAlbumToPlayListResponse.cs

@@ -1,4 +0,0 @@
-namespace Musify.Application.PlayLists.Responses
-{
-    public record AddAlbumToPlayListResponse(int AddedCount);
-}

backend/Core/Musify.Application/PlayLists/Responses/PlayListApplicationResponse.cs

@@ -1,46 +0,0 @@
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-
-namespace Musify.Application.PlayLists.Responses
-{
-    public record PlayListApplicationResponse(
-        Guid Id,
-        string Name,
-        string? Description,
-        string? SmallImageKeyName,
-        string? MediumImageKeyName,
-        string? LargeImageKeyName,
-        PlayListVisibility Visibility,
-        DateTime CreatedAt,
-        DateTime UpdatedAt,
-        IReadOnlyList<Guid> CoverTrackIds,
-        long OwnerUserId,
-        int TrackCount,
-        double DurationSeconds)
-    {
-        public const int CoverTrackCount = PlayListProjections.CoverTrackCount;
-
-        public static PlayListApplicationResponse FromEntity(
-            PlayList playList,
-            IReadOnlyList<Guid>? coverTrackIds = null,
-            int trackCount = 0,
-            double durationSeconds = 0)
-        {
-            return new PlayListApplicationResponse(
-                playList.Id,
-                playList.Name,
-                playList.Description,
-                playList.Pictures?.SmallName,
-                playList.Pictures?.MediumName,
-                playList.Pictures?.LargeName,
-                playList.Visibility,
-                playList.CreatedAt,
-                playList.UpdatedAt,
-                coverTrackIds ?? [],
-                playList.OwnerUserId,
-                trackCount,
-                durationSeconds);
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/Responses/PlayListProjections.cs

@@ -1,39 +0,0 @@
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists.Responses
-{
-    public static class PlayListProjections
-    {
-        public const int CoverTrackCount = 4;
-
-        public static IQueryable<PlayList> Active(this IQueryable<PlayList> query) =>
-            query.Where(playList => playList.LifeCycleStatus == LifeCycleStatus.Active);
-
-        public static IQueryable<PlayList> VisibleTo(this IQueryable<PlayList> query, long? viewerId) =>
-            query.Where(playList => playList.Visibility == PlayListVisibility.Public || playList.OwnerUserId == viewerId);
-
-        public static IQueryable<PlayListApplicationResponse> SelectResponse(this IQueryable<PlayList> query) =>
-            query.Select(playList => new PlayListApplicationResponse(
-                playList.Id,
-                playList.Name,
-                playList.Description,
-                playList.Pictures!.SmallName,
-                playList.Pictures!.MediumName,
-                playList.Pictures!.LargeName,
-                playList.Visibility,
-                playList.CreatedAt,
-                playList.UpdatedAt,
-                playList.PlayListTracks
-                    .Where(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && playListTrack.Track.IsPublished)
-                    .OrderBy(playListTrack => playListTrack.Position)
-                    .Take(CoverTrackCount)
-                    .Select(playListTrack => playListTrack.TrackId)
-                    .ToList(),
-                playList.OwnerUserId,
-                playList.PlayListTracks.Count(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && playListTrack.Track.IsPublished),
-                playList.PlayListTracks
-                    .Where(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && playListTrack.Track.IsPublished)
-                    .Sum(playListTrack => playListTrack.Track.DurationSeconds)));
-    }
-}

backend/Core/Musify.Application/PlayLists/UpdatePlayList.cs

@@ -1,49 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.PlayLists.Responses;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists
-{
-    public record UpdatePlayListCommand(
-        long UserId,
-        Guid PlayListId,
-        string NewName,
-        string? NewDescription,
-        PlayListVisibility NewVisibility)
-        : ICommand<ErrorOr<PlayListApplicationResponse>>;
-
-    public class UpdatePlayListCommandHandler(
-        IDatabase database,
-        ILogger<UpdatePlayListCommandHandler> logger)
-        : ICommandHandler<UpdatePlayListCommand, ErrorOr<PlayListApplicationResponse>>
-    {
-        public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(UpdatePlayListCommand request, CancellationToken cancellationToken)
-        {
-            var found = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-            if (found.IsError)
-                return found.Errors;
-
-            var playList = found.Value;
-
-            playList.Name = request.NewName.Trim();
-            playList.NormalizedName = TextNormalizer.Normalize(request.NewName);
-            playList.Description = string.IsNullOrWhiteSpace(request.NewDescription) ? null : request.NewDescription.Trim();
-            playList.Visibility = request.NewVisibility;
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Updated playlist {PlayListId}", playList.Id);
-
-            return await database.PlayLists
-                .AsNoTracking()
-                .Where(p => p.Id == playList.Id)
-                .SelectResponse()
-                .SingleAsync(cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/PlayLists/UpdatePlayListPicture.cs

@@ -1,59 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Pictures;
-using Musify.Application.PlayLists.Responses;
-using Musify.Application.Services;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists
-{
-    public record UpdatePlayListPictureCommand(long UserId, Guid PlayListId, Guid PictureIntentId)
-        : ICommand<ErrorOr<PlayListApplicationResponse>>;
-
-    public class UpdatePlayListPictureCommandHandler(
-        IEventBus eventBus,
-        IDatabase database,
-        UploadIntentValidator uploadIntentValidator,
-        ILogger<UpdatePlayListPictureCommandHandler> logger,
-        PlayListConfiguration playListConfiguration)
-        : ICommandHandler<UpdatePlayListPictureCommand, ErrorOr<PlayListApplicationResponse>>
-    {
-        public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(UpdatePlayListPictureCommand request, CancellationToken cancellationToken)
-        {
-            var found = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-            if (found.IsError)
-                return found.Errors;
-
-            var playList = found.Value;
-
-            var prepared = await PictureSourceChange.PrepareAsync(
-                uploadIntentValidator, request.PictureIntentId, request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration, cancellationToken);
-            if (prepared.IsError)
-                return prepared.Errors;
-
-            var picture = prepared.Value;
-            playList.Pictures = picture.Pictures;
-
-            await eventBus.PublishAsync(
-                new UpdatePlayListPictureSourceEvent(
-                    playList.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-                cancellationToken);
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Updated picture of playlist {PlayListId}", playList.Id);
-
-            return await database.PlayLists
-                .AsNoTracking()
-                .Where(p => p.Id == playList.Id)
-                .SelectResponse()
-                .SingleAsync(cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Services/TrackStreamIssuer.cs

@@ -1,35 +0,0 @@
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Tracks.Responses;
-
-namespace Musify.Application.Services
-{
-    public sealed class TrackStreamIssuer(
-        IStreamTicketService ticketService,
-        TrackConfiguration trackConfiguration,
-        StreamGatewayConfiguration streamGatewayConfiguration,
-        PlaybackConfiguration playbackConfiguration)
-    {
-        public TrackStreamResponse Issue(string audioFolderName, long? userId, Guid? listenId)
-        {
-            var folderPath = trackConfiguration.Routes.BuildProcessedAudioPath(audioFolderName);
-            var ticket = ticketService.IssueTicket(userId, $"{folderPath}/", AnonymousFragmentBytes(userId));
-
-            var manifestUrl = string.Join('/',
-                streamGatewayConfiguration.PublicBaseUrl.TrimEnd('/'),
-                "media",
-                folderPath,
-                streamGatewayConfiguration.AudioFileName);
-
-            return new TrackStreamResponse(manifestUrl, ticket.Token, ticket.ExpiresInSeconds, listenId);
-        }
-
-        private long? AnonymousFragmentBytes(long? userId)
-        {
-            if (userId != null || playbackConfiguration.AnonymousFragmentSeconds <= 0)
-                return null;
-
-            return (long)playbackConfiguration.AnonymousFragmentSeconds * playbackConfiguration.EstimatedAudioBytesPerSecond;
-        }
-    }
-}

backend/Core/Musify.Application/Services/UploadIntentIssuer.cs

@@ -1,138 +0,0 @@
-using ErrorOr;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Pictures.Responses;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Services
-{
-    public sealed record UploadRequest(
-        UploadIntentPurpose Purpose,
-        PictureRoutes Routes,
-        string FileType,
-        string ContentType,
-        long? ExpectedSizeBytes,
-        int? SharedKeyGroup = null);
-
-    public sealed record IssuedUpload(
-        Guid IntentId,
-        string Key,
-        string ObjectName,
-        string ContentType,
-        string UploadUrl);
-
-    public sealed class UploadIntentIssuer(
-        IDatabase database,
-        IStorageService storageService,
-        UploadIntentValidator uploadIntentValidator,
-        ApplicationStorageConfiguration storageConfiguration,
-        UploadIntentConfiguration uploadIntentConfiguration,
-        ILogger<UploadIntentIssuer> logger)
-    {
-        public async Task<ErrorOr<IReadOnlyList<IssuedUpload>>> IssueAsync(
-            long userId,
-            IReadOnlyList<UploadRequest> requests,
-            CancellationToken cancellationToken)
-        {
-            var userExists = await database.Users
-                .AsNoTracking()
-                .AnyAsync(user => user.Id == userId, cancellationToken);
-            if (!userExists)
-                return AppErrors.NotFound("User", userId);
-
-            var sharedKeys = new Dictionary<int, string>();
-            var planned = requests
-                .Select(request =>
-                {
-                    var objectName = $"{Guid.NewGuid()}.{request.FileType.TrimStart('.').ToLowerInvariant()}";
-                    var key = request.Routes.BuildTempPath(uploadIntentConfiguration.TempRootPrefix, userId, objectName);
-                    if (request.SharedKeyGroup is { } group)
-                        key = sharedKeys.TryAdd(group, key) ? key : sharedKeys[group];
-
-                    var size = request.ExpectedSizeBytes ?? DefaultSize(request.Purpose);
-                    return (Request: request, ObjectName: objectName, Key: key, Size: size);
-                })
-                .ToList();
-
-            await using var transaction = await database.BeginTransactionAsync(
-                System.Data.IsolationLevel.Serializable, cancellationToken);
-
-            var quota = await uploadIntentValidator.CheckQuotaAsync(
-                userId, planned.Sum(item => item.Size), planned.Count, cancellationToken);
-            if (quota.IsError)
-                return quota.Errors;
-
-            var expiresIn = TimeSpan.FromSeconds(uploadIntentConfiguration.UploadUrlExpiresInSeconds);
-            var expiresAt = DateTime.UtcNow + expiresIn;
-            var issued = new List<IssuedUpload>(planned.Count);
-
-            foreach (var item in planned)
-            {
-                var uploadUrl = await storageService.GetUploadUrlAsync(
-                    storageConfiguration.Bucket, item.Key, item.Request.ContentType, expiresIn, cancellationToken: cancellationToken);
-
-                var intent = new UploadIntent
-                {
-                    UserId = userId,
-                    Bucket = storageConfiguration.Bucket,
-                    Key = item.Key,
-                    ObjectName = item.ObjectName,
-                    ContentType = item.Request.ContentType,
-                    ExpectedSizeBytes = item.Size,
-                    Purpose = item.Request.Purpose,
-                    ExpiresAt = expiresAt,
-                };
-
-                await database.UploadIntents.AddAsync(intent, cancellationToken);
-                issued.Add(new IssuedUpload(intent.Id, item.Key, item.ObjectName, item.Request.ContentType, uploadUrl));
-            }
-
-            await database.SaveChangesAsync(cancellationToken);
-            await transaction.CommitAsync(cancellationToken);
-
-            logger.LogInformation("Issued {Count} upload intents for user {UserId} ({Purposes})",
-                issued.Count, userId, string.Join('/', planned.Select(item => item.Request.Purpose)));
-
-            return issued;
-        }
-
-        public async Task<ErrorOr<IssuedUpload>> IssueOneAsync(long userId, UploadRequest request, CancellationToken cancellationToken)
-        {
-            var issued = await IssueAsync(userId, [request], cancellationToken);
-            return issued.IsError ? issued.Errors : issued.Value[0];
-        }
-
-        public async Task<ErrorOr<PictureUploadResponse>> IssuePictureAsync(
-            long userId,
-            UploadIntentPurpose purpose,
-            IPictureOwnerConfiguration owner,
-            string fileType,
-            string contentType,
-            long? expectedSizeBytes,
-            CancellationToken cancellationToken)
-        {
-            var issued = await IssueOneAsync(
-                userId, new UploadRequest(purpose, owner.Routes, fileType, contentType, expectedSizeBytes), cancellationToken);
-            if (issued.IsError)
-                return issued.Errors;
-
-            return new PictureUploadResponse(
-                issued.Value.IntentId,
-                storageConfiguration.Bucket,
-                issued.Value.Key,
-                issued.Value.ObjectName,
-                issued.Value.ContentType,
-                uploadIntentConfiguration.UploadUrlExpiresInSeconds,
-                issued.Value.UploadUrl);
-        }
-
-        private long DefaultSize(UploadIntentPurpose purpose) =>
-            purpose == UploadIntentPurpose.TrackAudio
-                ? uploadIntentConfiguration.DefaultExpectedAudioSizeBytes
-                : uploadIntentConfiguration.DefaultExpectedPictureSizeBytes;
-    }
-}

backend/Core/Musify.Application/Services/UploadIntentValidator.cs

@@ -1,78 +0,0 @@
-using ErrorOr;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Services
-{
-    public sealed class UploadIntentValidator(
-        IDatabase database,
-        IStorageService storageService,
-        UploadIntentConfiguration config)
-    {
-        public async Task<ErrorOr<Success>> CheckQuotaAsync(
-            long userId,
-            long requiredBytes,
-            int requiredIntentCount,
-            CancellationToken cancellationToken)
-        {
-            var now = DateTime.UtcNow;
-            var pictureDefault = config.DefaultExpectedPictureSizeBytes;
-            var audioDefault = config.DefaultExpectedAudioSizeBytes;
-
-            var active = await database.UploadIntents
-                .AsNoTracking()
-                .Where(intent => intent.UserId == userId && intent.Status == UploadIntentStatus.Issued && intent.ExpiresAt > now)
-                .GroupBy(_ => 1)
-                .Select(group => new
-                {
-                    Count = group.Count(),
-                    Bytes = group.Sum(intent => intent.ExpectedSizeBytes
-                        ?? (intent.Purpose == UploadIntentPurpose.TrackAudio ? audioDefault : pictureDefault))
-                })
-                .SingleOrDefaultAsync(cancellationToken);
-
-            if ((active?.Count ?? 0) + requiredIntentCount > config.MaxActiveUploadIntentsPerUser)
-                return Error.Validation(description: "Upload intent limit exceeded. Wait for existing uploads to complete or expire.");
-
-            if ((active?.Bytes ?? 0) + requiredBytes > config.MaxActiveUploadBytesPerUser)
-                return Error.Validation(description: "Upload byte quota exceeded. Wait for existing uploads to complete or expire.");
-
-            return Result.Success;
-        }
-
-        public async Task<ErrorOr<UploadIntent>> ValidateAndLoadAsync(
-            Guid intentId,
-            long userId,
-            UploadIntentPurpose purpose,
-            CancellationToken cancellationToken)
-        {
-            var intent = await database.UploadIntents
-                .FirstOrDefaultAsync(i => i.Id == intentId, cancellationToken);
-
-            if (intent == null || intent.UserId != userId)
-                return AppErrors.NotFound("UploadIntent", intentId);
-
-            if (intent.Purpose != purpose)
-                return Error.Validation(description: "Upload intent was issued for a different purpose.");
-
-            if (intent.IsConsumed)
-                return AppErrors.Conflict("UploadIntent.Consumed", "Upload intent has already been consumed.");
-
-            if (intent.IsExpiredAt(DateTime.UtcNow))
-                return Error.Validation(description: "Upload intent has expired.");
-
-            var metadata = await storageService.HeadObjectAsync(intent.Bucket, intent.Key, cancellationToken);
-            if (metadata == null)
-                return Error.NotFound("UploadIntent.ObjectMissing", "Uploaded object not found in storage. Upload the file first.");
-
-            if (metadata.ContentLength > config.MaxUploadBytes)
-                return Error.Validation(description: $"Uploaded file exceeds the maximum allowed size of {config.MaxUploadBytes} bytes.");
-
-            return intent;
-        }
-    }
-}

backend/Core/Musify.Application/Shared/AppErrors.cs

@@ -1,16 +0,0 @@
-using ErrorOr;
-
-namespace Musify.Application.Shared
-{
-    public static class AppErrors
-    {
-        public static Error NotFound(string entity, object id) =>
-            Error.NotFound($"{entity}.NotFound", $"{entity} {id} was not found.");
-
-        public static Error Forbidden(string entity, object id) =>
-            Error.Forbidden($"{entity}.Forbidden", $"You do not have permission to modify {entity} {id}.");
-
-        public static Error Conflict(string code, string description) =>
-            Error.Conflict(code, description);
-    }
-}

backend/Core/Musify.Application/Shared/ImageSize.cs

@@ -1,12 +0,0 @@
-namespace Musify.Application.Shared
-{
-    public record ImageSize(
-        string SavePath,
-        int Width,
-        int Height);
-
-    public record ImageSizes(
-        ImageSize Small,
-        ImageSize Medium,
-        ImageSize Large);
-}

backend/Core/Musify.Application/Shared/OwnershipExtensions.cs

@@ -1,25 +0,0 @@
-using ErrorOr;
-using Microsoft.EntityFrameworkCore;
-using Musify.Domain.Abstractions;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Shared
-{
-    public static class OwnershipExtensions
-    {
-        public static async Task<ErrorOr<T>> FindOwnedAsync<T>(
-            this DbSet<T> set, Guid id, long userId, CancellationToken cancellationToken)
-            where T : class, IOwnedEntity, IHasLifeCycle
-        {
-            var entity = await set.SingleOrDefaultAsync(
-                e => e.Id == id && e.LifeCycleStatus == LifeCycleStatus.Active, cancellationToken);
-
-            if (entity == null)
-                return AppErrors.NotFound(typeof(T).Name, id);
-
-            return entity.OwnerUserId == userId
-                ? entity
-                : AppErrors.Forbidden(typeof(T).Name, id);
-        }
-    }
-}

backend/Core/Musify.Application/Shared/Pagination.cs

@@ -1,45 +0,0 @@
-using Microsoft.EntityFrameworkCore;
-
-namespace Musify.Application.Shared
-{
-    public record PageRequest(int PageNumber = 1, int PageSize = 20)
-    {
-        public const int MaxPageSize = 100;
-    }
-
-    public record PaginatedResponse<T>(
-        IReadOnlyList<T> Items,
-        int PageNumber,
-        int PageSize,
-        int PageCount,
-        int TotalItemCount,
-        bool HasNextPage,
-        bool HasPreviousPage);
-
-    public static class PaginationExtensions
-    {
-        public static async Task<PaginatedResponse<T>> ToPaginatedAsync<T>(
-            this IQueryable<T> query, PageRequest page, CancellationToken cancellationToken)
-        {
-            var pageNumber = Math.Max(page.PageNumber, 1);
-            var pageSize = Math.Clamp(page.PageSize, 1, PageRequest.MaxPageSize);
-
-            var totalCount = await query.CountAsync(cancellationToken);
-            var items = await query
-                .Skip((pageNumber - 1) * pageSize)
-                .Take(pageSize)
-                .ToListAsync(cancellationToken);
-
-            var pageCount = (int)Math.Ceiling(totalCount / (double)pageSize);
-
-            return new PaginatedResponse<T>(
-                items,
-                pageNumber,
-                pageSize,
-                pageCount,
-                totalCount,
-                HasNextPage: pageNumber < pageCount,
-                HasPreviousPage: pageNumber > 1 && pageCount > 0);
-        }
-    }
-}

backend/Core/Musify.Application/Shared/TextNormalizer.cs

@@ -1,7 +0,0 @@
-namespace Musify.Application.Shared
-{
-    public static class TextNormalizer
-    {
-        public static string Normalize(string value) => value.Trim().ToUpperInvariant();
-    }
-}

backend/Core/Musify.Application/Tracks/CreateTrack.cs

@@ -1,120 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Services;
-using Musify.Application.Shared;
-using Musify.Application.Tracks.Responses;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Tracks
-{
-    public record CreateTrackCommand(
-        long UserId,
-        string Title,
-        Guid? PictureIntentId,
-        Guid AudioIntentId,
-        IReadOnlyCollection<Genre> Tags,
-        bool IsExplicit = false)
-        : ICommand<ErrorOr<TrackApplicationResponse>>;
-
-    public class CreateTrackCommandHandler(
-        IDatabase database,
-        IEventBus eventBus,
-        UploadIntentValidator uploadIntentValidator,
-        ILogger<CreateTrackCommandHandler> logger,
-        TrackConfiguration trackConfiguration)
-        : ICommandHandler<CreateTrackCommand, ErrorOr<TrackApplicationResponse>>
-    {
-        public async ValueTask<ErrorOr<TrackApplicationResponse>> Handle(CreateTrackCommand request, CancellationToken cancellationToken)
-        {
-            var user = await database.Users
-                .SingleOrDefaultAsync(u => u.Id == request.UserId, cancellationToken);
-            if (user == null)
-            {
-                logger.LogWarning("User {UserId} not found", request.UserId);
-                return Error.NotFound(description: $"User {request.UserId} not found");
-            }
-
-            var distinctTags = request.Tags.Distinct().ToList();
-
-            if (request.PictureIntentId == request.AudioIntentId)
-                return Error.Validation(description: "Picture and audio must use different upload intents.");
-
-            UploadIntent? pictureIntent = null;
-            if (request.PictureIntentId is { } pictureIntentId)
-            {
-                var pictureValidation = await uploadIntentValidator.ValidateAndLoadAsync(
-                    pictureIntentId, request.UserId, UploadIntentPurpose.TrackPicture, cancellationToken);
-                if (pictureValidation.IsError)
-                    return pictureValidation.Errors;
-
-                pictureIntent = pictureValidation.Value;
-            }
-
-            var audioValidation = await uploadIntentValidator.ValidateAndLoadAsync(
-                request.AudioIntentId, request.UserId, UploadIntentPurpose.TrackAudio, cancellationToken);
-            if (audioValidation.IsError)
-                return audioValidation.Errors;
-
-            var audioIntent = audioValidation.Value;
-
-            var finalPictureKey = pictureIntent == null
-                ? null
-                : trackConfiguration.Routes.BuildOriginalPicturePath(request.UserId, pictureIntent.ObjectName);
-            var finalAudioKey = trackConfiguration.Routes.BuildOriginalAudioPath(request.UserId, audioIntent.ObjectName);
-            var audioProcessedFolderKey = trackConfiguration.Routes.BuildProcessedAudioPath(Guid.NewGuid().ToString());
-
-            var trackEntity = new Track
-            {
-                Title = request.Title.Trim(),
-                NormalizedTitle = TextNormalizer.Normalize(request.Title),
-                OwnerUserId = user.Id,
-                Owner = user,
-                IsExplicit = request.IsExplicit,
-                Pictures = new TrackPictures
-                {
-                    OriginalName = pictureIntent?.ObjectName,
-                    SmallName = trackConfiguration.Routes.PresetSmallPicture,
-                    MediumName = trackConfiguration.Routes.PresetMediumPicture,
-                    LargeName = trackConfiguration.Routes.PresetLargePicture,
-                    ProcessingStatus = pictureIntent == null ? ProcessingStatus.Completed : ProcessingStatus.Pending
-                },
-                Audio = new TrackAudio
-                {
-                    OriginalName = audioIntent.ObjectName,
-                    TranscodeStatus = ProcessingStatus.Pending
-                }
-            };
-
-            trackEntity.Tags = distinctTags
-                .Select(tag => new TrackTag { TrackId = trackEntity.Id, Tag = tag })
-                .ToList();
-
-            await database.Tracks.AddAsync(trackEntity, cancellationToken);
-
-            var sizes = trackConfiguration.PicturesSizes.ToImageSizes(trackConfiguration.Routes);
-            await eventBus.PublishAsync(
-                new CreateTrackResourcesEvent(
-                    trackEntity.Id,
-                    pictureIntent?.Id,
-                    audioIntent.Id,
-                    audioIntent.Bucket,
-                    pictureIntent?.Key,
-                    finalPictureKey,
-                    audioIntent.Key,
-                    finalAudioKey,
-                    audioProcessedFolderKey,
-                    sizes),
-                cancellationToken);
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            return TrackApplicationResponse.FromEntity(trackEntity, listensCount: 0);
-        }
-    }
-}

backend/Core/Musify.Application/Tracks/DeleteStaleUncountedListens.cs

@@ -1,33 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-
-namespace Musify.Application.Tracks
-{
-    public record DeleteStaleUncountedListensCommand : ICommand<int>;
-
-    public class DeleteStaleUncountedListensCommandHandler(
-        IDatabase database,
-        ILogger<DeleteStaleUncountedListensCommandHandler> logger)
-        : ICommandHandler<DeleteStaleUncountedListensCommand, int>
-    {
-        public async ValueTask<int> Handle(DeleteStaleUncountedListensCommand request, CancellationToken cancellationToken)
-        {
-            var cutoff = DateTime.UtcNow.AddDays(-ListeningRules.UncountedRetentionDays);
-
-            var stale = await database.ListeningHistories
-                .Where(l => !l.IsCounted && l.ListenedAt < cutoff)
-                .ToListAsync(cancellationToken);
-
-            if (stale.Count == 0)
-                return 0;
-
-            database.ListeningHistories.RemoveRange(stale);
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Deleted {Count} uncounted listens older than {Days} days", stale.Count, ListeningRules.UncountedRetentionDays);
-            return stale.Count;
-        }
-    }
-}

backend/Core/Musify.Application/Tracks/DeleteTrack.cs

@@ -1,42 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Tracks
-{
-    public record DeleteTrackCommand(
-        long UserId,
-        Guid TrackId)
-        : ICommand<ErrorOr<Success>>;
-
-    public class DeleteTrackCommandHandler(
-        IDatabase database,
-        IEventBus eventBus,
-        ILogger<DeleteTrackCommandHandler> logger)
-        : ICommandHandler<DeleteTrackCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(DeleteTrackCommand request, CancellationToken cancellationToken)
-        {
-            var found = await database.Tracks.FindOwnedAsync(request.TrackId, request.UserId, cancellationToken);
-            if (found.IsError)
-                return found.Errors;
-
-            var track = found.Value;
-            if (track.Audio.IsInProgress)
-                return AppErrors.Conflict("Track.Processing", "Track is currently being processed and cannot be deleted.");
-
-            track.LifeCycleStatus = LifeCycleStatus.Removing;
-
-            await eventBus.PublishAsync(new DeleteTrackEvent(track.Id, request.UserId), cancellationToken);
-            await database.SaveChangesAsync(cancellationToken);
-
-            logger.LogInformation("Marked track {TrackId} as removing", request.TrackId);
-
-            return Result.Success;
-        }
-    }
-}

backend/Core/Musify.Application/Tracks/DeleteTracks.cs

@@ -1,60 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Shared;
-using Musify.Application.Tracks.Responses;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Tracks
-{
-    public record DeleteTracksCommand(long UserId, IReadOnlyList<Guid> TrackIds)
-        : ICommand<ErrorOr<DeleteTracksResponse>>;
-
-    public class DeleteTracksCommandHandler(
-        IDatabase database,
-        IEventBus eventBus,
-        ILogger<DeleteTracksCommandHandler> logger)
-        : ICommandHandler<DeleteTracksCommand, ErrorOr<DeleteTracksResponse>>
-    {
-        public async ValueTask<ErrorOr<DeleteTracksResponse>> Handle(DeleteTracksCommand request, CancellationToken cancellationToken)
-        {
-            var requestedIds = request.TrackIds.Distinct().ToList();
-
-            var tracks = await database.Tracks
-                .Where(track => requestedIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active)
-                .ToListAsync(cancellationToken);
-
-            var foreign = tracks.FirstOrDefault(track => track.OwnerUserId != request.UserId);
-            if (foreign != null)
-                return AppErrors.Forbidden("Track", foreign.Id);
-
-            var deleted = new List<Guid>();
-            var failed = new List<Guid>();
-
-            foreach (var trackId in requestedIds)
-            {
-                var track = tracks.SingleOrDefault(candidate => candidate.Id == trackId);
-                if (track == null || track.Audio.IsInProgress)
-                {
-                    failed.Add(trackId);
-                    continue;
-                }
-
-                track.LifeCycleStatus = LifeCycleStatus.Removing;
-                await eventBus.PublishAsync(new DeleteTrackEvent(track.Id, request.UserId), cancellationToken);
-                deleted.Add(trackId);
-            }
-
-            if (deleted.Count > 0)
-            {
-                await database.SaveChangesAsync(cancellationToken);
-                logger.LogInformation("Marked {Count} tracks of user {UserId} as removing", deleted.Count, request.UserId);
-            }
-
-            return new DeleteTracksResponse(deleted, failed);
-        }
-    }
-}

backend/Core/Musify.Application/Tracks/GetLastTrackListenedByUserId.cs

@@ -1,26 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Tracks.Responses;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Tracks
-{
-    public record GetLastTrackListenedByUserIdQuery(long UserId) : IQuery<TrackApplicationResponse?>;
-
-    public class GetLastTrackListenedByUserIdQueryHandler(IDatabase database)
-        : IQueryHandler<GetLastTrackListenedByUserIdQuery, TrackApplicationResponse?>
-    {
-        public async ValueTask<TrackApplicationResponse?> Handle(GetLastTrackListenedByUserIdQuery query, CancellationToken cancellationToken)
-        {
-            return await database.ListeningHistories
-                .AsNoTracking()
-                .Where(t => t.UserId == query.UserId && t.IsCounted && t.Track.LifeCycleStatus == LifeCycleStatus.Active && t.Track.IsPublished)
-                .OrderByDescending(t => t.ListenedAt)
-                .ThenBy(t => t.Id)
-                .Select(t => t.Track)
-                .SelectResponse()
-                .FirstOrDefaultAsync(cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Tracks/GetListeningHistory.cs

@@ -1,41 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Tracks.Responses;
-
-namespace Musify.Application.Tracks
-{
-    public record GetListeningHistoryQuery(long UserId) : IQuery<IReadOnlyList<TrackApplicationResponse>>;
-
-    public class GetListeningHistoryQueryHandler(IDatabase database)
-        : IQueryHandler<GetListeningHistoryQuery, IReadOnlyList<TrackApplicationResponse>>
-    {
-        public const int ListSize = 15;
-
-        public async ValueTask<IReadOnlyList<TrackApplicationResponse>> Handle(GetListeningHistoryQuery query, CancellationToken cancellationToken)
-        {
-            var recentTrackIds = await database.ListeningHistories
-                .AsNoTracking()
-                .Where(l => l.UserId == query.UserId && l.IsCounted)
-                .GroupBy(l => l.TrackId)
-                .OrderByDescending(g => g.Max(l => l.ListenedAt))
-                .ThenBy(g => g.Key)
-                .Select(g => g.Key)
-                .Take(ListSize)
-                .ToListAsync(cancellationToken);
-
-            var tracksById = await database.Tracks
-                .AsNoTracking()
-                .Active()
-                .WherePublished()
-                .Where(t => recentTrackIds.Contains(t.Id))
-                .SelectResponse()
-                .ToDictionaryAsync(t => t.Id, cancellationToken);
-
-            return recentTrackIds
-                .Where(id => tracksById.ContainsKey(id))
-                .Select(id => tracksById[id])
-                .ToList();
-        }
-    }
-}

backend/Core/Musify.Application/Tracks/GetTrackStatusCounts.cs

@@ -1,40 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Tracks.Responses;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Tracks
-{
-    public record GetTrackStatusCountsQuery(long UserId)
-        : IQuery<TrackStatusCountsResponse>;
-
-    public class GetTrackStatusCountsQueryHandler(IDatabase database)
-        : IQueryHandler<GetTrackStatusCountsQuery, TrackStatusCountsResponse>
-    {
-        public async ValueTask<TrackStatusCountsResponse> Handle(GetTrackStatusCountsQuery request, CancellationToken cancellationToken)
-        {
-            var counts = await database.Tracks
-                .AsNoTracking()
-                .Active()
-                .Where(track => track.OwnerUserId == request.UserId)
-                .GroupBy(track => new { track.Audio.TranscodeStatus, track.IsPublished })
-                .Select(group => new { group.Key.TranscodeStatus, group.Key.IsPublished, Count = group.Count() })
-                .ToListAsync(cancellationToken);
-
-            int CountOf(ProcessingStatus status) => counts.Where(c => c.TranscodeStatus == status).Sum(c => c.Count);
-
-            var published = counts.Where(c => c.IsPublished).Sum(c => c.Count);
-            var total = counts.Sum(c => c.Count);
-
-            return new TrackStatusCountsResponse(
-                total,
-                CountOf(ProcessingStatus.Pending),
-                CountOf(ProcessingStatus.Processing),
-                CountOf(ProcessingStatus.Completed),
-                CountOf(ProcessingStatus.Failed),
-                published,
-                total - published);
-        }
-    }
-}

backend/Core/Musify.Application/Tracks/GetTracks.cs

@@ -1,39 +0,0 @@
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Application.Tracks.Responses;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Tracks
-{
-    public record GetTracksQuery(string? Name, int PageNumber, int PageSize, Genre? Genre = null)
-        : IQuery<PaginatedResponse<TrackApplicationResponse>>;
-
-    public class GetTracksQueryHandler(IDatabase database)
-        : IQueryHandler<GetTracksQuery, PaginatedResponse<TrackApplicationResponse>>
-    {
-        public async ValueTask<PaginatedResponse<TrackApplicationResponse>> Handle(GetTracksQuery request, CancellationToken cancellationToken)
-        {
-            var tracksQuery = database.Tracks
-                .AsNoTracking()
-                .Active()
-                .WherePublished();
-
-            if (!string.IsNullOrWhiteSpace(request.Name))
-            {
-                var normalizedName = TextNormalizer.Normalize(request.Name);
-                tracksQuery = tracksQuery.Where(track => track.NormalizedTitle.Contains(normalizedName));
-            }
-
-            if (request.Genre is { } genre)
-                tracksQuery = tracksQuery.Where(track => track.Tags.Any(tag => tag.Tag == genre));
-
-            return await tracksQuery
-                .OrderByDescending(track => track.CreatedAt)
-                .ThenBy(track => track.Id)
-                .SelectResponse()
-                .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
-        }
-    }
-}

backend/Core/Musify.Application/Tracks/GetTracksByUserId.cs

@@ -1,72 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Application.Tracks.Responses;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Tracks
-{
-    public record GetTracksByUserIdQuery(
-        long UserId,
-        string? Name,
-        int PageNumber,
-        int PageSize,
-        IReadOnlyList<ProcessingStatus>? Statuses = null,
-        long? ViewerId = null,
-        bool? IsPublished = null,
-        bool? IncludeCoauthored = null)
-        : IQuery<ErrorOr<PaginatedResponse<UserTrackApplicationResponse>>>;
-
-    public class GetTracksByUserIdQueryHandler(IDatabase database)
-        : IQueryHandler<GetTracksByUserIdQuery, ErrorOr<PaginatedResponse<UserTrackApplicationResponse>>>
-    {
-        public async ValueTask<ErrorOr<PaginatedResponse<UserTrackApplicationResponse>>> Handle(GetTracksByUserIdQuery request, CancellationToken cancellationToken)
-        {
-            var tracksQuery = database.Tracks
-                .AsNoTracking()
-                .Active();
-
-            var isOwnerView = request.ViewerId == request.UserId;
-            var includeCoauthored = request.IncludeCoauthored ?? !isOwnerView;
-
-            tracksQuery = includeCoauthored
-                ? tracksQuery.Where(track => track.OwnerUserId == request.UserId
-                    || track.Coauthors.Any(coauthor => coauthor.UserId == request.UserId && coauthor.Status == CoauthorStatus.Accepted))
-                : tracksQuery.Where(track => track.OwnerUserId == request.UserId);
-
-            tracksQuery = isOwnerView
-                ? tracksQuery.Where(track => track.OwnerUserId == request.UserId || track.IsPublished)
-                : tracksQuery.WherePublished();
-
-            if (!string.IsNullOrWhiteSpace(request.Name))
-            {
-                var normalizedName = TextNormalizer.Normalize(request.Name);
-                tracksQuery = tracksQuery.Where(track => track.NormalizedTitle.Contains(normalizedName));
-            }
-
-            if (request.Statuses is { Count: > 0 } statuses)
-            {
-                var statusList = statuses.Distinct().ToList();
-                tracksQuery = tracksQuery.Where(track => statusList.Contains(track.Audio.TranscodeStatus));
-            }
-
-            if (request.IsPublished is { } isPublished)
-                tracksQuery = tracksQuery.Where(track => track.IsPublished == isPublished);
-
-            var page = await tracksQuery
-                .OrderByDescending(track => track.CreatedAt)
-                .ThenBy(track => track.Id)
-                .SelectUserResponse(includeInvites: request.ViewerId != null)
-                .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
-
-            // Invitations are private to the track owner.
-            var items = page.Items
-                .Select(track => track.OwnerUserId == request.ViewerId ? track : track with { CoauthorInvites = [] })
-                .ToList();
-
-            return page with { Items = items };
-        }
-    }
-}

backend/Core/Musify.Application/Tracks/ListeningRules.cs

@@ -1,14 +0,0 @@
-namespace Musify.Application.Tracks
-{
-    public static class ListeningRules
-    {
-        public const double CountedThresholdSeconds = 30;
-        public const double CountedThresholdFraction = 0.5;
-        public const double DurationToleranceSeconds = 2;
-        public const double ClockToleranceSeconds = 5;
-        public const int UncountedRetentionDays = 8;
-
-        public static double CountedThreshold(double durationSeconds) =>
-            Math.Min(CountedThresholdSeconds, durationSeconds * CountedThresholdFraction);
-    }
-}

backend/Core/Musify.Application/Tracks/RecordListeningProgress.cs

@@ -1,42 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-
-namespace Musify.Application.Tracks
-{
-    public record RecordListeningProgressCommand(
-        long UserId,
-        Guid ListenId,
-        double PlayedSeconds)
-        : ICommand<ErrorOr<Success>>;
-
-    public class RecordListeningProgressCommandHandler(IDatabase database)
-        : ICommandHandler<RecordListeningProgressCommand, ErrorOr<Success>>
-    {
-        public async ValueTask<ErrorOr<Success>> Handle(RecordListeningProgressCommand request, CancellationToken cancellationToken)
-        {
-            var listen = await database.ListeningHistories
-                .Include(l => l.Track)
-                .SingleOrDefaultAsync(l => l.Id == request.ListenId && l.UserId == request.UserId, cancellationToken);
-
-            if (listen == null)
-                return AppErrors.NotFound("Listen", request.ListenId);
-
-            var now = DateTime.UtcNow;
-            var durationCap = listen.Track.DurationSeconds + ListeningRules.DurationToleranceSeconds;
-            var clockCap = (now - listen.ListenedAt).TotalSeconds + ListeningRules.ClockToleranceSeconds;
-            var accepted = Math.Min(request.PlayedSeconds, Math.Min(durationCap, clockCap));
-
-            listen.PlayedSeconds = Math.Max(listen.PlayedSeconds ?? 0, accepted);
-            listen.LastProgressAt = now;
-            listen.IsCounted = listen.IsCounted
-                || listen.PlayedSeconds >= ListeningRules.CountedThreshold(listen.Track.DurationSeconds);
-
-            await database.SaveChangesAsync(cancellationToken);
-
-            return Result.Success;
-        }
-    }
-}