Musify/backend/Tests/Musify.Application.Tests/TestSupport/TestDatabase.cs

using ErrorOr;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using Musify.Application.Contracts;
using Musify.Domain.Entities;
using Musify.Infrastructure.Persistence;

namespace Musify.Application.Tests.TestSupport
{
    public sealed class TestDatabase : DbContext, IDatabase
    {
        private readonly SqliteConnection connection;

        private TestDatabase(SqliteConnection connection, DbContextOptions<TestDatabase> options)
            : base(options)
        {
            this.connection = connection;
        }

        public static async Task<TestDatabase> CreateAsync()
        {
            var connection = new SqliteConnection("Filename=:memory:");
            await connection.OpenAsync();

            var options = new DbContextOptionsBuilder<TestDatabase>()
                .UseSqlite(connection)
                .Options;

            var database = new TestDatabase(connection, options);
            await database.Database.EnsureCreatedAsync();
            return database;
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            ModelConfiguration.Apply(modelBuilder);
        }

        public DbSet<User> Users => Set<User>();

        public DbSet<PlayList> PlayLists => Set<PlayList>();

        public DbSet<Album> Albums => Set<Album>();

        public DbSet<AlbumHasTrack> AlbumHasTracks => Set<AlbumHasTrack>();

        public DbSet<Track> Tracks => Set<Track>();

        public DbSet<PlayListHasTrack> PlayListHasTracks => Set<PlayListHasTrack>();

        public DbSet<Mix> Mixes => Set<Mix>();

        public DbSet<MixItem> MixItems => Set<MixItem>();

        public DbSet<UploadIntent> UploadIntents => Set<UploadIntent>();

        public DbSet<ListeningHistory> ListeningHistories => Set<ListeningHistory>();

        public DbSet<TrackLike> TrackLikes => Set<TrackLike>();

        public DbSet<TrackTag> TrackTags => Set<TrackTag>();

        public DbSet<UserFollow> UserFollows => Set<UserFollow>();

        public DbSet<TrackCoauthor> TrackCoauthors => Set<TrackCoauthor>();

        public async Task<IDatabaseTransaction> BeginTransactionAsync(System.Data.IsolationLevel isolationLevel, CancellationToken cancellationToken)
        {
            var transaction = await Database.BeginTransactionAsync(isolationLevel, cancellationToken);
            return new SqliteDatabaseTransaction(transaction);
        }

        public async Task<ErrorOr<Success>> TrySaveChangesAsync(Error onUniqueViolation, CancellationToken cancellationToken)
        {
            try
            {
                await SaveChangesAsync(cancellationToken);
                return Result.Success;
            }
            catch (DbUpdateException exception) when (exception.InnerException is SqliteException { SqliteErrorCode: 19 })
            {
                return onUniqueViolation;
            }
        }

        public override async ValueTask DisposeAsync()
        {
            await base.DisposeAsync();
            await connection.DisposeAsync();
        }

        private sealed class SqliteDatabaseTransaction(Microsoft.EntityFrameworkCore.Storage.IDbContextTransaction inner)
            : IDatabaseTransaction
        {
            public Task CommitAsync(CancellationToken cancellationToken = default) =>
                inner.CommitAsync(cancellationToken);

            public ValueTask DisposeAsync() => inner.DisposeAsync();
        }
    }
}