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);
        }
    }
}