Musify/backend/Musify.Application/Tracks/Handlers/GetTrackByIdQueryHandler.cs

using ErrorOr;
using Mediator;
using Microsoft.EntityFrameworkCore;
using Musify.Application.Contracts;
using Musify.Application.Tracks.Queries;
using Musify.Application.Tracks.Responses;

namespace Musify.Application.Tracks.Handlers
{
    public class GetTrackByIdQueryHandler(IDatabase database)
        : IQueryHandler<GetTrackByIdQuery, ErrorOr<TrackApplicationResponse> >
    {
        public async ValueTask<ErrorOr<TrackApplicationResponse>> Handle(GetTrackByIdQuery request, CancellationToken cancellationToken)
        {
            var track = await database.Tracks.AsNoTracking()
                .Where(t => t.Id == request.TrackId)
                .Select(t => TrackApplicationResponse.FromEntity(t))
                .SingleOrDefaultAsync(cancellationToken);

            if (track is null)
                return Error.NotFound();

            return track;
        }
    }
}