using Musify.Application.Genres;
using Musify.Application.Tests.TestSupport;
using Musify.Domain.ValueObjects;
using Xunit;

namespace Musify.Application.Tests.Genres
{
    public sealed class GetGenresQueryHandlerTests : HandlerTestBase
    {
        private GetGenresQueryHandler CreateHandler() => new(Database);

        [Fact]
        public async Task Handle_NoTracks_ReturnsEmpty()
        {
            var result = await CreateHandler().Handle(new GetGenresQuery(), TestContext.Current.CancellationToken);

            Assert.Empty(result);
        }

        [Fact]
        public async Task Handle_ReturnsOnlyGenresInUse_MostPopulatedFirst()
        {
            var owner = TestEntities.User();
            var rockA = TestEntities.Track(owner, "Rock A", tags: [Genre.Rock]);
            var rockB = TestEntities.Track(owner, "Rock B", tags: [Genre.Rock, Genre.Indie]);
            var jazz = TestEntities.Track(owner, "Jazz", tags: [Genre.Jazz]);
            await SeedAsync(
                owner, rockA, rockB, jazz);

            var result = await CreateHandler().Handle(new GetGenresQuery(), TestContext.Current.CancellationToken);

            Assert.Equal(
                [(Genre.Rock, 2), (Genre.Jazz, 1), (Genre.Indie, 1)],
                result.Select(r => (r.Genre, r.TrackCount)));
        }

    }
}