Musify/backend/Tests/Musify.Application.Tests/YouTube/GetYouTubeAlbumQueryHandlerTests.cs

using ErrorOr;
using Microsoft.EntityFrameworkCore;
using Musify.Application.Contracts;
using Musify.Application.Services;
using Musify.Application.Tests.TestSupport;
using Musify.Application.YouTube;
using NSubstitute;
using Xunit;

namespace Musify.Application.Tests.YouTube
{
    public sealed class GetYouTubeAlbumQueryHandlerTests : HandlerTestBase
    {
        private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();

        private GetYouTubeAlbumQueryHandler CreateHandler()
        {
            var provisioner = new YouTubeTrackProvisioner(
                Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());

            return new GetYouTubeAlbumQueryHandler(youTubeMusicService, provisioner, NoOpLogger<GetYouTubeAlbumQueryHandler>());
        }

        private static YouTubeAlbumDetail BuildDetail() => new(
            new YouTubeAlbumResult("album-1", "Album Title", "Album Artist", "https://img/thumb.jpg", 2024, false, false, []),
            Description: "An album",
            TotalDurationSeconds: 600,
            Tracks: [new YouTubeAlbumTrack("track-1", "Track One", 200, 1, false)]);

        [Fact]
        public async Task Handle_EmptyAlbumId_ReturnsValidationError()
        {
            var result = await CreateHandler().Handle(new GetYouTubeAlbumQuery(string.Empty), TestContext.Current.CancellationToken);

            Assert.Equal(ErrorType.Validation, result.FirstError.Type);
        }

        [Fact]
        public async Task Handle_ServiceSucceeds_MaterializesAlbumAndReturnsDetail()
        {
            var detail = BuildDetail();
            youTubeMusicService.GetAlbumAsync("album-1", Arg.Any<CancellationToken>()).Returns(detail);

            var result = await CreateHandler().Handle(new GetYouTubeAlbumQuery("album-1"), TestContext.Current.CancellationToken);

            Assert.False(result.IsError);
            Assert.Same(detail, result.Value);
            Assert.NotEmpty(await Database.ExternalAlbums.ToListAsync(TestContext.Current.CancellationToken));
        }

        [Fact]
        public async Task Handle_ServiceFails_ReturnsError()
        {
            youTubeMusicService.GetAlbumAsync("missing", Arg.Any<CancellationToken>())
                .Returns(Error.NotFound(description: "Album not found"));

            var result = await CreateHandler().Handle(new GetYouTubeAlbumQuery("missing"), TestContext.Current.CancellationToken);

            Assert.True(result.IsError);
        }
    }
}