using ErsatzTV.Application;
using ErsatzTV.Application.MediaCollections;
using ErsatzTV.Application.Search;
using ErsatzTV.Core;
using ErsatzTV.Core.Api.LibraryBrowse;
using ErsatzTV.Core.Domain;
using ErsatzTV.Core.Errors;
using ErsatzTV.Core.Interfaces.Repositories;
using ErsatzTV.Infrastructure.Data;
using LanguageExt;
using ErsatzTV.Tests.Support;
using NSubstitute;
using NUnit.Framework;
using Shouldly;
using Unit = LanguageExt.Unit;

namespace ErsatzTV.Tests.Application.MediaCollections;

[TestFixture]
public class CollectionHandlerTests : MediaCollectionHandlerTestBase
{
    [Test]
    public async Task Update_Should_Return_NotFoundError_When_Collection_Missing()
    {
        var handler = new UpdateCollectionHandler(
            Db.Factory,
            Substitute.For<IMediaCollectionRepository>(),
            Worker,
            SearchTargets);

        Either<BaseError, Unit> result =
            await handler.Handle(new UpdateCollection(999, "Updated"), CancellationToken.None);

        LeftOf(result).ShouldBeOfType<NotFoundError>();
    }

    [Test]
    public async Task Delete_Should_Return_NotFoundError_When_Collection_Missing()
    {
        var handler = new DeleteCollectionHandler(Db.Factory, SearchTargets);

        Either<BaseError, Unit> result =
            await handler.Handle(new DeleteCollection(999), CancellationToken.None);

        LeftOf(result).ShouldBeOfType<NotFoundError>();
    }

    [Test]
    public async Task AddItems_Should_Return_NotFoundError_When_Collection_Missing()
    {
        IMovieRepository movieRepository = Substitute.For<IMovieRepository>();
        movieRepository.AllMoviesExist(Arg.Any<List<int>>()).Returns(true);
        ITelevisionRepository televisionRepository = Substitute.For<ITelevisionRepository>();
        televisionRepository.AllShowsExist(Arg.Any<List<int>>()).Returns(true);
        televisionRepository.AllSeasonsExist(Arg.Any<List<int>>()).Returns(true);
        televisionRepository.AllEpisodesExist(Arg.Any<List<int>>()).Returns(true);

        var handler = new AddItemsToCollectionHandler(
            Db.Factory,
            Substitute.For<IMediaCollectionRepository>(),
            movieRepository,
            televisionRepository,
            Worker,
            System.Threading.Channels.Channel.CreateUnbounded<ISearchIndexBackgroundServiceRequest>().Writer);

        Either<BaseError, Unit> result =
            await handler.Handle(MakeAddItems(collectionId: 999, movieIds: [1]), CancellationToken.None);

        LeftOf(result).ShouldBeOfType<NotFoundError>();
    }

    [Test]
    public async Task AddItems_Should_Return_ValidationError_When_Generic_MediaItem_Missing()
    {
        await SeedCollection(1);
        IMovieRepository movieRepository = Substitute.For<IMovieRepository>();
        movieRepository.AllMoviesExist(Arg.Any<List<int>>()).Returns(true);
        ITelevisionRepository televisionRepository = Substitute.For<ITelevisionRepository>();
        televisionRepository.AllShowsExist(Arg.Any<List<int>>()).Returns(true);
        televisionRepository.AllSeasonsExist(Arg.Any<List<int>>()).Returns(true);
        televisionRepository.AllEpisodesExist(Arg.Any<List<int>>()).Returns(true);

        var handler = new AddItemsToCollectionHandler(
            Db.Factory,
            Substitute.For<IMediaCollectionRepository>(),
            movieRepository,
            televisionRepository,
            Worker,
            System.Threading.Channels.Channel.CreateUnbounded<ISearchIndexBackgroundServiceRequest>().Writer);

        Either<BaseError, Unit> result =
            await handler.Handle(
                new AddItemsToCollection(1, [], [], [], [], [], [], [], [], [], [999]),
                CancellationToken.None);

        BaseError error = LeftOf(result);
        error.ShouldNotBeOfType<NotFoundError>();
        error.Value.ShouldContain("Media item does not exist");
    }

    [Test]
    public async Task RemoveItems_Should_Return_NotFoundError_When_Collection_Missing()
    {
        var handler = new RemoveItemsFromCollectionHandler(
            Db.Factory,
            Substitute.For<IMediaCollectionRepository>(),
            Worker,
            System.Threading.Channels.Channel.CreateUnbounded<ISearchIndexBackgroundServiceRequest>().Writer);

        Either<BaseError, Unit> result =
            await handler.Handle(
                new RemoveItemsFromCollection(999) { MediaItemIds = [1] },
                CancellationToken.None);

        LeftOf(result).ShouldBeOfType<NotFoundError>();
    }

    [Test]
    public async Task RemoveItems_Should_Return_NotFoundError_When_Association_Missing()
    {
        await SeedCollection(1);
        var handler = new RemoveItemsFromCollectionHandler(
            Db.Factory,
            Substitute.For<IMediaCollectionRepository>(),
            Worker,
            System.Threading.Channels.Channel.CreateUnbounded<ISearchIndexBackgroundServiceRequest>().Writer);

        Either<BaseError, Unit> result =
            await handler.Handle(
                new RemoveItemsFromCollection(1) { MediaItemIds = [999] },
                CancellationToken.None);

        LeftOf(result).ShouldBeOfType<NotFoundError>();
    }

    [Test]
    public async Task GetItems_Should_Return_NotFoundError_When_Collection_Missing()
    {
        var handler = new GetCollectionItemsHandler(Db.Factory);

        Either<BaseError, PagedLibraryBrowseItemsResponseModel> result =
            await handler.Handle(new GetCollectionItems(999, 0, 100), CancellationToken.None);

        LeftOf(result).ShouldBeOfType<NotFoundError>();
    }

    [Test]
    public async Task GetItems_Should_Return_Members_With_Rooted_Artwork()
    {
        await SeedCollectionWithMovie(collectionId: 1, movieId: 10, title: "Fake Movie", poster: "movie.jpg");
        var handler = new GetCollectionItemsHandler(Db.Factory);

        Either<BaseError, PagedLibraryBrowseItemsResponseModel> result =
            await handler.Handle(new GetCollectionItems(1, 0, 100), CancellationToken.None);

        PagedLibraryBrowseItemsResponseModel page = result.Match(
            Left: _ => throw new AssertionException("Expected a Right result"),
            Right: value => value);

        page.TotalCount.ShouldBe(1);
        page.Page.Count.ShouldBe(1);
        page.Page[0].Title.ShouldBe("Fake Movie");
        page.Page[0].MediaItemId.ShouldBe(10);
        page.Page[0].MediaType.ShouldBe(LibraryBrowseMediaType.Movie);
        page.Page[0].Artwork.ShouldBe("/artwork/posters/movie.jpg");
    }

    private async Task SeedCollectionWithMovie(int collectionId, int movieId, string title, string poster)
    {
        await using TvContext context = Db.CreateContext();
        var library = new LocalLibrary
        {
            Id = collectionId,
            Name = "Local",
            MediaKind = LibraryMediaKind.Movies,
            Paths = []
        };
        var path = new LibraryPath
        {
            Id = collectionId,
            Path = "/media",
            Library = library,
            LibraryFolders = [],
            MediaItems = []
        };
        library.Paths.Add(path);

        var collection = new Collection { Id = collectionId, Name = "Collection", MediaItems = [] };
        var movie = new Movie
        {
            Id = movieId,
            LibraryPath = path,
            Collections = [collection],
            CollectionItems = [],
            TraktListItems = [],
            MediaVersions = [new MediaVersion { Duration = TimeSpan.FromMinutes(42) }],
            MovieMetadata =
            [
                new MovieMetadata
                {
                    Title = title,
                    SortTitle = title,
                    Artwork = [new Artwork { Path = poster, ArtworkKind = ArtworkKind.Poster }],
                    Genres = [],
                    Tags = [],
                    Studios = [],
                    Actors = [],
                    Guids = [],
                    Subtitles = [],
                    Directors = [],
                    Writers = []
                }
            ]
        };
        collection.MediaItems.Add(movie);

        context.LocalLibraries.Add(library);
        context.Collections.Add(collection);
        context.Movies.Add(movie);
        await context.SaveChangesAsync();
    }

    private static AddItemsToCollection MakeAddItems(int collectionId, List<int>? movieIds = null) =>
        new(
            collectionId,
            movieIds ?? [],
            [],
            [],
            [],
            [],
            [],
            [],
            [],
            [],
            []);

    private static BaseError LeftOf<TR>(Either<BaseError, TR> either) =>
        either.Match(Left: e => e, Right: _ => throw new AssertionException("Expected a Left result"));
}