using ErsatzTV.Core.Domain;
using ErsatzTV.Infrastructure.Data;
using ErsatzTV.Infrastructure.Data.Repositories;
using ErsatzTV.Tests.Support;
using LanguageExt;
using Microsoft.EntityFrameworkCore;
using NSubstitute;
using NUnit.Framework;
using Shouldly;
using IFileSystem = System.IO.Abstractions.IFileSystem;

namespace ErsatzTV.Tests.Integration;

[TestFixture]
public class LibraryRepositoryTests
{
    private InMemoryTvContext _db = null!;
    private LibraryRepository _repository = null!;

    [SetUp]
    public async Task SetUp()
    {
        _db = await InMemoryTvContext.CreateAsync();
        _repository = new LibraryRepository(Substitute.For<IFileSystem>(), _db.Factory);
    }

    [TearDown]
    public async Task TearDown() => await _db.DisposeAsync();

    // Regression for ersatztv#488: the Jellyfin (remote) sync path takes its LibraryPath straight off the
    // JellyfinLibrary entity, so LibraryPath.LibraryFolders is never eager-loaded (null). GetOrAddFolder
    // used to read that navigation collection directly and threw ArgumentNullException on the very first
    // item of every Jellyfin music-video scan. The repository must resolve the folder from the database
    // instead, so an unloaded collection is not a precondition.
    [Test]
    public async Task GetOrAddFolder_Should_Create_Folder_When_LibraryFolders_Not_Loaded()
    {
        int libraryPathId = await SeedLibraryPath("/data/music");

        // mimic the Jellyfin path: Paths is populated, but LibraryFolders was never included
        var libraryPath = new LibraryPath { Id = libraryPathId, Path = "/data/music", LibraryFolders = null };

        LibraryFolder result =
            await _repository.GetOrAddFolder(libraryPath, Option<int>.None, "/data/music/artist1");

        result.ShouldNotBeNull();
        result.Id.ShouldBeGreaterThan(0);
        result.Path.ShouldBe("/data/music/artist1");
        result.LibraryPathId.ShouldBe(libraryPathId);

        await using TvContext context = _db.CreateContext();
        List<LibraryFolder> folders = await context.LibraryFolders
            .Where(f => f.LibraryPathId == libraryPathId)
            .ToListAsync();
        folders.Count.ShouldBe(1);
        folders[0].Path.ShouldBe("/data/music/artist1");
    }

    // Re-scanning must be idempotent: a second GetOrAddFolder for the same path returns the existing row
    // rather than inserting a duplicate LibraryFolder (there is no unique constraint behind it).
    [Test]
    public async Task GetOrAddFolder_Should_Be_Idempotent_On_Rescan()
    {
        int libraryPathId = await SeedLibraryPath("/data/music");
        var libraryPath = new LibraryPath { Id = libraryPathId, Path = "/data/music", LibraryFolders = null };

        LibraryFolder first =
            await _repository.GetOrAddFolder(libraryPath, Option<int>.None, "/data/music/artist1");
        LibraryFolder second =
            await _repository.GetOrAddFolder(libraryPath, Option<int>.None, "/data/music/artist1");

        second.Id.ShouldBe(first.Id);

        await using TvContext context = _db.CreateContext();
        int count = await context.LibraryFolders.CountAsync(f => f.LibraryPathId == libraryPathId);
        count.ShouldBe(1);
    }

    // Covers the maybeParentFolder = Some(...) branch: on a folder already in the db, the parent id is
    // persisted through the raw Dapper UPDATE against the no-tracking entity (not change tracking), and the
    // returned object reflects it. Guards the AsNoTracking + raw-UPDATE interaction the DB-lookup fix relies on.
    [Test]
    public async Task GetOrAddFolder_Should_Persist_ParentId_On_Existing_Folder()
    {
        int libraryPathId = await SeedLibraryPath("/data/music");
        var libraryPath = new LibraryPath { Id = libraryPathId, Path = "/data/music", LibraryFolders = null };

        LibraryFolder parent =
            await _repository.GetOrAddFolder(libraryPath, Option<int>.None, "/data/music");
        // first pass creates the child with no parent
        LibraryFolder child =
            await _repository.GetOrAddFolder(libraryPath, Option<int>.None, "/data/music/artist1");
        child.ParentId.ShouldBeNull();

        // second pass supplies the parent — the existing row must be updated, not duplicated
        LibraryFolder updated =
            await _repository.GetOrAddFolder(libraryPath, Option<int>.Some(parent.Id), "/data/music/artist1");
        updated.Id.ShouldBe(child.Id);
        updated.ParentId.ShouldBe(parent.Id);

        await using TvContext context = _db.CreateContext();
        LibraryFolder persisted = await context.LibraryFolders.SingleAsync(f => f.Id == child.Id);
        persisted.ParentId.ShouldBe(parent.Id);
        int count = await context.LibraryFolders.CountAsync(f => f.Path == "/data/music/artist1");
        count.ShouldBe(1);
    }

    private async Task<int> SeedLibraryPath(string path)
    {
        await using TvContext context = _db.CreateContext();
        var libraryPath = new LibraryPath { Path = path };
        await context.LibraryPaths.AddAsync(libraryPath);
        await context.SaveChangesAsync();
        return libraryPath.Id;
    }
}