using Data.Data.Repositories;
using DeepDrftData.Data;
using DeepDrftData.Repositories;
using DeepDrftModels.DTOs;
using DeepDrftModels.Entities;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging.Abstractions;
using Models.Common;

namespace DeepDrftTests;

/// <summary>
/// Query-shape tests for the Phase 2.2/2.3 filter and distinct-browse repository methods.
///
/// Provider note: these run on the EF in-memory provider, which executes LINQ in process. That
/// covers exact-match equality, null passthrough, GroupBy/Count, and ordering — every predicate
/// in <see cref="TrackRepository.GetPagedFilteredAsync"/> except the free-text branch. That branch
/// uses <c>EF.Functions.ILike</c>, an Npgsql-only relational function with no in-memory translation,
/// so the SearchText case is a Postgres integration test gated on a DSN (see SearchText_*). It is
/// ignored when no test database is configured rather than asserted against a provider that never
/// runs the predicate.
/// </summary>
[TestFixture]
public class TrackFilterQueryTests
{
    private DeepDrftContext _context = null!;

    [SetUp]
    public void SetUp()
    {
        var options = new DbContextOptionsBuilder<DeepDrftContext>()
            .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString())
            .Options;
        _context = new DeepDrftContext(options);
    }

    [TearDown]
    public void TearDown()
    {
        _context.Dispose();
    }

    private TrackRepository CreateRepository()
        => new(_context, NullLogger<Repository<DeepDrftContext, TrackEntity>>.Instance);

    private static TrackEntity Track(
        string name, string artist, string? album = null, string? genre = null, string? image = null)
        => new()
        {
            EntryKey = Guid.NewGuid().ToString("N"),
            TrackName = name,
            Artist = artist,
            Album = album,
            Genre = genre,
            ImagePath = image,
        };

    private async Task SeedAsync(params TrackEntity[] tracks)
    {
        _context.Tracks.AddRange(tracks);
        await _context.SaveChangesAsync();
    }

    private static PagingParameters<TrackEntity> DefaultPaging()
        => new() { Page = 1, PageSize = 20, OrderBy = t => t.Id, IsDescending = false };

    // Case 2 — exact album match: returns only rows whose Album equals the filter value, and
    // TotalCount reflects the filtered set, not the table.
    [Test]
    public async Task GetPagedFilteredAsync_WithExactAlbum_ReturnsOnlyThatAlbum()
    {
        await SeedAsync(
            Track("One", "A", album: "Blue"),
            Track("Two", "B", album: "Blue"),
            Track("Three", "C", album: "Red"),
            Track("Four", "D", album: null));

        var repo = CreateRepository();
        var result = await repo.GetPagedFilteredAsync(DefaultPaging(), new TrackFilter { Album = "Blue" });

        Assert.That(result.TotalCount, Is.EqualTo(2));
        Assert.That(result.Items.Select(t => t.TrackName), Is.EquivalentTo(new[] { "One", "Two" }));
    }

    // Case 2b — exact genre match composes the same way as album.
    [Test]
    public async Task GetPagedFilteredAsync_WithExactGenre_ReturnsOnlyThatGenre()
    {
        await SeedAsync(
            Track("One", "A", genre: "Techno"),
            Track("Two", "B", genre: "House"),
            Track("Three", "C", genre: "Techno"));

        var repo = CreateRepository();
        var result = await repo.GetPagedFilteredAsync(DefaultPaging(), new TrackFilter { Genre = "Techno" });

        Assert.That(result.TotalCount, Is.EqualTo(2));
        Assert.That(result.Items.Select(t => t.TrackName), Is.EquivalentTo(new[] { "One", "Three" }));
    }

    // Case 3 — null filter is a passthrough: same items and count as the unfiltered base GetPagedAsync.
    [Test]
    public async Task GetPagedFilteredAsync_WithNullFilter_MatchesUnfilteredPagedQuery()
    {
        await SeedAsync(
            Track("One", "A", album: "Blue"),
            Track("Two", "B", album: "Red"),
            Track("Three", "C"));

        var repo = CreateRepository();
        var baseline = await repo.GetPagedAsync(DefaultPaging());
        var filtered = await repo.GetPagedFilteredAsync(DefaultPaging(), filter: null);

        Assert.That(filtered.TotalCount, Is.EqualTo(baseline.TotalCount));
        Assert.That(
            filtered.Items.Select(t => t.Id),
            Is.EqualTo(baseline.Items.Select(t => t.Id)).AsCollection);
    }

    // Case 4 — distinct albums: excludes null-album rows, counts per group, and takes the cover from
    // the first track in the group that has a non-null ImagePath. Ordered by album ascending.
    [Test]
    public async Task GetDistinctAlbumsAsync_GroupsCountsAndPicksCover()
    {
        await SeedAsync(
            Track("One", "A", album: "Zephyr", image: null),
            Track("Two", "A", album: "Zephyr", image: "cover-z"),
            Track("Three", "B", album: "Aria", image: "cover-a"),
            Track("Four", "C", album: null, image: "ignored"));

        var repo = CreateRepository();
        var albums = await repo.GetDistinctAlbumsAsync();

        Assert.That(albums.Select(a => a.Album), Is.EqualTo(new[] { "Aria", "Zephyr" }).AsCollection,
            "albums sort ascending and the null-album track is excluded");

        var zephyr = albums.Single(a => a.Album == "Zephyr");
        Assert.That(zephyr.TrackCount, Is.EqualTo(2));
        Assert.That(zephyr.CoverImageKey, Is.EqualTo("cover-z"),
            "cover is the first non-null ImagePath in the group");

        var aria = albums.Single(a => a.Album == "Aria");
        Assert.That(aria.TrackCount, Is.EqualTo(1));
        Assert.That(aria.CoverImageKey, Is.EqualTo("cover-a"));
    }

    // Case 5 — distinct genres: excludes null-genre rows, counts per group, ordered genre ascending.
    [Test]
    public async Task GetDistinctGenresAsync_GroupsCountsAndExcludesNull()
    {
        await SeedAsync(
            Track("One", "A", genre: "Techno"),
            Track("Two", "B", genre: "Ambient"),
            Track("Three", "C", genre: "Techno"),
            Track("Four", "D", genre: null));

        var repo = CreateRepository();
        var genres = await repo.GetDistinctGenresAsync();

        Assert.That(genres.Select(g => g.Genre), Is.EqualTo(new[] { "Ambient", "Techno" }).AsCollection,
            "genres sort ascending and the null-genre track is excluded");
        Assert.That(genres.Single(g => g.Genre == "Techno").TrackCount, Is.EqualTo(2));
        Assert.That(genres.Single(g => g.Genre == "Ambient").TrackCount, Is.EqualTo(1));
    }

    // Case 1 — free-text search across TrackName/Artist/Album, case-insensitive. EF.Functions.ILike
    // is Npgsql-only and does not translate on the in-memory provider, so this runs only against a
    // real Postgres database supplied via the DEEPDRFT_TEST_PG environment variable. Without it the
    // test is ignored rather than asserted against a provider that cannot execute the predicate.
    [Test]
    public async Task GetPagedFilteredAsync_WithSearchText_MatchesNameArtistOrAlbumCaseInsensitive()
    {
        var dsn = Environment.GetEnvironmentVariable("DEEPDRFT_TEST_PG");
        if (string.IsNullOrWhiteSpace(dsn))
            Assert.Ignore("Set DEEPDRFT_TEST_PG to a Postgres connection string to run the ILike search test.");

        var options = new DbContextOptionsBuilder<DeepDrftContext>()
            .UseNpgsql(dsn)
            .Options;
        await using var pg = new DeepDrftContext(options);
        await pg.Database.EnsureCreatedAsync();

        try
        {
            pg.Tracks.AddRange(
                Track("Jazz Odyssey", "Spinal Tap", album: "Smell the Glove"),
                Track("Quiet Storm", "jazzmin", album: "Nightfall"),
                Track("Loud Noises", "Brick", album: "All JAZZ Hands"),
                Track("Unrelated", "Nobody", album: "Silence"));
            await pg.SaveChangesAsync();

            var repo = new TrackRepository(
                pg, NullLogger<Repository<DeepDrftContext, TrackEntity>>.Instance);
            var result = await repo.GetPagedFilteredAsync(DefaultPaging(), new TrackFilter { SearchText = "jazz" });

            Assert.That(result.Items.Select(t => t.TrackName),
                Is.EquivalentTo(new[] { "Jazz Odyssey", "Quiet Storm", "Loud Noises" }),
                "ILike matches 'jazz' case-insensitively in TrackName, Artist, or Album");
        }
        finally
        {
            await pg.Database.EnsureDeletedAsync();
        }
    }
}