using System;
using System.IO;
using System.Linq;
using Microsoft.Data.Sqlite;
using Xunit;
using ytLive.Services;
using ytLive.ViewModels;

namespace ytLive.Tests;

/// <summary>
/// 2026-11-06: replacing a bundled background reached new installs only. Default art is hash-keyed into the
/// layout database on first seed, so an existing profile kept the old image for ever. A version-stamp heal
/// failed twice (first it iterated `AllBackgrounds()`, which returns only the LIVE scene's rows; then the
/// constant and the embedded resource were built at different moments). The seed now compares BYTES, which
/// is what this test pins: a profile already pointing at other art is re-stamped without any version bump.
/// </summary>
[Collection("RealApp")]
public sealed class BackgroundDefaultArtTests
{
    private readonly RealAppHost _app;

    public BackgroundDefaultArtTests(RealAppHost app) => _app = app;

    [Fact]
    public void ReplacingTheBundledArt_ReSeedsAnExistingProfile() => _app.Run(() =>
    {
        // The bundled art is a WPF resource, so this needs a real Application to resolve the pack URI.
        var tempDb = Path.Combine(Path.GetTempPath(), $"ytLlive-art-{Guid.NewGuid():N}.db");
        MainViewModel.LayoutPathOverride = tempDb;
        try
        {
            // First launch: the seeded art is whatever ships today.
            var first = new MainViewModel();
            var firstId = StartingBackgroundId(first);
            Assert.False(string.IsNullOrWhiteSpace(firstId), "the bundled Starting art never seeded");
            var firstBytes = AssetLength(tempDb, firstId!);

            // Simulate a profile stamped with the OLD art. No version flag is touched — the seed has to
            // notice the bytes are not the shipped ones by itself.
            using (var connection = new SqliteConnection($"Data Source={tempDb}"))
            {
                connection.Open();
                using var plant = connection.CreateCommand();
                plant.CommandText = """
                    INSERT OR REPLACE INTO Asset (Id, Hash, Data, PixelWidth, PixelHeight)
                    VALUES ('old-art', 'deadbeef', zeroblob(1024), 1920, 1080);
                    UPDATE Source SET AssetId = 'old-art' WHERE IsBackground = 1;
                    """;
                plant.ExecuteNonQuery();
            }
            SqliteConnection.ClearAllPools();

            var second = new MainViewModel();
            var secondId = StartingBackgroundId(second);
            Assert.NotNull(secondId);

            // Re-stamped to the SHIPPED art — which, being the same bytes, is the same asset row the
            // first launch created. What matters is that the planted "old art" is gone.
            Assert.NotEqual("old-art", secondId);
            Assert.Equal(firstId, secondId);
            Assert.Equal(File.ReadAllBytes(Path.Combine(
                AppContext.BaseDirectory, "..", "..", "..", "..", "Assets", "starting-background.jpg")).Length,
                AssetLength(tempDb, secondId!));
            Assert.NotEqual(firstBytes, 0);

            // Idempotent: a third launch finds the shipped bytes already in place and must not re-seed.
            var third = new MainViewModel();
            Assert.Equal(secondId, StartingBackgroundId(third));
        }
        finally
        {
            MainViewModel.LayoutPathOverride = null;
            SqliteConnection.ClearAllPools();
            try { File.Delete(tempDb); } catch { /* best-effort cleanup */ }
        }
    });

    private static string? StartingBackgroundId(MainViewModel vm)
        => vm.Scenes
            .Where(scene => ytLive.Models.SceneCatalog.Is(scene.Name, ytLive.Models.SceneCatalog.Starting))
            .SelectMany(scene => scene.Elements.OfType<ytLive.Models.Source>())
            .FirstOrDefault(element => element.IsBackground)?.AssetId;

    private static int AssetLength(string dbPath, string assetId)
    {
        using var connection = new SqliteConnection($"Data Source={dbPath}");
        connection.Open();
        using var cmd = connection.CreateCommand();
        cmd.CommandText = "SELECT length(Data) FROM Asset WHERE Id = $id;";
        cmd.Parameters.AddWithValue("$id", assetId);
        return Convert.ToInt32(cmd.ExecuteScalar());
    }
}