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

namespace ytLive.Tests;

/// <summary>
/// TASK 25 integration: a pre-consolidation DB (static Background + stray
/// "Game Capture" duplicates, wrong flavor on Live, orphaned settings keys)
/// heals to the locked model — exactly one Background per screen, index 0,
/// right flavor, right name — and a save purges the orphaned keys.
/// Real-App + temp-DB pattern (see SourceNamingTests).
/// </summary>
[Collection("RealApp")]
public sealed class BackgroundHealIntegrationTests
{
    [Fact]
    public void Dirty_Layout_Heals_To_One_Locked_Background_Per_Scene()
    {
        _app.Run(Run);
    }

    private readonly RealAppHost _app;

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

    private void Run()
    {
        var tempDb = Path.Combine(Path.GetTempPath(), $"ytLlive-bgheal-{Guid.NewGuid():N}.db");
        MainViewModel.LayoutPathOverride = tempDb;
        var window = default(MainWindow);
        try
        {
            using (var schema = new ytLive.Services.LayoutStore(tempDb)) { }
            SqliteConnection.ClearAllPools();
            SeedDirtyDatabase(tempDb);

            window = new MainWindow();
            var vm = (MainViewModel)window.DataContext;

            foreach (var name in SceneCatalog.All)
            {
                var scene = vm.Scenes.Single(s => SceneCatalog.Is(s.Name, name));
                Assert.True(scene.HasBackground, $"{name}: HasBackground must be true");

                var background = Assert.Single(
                    scene.Elements.OfType<Source>().Where(s => s.IsBackground).ToList(),
                    s => s.IsBackground);
                Assert.Equal("Background", background.Name);
                Assert.Equal(0, scene.Elements.IndexOf(background));

                var wantedType = SceneCatalog.Is(name, SceneCatalog.Live)
                    ? SourceType.DisplayCapture
                    : SourceType.Background;
                Assert.True(background.Type == wantedType,
                    $"{name}: expected {wantedType}, got {background.Type}");
            }

            vm.SaveLayoutNow();

            using (var connection = new SqliteConnection($"Data Source={tempDb}"))
            {
                connection.Open();

                using (var dupes = connection.CreateCommand())
                {
                    dupes.CommandText =
                        "SELECT COUNT(*) FROM Source WHERE Name = 'Game Capture';";
                    Assert.Equal(0L, (long)dupes.ExecuteScalar()!);
                }

                using (var perScene = connection.CreateCommand())
                {
                    perScene.CommandText =
                        @"SELECT s.Name, COUNT(*) FROM Source src
                          JOIN Scene s ON s.Id = src.SceneId
                          WHERE src.IsBackground = 1 GROUP BY s.Name;";
                    using var reader = perScene.ExecuteReader();
                    var counts = new System.Collections.Generic.Dictionary<string, long>();
                    while (reader.Read())
                        counts[reader.GetString(0)] = reader.GetInt64(1);
            var live = vm.Scenes.Single(s => SceneCatalog.Is(s.Name, SceneCatalog.Live));
            vm.StagedScene = live;

            // Layering invariant: the Live screen's background is capture-flavored,
            // so it must never feed ActiveBackgroundImage (that image renders above
            // the capture and would cover it permanently).
            Assert.Null(vm.ActiveBackgroundImage);

            foreach (var name in SceneCatalog.All)
                        Assert.True(counts.TryGetValue(name, out var c) && c == 1,
                            $"{name}: expected exactly 1 background row");
                }

                using (var staleKeys = connection.CreateCommand())
                {
                    staleKeys.CommandText =
                        @"SELECT COUNT(*) FROM Settings
                          WHERE (Key LIKE 'BackgroundUseDefault\_%' ESCAPE '\'
                              OR Key LIKE 'BackgroundPath\_%' ESCAPE '\')
                          AND SUBSTR(Key, INSTR(Key, '_') + 1) IN ('bg-stray-1','bg-stray-2');";
                    Assert.Equal(0L, (long)staleKeys.ExecuteScalar()!);
                }
            }
        }
        finally
        {
            window?.Close();
            MainViewModel.LayoutPathOverride = null;
            SqliteConnection.ClearAllPools();
            try { File.Delete(tempDb); } catch { /* best-effort cleanup */ }
        }
    }

    /// <summary>Recreates the rot observed in the user's real DB: duplicate
    /// capture-flavored rows beside static ones, a misnamed Live background,
    /// and settings keys pointing at rows that shouldn't exist.</summary>
    private static void SeedDirtyDatabase(string path)
    {
        using var connection = new SqliteConnection($"Data Source={path}");
        connection.Open();

        var scenes = new (string Id, string Name)[]
        {
            ("scene-starting", "Starting"),
            ("scene-live", "Live"),
            ("scene-brb", "BRB"),
            ("scene-chat", "Chat"),
            ("scene-ending", "Ending"),
        };
        foreach (var (id, name) in scenes)
        {
            using var cmd = connection.CreateCommand();
            cmd.CommandText =
                "INSERT INTO Scene (Id, Name, HasBackground, SortOrder) VALUES ($id, $name, 1, $order);";
            cmd.Parameters.AddWithValue("$id", id);
            cmd.Parameters.AddWithValue("$name", name);
            cmd.Parameters.AddWithValue("$order", Array.IndexOf(scenes, (id, name)));
            cmd.ExecuteNonQuery();
        }

        InsertSource(connection, "bg-static-1", "scene-starting", "Background", "Background", 0);
        InsertSource(connection, "bg-stray-1", "scene-starting", "Game Capture", "DisplayCapture", 1);
        InsertSource(connection, "bg-live-1", "scene-live", "Game Capture", "DisplayCapture", 0);
        InsertSource(connection, "bg-static-2", "scene-chat", "Background", "Background", 0);
        InsertSource(connection, "bg-stray-2", "scene-chat", "Game Capture", "DisplayCapture", 1);

        using (var key1 = connection.CreateCommand())
        {
            key1.CommandText = "INSERT INTO Settings (Key, Value) VALUES ('BackgroundUseDefault_bg-stray-1', '0');";
            key1.ExecuteNonQuery();
        }
        using (var key2 = connection.CreateCommand())
        {
            key2.CommandText = "INSERT INTO Settings (Key, Value) VALUES ('BackgroundPath_bg-stray-2', 'C:\\\\nope.png');";
            key2.ExecuteNonQuery();
        }
    }

    private static void InsertSource(
        SqliteConnection connection, string id, string sceneId,
        string name, string type, int sortOrder)
    {
        using var cmd = connection.CreateCommand();
        cmd.CommandText =
            @"INSERT INTO Source (Id, SceneId, Type, Name, IsEnabled, X, Y, Width, Height, IsBackground, SortOrder)
              VALUES ($id, $sceneId, $type, $name, 1, 0, 0, 1920, 1080, 1, $sortOrder);";
        cmd.Parameters.AddWithValue("$id", id);
        cmd.Parameters.AddWithValue("$sceneId", sceneId);
        cmd.Parameters.AddWithValue("$type", type);
        cmd.Parameters.AddWithValue("$name", name);
        cmd.Parameters.AddWithValue("$sortOrder", sortOrder);
        cmd.ExecuteNonQuery();
    }
}