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 26 integration: the (+) menu's Webcam row gates on the app-wide webcam
/// identity — one camera per app, so the row must stay disabled while ANY scene
/// shows the webcam (not just the staged one), and re-enable only after the
/// last config anywhere is removed (which also drops the identity).
/// Real-App + temp-DB pattern (see BackgroundHealIntegrationTests).
/// </summary>
[Collection("RealApp")]
public sealed class WebcamMenuGateTests
{
    [Fact]
    public void CanAddWebcam_Gates_On_The_AppWide_Webcam_Identity()
    {
        _app.Run(Run);
    }

    private readonly RealAppHost _app;

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

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

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

            var starting = vm.Scenes.Single(s => SceneCatalog.Is(s.Name, SceneCatalog.Starting));
            var live = vm.Scenes.Single(s => SceneCatalog.Is(s.Name, SceneCatalog.Live));

            vm.StagedScene = live;
            Assert.True(live.WebcamConfig == null, "Live must not carry the webcam config");
            Assert.False(vm.CanAddWebcam,
                "webcam exists in another scene — Add Webcam must be greyed out app-wide");

            vm.StagedScene = starting;
            Assert.False(vm.CanAddWebcam, "staged scene itself has the webcam");

            var config = starting.WebcamConfig!;
            vm.RemoveSourceCommand.Execute(config);

            Assert.True(vm.CanAddWebcam,
                "last webcam config anywhere was removed — identity cleared, picker may run again");

            vm.SaveLayoutNow();
            using (var connection = new SqliteConnection($"Data Source={tempDb}"))
            {
                connection.Open();
                using var webcams = connection.CreateCommand();
                webcams.CommandText = "SELECT COUNT(*) FROM Webcam;";
                Assert.Equal(0L, (long)webcams.ExecuteScalar()!);
            }
        }
        finally
        {
            window?.Close();
            MainViewModel.LayoutPathOverride = null;
            SqliteConnection.ClearAllPools();
            try { File.Delete(tempDb); } catch { /* best-effort cleanup */ }
        }
    }

    /// <summary>Five canonical scenes + a webcam identity used by exactly one
    /// non-staged-by-default scene (Starting), so staging any other screen
    /// reproduces the old per-scene gate's false "available".</summary>
    private static void SeedDatabaseWithWebcam(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();
        }

        using (var webcam = connection.CreateCommand())
        {
            webcam.CommandText =
                "INSERT INTO Webcam (Id, DeviceId, Name) VALUES ('wc-1', 'test-camera', 'Test Cam');";
            webcam.ExecuteNonQuery();
        }

        using (var config = connection.CreateCommand())
        {
            config.CommandText =
                @"INSERT INTO WebcamSceneConfig
                  (SceneId, WebcamId, IsVisible, X, Y, Width, Height, Opacity, SortOrder)
                  VALUES ('scene-starting', 'wc-1', 1, 100, 100, 480, 270, 1, 0);";
            config.ExecuteNonQuery();
        }
    }
}