using Friflo.Engine.ECS;
using Microsoft.Xna.Framework;
using MrGameEng.Assets;
using MrGameEng.Audio;
using MrGameEng.Core;
using MrGameEng.Graphics;
using MrGameEng.Input;
using MrGameEng.UI;
using Myra.Graphics2D.UI;

namespace MrGameEng.Sample.Scenes;

/// <summary>
/// Интерактивная демо-сцена: ассеты через сгенерированные хендлы, анимация, слои
/// (мир + Y-sort + screen-space HUD), камера с зумом/поворотом, ввод, звук и музыка.
/// WASD — игрок, колесо — зум, Q/E — поворот, Space — звук, P — пауза, M — музыка, Tab — стресс-сцена.
/// </summary>
public sealed class MainScene : Scene
{
    private const int DecorCount = 1500;
    private static readonly RectF WorldBounds = new(-2000f, -2000f, 4000f, 4000f);

    protected override void OnLoad()
    {
        var assets = Context.Services.GetOrDefault<AssetManager>() ?? Context.UseAssets();
        var audio = Context.Services.GetOrDefault<AudioManager>() ?? Context.UseAudio();
        var input = this.UseInput();
        var actions = SampleInput.CreateActions(input);
        this.UseSpriteAnimation();

        var renderer = this.UseRenderer2D(new Renderer2DOptions { VirtualResolution = new Point(1280, 720) });
        SampleLayers.EnsureRegistered(renderer);

        var playerTexture = assets.Load(GameAssets.Textures.Player);
        var shapesTexture = assets.Load(GameAssets.Textures.Shapes);
        var beep = assets.Load(GameAssets.Sounds.Beep);

        var shapeRegions = new[]
        {
            new Texture2DRegion(shapesTexture, new Rectangle(0, 0, 32, 32)),
            new Texture2DRegion(shapesTexture, new Rectangle(32, 0, 32, 32)),
            new Texture2DRegion(shapesTexture, new Rectangle(0, 32, 32, 32)),
            new Texture2DRegion(shapesTexture, new Rectangle(32, 32, 32, 32)),
        };

        // Декорации по всему миру: уезжаешь камерой — попадают под culling (см. заголовок окна).
        var random = new Random(42);
        for (var i = 0; i < DecorCount; i++)
        {
            var sprite = new Sprite(shapeRegions[random.Next(shapeRegions.Length)]);
            sprite.CenterOrigin();
            sprite.Color = Color.White * 0.35f;
            Store.CreateEntity(
                new Transform2D(
                    new Vector2(
                        random.NextSingle() * WorldBounds.Width + WorldBounds.Left,
                        random.NextSingle() * WorldBounds.Height + WorldBounds.Top),
                    rotation: random.NextSingle() * MathF.Tau,
                    scale: new Vector2(0.5f + random.NextSingle())),
                sprite);
        }

        // Бродячие "существа" на Y-sort слое: кто ниже на экране — тот ближе.
        for (var i = 0; i < 200; i++)
        {
            var sprite = new Sprite(shapeRegions[random.Next(shapeRegions.Length)], SampleLayers.Actors);
            sprite.CenterOrigin();
            var angle = random.NextSingle() * MathF.Tau;
            Store.CreateEntity(
                new Transform2D(new Vector2(random.Next(-600, 600), random.Next(-400, 400))),
                sprite,
                new Velocity { Value = new Vector2(MathF.Cos(angle), MathF.Sin(angle)) * (40f + random.Next(80)) });
        }

        // Игрок: анимированный спрайт (2 кадра из атласа player.png), Y-sort слой.
        var playerSprite = new Sprite(new Texture2DRegion(playerTexture, new Rectangle(0, 0, 32, 32)), SampleLayers.Actors);
        playerSprite.CenterOrigin();
        var blink = new SpriteAnimationClip(
        [
            new Texture2DRegion(playerTexture, new Rectangle(0, 0, 32, 32)),
            new Texture2DRegion(playerTexture, new Rectangle(32, 0, 32, 32)),
        ], framesPerSecond: 3f);

        var player = Store.CreateEntity(
            new Transform2D(Vector2.Zero, scale: new Vector2(2f)),
            playerSprite,
            new SpriteAnimator(blink));

        var camera = Store.CreateEntity(new Camera(Vector2.Zero, zoom: 1f, bounds: WorldBounds));

        // HUD: золотой квадрат в углу на screen-space слое — не двигается с камерой.
        var hud = new Sprite(shapeRegions[3], SampleLayers.Ui);
        Store.CreateEntity(new Transform2D(new Vector2(16f, 16f)), hud);

        // UI (Myra): HUD со статистикой, слайдер громкости, кнопка перехода. После UseRenderer2D!
        var desktop = this.UseUI();
        var statsLabel = new Label();
        var volumeSlider = new HorizontalSlider { Minimum = 0f, Maximum = 1f, Value = audio.Music.Volume, Width = 180 };
        volumeSlider.ValueChanged += (_, _) => audio.Music.Volume = volumeSlider.Value;
        var switchButton = new Button { Content = new Label { Text = "Stress scene (Tab)" } };
        switchButton.Click += (_, _) =>
        {
            if (!Context.Scenes.IsTransitioning)
            {
                Context.Scenes.Switch(new StressScene(), Transition.Fade(0.8f));
            }
        };

        var panel = new VerticalStackPanel { Left = 12, Top = 12, Spacing = 6 };
        panel.Widgets.Add(statsLabel);
        panel.Widgets.Add(new Label { Text = "Music volume (M — pause)" });
        panel.Widgets.Add(volumeSlider);
        panel.Widgets.Add(switchButton);
        desktop.Root = panel;

        UpdateSystems.Add(new PlayerControlSystem(player, actions, audio, beep));
        UpdateSystems.Add(new BounceSystem(WorldBounds));
        UpdateSystems.Add(new CameraControlSystem(camera, player, input));
        UpdateSystems.Add(new SceneHotkeysSystem(Context, actions, () => new StressScene(), Transition.Fade(0.8f)));
        UpdateSystems.Add(new StatsSystem(Context, renderer, "Main", statsLabel));

        var music = audio.Music;
        if (!music.IsPlaying)
        {
            music.Volume = 0.4f;
            music.Play(assets.Load(GameAssets.Music.Theme));
        }
    }
}