using System.Collections;
using System.Collections.Generic;
using Cysharp.Threading.Tasks;
using Gameplay;
using Gameplay.SubSystems;
using PhxhSDK;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.SceneManagement;

/// <summary>
/// 游戏场景的通用业务逻辑
/// </summary>
public class GameSceneHelper : Singlenton<GameSceneHelper>
{
    private Stack<(string, GameSceneManager.SceneHandle)> _uiViewSceneStack = new();

    /// <summary>
    /// 打开UI预览场景，当某个UI需要单独渲染场景时使用(如PVP布阵，营地等)
    /// 该函数会使得预览场景中的相机只渲染UI场景内的物件
    /// 并处理了光照，全局GI，Volume，单一主相机
    /// </summary>
    /// <param name="scenePath"></param>
    /// <returns></returns>
    public async UniTask<GameSceneManager.SceneHandle> LoadSceneForUIView(string scenePath)
    {
        var sceneHandle = await GameSceneManager.Instance.LoadSceneAsync(scenePath, LoadSceneMode.Additive);
        if (sceneHandle == null)
        {
            return null;
        }

        if (_uiViewSceneStack.Count > 0)
        {
            //如果之前加载过UIView场景，则使得上一个场景不影响当前场景
            var lastUIViewSceneData = _uiViewSceneStack.Peek();
            SetSceneActiveForUIView(lastUIViewSceneData.Item2, false);
        }

        SetSceneActiveForUIView(sceneHandle, true);

        _uiViewSceneStack.Push((scenePath, sceneHandle));
        return sceneHandle;
    }

    public async UniTask UnloadSceneForUIView()
    {
        if (_uiViewSceneStack.Count == 0)
        {
            DebugUtil.LogError($"没有加载过UIView场景");
            return;
        }

        var sceneData = _uiViewSceneStack.Pop();
        await GameSceneManager.Instance.UnLoadSceneAsync(sceneData.Item1);
        CameraManager.Instance.RevertMainCamera();
        if (_uiViewSceneStack.Count > 0)
        {
            var lastUIViewSceneData = _uiViewSceneStack.Peek();
            SetSceneActiveForUIView(lastUIViewSceneData.Item2, true);
        }
    }

    private void SetSceneActiveForUIView(GameSceneManager.SceneHandle sceneHandle, bool isActive)
    {
        var scene = sceneHandle.Scene;
        var groundLayer = LayerMask.NameToLayer("Ground");
        var UIViewLayer = isActive ? LayerMask.NameToLayer("UIView") : LayerMask.NameToLayer("Default");
        var UIViewMask = isActive ? LayerMask.GetMask("UIView", "Ground") : LayerMask.GetMask("Default", "Ground");
        //调整所有物品的层级
        var roots = scene.GetRootGameObjects();
        foreach (var root in roots)
        {
            //将所有gameObject设置为UIView层
            root.SetLayerEx(UIViewLayer, groundLayer);
        }

        var sceneMainCamera = sceneHandle.SceneMainCamera;
        if (sceneMainCamera != null)
            sceneMainCamera.cullingMask = UIViewMask;

        //设置光源culling mask
        var lights = Object.FindObjectsOfType<Light>();
        foreach (var light in lights)
        {
            if (light.gameObject.scene != scene)
                continue;
            light.cullingMask = UIViewMask;
        }

        //设置Volume
        var volumes = Object.FindObjectsOfType<Volume>(true);
        foreach (var volume in volumes)
        {
            if (volume.gameObject.scene != scene)
                continue;
            volume.gameObject.SetActive(isActive);
        }

        if (isActive)
        {
            //切换全局GI
            SceneManager.SetActiveScene(scene);
            //切换主相机
            CameraManager.Instance.SwitchMainCamera(sceneMainCamera);
        }
    }
}