using System;
using Framework;
using PhxhSDK;
using UnityEngine;
using Constants = Framework.Constants;

/// <summary>
/// 截图管理器
/// 负责管理游戏内的模糊截图功能（用于UI背景等）
/// </summary>
public class ScreenshotManager
{
    #region Singleton
    private static ScreenshotManager _instance;
    public static ScreenshotManager Instance
    {
        get
        {
            if (_instance == null)
            {
                _instance = new ScreenshotManager();
            }
            return _instance;
        }
    }
    
    private ScreenshotManager() { }
    #endregion
    
    private const string SCREEN_SNAPSHOT = "ScreenSnapshot";
    
    private RenderTexture _screenTexture;
    
    /// <summary>
    /// 截取当前屏幕并应用模糊效果
    /// </summary>
    /// <param name="captureUI">是否截取UI相机内容（默认true），false则截取主相机</param>
    public void CaptureScreenshot(bool captureUI = true)
    {
        try
        {
            //int width = PerformanceManager.instance.ScreenSize.x / 2;
            //int height = PerformanceManager.instance.ScreenSize.y / 2;
            
            int width = Screen.width / 2;
            int height = Screen.height / 2;

            // 创建或更新 RenderTexture
            if (null == _screenTexture)
            {
                _screenTexture = RenderTexturePool.Instance.Create(SCREEN_SNAPSHOT, width, height, RenderTexturePool.DEFAULT_DEPTH);
                _screenTexture.filterMode = FilterMode.Trilinear;
            }
            else if (_screenTexture.width != width || _screenTexture.height != height)
            {
                RenderTexturePool.Instance.Destroy(_screenTexture, true);
                _screenTexture = RenderTexturePool.Instance.Create(SCREEN_SNAPSHOT, width, height, RenderTexturePool.DEFAULT_DEPTH);
                _screenTexture.filterMode = FilterMode.Trilinear;
            }

            CameraManager.Instance.SetMainCameraActive(false);
            
            // 渲染截图
            Camera usingCamera = captureUI ? CameraManager.Instance.UICamera : CameraManager.Instance.MainCamera;
            if (usingCamera != null)
            {
                Rect rect = usingCamera.rect;
                usingCamera.rect = new Rect(0f, 0f, 1f, 1f);
                usingCamera.targetTexture = _screenTexture;
                usingCamera.Render();
                usingCamera.targetTexture = captureUI ? null : CameraManager.Instance.DefaultRenderTarget;
                usingCamera.rect = rect;
            }
            else
            {
                DebugUtil.LogError("ScreenshotManager: usingCamera is null");
            }

            // 高斯模糊处理
            ApplyGaussianBlur();
        }
        catch (Exception e)
        {
            DebugUtil.LogError($"ScreenshotManager.CaptureScreenshot error: {e}");
        }
    }

    /// <summary>
    /// 应用高斯模糊效果
    /// </summary>
    private void ApplyGaussianBlur()
    {
        var material = AssetManager.Instance.GetPreLoadResult<Material>(Constants.BLUR_MAT_PATH);
        if (material == null)
        {
            DebugUtil.LogError("ScreenshotManager: Blur material not found");
            return;
        }

        // 需要用一个缓存的rt,不然移动平台会出现方块
        RenderTexture cacheRt = CameraManager.Instance.DefaultRenderTarget;
        Graphics.Blit(_screenTexture, cacheRt, material);
        Graphics.Blit(cacheRt, _screenTexture);
    }

    /// <summary>
    /// 重置截图状态（恢复主相机）
    /// </summary>
    public void ResetScreenshot()
    {
        CameraManager.Instance.SetMainCameraActive(true);
    }

    /// <summary>
    /// 获取截图的 Texture2D
    /// </summary>
    public Texture2D GetScreenTexture2D()
    {
        if (_screenTexture == null)
        {
            DebugUtil.LogWarning("ScreenshotManager: No screenshot available");
            return null;
        }

        Texture2D texture2D = PhxhSDK.Utils.CreateTexture2D(_screenTexture.name, _screenTexture.width, _screenTexture.height);
        RenderTexture.active = _screenTexture;
        texture2D.ReadPixels(new Rect(0f, 0f, _screenTexture.width, _screenTexture.height), 0, 0);
        texture2D.Apply();
        RenderTexture.active = null;

        return texture2D;
    }
}