using OpenCVForUnity;
using OpenCVForUnity.CoreModule;
using OpenCVForUnity.ImgprocModule;
using OpenCVForUnity.UnityUtils;

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// WebCam色彩图处理
/// </summary>
public class WebCamTextureProcesser : MonoBehaviour
{
  public static WebCamTextureProcesser Instance;

  private WebCamDevice webCamDevice;
  private WebCamTexture webCamTexture;
  private Mat rgbaMat;

  private Color32[] colors;
  private bool isInitWaiting = false;
  private bool hasInitDone = false; // 如果Init完毕

  // ==================================================

  private void Awake() => Instance = this;
  private void Start() => Init();
  private void Update() => ProcessWebCamTexture();
  private void OnDestroy() => Dispose();

  // ==================================================

  private void Init()
  {
    if (isInitWaiting)
    {
      return;
    }
    StartCoroutine(nameof(InitAction));
    return;
  }
  private IEnumerator InitAction()
  {
    if (hasInitDone) // 防止重复安装
    {
      Dispose();
    }
    isInitWaiting = true;

    CreateCamera(); // 创建相机

    while (true)
    {
      if (webCamTexture.didUpdateThisFrame)
      {
        isInitWaiting = false;
        hasInitDone = true;

        if (colors == null || colors.Length != webCamTexture.width * webCamTexture.height) // 确定color尺寸
        {
          colors = new Color32[webCamTexture.width * webCamTexture.height];
        }
        if (orginalPreviewTexture2D == null || orginalPreviewTexture2D.width != webCamTexture.width || orginalPreviewTexture2D.height != webCamTexture.height) // 确定texture2d尺寸
        {
          orginalPreviewTexture2D = new Texture2D(webCamTexture.width, webCamTexture.height, TextureFormat.RGBA32, false);
        }

        rgbaMat = new Mat(webCamTexture.height, webCamTexture.width, CvType.CV_8UC4, new Scalar(0, 0, 0, 255)); // 高、宽

        // UpdateOriginalPreview(); // ?这里为什么会有预览
        break;
      }
      else
      {
        yield return null;
      }
    }
    yield break;
  }

  // ==================================================
  #region 色彩画面处理
  private void ProcessWebCamTexture()
  {
    if (hasInitDone && webCamTexture.isPlaying && webCamTexture.didUpdateThisFrame)
    {
      Utils.webCamTextureToMat(webCamTexture, rgbaMat, colors);

      transform.GetComponent<FacialRecognitionHandler>().DetectFace(rgbaMat); // 传入mat 检测人脸 // 会导致原数据反转？

      UpdateOriginalPreview();
    }
    return;
  }
  #endregion

  // ==================================================
  #region 释放资源
  private void Dispose()
  {
    isInitWaiting = false;
    hasInitDone = false;

    if (webCamTexture != null)
    {
      webCamTexture.Stop();
      Destroy(webCamTexture);
      webCamTexture = null;
    }
    if (rgbaMat != null)
    {
      rgbaMat.Dispose();
      rgbaMat = null;
    }
    if (orginalPreviewTexture2D != null)
    {
      Destroy(orginalPreviewTexture2D);
      orginalPreviewTexture2D = null;
    }
    return;
  }
  #endregion

  // ==================================================
  #region 创建、配置WebCamera
  [SerializeField] private string requestedDeviceName = "MX Brio"; // "GC21 Video" // "Logitech BRIO"
  private int requestedWidth = 480; // 440
  private int requestedHeight = 270; // 440
  private int requestedFPS = 30;
  private void CreateCamera()
  {
    foreach (WebCamDevice device in WebCamTexture.devices)
    {
      if (device.name == requestedDeviceName)
      {
        webCamDevice = device;
        webCamTexture = new WebCamTexture(webCamDevice.name, requestedWidth, requestedHeight, requestedFPS);
        webCamTexture.Play();
        Debug.Log($"[WTP] Name:{webCamTexture.deviceName} / Width:{webCamTexture.width} / Height:{webCamTexture.height} / FPS:{webCamTexture.requestedFPS}");
        Debug.Log($"[WTP] VideoRotationAngle:{webCamTexture.videoRotationAngle} / VideoVerticallyMirrored:{webCamTexture.videoVerticallyMirrored} / IsFrongFacing:{webCamDevice.isFrontFacing}");
        return;
      }
    }
    return;
  }
  #endregion

  // ==================================================
  #region 预览画面
  private bool allowPreview = false;
  public void SwitchPreview(bool value)
  {
    allowPreview = value;
    return;
  }

  [SerializeField] private Image originalPreviewImage;
  private Texture2D orginalPreviewTexture2D;
  private void UpdateOriginalPreview()
  {
    if (!allowPreview)
    {
      return;
    }

    if (originalPreviewImage == null)
    {
      return;
    }

    Utils.matToTexture2D(rgbaMat, orginalPreviewTexture2D, colors); // Mat更新为texture2d
    // texture2D = RotateTexutre(texture2D, false);
    originalPreviewImage.sprite = Sprite.Create(orginalPreviewTexture2D, new UnityEngine.Rect(0, 0, orginalPreviewTexture2D.width, orginalPreviewTexture2D.height), Vector2.zero);
    return;
  }
  #endregion

  // ==================================================
  // 按钮

  public void OnPlayButtonClick()
  {
    if (hasInitDone)
    {
      webCamTexture.Play();
    }
    return;
  }

  public void OnPauseButtonClick()
  {
    if (hasInitDone)
    {
      webCamTexture.Pause();
    }
    return;
  }

  public void OnStopButtonClick()
  {
    if (hasInitDone)
    {
      webCamTexture.Stop();
    }
    return;
  }

  // ==================================================
  //  Texture画面旋转 // 不必要的 // 旋转处理在FaceDetecter中进行
  // private Texture2D RotateTexutre(Texture2D originalTexture, bool clockwise)
  // {
  //   Color32[] original = originalTexture.GetPixels32();
  //   Color32[] rotated = new Color32[original.Length];
  //   int w = originalTexture.width;
  //   int h = originalTexture.height;

  //   int iRotated, iOriginal;

  //   for (int j = 0; j < h; ++j)
  //   {
  //     for (int i = 0; i < w; ++i)
  //     {
  //       iRotated = (i + 1) * h - j - 1;
  //       iOriginal = clockwise ? original.Length - 1 - (j * w + i) : j * w + i;
  //       rotated[iRotated] = original[iOriginal];
  //     }
  //   }

  //   Texture2D newTexture = new Texture2D(originalTexture.height, originalTexture.width, TextureFormat.RGBA32, false);
  //   newTexture.SetPixels32(rotated);
  //   newTexture.Apply();
  //   return newTexture;
  // }
}