import { Mesh, MeshBasicMaterial, Raycaster, Scene, Vector3, WebGLRenderer, WebGLRendererParameters } from "three";
import { boardMaterial, CameraControls, PointPick, selectMaterial } from ".";
import { CameraUpdate } from "./CameraUpdate";
import { ColorMaterial } from "./ColorPalette";
import { cZeroVec, GetBox, GetBoxArr } from "./GeUtils";
import { PlaneExt } from "./PlaneExt";

export class ViewerSettings
{
  boardMaterial: MeshBasicMaterial = boardMaterial;
  selectMaterial: MeshBasicMaterial = selectMaterial;
  selectByPointCallback: (meshId: number) => void = () => { };
}

export class Viewer
{
  m_LookTarget: any;
  m_Camera: CameraUpdate = new CameraUpdate();
  m_CameraCtrl: CameraControls;
  m_bNeedUpdate: boolean = true;
  m_Render: WebGLRenderer;//渲染器  //暂时只用这个类型
  m_DomEl: HTMLElement;    //画布容器

  _Height: number;
  _Width: number;

  m_Scene: Scene = new Scene();

  _Settings = new ViewerSettings();
  /**
   * 
   * @param {HTMLElement} canvasContainer 可以传入一个div或者一个画布
   * @memberof Viewer
   */
  constructor(canvasContainer: HTMLElement, setupAction: (settings: ViewerSettings) => void = null)
  {
    if (setupAction)
    {
      setupAction(this._Settings);
    }

    this.m_DomEl = canvasContainer;
    this.initRender(canvasContainer);
    this.OnSize();
    this.StartRender();
    this.m_CameraCtrl = new CameraControls(this);
    window.addEventListener("resize", () =>
    {
      this.OnSize();
    });

    this.m_Render.domElement.addEventListener("mousemove", (e: MouseEvent) =>
    {
      this.SelectByPoint(e.offsetX, e.offsetY);
    })
  }

  //初始化render
  initRender(canvasContainer: HTMLElement)
  {
    let params: WebGLRendererParameters = {
      antialias: true,//antialias:true/false是否开启反锯齿
      precision: "highp",//precision:highp/mediump/lowp着色精度选择
      alpha: true//alpha:true/false是否可以设置背景色透明
    };
    if (canvasContainer instanceof HTMLCanvasElement)
    {
      params.canvas = canvasContainer;
      this.m_Render = new WebGLRenderer(params);
    }
    else
    {
      this.m_Render = new WebGLRenderer(params);
      //加到画布
      canvasContainer.appendChild(this.m_Render.domElement);
    }

    this.m_Render.autoClear = true;

    //如果设置，那么它希望所有的纹理和颜色都是预乘的伽玛。默认值为false。
    // this.m_Render.gammaInput = true;
    // this.m_Render.gammaOutput = true;
    // this.m_Render.shadowMap.enabled = true;
    // this.m_Render.toneMapping = ReinhardToneMapping;
    //设置设备像素比。 这通常用于HiDPI设备，以防止模糊输出画布。
    this.m_Render.setPixelRatio(window.devicePixelRatio);
    this.m_Render.physicallyCorrectLights = true;
    //this.m_Render.toneMappingExposure = Math.pow(1, 5.0); // to allow for very bright scenes.

    //设置它的背景色为黑色
    this.m_Render.setClearColor(0xffffff, 1);


    this.OnSize();
  }

  OnSize = (width?, height?) =>
  {
    this._Width = width ? width : this.m_DomEl.clientWidth;
    this._Height = height ? height : this.m_DomEl.clientHeight;

    //校验.成为2的倍数 避免外轮廓错误.
    if (this._Width % 2 == 1)
      this._Width -= 1;
    if (this._Height % 2 == 1)
      this._Height -= 1;

    this.m_Render.setSize(this._Width, this._Height);
    this.m_Camera.SetSize(this._Width, this._Height);
  }

  StartRender = () =>
  {
    requestAnimationFrame(this.StartRender);
    if (this.m_Scene != null && this.m_bNeedUpdate)
    {
      this.Render();
      this.m_bNeedUpdate = false;
    }
  }
  Render()
  {
    this.m_Render.render(this.m_Scene, this.m_Camera.Camera);
  }

  ScreenToWorld(pt: Vector3, planVec?: Vector3)
  {
    //变换和求交点
    let plan = new PlaneExt(planVec || new Vector3(0, 0, 1));
    let raycaster = new Raycaster();
    // 射线从相机射线向屏幕点位置
    raycaster.setFromCamera(
      {
        x: (pt.x / this._Width) * 2 - 1,
        y: - (pt.y / this._Height) * 2 + 1
      }
      , this.m_Camera.Camera
    )
    plan.intersectRay(raycaster.ray, pt, true);
  }
  WorldToScreen(pt: Vector3)
  {
    let widthHalf = this._Width * 0.5;
    let heightHalf = this._Height * 0.5;

    pt.project(this.m_Camera.Camera);

    pt.x = (pt.x * widthHalf) + widthHalf;
    pt.y = - (pt.y * heightHalf) + heightHalf;
  }

  /**
   * 更新视角观测目标(物体中心)
   * 
   * @memberof Viewer
   */
  UpdateLockTarget()
  {
    let renderList = this.m_Render.renderLists.get(this.m_Scene, this.m_Camera.Camera);
    let box = GetBoxArr(renderList.opaque.map(o => o.object));
    if (box)
      this.m_LookTarget = box.getCenter(new Vector3());
    else
      this.m_LookTarget = cZeroVec;
  }
  Rotate(mouseMove: Vector3)
  {
    this.m_Camera.Rotate(mouseMove, this.m_LookTarget);
    this.m_bNeedUpdate = true;
  }
  Pan(mouseMove: Vector3)
  {
    this.m_Camera.Pan(mouseMove);
    this.m_bNeedUpdate = true;
  }
  Zoom(scale: number, center?: Vector3)
  {
    this.m_Camera.Zoom(scale, center);
    this.m_bNeedUpdate = true;
  }
  ZoomAll()
  {
    this.m_Camera.ZoomExtensBox3(GetBox(this.m_Scene, true));
    this.m_bNeedUpdate = true;
  }

  ViewToTop()
  {
    this.m_Camera.LookAt(new Vector3(0, 0, -1));
    this.m_bNeedUpdate = true;
  }
  ViewToFront()
  {
    this.m_Camera.LookAt(new Vector3(0, 1, 0));
    this.m_bNeedUpdate = true;
  }
  ViewToSwiso()
  {
    this.m_Camera.LookAt(new Vector3(1, 1, -1));
    this.m_bNeedUpdate = true;
  }

  oldMesh: Mesh;
  SelectByPoint(x: number, y: number)
  {
    let mesh = PointPick(this, x, y);
    if (this.oldMesh)
      this.oldMesh.material = this._Settings.boardMaterial;
    if (mesh && mesh.material !== ColorMaterial.GetBasicMaterial(1))
    {
      this.oldMesh = mesh;
      mesh.material = this._Settings.selectMaterial;
      if (this._Settings.selectByPointCallback)
      {
        this._Settings.selectByPointCallback(mesh.id);
      }
    }
    this.m_bNeedUpdate = true;
  }
  SelectBlock(blockMeshMap: Map<number, number>, dataID: number)
  {
    if (blockMeshMap.has(dataID))
    {
      let meshId = blockMeshMap.get(dataID);
      if (this.oldMesh)
        this.oldMesh.material = this._Settings.boardMaterial;
      this.m_Scene.children.forEach(obj =>
      {
        if (obj instanceof Mesh)
        {
          if (obj.id == meshId)
          {
            this.oldMesh = obj;
            obj.material = this._Settings.selectMaterial;
            this.m_bNeedUpdate = true;
          }
        }

      })
    }
  }
}