import * as THREE from "three";
import { Mesh } from "three";
import { CameraControls, PointPick, boardMaterial, selectMaterial } from ".";
import { CameraUpdate } from "./CameraUpdate";
import { ColorMaterial } from "./ColorPalette";
import { GetBox, GetBoxArr, cZeroVec } from "./GeUtils";
import { PlaneExt } from "./PlaneExt";

export class Viewer
{
    m_LookTarget: any;
    m_Camera: CameraUpdate = new CameraUpdate();
    m_bNeedUpdate: boolean = true;
    m_Render: THREE.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: THREE.Scene = new THREE.Scene();

    //构造
    constructor(canvasContainer: HTMLElement)
    {
        this.m_DomEl = canvasContainer;
        this.initRender(canvasContainer);
        this.OnSize();
        this.StartRender();
        new CameraControls(this);
        window.addEventListener("resize", () =>
        {
            this.OnSize();
        });

        let oldMesh: Mesh;
        this.m_Render.domElement.addEventListener("mousemove", (e: MouseEvent) =>
        {
            let mesh = PointPick(this, e.offsetX, e.offsetY);
            if (oldMesh)
                oldMesh.material = boardMaterial;
            if (mesh && mesh.material !== ColorMaterial.GetLineMaterial(1))
            {
                oldMesh = mesh;
                mesh.material = selectMaterial;
            }
            this.m_bNeedUpdate = true;
        })
    }

    //初始化render
    initRender(canvasContainer: HTMLElement)
    {
        this.m_Render = new THREE.WebGLRenderer(
            {
                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
                // premultipliedAlpha: false,//?
                // stencil: false,//?
                // preserveDrawingBuffer: true,//preserveDrawingBuffer:true/false是否保存绘图缓冲
                // maxLights: 1//maxLights:最大灯光数
            }
        );
        //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 = THREE.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: THREE.Vector3, planVec?: THREE.Vector3)
    {
        //变换和求交点
        let plan = new PlaneExt(planVec || new THREE.Vector3(0, 0, 1));
        let raycaster = new THREE.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: THREE.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 THREE.Vector3());
        else
            this.m_LookTarget = cZeroVec;
    }
    Rotate(mouseMove: THREE.Vector3)
    {
        this.m_Camera.Rotate(mouseMove, this.m_LookTarget);
        this.m_bNeedUpdate = true;
    }
    Pan(mouseMove: THREE.Vector3)
    {
        this.m_Camera.Pan(mouseMove);
        this.m_bNeedUpdate = true;
    }
    Zoom(scale: number, center?: THREE.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 THREE.Vector3(0, 0, -1));
        this.m_bNeedUpdate = true;
    }
    ViewToFront()
    {
        this.m_Camera.LookAt(new THREE.Vector3(0, 1, 0));
        this.m_bNeedUpdate = true;
    }
    ViewToSwiso()
    {
        this.m_Camera.LookAt(new THREE.Vector3(1, 1, -1));
        this.m_bNeedUpdate = true;
    }
}