import { Vector3 } from 'three';
import type { Viewer } from './Viewer';

/**
 * 材质编辑器的场景鼠标控制.
 */
export class MaterialEditorCamerControl
{
    private Viewer: Viewer;

    //State.
    private _MouseIsDown: boolean = false;
    private _StartPoint: Vector3 = new Vector3();
    private _EndPoint = new Vector3();
    private pointId: number;

    constructor(view: Viewer)
    {
        this.Viewer = view;

        this.initMouseControl();
    }
    initMouseControl()
    {
        let el = this.Viewer.Renderer.domElement;
        el.addEventListener("pointerdown", (e) => { this.pointId = e.pointerId; }, false);
        el.addEventListener("mousedown", this.onMouseDown, false);
        el.addEventListener("mousemove", this.onMouseMove, false);
        el.addEventListener("mouseup", this.onMouseUp, false);
        el.addEventListener('wheel', this.onMouseWheel, false);
    }
    onMouseDown = (event: MouseEvent) =>
    {
        this.requestPointerLock();
        this._MouseIsDown = true;
        this._StartPoint.set(event.offsetX, event.offsetY, 0);
    };
    onMouseUp = (event: MouseEvent) =>
    {
        this._MouseIsDown = false;
        this.exitPointerLock();
    };
    onMouseMove = (event: MouseEvent) =>
    {
        event.preventDefault();
        if (this._MouseIsDown)
        {
            this._EndPoint.set(event.offsetX, event.offsetY, 0);
            let changeVec: Vector3 = new Vector3();
            changeVec.subVectors(this._EndPoint, this._StartPoint);
            this._StartPoint.copy(this._EndPoint);

            this.Viewer.Rotate(changeVec);
        }
    };
    onMouseWheel = (event: WheelEvent) =>
    {
        if (event.deltaY < 0)
        {
            this.Viewer.Zoom(0.6);
        }
        else if (event.deltaY > 0)
        {
            this.Viewer.Zoom(1.4);
        }
    };

    requestPointerLock()
    {
        if (this.Viewer.Renderer.domElement.setPointerCapture)
            this.Viewer.Renderer.domElement.setPointerCapture(this.pointId);
    }

    exitPointerLock()
    {
        if (this.Viewer.Renderer.domElement.releasePointerCapture && this.pointId !== undefined)
        {
            try
            {
                this.Viewer.Renderer.domElement.releasePointerCapture(this.pointId);
            }
            catch (error) { }
        }
    }
}