import { Vector3, Matrix } from '@babylonjs/core/Maths/math.vector';
import { Scene } from '@babylonjs/core/scene';
import { Camera } from '@babylonjs/core/Cameras/camera';
import { Monobehiver } from '../base/Monobehiver';
import { PointerEventTypes, PointerInfo } from '@babylonjs/core';

interface DomElement {
    dom: HTMLElement;
    position: Vector3;
    offset?: { x: number; y: number };
    visible: boolean;
}

/**
 * DOM 2D转3D坐标管理类
 * 将DOM元素固定在3D场景的特定坐标上
 */
export class AppDomTo3D extends Monobehiver {
    private domElements: Map<string, DomElement>;
    private scene: Scene | null;
    private camera: Camera | null;
    private pointerDownPos: Vector3;
    private pointerUpPos: Vector3;

    constructor(mainApp: any) {
        super(mainApp);
        this.domElements = new Map();
        this.scene = null;
        this.camera = null;
        this.pointerDownPos = Vector3.Zero();
        this.pointerUpPos = Vector3.Zero();
    }

    /**
     * 初始化
     */
    init(): void {
        this.scene = this.mainApp.appScene.object;
        this.camera = this.mainApp.appCamera.object;

        // 监听场景点击事件，点击空白处隐藏DOM
        if (this.scene) {
            this.scene.onPointerObservable.add((pointerInfo: PointerInfo) => {
                const { type, event, pickInfo } = pointerInfo;

                if (type === PointerEventTypes.POINTERDOWN) {
                    this.pointerDownPos.set(event.clientX, 0, event.clientY);
                } else if (type === PointerEventTypes.POINTERUP) {
                    this.pointerUpPos.set(event.clientX, 0, event.clientY);
                    const distance = Vector3.Distance(this.pointerDownPos, this.pointerUpPos);

                    // 只有在没有移动的情况下才处理单击（距离小于5像素）
                    if (distance < 5) {
                        // 如果没有点击到任何物体，隐藏所有DOM
                        if (!pickInfo || !pickInfo.hit) {
                            this.hideAll();
                        }
                    }
                }
            });
        }
    }

    /**
     * 添加DOM元素到3D坐标
     * @param id 唯一标识符
     * @param dom DOM元素
     * @param position 3D坐标 [x, y, z]
     * @param offset 2D偏移量 { x, y }，可选
     */
    attach(id: string, dom: HTMLElement, position: [number, number, number], offset?: { x: number; y: number }): void {
        const vector3 = new Vector3(position[0], position[1], position[2]);

        // 设置DOM样式
        dom.style.position = 'absolute';
        dom.style.pointerEvents = 'auto';
        dom.style.zIndex = '1000';
        dom.style.display = 'block';

        // 存储DOM元素信息
        this.domElements.set(id, {
            dom,
            position: vector3,
            offset: offset || { x: 0, y: 0 },
            visible: true
        });

        // 立即更新一次位置
        this.updateSingleDomPosition(id);
    }

    /**
     * 移除DOM元素
     * @param id 唯一标识符
     */
    detach(id: string): void {
        const element = this.domElements.get(id);
        if (element) {
            element.dom.style.display = 'none';
            this.domElements.delete(id);
        }
    }

    /**
     * 更新DOM元素的3D坐标
     * @param id 唯一标识符
     * @param position 新的3D坐标 [x, y, z]
     */
    updatePosition(id: string, position: [number, number, number]): void {
        const element = this.domElements.get(id);
        if (element) {
            element.position.set(position[0], position[1], position[2]);
        }
    }

    /**
     * 更新所有DOM元素的位置
     */
    updateDomPositions(): void {
        this.domElements.forEach((_, id) => {
            this.updateSingleDomPosition(id);
        });
    }

    /**
     * 更新单个DOM元素的位置
     */
    private updateSingleDomPosition(id: string): void {
        const element = this.domElements.get(id);
        if (!element || !this.scene || !this.camera) return;

        const { dom, position, offset, visible } = element;

        // 如果标记为不可见，直接隐藏
        if (!visible) {
            dom.style.display = 'none';
            return;
        }

        // 将3D坐标转换为2D屏幕坐标
        const engine = this.scene.getEngine();
        const width = engine.getRenderWidth();
        const height = engine.getRenderHeight();

        // 使用正确的矩阵：单位矩阵 + 变换矩阵
        const worldMatrix = Matrix.Identity();
        const transformMatrix = this.scene.getTransformMatrix();
        const viewport = this.camera.viewport.toGlobal(width, height);

        const screenPos = Vector3.Project(
            position,
            worldMatrix,
            transformMatrix,
            viewport
        );

        // 检查是否在相机视野内
        if (screenPos.z < 0 || screenPos.z > 1) {
            console.log('DOM 不在视野内，隐藏');
            dom.style.display = 'none';
            return;
        }

        // 应用偏移量并更新DOM位置
        dom.style.display = 'block';
        dom.style.left = `${screenPos.x + (offset?.x || 0)}px`;
        dom.style.top = `${screenPos.y + (offset?.y || 0)}px`;
    }

    /**
     * 清理所有DOM元素
     */
    clean(): void {
        this.domElements.forEach((element) => {
            element.dom.style.display = 'none';
        });
        this.domElements.clear();
    }

    /**
     * 获取所有已附加的DOM元素ID列表
     */
    getAttachedIds(): string[] {
        return Array.from(this.domElements.keys());
    }

    /**
     * 隐藏所有DOM元素
     */
    hideAll(): void {
        console.log('hideAll 被调用，当前元素数量:', this.domElements.size);
        this.domElements.forEach((element, id) => {
            console.log('隐藏元素:', id, element.dom);
            element.visible = false;
            element.dom.style.display = 'none';
        });
    }
}