// CameraOrbit.ts
import { _decorator, Component, Node, Vec3, EventTouch, input, Input, v3 } from 'cc';
const { ccclass, property } = _decorator;

@ccclass('CameraOrbit')
export class CameraOrbit extends Component {
    @property(Node)
    public targetNode: Node | null = null;  // 需通过脚本动态设置目标节点

    private lastTouchX: number = 0;
    private readonly rotationSpeed: number = 0.6;
    private isTouching: boolean = false;
    private currentAngle: number = 0;
    
    // 动态计算参数
    private radius: number = 5;        // 初始默认值，会自动修正
    private heightOffset: number = 2;  // 初始默认值，会自动修正
    private centerOffset = v3(0, 1, 0);// 中心点Y偏移（角色腰部高度）

    // 初始化时自动校准参数
    private isInitialized: boolean = false;

    start() {
        this.tryInitialize();
    }

    // 每帧更新摄像机位置
    lateUpdate() {
        if (!this.isInitialized) return;
        this.updateCameraPosition(true); // true表示保持当前角度
    }

    // 动态设置目标节点
    public setTarget(node: Node) {
        this.targetNode = node;
        this.tryInitialize();
    }

    private tryInitialize() {
        if (!this.targetNode || this.isInitialized) return;
        
        // 计算机型参数与目标的相对关系
        const targetWorldPos = this.targetNode.worldPosition;
        const cameraWorldPos = this.node.worldPosition;

        // 计算水平距离（半径）
        const dx = cameraWorldPos.x - targetWorldPos.x;
        const dz = cameraWorldPos.z - targetWorldPos.z;
        this.radius = Math.sqrt(dx * dx + dz * dz);

        // 计算起始角度（世界坐标系）
        this.currentAngle = Math.atan2(dx, dz) * 180 / Math.PI;

        // 计算高度差
        this.heightOffset = cameraWorldPos.y - targetWorldPos.y;

        this.isInitialized = true;
    }

    private updateCameraPosition(keepAngle: boolean = false) {
        if (!this.isInitialized) return;
        
        const targetWorldPos = this.targetNode!.worldPosition.clone()
            .add(this.centerOffset);
        
        // 计算水平坐标
        const angleRad = this.currentAngle * Math.PI / 180;
        const x = targetWorldPos.x + Math.sin(angleRad) * this.radius;
        const z = targetWorldPos.z + Math.cos(angleRad) * this.radius;
        
        // 设置摄像机世界坐标
        this.node.worldPosition = new Vec3(
            x,
            targetWorldPos.y + this.heightOffset,
            z
        );
        
        // 确保准确朝向目标中心点
        this.node.lookAt(targetWorldPos);
    }

    // 触摸事件处理（保持不变）
    onEnable() {
        input.on(Input.EventType.TOUCH_START, this.onTouchStart, this);
        input.on(Input.EventType.TOUCH_MOVE, this.onTouchMove, this);
        input.on(Input.EventType.TOUCH_END, this.onTouchEnd, this);
        input.on(Input.EventType.TOUCH_CANCEL, this.onTouchEnd, this);
    }

    onDisable() {
        input.off(Input.EventType.TOUCH_START, this.onTouchStart, this);
        input.off(Input.EventType.TOUCH_MOVE, this.onTouchMove, this);
        input.off(Input.EventType.TOUCH_END, this.onTouchEnd, this);
        input.off(Input.EventType.TOUCH_CANCEL, this.onTouchEnd, this);
    }

    private onTouchStart(event: EventTouch) {
        this.isTouching = true;
        this.lastTouchX = event.getLocationX();
    }

    private onTouchMove(event: EventTouch) {
        if (!this.isTouching) return;

        const currentTouchX = event.getLocationX();
        const deltaX = currentTouchX - this.lastTouchX;
        
        // 更新角度
        this.currentAngle -= deltaX * this.rotationSpeed;
        this.currentAngle = (this.currentAngle + 360) % 360;
        
        // 立即更新摄像机位置
        this.updateCameraPosition();
        this.lastTouchX = currentTouchX;
    }

    private onTouchEnd() {
        this.isTouching = false;
    }
}