import { _decorator, Component, Node, UITransform, Vec2, Vec3 } from 'cc';
const { ccclass, executeInEditMode } = _decorator;

/**
 * line 长度/角度随 startPos→endPos 更新（移动 endPos 即自动拉线）。
 * 子节点 Spine 动画不改；收招须 resetEndPos，否则拆字换格后 endPos 留在旧世界坐标会拉出乱线。
 */
@ccclass('SkillEye')
@executeInEditMode(true)
export class SkillEye extends Component {

    startPos: Node;
    endPos: Node;
    line: Node;

    dir: Vec2 = new Vec2();

    private _endPosRestLocal: Vec3 | null = null;
    /** line UITransform 宽度：scale=1 时光束本地长度（戬/杨 prefab ≈543） */
    private _beamBaseLen = 0;

    protected onLoad(): void {
        this.ensureBound();
    }

    ensureBound(): void {
        if (!this.startPos?.isValid) {
            this.startPos = this.node.getChildByName('startPos');
        }
        if (!this.endPos?.isValid) {
            this.endPos = this.node.getChildByName('endPos')
                ?? this.node.getChildByPath('line/endPos');
        }
        if (!this.line?.isValid) {
            this.line = this.node.getChildByName('line');
        }
        if (this.endPos?.isValid && !this._endPosRestLocal) {
            this._endPosRestLocal = this.endPos.position.clone();
        }
        if (this.line?.isValid && this._beamBaseLen <= 0) {
            this._beamBaseLen = this.line.getComponent(UITransform)?.width ?? 200;
        }
    }

    protected update(_dt: number): void {
        if (this.line?.active) this.refreshBeam();
    }

    refreshBeam(): void {
        this.ensureBound();
        if (!this.startPos?.isValid || !this.endPos?.isValid || !this.line?.isValid) return;
        if (!this.endPos.active) return;

        this.line.setPosition(this.startPos.position);

        const sx = this.startPos.position.x;
        const sy = this.startPos.position.y;
        const ex = this.endPos.position.x;
        const ey = this.endPos.position.y;
        const dx = ex - sx;
        const dy = ey - sy;
        const distance = Math.hypot(dx, dy);
        if (distance <= 1e-4) {
            this.line.setScale(0, 1, 1);
            return;
        }

        this.dir.set(sx - ex, sy - ey);
        this.dir.normalize();
        this.line.angle = Math.atan2(this.dir.y, this.dir.x) * 180 / Math.PI - 180;

        const baseLen = this._beamBaseLen > 0 ? this._beamBaseLen : 200;
        this.line.setScale(distance / baseLen, 1, 1);
    }

    /** endPos 落到目标世界坐标（UI 层级走父节点 convertToNodeSpaceAR） */
    setEndWorldPos(world: Readonly<Vec3>): void {
        this.ensureBound();
        if (!this.endPos?.isValid) return;
        const parent = this.endPos.parent;
        const ui = parent?.getComponent(UITransform);
        if (ui) {
            this.endPos.setPosition(ui.convertToNodeSpaceAR(world as Vec3));
        } else {
            this.endPos.setWorldPosition(world);
        }
        this.refreshBeam();
    }

    /** 收招/隐藏：endPos 回到预制体本地坐标，避免换格后 startPos/endPos 各画一条线 */
    resetEndPos(): void {
        this.ensureBound();
        if (this.endPos?.isValid && this._endPosRestLocal) {
            this.endPos.setPosition(this._endPosRestLocal);
        }
    }
}