import { _decorator, Camera, Component, director, Node, tween, Vec3 } from 'cc';
import { EventDispatcher } from 'db://assets/core_tgx/easy_ui_framework/EventDispatcher';
import { GameEvent } from '../Enum/GameEvent';
const { ccclass, property } = _decorator;

//相机切分动画时长
export const CAMERA_SPLIT_DURATION = 3;

@ccclass('BulletComponent')
export class BulletComponent extends Component {

    target: Node = null!;

    @property(Camera)
    camera: Camera = null!; // 相机节点

    protected onLoad(): void {
        EventDispatcher.instance.on(GameEvent.EVENT_CAMERA_SPLIT, this.camerSlip, this);
    }

    private camerSlip(target: Node) {
        this.hideGun();
        this.target = target;
        this.lookAtTarget();
        this.flyToTarget();
    }

    private hideGun() {
       const gun = this.camera.node.getChildByName('gun'); 
       gun.active = false;
    }

    //朝向目标
    lookAtTarget() {
        if (!this.target) return;

        // 计算子弹到目标的方向
        const direction = new Vec3();
        Vec3.subtract(direction, this.target.worldPosition, this.node.worldPosition);
        direction.normalize();

        // 计算朝向角度（注意Y轴旋转180度）
        const angle = Math.atan2(direction.x, direction.z) * 180 / Math.PI;

        // 设置子弹旋转
        this.node.setRotationFromEuler(0, angle, 0);
    }

    //飞向目标
    flyToTarget() {
        if (!this.target || !this.camera) return;

        // 1. 计算相机起始位置（子弹后方）
        const bulletDir = new Vec3();
        Vec3.subtract(bulletDir, this.target.worldPosition, this.node.worldPosition);
        bulletDir.normalize();

        const startCameraPos = new Vec3();
        Vec3.scaleAndAdd(startCameraPos, this.node.worldPosition, bulletDir, -5);

        this.camera.node.worldPosition = startCameraPos;
        this.camera.node.lookAt(this.node.worldPosition);

        // 2. 子弹飞行+相机跟随
        const targetPos = this.target.worldPosition.clone();
        let elapsedTime = 0;

        tween(this.node)
            .to(CAMERA_SPLIT_DURATION, { worldPosition: new Vec3(targetPos.x, targetPos.y, targetPos.z) }, {
                onUpdate: (target, ratio) => {
                    elapsedTime = ratio! * 3;

                    // 第一秒：相机跟随子弹后方
                    if (elapsedTime <= 1) {
                        const followPos = new Vec3();
                        Vec3.scaleAndAdd(followPos, this.node.worldPosition, bulletDir, -5);
                        followPos.y += 1;

                        this.camera.node.worldPosition = followPos;
                        this.camera.node.lookAt(this.node.worldPosition);
                    }
                    // 第二秒：平滑移动到侧后方45度
                    else if (elapsedTime <= 2) {
                        // 计算侧后方45度方向向量
                        const sideBackDir = new Vec3();
                        Vec3.rotateY(sideBackDir, bulletDir, Vec3.UP, Math.PI / 2);

                        // 起始位置(后方)和目标位置(侧后方)
                        const startPos = new Vec3();
                        Vec3.scaleAndAdd(startPos, this.node.worldPosition, bulletDir, -5);
                        startPos.y += 3;

                        const targetPos = new Vec3();
                        Vec3.scaleAndAdd(targetPos, this.node.worldPosition, sideBackDir, -5);
                        targetPos.y += 3;

                        // 使用lerp平滑过渡
                        const currentPos = new Vec3();
                        const progress = (elapsedTime - 1) / 1; // 0-1之间的进度
                        Vec3.lerp(currentPos, startPos, targetPos, progress);

                        this.camera.node.worldPosition = currentPos;
                        this.camera.node.lookAt(this.node.worldPosition);
                    }
                    // 第三秒：相机对准目标节点
                    else {
                        this.node.setScale(1, 1, 1);
                        // 计算目标点前方5单位的位置（距离从10改为5）
                        const targetViewPos = new Vec3(
                            this.target.worldPosition.x,
                            this.target.worldPosition.y + 2, // 高度偏移2单位
                            this.target.worldPosition.z + 3 // 前方5单位
                        );

                        this.camera.node.worldPosition = targetViewPos;
                        this.camera.node.lookAt(this.target.worldPosition);
                    }
                }
            })
            .start();
    }

    protected onDestroy(): void {
        EventDispatcher.instance.off(GameEvent.EVENT_CAMERA_SPLIT, this.camerSlip, this);
    }
}