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

@ccclass('Enemy')
export class Enemy extends Component {
    @property
    speed: number = 50;

    @property
    changeDirectionTime: number = 3;

    private _direction: Vec3 = new Vec3(0, 0, 0);
    private _canvasSize: { width: number, height: number } = { width: 0, height: 0 };
    private _changeDirectionTimer: number = 0;

    start() {
        // 获取画布大小
        const canvas = this.node.parent.getComponent(UITransform);
        this._canvasSize.width = canvas.width;
        this._canvasSize.height = canvas.height;
        
        // 设置初始随机方向
        this.setRandomDirection();
        
        // 定时改变方向
        this.schedule(this.setRandomDirection, this.changeDirectionTime);
    }

    update(dt: number) {
        // 移动敌人
        const movement = new Vec3(
            this._direction.x * this.speed * dt,
            this._direction.y * this.speed * dt,
            0
        );
        this.node.position = Vec3.add(new Vec3(), this.node.position, movement);
        
        // 检查边界
        this.checkBoundary();
    }

    setRandomDirection() {
        const angle = Math.random() * Math.PI * 2;
        this._direction.x = Math.cos(angle);
        this._direction.y = Math.sin(angle);
        this._direction.normalize();
    }

    checkBoundary() {
        const halfWidth = this._canvasSize.width / 2 - 20;
        const halfHeight = this._canvasSize.height / 2 - 20;
        const pos = this.node.position;
        
        // 检查X轴边界
        if (pos.x > halfWidth || pos.x < -halfWidth) {
            this._direction.x *= -1;
            
            // 调整位置，避免卡在边界
            if (pos.x > halfWidth) {
                this.node.position = new Vec3(halfWidth, pos.y, pos.z);
            } else if (pos.x < -halfWidth) {
                this.node.position = new Vec3(-halfWidth, pos.y, pos.z);
            }
        }
        
        // 检查Y轴边界
        if (pos.y > halfHeight || pos.y < -halfHeight) {
            this._direction.y *= -1;
            
            // 调整位置，避免卡在边界
            if (pos.y > halfHeight) {
                this.node.position = new Vec3(pos.x, halfHeight, pos.z);
            } else if (pos.y < -halfHeight) {
                this.node.position = new Vec3(pos.x, -halfHeight, pos.z);
            }
        }
    }
}