// assets/scripts/GoalkeeperAI.ts
import { _decorator, Component, Node, RigidBody, Vec3, math } from "cc";
const { ccclass, property } = _decorator;

@ccclass("GoalkeeperAI")
export class GoalkeeperAI extends Component {
  @property(Node) ball!: Node;
  @property({ tooltip: "球门线Z（世界坐标）" }) goalLineZ = 10;
  @property({ tooltip: "守门员水平活动范围X" }) rangeX = 3.5;
  @property({ tooltip: "移动速度（m/s）" }) speed = 6;
  @property({ tooltip: "反应延迟（秒）" }) reactDelay = 0.15;

  private targetX = 0;
  private tAcc = 0;
  private tmp = new Vec3();

  update(dt: number) {
    if (!this.ball) return;

    // 简化预测：用当前速度线性外推到球门线的交点
    const rb = this.ball.getComponent(RigidBody);
    if (!rb) return;
    rb.getLinearVelocity(this.tmp);
    const v = this.tmp.clone();
    const bp = this.ball.worldPosition.clone();

    if (Math.abs(v.z) < 0.1) return; // 几乎不朝球门方向飞

    const timeToLine = (this.goalLineZ - bp.z) / v.z; // z 轴朝向球门
    if (timeToLine < 0) return; // 已过线或背离

    this.tAcc += dt;
    if (this.tAcc >= this.reactDelay) {
      const predictX = bp.x + v.x * timeToLine;
      this.targetX = math.clamp(predictX, -this.rangeX, this.rangeX);
      this.tAcc = 0; // 下次再延迟
    }

    // 移动守门员
    const p = this.node.worldPosition;
    const dx = this.targetX - p.x;
    const step = math.clamp(dx, -this.speed * dt, this.speed * dt);
    this.node.setWorldPosition(p.x + step, p.y, p.z);
  }
}