import * as THREE from "three";
import {
  computeExplodedWorldOffset,
  EXPLOSION_PROGRESS_MAX,
} from "@/lib/3d/explosion-math";

describe("engine explosion", () => {
  it("progress 超过 1 时应继续增大爆炸幅度（用于更大最大值）", () => {
    const v = new THREE.Vector3(10, -20, 30);

    const offset1 = computeExplodedWorldOffset(v, 1, 0.2);
    const offset2 = computeExplodedWorldOffset(v, 2, 0.2);
    const offset3 = computeExplodedWorldOffset(v, 3, 0.2);

    expect(offset2.x).toBeCloseTo(offset1.x * 2, 5);
    expect(offset2.y).toBeCloseTo(offset1.y * 2, 5);
    expect(offset2.z).toBeCloseTo(offset1.z * 2, 5);

    // 超过最大值应被裁剪到 EXPLOSION_PROGRESS_MAX
    const offsetMax = computeExplodedWorldOffset(v, EXPLOSION_PROGRESS_MAX, 0.2);
    expect(offset3.x).toBeCloseTo(offsetMax.x, 5);
    expect(offset3.y).toBeCloseTo(offsetMax.y, 5);
    expect(offset3.z).toBeCloseTo(offsetMax.z, 5);
  });

  it("爆炸位移应按相对中心距离同比放大，不能强制整体上抬", () => {
    const lowerWheel = new THREE.Vector3(0, -100, 0);
    const lowerBoard = new THREE.Vector3(0, -40, 0);

    const wheelOffset = computeExplodedWorldOffset(lowerWheel, 1, 0.2);
    const boardOffset = computeExplodedWorldOffset(lowerBoard, 1, 0.2);

    expect(wheelOffset.y).toBeLessThan(0);
    expect(boardOffset.y).toBeLessThan(0);
    expect(Math.abs(wheelOffset.y)).toBeGreaterThan(Math.abs(boardOffset.y));
  });

  it("相对中心更远的底部部件，爆炸后仍应保持在更下方", () => {
    const wheelOriginal = new THREE.Vector3(0, -100, 0);
    const boardOriginal = new THREE.Vector3(0, -40, 0);

    const wheelExploded = wheelOriginal
      .clone()
      .add(computeExplodedWorldOffset(wheelOriginal, 1, 0.2));
    const boardExploded = boardOriginal
      .clone()
      .add(computeExplodedWorldOffset(boardOriginal, 1, 0.2));

    expect(wheelExploded.y).toBeLessThan(boardExploded.y);
  });
});