import * as Phaser from "phaser";

/**
 * 生命值（爱心）显示组件。
 * 使用参数化心形曲线渲染一行爱心图标，表示剩余生命值。
 */
export class HeartDisplay {
  private heartGraphics: Phaser.GameObjects.Graphics[] = [];
  private heartStates: boolean[] = [];
  private heartDrawSize: number;

  constructor(
    scene: Phaser.Scene,
    parent: Phaser.GameObjects.Container,
    options: {
      startX: number;
      y: number;
      spacing: number;
      drawSize: number;
      maxLives: number;
      initialLives: number;
    },
  ) {
    this.heartDrawSize = options.drawSize;

    for (let i = 0; i < options.maxLives; i++) {
      const isAlive = i < options.initialLives;
      const g = scene.add.graphics();
      g.setPosition(options.startX + i * options.spacing, options.y);
      this.heartGraphics.push(g);
      this.heartStates.push(isAlive);
      parent.add(g);
      this.drawHeartIcon(g, this.heartDrawSize, isAlive);
    }
  }

  /**
   * 设置当前生命值，更新爱心图标的显示状态。
   * @param lives 当前生命值
   */
  public setLives(lives: number): void {
    const clamped = Math.max(0, Math.min(lives, this.heartGraphics.length));
    this.heartGraphics.forEach((g, index) => {
      const isAlive = index < clamped;
      if (this.heartStates[index] !== isAlive) {
        this.heartStates[index] = isAlive;
        this.drawHeartIcon(g, this.heartDrawSize, isAlive);
      }
    });
  }

  /**
   * 使用参数化心形曲线绘制爱心图标（纯前端绘制）。
   * @param g 图形对象
   * @param size 爱心大小
   * @param alive 是否存活（存活为红色，否则为灰色）
   */
  private drawHeartIcon(
    g: Phaser.GameObjects.Graphics,
    size: number,
    alive: boolean,
  ): void {
    g.clear();

    const fillColor = alive ? 0xeb5757 : 0xcccccc;
    const fillAlpha = alive ? 1 : 0.4;

    // 使用参数化心形曲线构建爱心路径
    const points: { x: number; y: number }[] = [];
    const numPoints = 50;
    for (let i = 0; i <= numPoints; i++) {
      const t = (i / numPoints) * Math.PI * 2;
      const px = (size * 16 * Math.pow(Math.sin(t), 3)) / 16;
      const py =
        (-size *
          (13 * Math.cos(t) -
            5 * Math.cos(2 * t) -
            2 * Math.cos(3 * t) -
            Math.cos(4 * t))) /
        16;
      points.push({ x: px, y: py });
    }

    if (points.length === 0) return;

    // 填充爱心主体
    g.fillStyle(fillColor, fillAlpha);
    g.beginPath();
    g.moveTo(points[0].x, points[0].y);
    for (let i = 1; i < points.length; i++) {
      g.lineTo(points[i].x, points[i].y);
    }
    g.closePath();
    g.fillPath();
  }
}