const PAD = 14;
const HP_W = 180;
const HP_H = 16;
const XP_W = 180;
const XP_H = 10;
const LIFE_R = 8;
const LIFE_GAP = 22;

export class HUD {
  constructor(scene, player, xpSystem) {
    this.scene = scene;
    this.player = player;
    this.xpSystem = xpSystem;

    // Fix to camera
    const cam = scene.cameras.main;
    const cx = cam.x;
    const cy = cam.y;

    // --- HP Bar ---
    this._hpLabel = scene.add.text(PAD, PAD, 'HP', { fontSize: '13px', fill: '#ffffff' }).setScrollFactor(0).setDepth(10);
    this._hpBg = scene.add.rectangle(PAD + HP_W / 2, PAD + 8, HP_W, HP_H, 0x333333).setScrollFactor(0).setDepth(10);
    this._hpFill = scene.add.rectangle(PAD + HP_W / 2, PAD + 8, HP_W, HP_H, 0xff3333).setScrollFactor(0).setDepth(10);
    this._hpLabel.setY(PAD - 2);
    this._hpBg.setY(PAD + 20);
    this._hpFill.setY(PAD + 20);

    // --- Life icons ---
    this._lifeIcons = [];
    for (let i = 0; i < 3; i++) {
      const lx = PAD + LIFE_R + i * LIFE_GAP;
      const icon = scene.add.circle(lx, PAD + 48, LIFE_R, 0x00ccff).setScrollFactor(0).setDepth(10);
      this._lifeIcons.push(icon);
    }

    // --- XP Bar ---
    const xpY = PAD + 64;
    this._xpBg = scene.add.rectangle(PAD + XP_W / 2, xpY, XP_W, XP_H, 0x333333).setScrollFactor(0).setDepth(10);
    this._xpFill = scene.add.rectangle(PAD + XP_W / 2, xpY, XP_W, XP_H, 0x44ffaa).setScrollFactor(0).setDepth(10);
    this._xpLabel = scene.add.text(PAD, xpY + 8, 'Level 1', { fontSize: '12px', fill: '#aaffcc' }).setScrollFactor(0).setDepth(10);

    // --- Zone/Wave indicator ---
    this._zoneText = scene.add.text(0, PAD, 'Zone 1 — Wave 1/3', { fontSize: '14px', fill: '#ffffff' })
      .setScrollFactor(0).setDepth(10).setOrigin(1, 0);
    this._zoneText.setX(scene.scale.width - PAD);

    // Listen for wave/zone updates
    scene.events.on('wave-start', ({ zone, wave, totalWaves }) => {
      this._zoneText.setText(`Zone ${zone} — Wave ${wave}/${totalWaves}`);
    });
    scene.events.on('zone-clear', ({ zone }) => {
      this._zoneText.setText(`Zone ${zone} Complete!`);
    });
  }

  update() {
    // HP bar
    const hpRatio = Math.max(0, this.player.hp / this.player.stats.maxHp);
    this._hpFill.width = HP_W * hpRatio;
    this._hpFill.x = PAD + (HP_W * hpRatio) / 2;

    // Lives
    this._lifeIcons.forEach((icon, i) => {
      icon.setAlpha(i < this.player.lives ? 1 : 0.2);
    });

    // XP bar
    const xpRatio = this.xpSystem.progress;
    this._xpFill.width = XP_W * xpRatio;
    this._xpFill.x = PAD + (XP_W * xpRatio) / 2;
    this._xpLabel.setText(`Level ${this.xpSystem.level}`);
  }

  destroy() {
    this.scene.events.off('wave-start');
    this.scene.events.off('zone-clear');
    [this._hpLabel, this._hpBg, this._hpFill, this._xpBg, this._xpFill, this._xpLabel, this._zoneText, ...this._lifeIcons]
      .forEach(o => o?.destroy());
  }
}