import { WEAPONS, WEAPON_CONFIG } from '../utils/constants.js'

/**
 * HUD界面类
 * 显示游戏中的血量、武器、弹药等信息
 */
export class HUD {
  constructor(container) {
    this.container = container
    this.container.className = 'hud-container'
    this.container.innerHTML = ''
    this.visible = false
    this._build()
  }

  /**
   * 构建HUD界面元素
   */
  _build() {
    // 血量条
    this.healthBar = document.createElement('div')
    this.healthBar.className = 'hud-health-bar'
    this.healthBar.innerHTML = '<div class="hud-health-fill"></div><span class="hud-health-text">100</span>'
    this.container.appendChild(this.healthBar)

    // 武器面板
    this.weaponPanel = document.createElement('div')
    this.weaponPanel.className = 'hud-weapon-panel'

    // 武器列表
    const weaponList = [WEAPONS.PISTOL, WEAPONS.MACHINE_GUN, WEAPONS.SHOTGUN, WEAPONS.GRENADE]
    this.weaponSlots = []
    for (let i = 0; i < weaponList.length; i++) {
      const slot = document.createElement('div')
      slot.className = 'hud-weapon-slot'
      slot.dataset.index = i

      // 按键提示（1-4）
      const keyLabel = document.createElement('span')
      keyLabel.className = 'hud-weapon-key'
      keyLabel.textContent = (i + 1).toString()

      // 武器名称
      const weaponName = document.createElement('span')
      weaponName.className = 'hud-weapon-name'
      weaponName.textContent = WEAPON_CONFIG[weaponList[i]].name

      // 弹药数量
      const ammoText = document.createElement('span')
      ammoText.className = 'hud-weapon-ammo'

      slot.appendChild(keyLabel)
      slot.appendChild(weaponName)
      slot.appendChild(ammoText)
      this.weaponSlots.push({ slot, ammoText })
      this.weaponPanel.appendChild(slot)
    }

    this.container.appendChild(this.weaponPanel)

    // 手雷蓄力条（默认隐藏）
    this.grenadeChargeBar = document.createElement('div')
    this.grenadeChargeBar.className = 'hud-grenade-charge'
    this.grenadeChargeBar.innerHTML = '<div class="hud-grenade-charge-fill"></div>'
    this.grenadeChargeBar.style.display = 'none'
    this.container.appendChild(this.grenadeChargeBar)

    // 信息面板（波次、分数、时间）
    this.infoPanel = document.createElement('div')
    this.infoPanel.className = 'hud-info-panel'

    this.waveText = document.createElement('span')
    this.waveText.className = 'hud-info-item'
    this.waveText.textContent = 'Wave: 0'

    this.scoreText = document.createElement('span')
    this.scoreText.className = 'hud-info-item'
    this.scoreText.textContent = 'Score: 0'

    this.timeText = document.createElement('span')
    this.timeText.className = 'hud-info-item'
    this.timeText.textContent = 'Time: 0:00'

    this.infoPanel.appendChild(this.waveText)
    this.infoPanel.appendChild(this.scoreText)
    this.infoPanel.appendChild(this.timeText)
    this.container.appendChild(this.infoPanel)

    // 准星
    this.crosshair = document.createElement('div')
    this.crosshair.className = 'hud-crosshair'
    this.container.appendChild(this.crosshair)

    // 击杀信息（最近5条）
    this.killFeed = document.createElement('div')
    this.killFeed.className = 'hud-kill-feed'
    this.container.appendChild(this.killFeed)
  }

  /**
   * 显示HUD
   */
  show() {
    this.visible = true
    this.container.style.display = 'flex'
  }

  /**
   * 隐藏HUD
   */
  hide() {
    this.visible = false
    this.container.style.display = 'none'
  }

  /**
   * 更新血量显示
   * @param {number} health 血量值 0-100
   */
  updateHealth(health) {
    const fill = this.healthBar.querySelector('.hud-health-fill')
    const text = this.healthBar.querySelector('.hud-health-text')
    const pct = Math.max(0, Math.min(100, health))
    fill.style.width = pct + '%'
    // 颜色根据血量变化：绿色>60，橙色>30，红色<=30
    if (pct > 60) fill.style.backgroundColor = '#44ff44'
    else if (pct > 30) fill.style.backgroundColor = '#ffaa00'
    else fill.style.backgroundColor = '#ff4444'
    text.textContent = Math.ceil(pct)
  }

  /**
   * 更新武器显示
   * @param {number} currentIndex 当前武器索引
   * @param {Object} ammo 各武器弹药数
   */
  updateWeapons(currentIndex, ammo) {
    const weaponList = [WEAPONS.PISTOL, WEAPONS.MACHINE_GUN, WEAPONS.SHOTGUN, WEAPONS.GRENADE]
    for (let i = 0; i < this.weaponSlots.length; i++) {
      const slot = this.weaponSlots[i]
      // 高亮当前武器
      slot.slot.classList.toggle('hud-weapon-active', i === currentIndex)
      const weaponKey = weaponList[i]
      const currentAmmo = ammo[weaponKey]
      if (currentAmmo === Infinity) {
        slot.ammoText.textContent = '∞'
      } else {
        slot.ammoText.textContent = currentAmmo + '/' + WEAPON_CONFIG[weaponKey].maxAmmo
      }
    }
  }

  /**
   * 更新手雷蓄力显示
   * @param {number} percent 蓄力百分比 0-1
   */
  updateGrenadeCharge(percent) {
    if (percent > 0) {
      this.grenadeChargeBar.style.display = 'block'
      const fill = this.grenadeChargeBar.querySelector('.hud-grenade-charge-fill')
      fill.style.width = (percent * 100) + '%'
    } else {
      this.grenadeChargeBar.style.display = 'none'
    }
  }

  /**
   * 更新游戏信息
   * @param {number} wave 当前波次
   * @param {number} score 分数
   * @param {number} time 游戏时间（秒）
   */
  updateInfo(wave, score, time) {
    this.waveText.textContent = 'Wave: ' + wave
    this.scoreText.textContent = 'Score: ' + score
    const mins = Math.floor(time / 60)
    const secs = Math.floor(time % 60)
    this.timeText.textContent = `Time: ${mins}:${secs.toString().padStart(2, '0')}`
  }

  /**
   * 添加击杀信息条目
   * @param {string} message 击杀信息文本
   */
  addKillFeed(message) {
    const entry = document.createElement('div')
    entry.className = 'hud-kill-entry'
    entry.textContent = message
    this.killFeed.appendChild(entry)
    // 4秒后自动移除
    setTimeout(() => {
      if (entry.parentNode) entry.parentNode.removeChild(entry)
    }, 4000)
    // 最多保留5条
    while (this.killFeed.children.length > 5) {
      this.killFeed.removeChild(this.killFeed.firstChild)
    }
  }
}