type KeyboardCallback = (e: KeyboardEvent) => void

export class KeyboardManager {
  private shortcuts: Map<string, KeyboardCallback> = new Map()
  private pressedKeys: Set<string> = new Set()
  private enabled: boolean = false

  constructor() {
    this.handleKeyDown = this.handleKeyDown.bind(this)
    this.handleKeyUp = this.handleKeyUp.bind(this)
  }

  /**
   * 启用快捷键监听
   */
  enable(): void {
    if (!this.enabled) {
      window.addEventListener('keydown', this.handleKeyDown)
      window.addEventListener('keyup', this.handleKeyUp)
      this.enabled = true
    }
  }

  /**
   * 禁用快捷键监听
   */
  disable(): void {
    if (this.enabled) {
      window.removeEventListener('keydown', this.handleKeyDown)
      window.removeEventListener('keyup', this.handleKeyUp)
      this.enabled = false
      this.pressedKeys.clear()
    }
  }

  /**
   * 绑定快捷键
   */
  bind(shortcut: string, callback: KeyboardCallback): void {
    this.shortcuts.set(this.normalizeShortcut(shortcut), callback)
  }

  /**
   * 解绑快捷键
   */
  unbind(shortcut: string): void {
    this.shortcuts.delete(this.normalizeShortcut(shortcut))
  }

  /**
   * 清除所有快捷键绑定
   */
  clear(): void {
    this.shortcuts.clear()
    this.pressedKeys.clear()
  }

  private handleKeyDown(e: KeyboardEvent): void {
    // 忽略在输入框中的按键
    if (this.shouldIgnoreInput(e)) {
      return
    }

    const key = this.normalizeKey(e.key.toLowerCase())
    this.pressedKeys.add(key)

    const currentShortcut = Array.from(this.pressedKeys).sort().join('+')
    const callback = this.shortcuts.get(currentShortcut)

    if (callback) {
      e.preventDefault()
      e.stopPropagation()
      callback(e)
    }
  }

  private handleKeyUp(e: KeyboardEvent): void {
    const key = this.normalizeKey(e.key.toLowerCase())
    this.pressedKeys.delete(key)
  }

  private normalizeKey(key: string): string {
    const keyMap: Record<string, string> = {
      'control': 'ctrl',
      'command': 'cmd',
      'meta': 'cmd',
      'escape': 'esc',
      ' ': 'space',
      'arrowup': 'up',
      'arrowdown': 'down',
      'arrowleft': 'left',
      'arrowright': 'right',
    }
    return keyMap[key] || key
  }

  private normalizeShortcut(shortcut: string): string {
    return shortcut
      .toLowerCase()
      .split('+')
      .map(key => this.normalizeKey(key.trim()))
      .sort()
      .join('+')
  }

  private shouldIgnoreInput(e: KeyboardEvent): boolean {
    const element = e.target as HTMLElement
    return element.tagName === 'INPUT' ||
           element.tagName === 'TEXTAREA' ||
           element.tagName === 'SELECT' ||
           element.isContentEditable
  }
}

// 导出单例实例
export const keyboardManager = new KeyboardManager()