export type KeyboardModifiers = {
  alt: boolean
  ctrl: boolean
  meta: boolean
  mod: boolean
  shift: boolean
}

export type Hotkey = KeyboardModifiers & {
  key?: string
}

type CheckHotkeyMatch = (event: KeyboardEvent) => boolean

export function parseHotkey(hotkey: string): Hotkey {
  const cleanedKey = hotkey.replace('cmd', 'meta')

  const keys = cleanedKey
    .toLowerCase()
    .split('+')
    .map((part) => part.trim())

  const modifiers: KeyboardModifiers = {
    alt: keys.includes('alt'),
    ctrl: keys.includes('ctrl'),
    meta: keys.includes('meta'),
    mod: keys.includes('mod'),
    shift: keys.includes('shift'),
  }

  const reservedKeys = ['alt', 'ctrl', 'meta', 'shift', 'mod']

  const freeKey = keys.find((key) => !reservedKeys.includes(key))

  return {
    ...modifiers,
    key: freeKey,
  }
}

function isExactHotkey(hotkey: Hotkey, event: KeyboardEvent): boolean {
  const { alt, ctrl, meta, mod, shift, key } = hotkey
  const { altKey, ctrlKey, metaKey, shiftKey, key: pressedKey } = event

  if (alt !== altKey) {
    return false
  }

  if (mod) {
    if (!ctrlKey && !metaKey) {
      return false
    }
  } else {
    if (ctrl !== ctrlKey) {
      return false
    }
    if (meta !== metaKey) {
      return false
    }
  }
  if (shift !== shiftKey) {
    return false
  }

  if (
    key &&
    (pressedKey.toLowerCase() === key.toLowerCase() ||
      event.code.replace('Key', '').toLowerCase() === key.toLowerCase())
  ) {
    return true
  }

  return false
}

export function getHotkeyMatcher(hotkey: string): CheckHotkeyMatch {
  return (event) => isExactHotkey(parseHotkey(hotkey), event)
}

type HotkeyItem = [string, (event: React.KeyboardEvent<HTMLElement>) => void]

export function getHotkeyHandler(hotkeys: HotkeyItem[]) {
  return (event: React.KeyboardEvent<HTMLElement>) => {
    hotkeys.forEach(([hotkey, handler]) => {
      if (getHotkeyMatcher(hotkey)(event.nativeEvent)) {
        event.preventDefault()
        handler(event)
      }
    })
  }
}