// Copy from https://github.com/sw-yx/svelte-actions/blob/main/src/shortcut.ts

export interface ShortcutConfig {
  /**
   * Should the event be active or not.
   * Allows to remove listener when not necessary.
   */
  active?: boolean
  alt?: boolean
  /**
   * The callback to be called when the shortcut is triggered.
   */
  callback?: (node: HTMLElement) => void
  /**
   * The code of the key to listen for.
   * {@link https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/code}
   */
  code: KeyboardEventInit['code']
  control?: boolean
  shift?: boolean
}

const callbackFallback = (node: HTMLElement) => node.click()

/**
 * Simplest possible way to add a keyboard shortcut to an element.
 * It either calls a callback or clicks on the node it was put on.
 *
 * @example
 * ```svelte
 * <div use:shortcut={{ code: 'KeyA', callback: () => alert('A') }}>
 * ```
 */
export default function shortcut(node: HTMLElement, config: ShortcutConfig) {
  const validate = (event: KeyboardEvent) => {
    const { alt = false, code, control = false, shift = false } = config

    return [
      code === event.code,
      alt === event.altKey,
      control == event.ctrlKey || control === event.metaKey,
      shift === event.shiftKey,
    ].every(Boolean)
  }

  const handleKeyboard = (event: KeyboardEvent) => {
    if (!validate(event)) {
      return
    }

    event.preventDefault()
    ;(config.callback || callbackFallback)(node)
  }

  const activate = () => {
    addEventListener('keydown', handleKeyboard)
  }

  const deactivate = () => {
    removeEventListener('keydown', handleKeyboard)
  }

  const init = () => {
    const { active = true } = config
    active ? activate() : deactivate()
  }

  init()

  return {
    update(updatedConfig) {
      config = updatedConfig
      init()
    },
    destroy() {
      deactivate()
    },
  }
}