import { useEffect, useMemo, type RefObject } from 'react'

function isTypingTarget(el: EventTarget | null): boolean {
  if (!el || !(el instanceof HTMLElement)) return false
  const tag = el.tagName
  if (tag === 'INPUT' || tag === 'TEXTAREA' || tag === 'SELECT') return true
  if (el.isContentEditable) return true
  return false
}

const SLASH_KEYS = ['Slash', 'NumpadDivide'] as const

/**
 * Focus the input when one of the given keys is pressed; prevents the key from being typed.
 * Skips when focus is in another input/textarea/select/contenteditable (same idea as useCloseOnWClick).
 */
export function useFocusInputShortcut(
  inputRef: RefObject<HTMLInputElement | null>,
  keyCodes: readonly string[],
  enabled = true,
) {
  const codesSet = useMemo(() => new Set(keyCodes), [keyCodes])

  useEffect(() => {
    if (!enabled) return

    const onKeyDown = (e: KeyboardEvent) => {
      if (!codesSet.has(e.code)) return
      if (e.repeat) return
      if (e.ctrlKey || e.metaKey || e.altKey) return
      if (isTypingTarget(e.target)) return
      const el = inputRef.current
      if (!el || el.disabled) return
      e.preventDefault()
      el.focus()
    }

    window.addEventListener('keydown', onKeyDown)
    return () => window.removeEventListener('keydown', onKeyDown)
  }, [enabled, inputRef, codesSet])
}

/** `/` or numpad `/` — focus JEI search (when JEI is mounted). */
export function useSlashFocusInput(inputRef: RefObject<HTMLInputElement | null>, enabled = true) {
  useFocusInputShortcut(inputRef, SLASH_KEYS, enabled)
}