export function isShiftKey(event: Pick<KeyboardEvent, "key" | "code">) {
  return (
    event.key === "Shift" ||
    event.code === "ShiftLeft" ||
    event.code === "ShiftRight"
  );
}

export function getAltDigitShortcut(
  event: Pick<KeyboardEvent, "key" | "code">,
) {
  const match = /^Digit([1-9])$/.exec(event.code);
  return match && event.key === match[1] ? Number(match[1]) : null;
}

export function dispatchCtrlW(target: EventTarget | null) {
  if (!target) return false;

  const event = new KeyboardEvent("keydown", {
    key: "w",
    code: "KeyW",
    ctrlKey: true,
    bubbles: true,
    cancelable: true,
  });
  return !target.dispatchEvent(event);
}

/** Match two consecutive Shift presses, never a typing or IME sequence. */
export function createCommandPaletteShortcutMatcher() {
  let lastShift: number | null = null;
  const reset = () => {
    lastShift = null;
  };
  const matches = (event: KeyboardEvent, now = Date.now()): boolean => {
    if (
      event.defaultPrevented ||
      event.isComposing ||
      event.keyCode === 229 ||
      event.repeat ||
      event.altKey
    ) {
      reset();
      return false;
    }
    if (isShiftKey(event) && !event.ctrlKey && !event.metaKey) {
      const matched = lastShift !== null && now - lastShift < 300;
      lastShift = matched ? null : now;
      return matched;
    }
    reset();
    return (
      (event.ctrlKey || event.metaKey) &&
      !event.shiftKey &&
      event.code === "KeyK"
    );
  };
  return { matches, reset };
}