export function createTemplateSelectorLockController(templateSelect) {
  var locked = false;
  var armed = false;
  var lockInput = null;

  function clearLockInput() {
    if (lockInput && lockInput.parentNode) {
      lockInput.parentNode.removeChild(lockInput);
    }
    lockInput = null;
  }

  function reset() {
    locked = false;
    armed = false;
    clearLockInput();
    if (!templateSelect) {
      return;
    }

    templateSelect.disabled = false;
    templateSelect.removeAttribute('aria-disabled');
    templateSelect.removeAttribute('title');
    templateSelect.classList.remove('is-locked');
  }

  function arm() {
    armed = true;
  }

  function syncLockedValue() {
    if (lockInput) {
      lockInput.value = templateSelect.value;
    }
  }

  function lock() {
    if (!templateSelect || locked) {
      return;
    }

    locked = true;
    lockInput = lockInput || document.createElement('input');
    lockInput.type = 'hidden';
    lockInput.name = templateSelect.name;
    lockInput.value = templateSelect.value;
    templateSelect.insertAdjacentElement('afterend', lockInput);
    templateSelect.disabled = true;
    templateSelect.setAttribute('aria-disabled', 'true');
    templateSelect.setAttribute('title', 'Template is locked after you edit its content.');
    templateSelect.classList.add('is-locked');
  }

  function markEdited() {
    if (!armed) {
      return false;
    }

    lock();
    syncLockedValue();
    return locked;
  }

  function sync() {
    if (!templateSelect) {
      return false;
    }

    if (locked) {
      syncLockedValue();
      return true;
    }

    return false;
  }

  return {
    reset: reset,
    arm: arm,
    markEdited: markEdited,
    sync: sync,
    isLocked: function () {
      return locked;
    }
  };
}