import Taro from '@tarojs/taro';

export type WecomCsSessionContext = {
  orderId?: string;
  orderNo?: string;
  from?: string;
};

type OpenCsChatOption = {
  extInfo: { url: string };
  corpId: string;
  showMessageCard?: boolean;
  sendMessageTitle?: string;
  sendMessagePath?: string;
};

type OpenCsChatFn = (option: OpenCsChatOption) => Promise<unknown>;

function getTaroOpenCsChat(): OpenCsChatFn | null {
  const api = (Taro as unknown as { openCustomerServiceChat?: OpenCsChatFn }).openCustomerServiceChat;
  return typeof api === 'function' ? api : null;
}

function getWxOpenCsChat(): ((option: OpenCsChatOption & {
  success?: () => void;
  fail?: (err: { errMsg?: string }) => void;
}) => void) | null {
  const wxApi = (
    globalThis as {
      wx?: {
        openCustomerServiceChat?: (option: OpenCsChatOption & {
          success?: () => void;
          fail?: (err: { errMsg?: string }) => void;
        }) => void;
      };
    }
  ).wx?.openCustomerServiceChat;
  return typeof wxApi === 'function' ? wxApi : null;
}

/** 小程序调起企业微信「微信客服」会话 */
export async function openWecomCustomerServiceChat(params: {
  url: string;
  corpId: string;
  session?: WecomCsSessionContext;
}): Promise<void> {
  const url = params.url.trim();
  const corpId = params.corpId.trim();
  if (!url || !corpId) {
    throw new Error('企微客服未配置');
  }

  const option: OpenCsChatOption = {
    extInfo: { url },
    corpId,
  };
  if (params.session?.orderNo || params.session?.orderId) {
    option.showMessageCard = true;
    option.sendMessageTitle = params.session.orderNo
      ? `订单 ${params.session.orderNo}`
      : '订单咨询';
    if (params.session.orderId) {
      option.sendMessagePath = `pages/order-detail/index?id=${params.session.orderId}`;
    }
  }

  const taroApi = getTaroOpenCsChat();
  if (taroApi) {
    await taroApi(option);
    return;
  }

  const wxApi = getWxOpenCsChat();
  if (!wxApi) {
    throw new Error('当前微信版本不支持企业微信客服');
  }

  await new Promise<void>((resolve, reject) => {
    wxApi({
      ...option,
      success: () => resolve(),
      fail: (err) => reject(new Error(err?.errMsg || '无法打开企业微信客服')),
    });
  });
}