import path from 'path';
import fs from 'fs';
import Cloud from 'alipay-serverless-server-sdk';
import { isPlainObject } from 'lodash';
import MPServerless from '@alicloud/mpserverless-node-sdk';
import getHttpClient from './utils/httpClient';
import { getServerSecret, guid, requireLocalFunction } from './utils/index';

export interface InvokeLocalFunctionOptions {
  /**
   * 小程序appId TS MODIFY
   */
  appId?: string;
  /**
   * 阿里云serverSecret
   */
  serverSecret?: string;
  /**
   * 空间id
   */
  spaceId: string;
  /**
   * 函数根目录
   */
  project: string;
  /**
   * 函数名称
   */
  name: string;
  /**
   * 函数参数
   */
  functionArgs?: object;
  /**
   * 只有在小程序端发请求运行云函数才能获取
   */
  token?: string;
  userAgent?: string;
  clientIp?: string;
  mpSource?: string;
}

/**
 * 重写云函数调用云函数
 */
function overrideFunctionInvokeFunction(originFn, options) {
  return async function (functionTarget, functionArgs) {
    const entry = path.join(options.project, functionTarget, 'index.js');

    const isExist = fs.existsSync(entry);

    // 本地存在另一个云函数
    if (isExist) {
      const result = await invokeLocalFunction({
        ...options,
        name: functionTarget,
        functionArgs,
        mpSource: 'function',
      });

      return {
        requestId: options.requestId,
        result,
      };
    }

    // 调用云端的
    return originFn(functionTarget, functionArgs);
  };
}

/**
 * 调用云端函数
 */
async function invokeLocalFunction(options: InvokeLocalFunctionOptions) {
  const { appId, spaceId, project, name, functionArgs, serverSecret } = options;
  const [serverSecretResult, userFn] = await Promise.all([
    // TS MODIFY
    serverSecret ? serverSecret : getServerSecret(appId!, spaceId),
    requireLocalFunction(project, name),
  ]);
  const requestId = guid();
  const httpClient = getHttpClient();
  const mpserverless = new MPServerless({
    // 必填参数
    spaceId,
    endpoint: 'https://api.bspapp.com',
    serverSecret: serverSecretResult,
    httpClient,
    logger: console,

    // 选填参数
    token: options.token,
    requestId,
    // userId: reqMeta.userId,
    //requestId: '12345678',
  });

  mpserverless.function.invoke = overrideFunctionInvokeFunction(
    mpserverless.function.invoke.bind(mpserverless.function),
    {
      requestId,
      ...options,
    }
  );

  const env = {
    MP_SPACE_ID: spaceId,
    MP_SOURCE: options.mpSource || 'function',
    MP_USER_AGENT: options.userAgent,
    MP_CLIENT_IP: options.clientIp,
  };

  const cloud = new Cloud(mpserverless as any);

  const functionResult = await userFn({
    requestId,
    args: isPlainObject(functionArgs) ? functionArgs : {},
    httpclient: httpClient,
    env,
    logger: console,
    basement: mpserverless, // for backward compatibility only
    mpserverless: mpserverless,
    cloud: cloud,
  });

  return functionResult;
}

export default invokeLocalFunction;