import axios from 'axios';

import { Util } from './sms.util';

type WeChatSettings = {
  wechatAppId: string;
  wechatSecret: string;
  wechatRedirectUrl: string;
  wechatLoginSuccessRedirectUrl: string;
  wechatAPIRedirectUrl: string;
  wechatAPIUserinfoUrl: string;
  wechatAPITokenUrl: string;
  wechatQrCodeUrl: string;
};

export class WeChatLoginUtil {
  private settings: WeChatSettings;

  private static instance: WeChatLoginUtil;

  constructor(settings: WeChatSettings) {
    this.settings = settings;
  }

  static getInstance() {
    if (!WeChatLoginUtil.instance) {
      WeChatLoginUtil.instance = new WeChatLoginUtil({
        wechatAppId: `${process.env.WECHAT_APPID}`,
        wechatSecret: `${process.env.WECHAT_APPSECRET}`,
        wechatRedirectUrl: `${process.env.WECHAT_REDIRECT_URL}`,
        wechatLoginSuccessRedirectUrl: `${process.env.WECHAT_LOGIN_SECCESS_REDIRECT_URL}`,
        wechatAPIRedirectUrl: `${process.env.WECHAT_API_REDIRECT_URL}`,
        wechatAPIUserinfoUrl: `${process.env.WECHAT_API_USERINFO_URL}`,
        wechatAPITokenUrl: `${process.env.WECHAT_API_TOKEN_URL}`,
        wechatQrCodeUrl: `${process.env.WECHAT_QRCODE_URL}`
      });
    }
    return WeChatLoginUtil.instance;
  }

  async getWeChatSDKConfig(): Promise<{
    appid: string;
    state: string;
    scope: string;
  }> {
    return {
      appid: this.settings.wechatAppId,
      state: Util.generateRandomNumber(30),
      scope: 'snsapi_login'
    };
  }

  async getWeChatQrCodeUrl(): Promise<{
    url: string;
    state: string;
  }> {
    const redirectUrl = encodeURIComponent(this.settings.wechatAPIRedirectUrl);
    const wechatQRCodeUrl = this.settings.wechatQrCodeUrl;
    const state = Util.generateRandomNumber(30);
    const qrCodeUrl = `${wechatQRCodeUrl}appid=${this.settings.wechatAppId}&redirect_uri=${redirectUrl}&response_type=code&scope=snsapi_login&state=${state}#wechat_redirect`;
    return {
      url: qrCodeUrl,
      state
    };
  }

  async getAccessToken(
    code: string
  ): Promise<{
    access_token: string;
    expires_in: number;
    refresh_token: string;
    openid: string;
    scope: string;
    unionid: string;
  }> {
    const wechatTokenUrl = this.settings.wechatAPITokenUrl;
    const tokenUrl = `${wechatTokenUrl}appid=${this.settings.wechatAppId}&secret=${this.settings.wechatSecret}&code=${code}&grant_type=authorization_code`;
    const response = await axios.get(tokenUrl);
    return response.data;
  }

  async getUserInfoByOpenId(
    accessToken: string,
    openID: string
  ): Promise<{
    openid: string;
    sex: number;
    nickname: string;
    language: string;
    city: string;
    province: string;
    country: string;
    headimgurl: string;
    unionid: string;
    privilege: any;
  }> {
    const wechatUserInfoUrl = `${process.env.WECHAT_API_USERINFO_URL}`;
    const userInfoUrl = `${wechatUserInfoUrl}access_token=${accessToken}&openid=${openID}&lang=zh_CN`;
    const response = await axios.get(userInfoUrl);
    return response.data;
  }
}