'use strict';

/**
 * channel.weixin — WeChat login via box-side WeChat SDK.
 *
 * method: login
 *   params : { callId, timeout, emit }
 *   returns: abort function (called on cancel)
 *
 * emit(msg) sends a sys-call reply back to VPS:
 *   action:'event',    event:'qrcode',  data:{ url, expire, index }
 *   action:'progress', event:'scanned', data:{ status:'waiting_confirm' }
 *   action:'finish',   event:'success', data:{ wxid }
 *   action:'finish',   event:'failed',  code, message
 *
 * TODO: integrate with a concrete WeChat SDK (wechaty / itchat / custom binary).
 */

const log = require('../logger');

function login({ callId, timeout = 180, emit }) {
  log.info('weixin', `login requested callId=${callId} timeout=${timeout}`);

  // TODO: start WeChat SDK, get QR code, watch for scan / confirm / expire
  // Example skeleton:
  //
  // const bot = startWechatyBot();
  //
  // bot.on('scan', (url, status) => {
  //   emit({ action: 'event', event: 'qrcode', data: { url, expire: 30, index: ++qrIndex } });
  // });
  // bot.on('login', (user) => {
  //   emit({ action: 'finish', event: 'success', data: { wxid: user.id } });
  // });
  // bot.on('error', (err) => {
  //   emit({ action: 'finish', event: 'failed', code: 1001, message: err.message });
  // });
  // bot.start();
  //
  // return () => bot.stop();   // ← abort function

  // Temporary stub: immediately report not implemented
  emit({ action: 'finish', event: 'failed', code: 501, message: 'weixin SDK not implemented' });

  return () => {
    log.info('weixin', `login cancelled callId=${callId}`);
  };
}

module.exports = { login };