const fs = require('fs');
const events = require('events');

const serverEnv = process.env['SERVER_ENV'];

const event = new events.EventEmitter();

function rspErr(rsp, errCode, errMsg) {
  rsp.send(JSON.stringify({
    'errcode': errCode,
    'errmsg': errMsg
  }));
}

function rspOk(rsp) {
  rsp.send(JSON.stringify({
    'errcode': 0,
    'errmsg': ''
  }));
}

function rspData(rsp, data) {
  data['errcode'] = 0;
  data['errmsg'] = '';
  rsp.send(JSON.stringify(data));
}

function readJsonFromFile(url) {
  const jsondata = fs.readFileSync(url, "utf8");
  const json = JSON.parse(jsondata);
  return json;
}

async function sleep(timeout) {
  return new Promise(function (resolve, reject) {
    setTimeout(function () {
      resolve();
    }, timeout);
  });
}

function emptyReplace(val, newVal) {
  return !val ? newVal : val;
}

function throwError(msg) {
  console.log(msg);
  throw msg;
}

function isOnlineEnv() {
  return !serverEnv;
}

function getUtcTime() {
  return Math.floor((new Date()).getTime() / 1000);
}

function formatDate(date) {
  const year = date.getFullYear();
  const month = date.getMonth() + 1;//月份是从0开始的
  const day = date.getDate();
  const hour = date.getHours();
  const min = date.getMinutes();
  const sec = date.getSeconds();
  return year + '-' +
    (month < 10 ? '0' + month : month) + '-' +
    (day < 10 ? '0' + day : day) + ' ' +
    (hour < 10 ? '0' + hour : hour) + ':' +
    (min < 10 ? '0' + min : min) + ':' +
    (sec < 10 ? '0' + sec : sec);
}

function pad(num, n) {
  let result = num.toString();
  let len = result.length;
  while(len < n) {
    result = '0' + result;
    len++;
  }
  return result;
}

function registerEventHandler(eventName, handler) {
  event.on(eventName, handler);
}

function emitEvent(eventName, ...args) {
  event.emit(eventName, ...args);
}

exports.rspErr = rspErr;
exports.rspOk = rspOk;
exports.rspData = rspData;
exports.readJsonFromFile = readJsonFromFile;
exports.sleep = sleep;
exports.emptyReplace = emptyReplace;
exports.throwError = throwError;
exports.isOnlineEnv = isOnlineEnv;
exports.getUtcTime = getUtcTime;
exports.formatDate = formatDate;
exports.pad = pad;
exports.registerEventHandler = registerEventHandler;
exports.emitEvent = emitEvent;