const fs = require('fs');
const crypto = require('crypto');
const crc32 = require('crc-32');
const serverEnv = process.env['SERVER_ENV'];

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

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

function rspData(rsp, data) {
  data['errcode'] = 0;
  data['errmsg'] = '';
  rsp.send(jsonEncode(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 randRange(min, max) {
  if (min >= max) {
    return min;
  }
  return min + Math.random() * max;
}

function jsonEncode(obj) {
  return JSON.stringify(obj);
}

function isArray(val) {
  return Array.isArray(val);
}

function isObject(val) {
  return typeof(obj) == "object";
}

function crc32Str(str) {
  return crc32.str('' + str);
}

function createAccountId(channel, gameId, openId) {
  const accountId = `${channel}_${gameId}_${openId}`;
  return accountId;
}

function extractChannel(accountId) {
  const ss = accountId.split('_');
  return ss[0];
}

function extractGameId(accountId) {
  const ss = accountId.split('_');
  return ss[1];
}

function extractOpenId(accountId) {
  const channel = extractChannel(accountId);
  const gameId = extractGameId(accountId);
  const openId = accountId.substr(accountId.indexOf(`${channel}_${gameId}_`));
  return openId;
}

function createSessionId(accountId, registerTime, secretKey) {
  const nowTime = getUtcTime();
  const rand = randRange(1, 1000000000);
  const sessionId = '' +
        nowTime + '_' +
        registerTime + '_' +
        rand + '_' +
        md5Str('' + accountId + secretKey + registerTime + nowTime);

  return sessionId;
}

function md5Str(data) {
  const hash = crypto.createHash('md5');
  return hash.update(data).digest('hex');
}

function getVal(obj, key, defVal = null) {
  if (!obj){
    return val;
  }
  return key in obj ? obj[key] : defVal;
}

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.randRange = randRange;
exports.jsonEncode = jsonEncode;
exports.isArray = isArray;
exports.isObject = isObject;
exports.crc32Str = crc32Str;
exports.createAccountId = createAccountId;
exports.extractChannel = extractChannel;
exports.extractGameId = extractGameId;
exports.extractOpenId = extractOpenId;
exports.createSessionId = createSessionId;
exports.md5Str = md5Str;
exports.getVal = getVal;