const express  = require('express');
const router   = express.Router();
const User     = require('../db/users');
const util     = require('../lib/util');
const jwt      = require('jsonwebtoken');
const {tokenSecret, refreshSecret, tokenLife, refreshTokenLife} = require("../config/tokenConfig.js")

const tokenList = {}

router.post("/login",(req, res, next) => {
  let isValid = true;
    const validationError = {
      name:'ValidationError',
      errors:{}
    };

    if(!req.body.username){
      isValid = false;
      validationError.errors.username = {message:'Username is required!'};
    }
    if(!req.body.password){
      isValid = false;
      validationError.errors.password = {message:'Password is required!'};
    }
    if(!isValid) return res.json(util.successFalse(validationError));
    else next();
  },

  function(req,res,next){
    User.findOne({username:req.body.username})
    .select({password:1,username:1,name:1,email:1})
    .exec(async function(err,user){
      if(err) return res.json(util.successFalse(err));
      else if(!user||!user.authenticate(req.body.password))
         return res.json(util.successFalse(null,'Username or Password is invalid'));
      else {
        const payload = {
          _id : user._id,
          username: user.username
        };
        const options = {expiresIn : tokenLife};
        const refreshOptions = {expiresIn : refreshTokenLife}
        try  {
          const token = await jwt.sign(payload, tokenSecret, options)
          const refreshToken = await jwt.sign(payload, refreshSecret, refreshOptions)
          const response = {token: token, username: req.body.username, refreshToken: refreshToken, expiresIn: Date.now() + tokenLife*1000}
          tokenList[refreshToken] = response
          res.json(util.successTrue(response))
        } catch(err) {
          return res.json(util.successFalse(err));
        }
      }
    });
})

// refresh request when access token expired
router.post("/refresh", (req, res, next) => {

   /**
   * @const postData = {
   *  {String} token,
   *  {String} refreshToken,
   *  {Number} expiresIn,
   *  {String} username,
   * }
   */
    const postData = req.body;
    if((postData.refreshToken) && (postData.refreshToken in tokenList)) {
      User.findOne({username:postData.username})
    .select({password:1,username:1,name:1,email:1})
    .exec(async function(err,user){
      if(err) return res.json(util.successFalse(err));
        const payload = {
          _id : user._id,
          username: user.username
        };
        const options = {expiresIn : tokenLife};
        try  {
          const token = await jwt.sign(payload, tokenSecret, options)
          const response = {token: token, username: req.body.username, refreshToken: postData.refreshToken, expiresIn: Date.now() + tokenLife*1000}
          tokenList[postData.refreshToken].token = response.token
          tokenList[postData.refreshToken].expiresIn = response.expiresIn
          res.json(util.successTrue(response))
        } catch(err) {
          console.log(err)
          return res.json(util.successFalse(err));
        }
    });
    }
})


module.exports = router;