"use strict";

// modules
const express = require('express');
const jwt = require('jsonwebtoken');
const bcrypt = require('bcryptjs');
const Q = require('q');
const _ = require('lodash');
const logger = require('debug')('cc:authenticate');

const apiAuthenticationMiddleware = require('../middleware/auth-middleware');
const checkAdmin = require('../middleware/permission-check').checkAdmin;

// HTTP status codes by name
const codes = require('./http-codes');

const config = require('../config/config');

const routerHandling = require('../middleware/router-handling');

const AppUserModel = require('../models/app-user');

const authenticate = express.Router();

// routes **********************
authenticate.route('/')
  .post((req, res, next) => {
    authCheck(req.body.username, req.body.password)
      .then((user) => {
        if (user) {
          // authentication successful
          res.send(user);
        } else {
          // authentication failed
          res.status(codes.unauthorized).send('Username or password is incorrect');
        }
      })
      .catch((err) => {
        res.status(codes.wrongrequest).send(err);
      });
  })

  .all(
    routerHandling.httpMethodNotAllowed
  );

let authCheck = (username, password) => {
  const deferred = Q.defer();

  AppUserModel.findOne({username: username}, (err, user) => {
    if (err) deferred.reject(err.name + ': ' + err.message);

    const diff = 3 * 60 * 24; // time till expiration [minutes]

    if (user && user.activated && bcrypt.compareSync(password, user.password)) {
      // authentication successful
      deferred.resolve({
        _id: user._id,
        username: user.username,
        permission: user.permission,
        token: jwt.sign({sub: user._id}, config.secret, {expiresIn: diff * 60}),
        tokenExpireDate: new Date(Date.now().valueOf() + diff * 60000 - 1000)
      });
    } else {
      // authentication failed
      deferred.resolve();
    }
  });

  return deferred.promise;
};


// ******************************** EDITING USING ADMIN PANEL ************************

authenticate.route('/editUser/:id')
  .patch(apiAuthenticationMiddleware, checkAdmin, (req, res, next) => {
    if (!req.body || (req.body._id && req.body._id !== req.params.id)) {
      // little bit different as in PUT. :id does not need to be in data, but if the _id and url id must match
      const err = new Error('id of PATCH resource and send JSON body are not equal ' + req.params.id + " " + req.body._id);
      err.status = codes.notfound;
      next(err);
      return; // prevent node to process this function further after next() has finished.
    }

    // increment version manually as we do not use .save(.)
    req.body.updatedAt = new Date();
    req.body.$inc = {__v: 1};

    // PATCH is easier with mongoose than PUT. You simply update by all data that comes from outside. no need to reset attributes that are missing.
    AppUserModel.findByIdAndUpdate(req.params.id, req.body, {new: true}, (err, item) => {
      if (err) {
        err.status = codes.wrongrequest;
      }
      else if (!item) {
        err = new Error("appUser not found");
        err.status = codes.notfound;
      }
      else {
        res.locals.items = item;
      }
      next(err);
    })
  })

  .all(
    routerHandling.httpMethodNotAllowed
  );


// ******************************** SIGNUP ************************

authenticate.route('/signup')
  .post((req, res, next) => {
    create(req.body)
      .then(() => {
        res.sendStatus(200);
      })
      .catch((err) => {
        res.status(400).send(err);
      });
  })

  .all(
    routerHandling.httpMethodNotAllowed
  );

let create = (userParam) => {
  const deferred = Q.defer();

  // validation
  AppUserModel.findOne(
    {username: userParam.username},
    (err, user) => {
      if (err) deferred.reject(err.name + ': ' + err.message);

      if (user) {
        // username already exists
        deferred.reject('Username "' + userParam.username + '" is already taken');
      } else {
        createUser();
      }
    });

  let createUser = () => {
    // set user object to userParam without the cleartext password
    const user = _.omit(userParam, 'password');

    // add hashed password to user object
    user.password = bcrypt.hashSync(userParam.password, 10);

    const newUser = new AppUserModel(user);
    newUser.save((err, doc) => {
      if (err) deferred.reject(err.name + ': ' + err.message);

      deferred.resolve();
    });
  };

  return deferred.promise;
};


authenticate.use(routerHandling.emptyResponse);


module.exports = authenticate;