var mongoose = require('mongoose');
var User = mongoose.model('User');
// Makes it work locally
var LocalStrategy = require('passport-local').Strategy;
var bCrypt = require('bcrypt-nodejs');

module.exports = function (passport) {

    // Passport needs to be able to serialize and deserialize users to support persistent login sessions
    passport.serializeUser(function (user, done) {
        console.log('serializing user:', user.username);
        done(null, user._id);
    });

    passport.deserializeUser(function (id, done) {
        User.findById(id, function (err, user) {
            console.log('deserializing user:', user.username);
            done(err, user);
        });
    });

    // login
    passport.use('login', new LocalStrategy({
        passReqToCallback: true
    },
        function (req, username, password, done) {
            // check in mongo if a user with username exists or not
            User.findOne({ 'username': username },
                function (err, user) {
                    // In case of any error, return using the done method
                    if (err)
                        return done(err);
                    // Username does not exist, log error & redirect back
                    if (!user) {
                        console.log('User Not Found with username ' + username);
                        return done(null, false)
                    }
                    // User exists but wrong password, log the error
                    if (!isValidPassword(user, password)) {
                        console.log('Invalid Password');
                        return done(null, false);
                    }
                    // User and password both match, return user from
                    // done method which will be treated like success
                    return done(null, user);
                }
            );
        }));

    passport.use('signup', new LocalStrategy({
        passReqToCallback: true
    },
        function (req, username, password, done) {
            findOrCreateUser = function () {
                // find a user in Mongo with provided username
                User.findOne({ 'username': username }, function (err, user) {
                    // In case of any error return
                    if (err) {
                        console.log('Error in SignUp: ' + err);
                        return done(err);
                    }
                    // already exists
                    if (user) {
                        console.log('User already exists');
                        return done(null, false);
                    } else {
                        // if there is no user with that email
                        // create the user
                        var newUser = new User();
                        // set the user's local credentials
                        newUser.username = username;
                        newUser.password = createHash(password);

                        // save the user
                        newUser.save(function (err) {
                            if (err) {
                                console.log('Error in Saving user: ' + err);
                                throw err;
                            }
                            console.log('User Registration succesful');
                            return done(null, newUser);
                        });
                    }
                });
            };

            // Delay the execution of findOrCreateUser and execute
            // the method in the next tick of the event loop
            process.nextTick(findOrCreateUser);
        }));

    var isValidPassword = function (user, password) {
        return bCrypt.compareSync(password, user.password);
    };

    // Generates hash using bCrypt
    var createHash = function (password) {
        return bCrypt.hashSync(password, bCrypt.genSaltSync(10), null);
    }

};