// TODO: Close Mongo connections upon exit
var express = require('express');
var mongoose = require('mongoose');
var fs = require('fs');
var https = require('https');
var shellCommand = require('child_process').exec;

var privateKey = fs.readFileSync('./../ssl/localhost.key').toString();
var certificate = fs.readFileSync('./../ssl/localhost.crt').toString();

// Instantiate express
var server = express()
    .use(express.static('./../'))
    .use(express.cookieParser())
    .use(express.bodyParser())
    .use(express.session({secret: 'Secret!'}))
    .set('views', './../');

https.createServer({
    key: privateKey,
    cert: certificate
}, server).listen(80, 'localhost');

// Connect to the database
mongoose.connect('localhost', 'users');

// Define our model
var User = mongoose.model('Users',
    mongoose.Schema({
        username: 'string',
        password: 'string',
        rights: 'string'
    })
);

// Clear the database
User.remove({}, function () {});

// Add admin
new User({
    username: 'admin',
    password: 'admin',
    rights: 'Administrator'
}).save();

new User({
    username: 'Steve',
    password: 'test',
    rights: 'Administrator'
}).save();

new User({
    username: 'Justin',
    password: 'test',
    rights: 'Operator'
}).save();

server.get('/usersList', function(req, res) {
    User.find({}, null, {sort: {username: 1}}, function (err, users) {
        res.send(users);
    });
});

server.get('/protocols', function(req, res) {
    var response = {};

    shellCommand('tdcli proto list  | grep -v dpi_', function (err, stdout, stderr) {
        var lines = stdout.split('n');

        for(var i = 2; i < lines.length; i += 1) {
            var line = lines[i];
            var name = line.split(/W+/)[1];
            var status = line.match(/(enabled|disabled)/)[0];

            response[name] = status;
        }

        res.send(response);
    });
});

server.get('/statistics', function(req, res) {
    var response = {};

    for(var i = 0; i < 3; i += 1) {
        response[i] = 0.25 + 1 / 2 * Math.random();
    }

    shellCommand('top -b -n 1', function (err, stdout, stderr) {
        var lines = stdout.split('n');
        var line;
        var elements;
        var memory;
        var cpu;

        for(i = 0; i < lines.length; i += 1) {
            line = lines[i];
            elements = line.split(/s+/);

            if(elements[0] == 'Mem:') {
                memory = +(elements[3].slice(0, -1));
            }

            if(elements[0] == 'Cpu(s):') {
                cpu = +((100 - +elements[4].slice(0, -4)).toFixed(1));
            }
        }

        response[3] = cpu;
        response[4] = memory;

        res.send(response);
    });
});

server.post('/login', function(req, res) {
    var receivedUsername = req.body.username;
    var receivedPassword = req.body.password;

    User.find({
        username: receivedUsername
    }, function (err, users) {
        if(printError(err)) return;

        var user = users[0];

        if(!user) {
            console.error('No user', receivedUsername);
            return;
        }

        var correctPassword = user.password;

        if(receivedPassword === correctPassword) {
            req.session.username = user.username;
            req.session.rights = user.rights;

            res.send({
                message: 'Valid'
            });
        } else {
            res.send({
                message: 'Invalid',
                correctPassword: correctPassword
            });
        }
    });
});

server.post('/logout', function(req, res) {
    req.session.username = undefined;
    req.session.rights = undefined;

    sendOK(res);
});

server.post('/newUser', function (req, res) {
    if (req.session.rights === 'Administrator') {
        var receivedUsername = req.body.username;

        User.find({
            username: receivedUsername
        }, function (err, users) {
            if(users.length !== 0) {
                res.send({
                    message: 'Error: User exists!'
                });
            } else {
                new User(req.body).save(function (err) {
                    if(printError(err)) return;
                });

                res.send({
                    message: 'OK'
                });
            }
        });
    } else {
        res.send({
            message: 'Error: Permission denied'
        });
    }
});

server.post('/removeUser', function (req, res) {
    var receivedUsername = req.body.username;

    User
        .find({username: receivedUsername})
        .remove(function (err) {
            if(printError(err)) {
                sendError(res);
            }
        });

    sendOK(res);
});

server.post('/editUser', function (req, res) {
    var oldUsername = req.body.oldUsername;
    var newUser = req.body.user;

    User.update({username: oldUsername}, {
        username: newUser.username,
        password: newUser.password,
        rights: newUser.rights
    }, function(err, numberAffected, rawResponse) {
        if(printError(err)) {
            sendError(res);
        }
    });

    sendOK(res);
});

function sendOK(res) {
    res.send({
        message: 'OK'
    });
}

function sendError(res) {
    res.send({
        message: 'Error'
    });
}

function printError(err) {
    if(err) {
        console.error('ERROR!');
    }

    return err;
}

User.update({username: oldUsername}, {
        username: newUser.username,
        password: newUser.password,
        rights: newUser.rights
    }, function(err, numberAffected, rawResponse) {
        if(printError(err)) {
            sendError(res);
        }
    });

    sendOK(res);

User
    .find({username: receivedUsername})
    .remove(function (err) {
        if(printError(err)) {
            sendError(res);
        }
    });