var bodyParser = require('body-parser');
var express = require('express');
var fs = require('fs');

var app = express();
var jsonParser = bodyParser.json();

app.use(express.static(__dirname + '/public'));

app.get('/api/users', function (req, res) {
    var content = fs.readFileSync('users.json', 'utf8');
    var users = JSON.parse(content);
    res.send(users);
});

app.get('/api/users/:id', function (req, res) {
    var id = req.params.id;
    var content = fs.readFileSync('users.json', 'utf8');
    var users = JSON.parse(content);
    var user = null;

    for (var i = 0; i < users.length; i++) {
        if (users[i].id == id) {
            user = users[i];
            break;
        }
    }

    if (user) {
        res.send(user);
    }
    else {
        res.status(404).send();
    }
});

app.post('/api/users', jsonParser, function (req, res) {
    if (!req.body) return res.sendStatus(400);

    var userName = req.body.name;
    var userAge = req.body.age;
    var user = { name: userName, age: userAge };

    var data = fs.readFileSync('users.json', 'utf8');
    var users = JSON.parse(data);

    var id = Math.max.apply(
        Math,
        users.map(function (o) {
            return o.id;
        })
    );

    user.id = id + 1;

    users.push(user);
    var data = JSON.stringify(users);

    fs.writeFileSync('users.json', data);
    res.send(user);
});

app.delete('/api/users/:id', function (req, res) {
    var id = req.params.id;
    var data = fs.readFileSync('users.json', 'utf8');
    var users = JSON.parse(data);
    var index = -1;

    for (var i = 0; i < users.length; i++) {
        if (users[i].id == id) {
            index = i;
            break;
        }
    }
    if (index > -1) {
        var user = users.splice(index, 1)[0];
        var data = JSON.stringify(users);
        fs.writeFileSync('users.json', data);

        res.send(user);
    }
    else {
        res.status(404).send();
    }
});

app.put('/api/users', jsonParser, function (req, res) {
    if (!req.body) {
        return res.sendStatus(400);
    }

    var userId = req.body.id;
    var userName = req.body.name;
    var userAge = req.body.age;

    var data = fs.readFileSync('users.json', 'utf8');
    var users = JSON.parse(data);
    var user;
    for (var i = 0; i < users.length; i++) {
        if (users[i].id == userId) {
            user = users[i];
            break;
        }
    }

    if (user) {
        user.age = userAge;
        user.name = userName;
        var data = JSON.stringify(users);
        fs.writeFileSync('users.json', data);
        res.send(user);
    }
    else {
        res.status(404).send(user);
    }
});

app.listen(3000, function () {
    console.log('STARTED');
});