const express = require('express');
const hbs = require('hbs');
const session = require('express-session');
const http = require('http');
const path = require('path');
const fs = require('fs');
const db = require('./db');

const cookieParser = require('cookie-parser');

const PORT = process.env.PORT || 8080;

const app = express(http);

hbs.registerPartials(path.resolve(__dirname, 'views', 'partials'));
app.set('view engine', 'hbs');
app.set('views', path.resolve(__dirname, 'views'));

app.use('/', express.static(path.resolve(__dirname, 'public')));
const jsonParser = express.json();
const urlEncodedParser = express.urlencoded({extended: true});
app.use(cookieParser());

app.use(session({
    secret: String(fs.readFileSync(path.resolve(__dirname, 'secret'))),
    resave: false,
    saveUninitialized: true
}));

app.get('/', (req, res) => {
    if (req.session.userID) {
        res.render('index.hbs', {
            isOfficer: req.session.profile.isOfficer,
            error: req.session.error
        });
    } else {
        res.render('login.hbs', {
            error: req.session.error
        });
    }
    req.session.info = null;
    req.session.error = null;
});

app.get('/profile', (req, res) => {
    if (!req.session.userID) {
        req.session.error = 'You must be logged in to view this page';
        res.redirect('/');

    } else {
        res.render('profile.hbs', {
            firstName: req.session.profile.firstName,
            lastName: req.session.profile.lastName,
            isOfficer: req.session.profile.isOfficer,
            error: req.session.error,
            info: req.session.info
        });
        req.session.info = null;
        req.session.error = null;
    }
});

app.get('/logout', (req, res) => {
    req.session.destroy();
    res.redirect('/');
});

app.get('*', (req, res) => {
    res.redirect('/');
});

app.post('/register', urlEncodedParser, async (req, res) => {
    if (!req.body || !req.body.username || !req.body.password || !req.body.password_confirm) {
        req.session.error = 'Missing required fields';
        res.redirect('/');
        return;
    }
    if (req.body.password !== req.body.password_confirm) {
        req.session.error = 'Passwords do not match';
        res.redirect('/');
        return;
    }
    try {
        let users = await db.all('SELECT * FROM users WHERE username = ?', [req.body.username]);
        if (users && users[0]) {
            req.session.error = 'User already exists';
            res.redirect('/');
            return;
        }
        let id = await db.run('INSERT INTO users (username, password, firstName, lastName) VALUES (?, ?, ?, ?)',
            [req.body.username, req.body.password, '', '']);
        req.session.userID = id;
        req.session.profile = {
            firstName: '',
            lastName: '',
        };
        res.redirect('/profile');
    } catch (err) {
        console.error(err);
        req.session.error = 'Internal server error';
        res.redirect('/');
    }
});

app.post('/login', urlEncodedParser, async (req, res) => {
    if (!req.body || !req.body.username || !req.body.password) {
        req.session.error = 'Missing required fields';
        res.redirect('/');
        return;
    }
    try {
        let users = await db.all('SELECT * FROM users WHERE username = ? AND password = ?',
            [req.body.username, req.body.password]);
        if (!users || !users.length) {
            req.session.error = 'Invalid username or password';
            res.redirect('/');
            return;
        }

        // Check if user is a police officer
        let officers = await db.all('SELECT * FROM officers WHERE userid = ?', [users[0].id]);
        req.session.userID = users[0].id;
        req.session.profile = {
            firstName: users[0].firstName,
            lastName: users[0].lastName,
        };
        if (officers && officers[0]) {
            req.session.profile.isOfficer = true;
        }
        res.redirect('/');
    } catch (err) {
        console.error(err);
        req.session.error = 'Internal server error';
        res.redirect('/');
    }

});

app.post('/profile', jsonParser, async (req, res) => {
    if (!req.session.userID) {
        req.session.error = 'You must be logged in to perform this action';
        res.status(403);
        res.send(req.session.error);
        return;
    }
    if (!req.body || Object.keys(req.body).length === 0) {
        req.session.error = 'Missing required fields';
        res.status(400);
        res.send(req.session.error);
        return;
    }
    let profile = Object.assign({}, req.session.profile);
    let requested = req.body;

    // Make sure we only update existing properties
    for (let key of Object.keys(requested)) {

        if (typeof(requested[key]) === 'string')
            requested[key] = requested[key].substring(0, 32);

        if (profile[key] !== undefined && typeof(profile[key]) === typeof(requested[key]))
            profile[key] = requested[key];
    }

    if (Object.keys(profile).length === 0) {
        req.session.error = 'Missing required fields';
        res.status(400);
        res.send(req.session.error);
        return;
    }

    try {
        await db.run('UPDATE users SET firstName = ?, lastName = ? WHERE id = ?',
            [profile.firstName, profile.lastName, req.session.userID]);
        req.session.profile.firstName = profile.firstName;
        req.session.profile.lastName = profile.lastName;
        if (profile.isOfficer)
            req.session.profile.isOfficer = true;
        req.session.info = 'Changes saved successfully';
        res.send('OK');
    } catch (err) {
        console.error(err);
        req.session.error = 'Internal server error';
        res.status(500);
        res.send(req.session.error);
    }

});

db.connect().then(() => {

    app.listen(PORT, () => {
        console.log(`We are live on port ${PORT}`);
    });

});