var express = require('express');
var app = express();
var nunjucks = require('nunjucks');
var passport = require('passport');
var LocalStrategy = require('passport-local').Strategy;
var crypto = require('crypto');
var sha256sum = crypto.createHash('sha256');
var fsextra = require('fs-extra');
var strftime = require('strftime');
var fs = require('fs');
var ini = require('ini');

var config;
var aaa;
var matrix;
var view_path = 'views';

function loggedIn(req, res, next) {
    if (req.user) {
        next();
    } else {
        res.redirect('/login');
    }
}

function matchedPasswordAndHash(password, hash) {
    sha256sum.update(password);
    return (hash == sha256sum.digest('hex'))
}

function renderConfigIndex(req, res) {
    
    masked = ['config.expresso.password'];
    
    res.render('config.index.html', { 
        gateway_name: config.globals.gateway_name, 
        title: 'CONFIG', configs: config,
        config_dirty: matrix.config_dirty,
        isMask: function(scope, keyword) {
            return masked.indexOf('config.' + scope + '.' + keyword) >= 0;
        },
    });
}

function renderConfigEdit(req, res) {
    res.render('config.edit.html', { 
        gateway_name: config.globals.gateway_name,
        title: 'Edit Config',
        scope: req.scope,
        keyword: req.keyword,
        old_value: config[req.scope][req.keyword]
    });
}

function submitConfigEdit(req, res) {
    
    if (config[req.body.scope][req.body.keyword] != req.body.newValue.trim()) {
        config[req.body.scope][req.body.keyword] = req.body.newValue.trim();
        matrix.config_dirty = 1;
    }
    
    res.redirect('/config');
}

function submitConfigSave(req, res) {
    fsextra.copy('config.ini', 'config.ini.backup-' + strftime('%F_%H%M%S', new Date()), function(err) {
        fs.writeFileSync('./config.ini', ini.stringify(config));
        matrix.config_dirty = 0;
        res.redirect('/config');
    });
}

function renderLoginPage(req, res) {
    res.render('signin.html', {title: 'Signin'});
}

function createServer() {
    if (!config.expresso || !config.expresso.listen_port) {
        console.log('Not starting expresso admin UI');
        return;
    }
    
    nunjucks.configure(view_path, {
        autoescape: true,
        noCache: true,
        express: app
    });
    
    app.use(express.static('public'));
    app.use(require('cookie-parser')());
    app.use(require('body-parser').urlencoded({ extended: true }));
    app.use(require('express-session')({ secret: 'keyboard cat', resave: false, saveUninitialized: false }));
    app.use(passport.initialize());
    app.use(passport.session());
    
    passport.use(new LocalStrategy(
        function(username, password, done) {
            
            if (username == 'admin' && matchedPasswordAndHash(password, config.expresso.password)) {
                var user = {
                    username: username,
                    last_login: Date.now() / 1000 | 0
                }
                
                return done(null, user);
            }
            
            return done(null, false, { message: 'Incorrect password.' });
        }
    ));
    
    passport.serializeUser(function(user, done) {
        done(null, user.username);
    });
    
    passport.deserializeUser(function(username, done) {
        var user = {
            username: username
        };
        done(null, user);
    });
    
    app.get('/', loggedIn, function(req, res) { res.redirect('/config'); });
    app.get('/config', loggedIn, renderConfigIndex);
    app.get('/login', renderLoginPage);
    app.post('/login', passport.authenticate('local', { successRedirect: '/config', failureRedirect: '/login' }));
    app.get('/logout', function(req, res){
        req.logout();
        res.redirect('/login');
    });
    
    app.param('scope', function(req, res, next, value) {
        req.scope = value;
        next();
    });
    
    app.param('keyword', function(req, res, next, value) {
        req.keyword = value;
        next();
    });
    
    app.get('/config/edit/:scope/:keyword', loggedIn, renderConfigEdit);
    app.post('/config/edit/:scope/:keyword', loggedIn, submitConfigEdit);
    
    app.get('/config/save', loggedIn, submitConfigSave);
    
    var server = app.listen(config.expresso.listen_port, function () {
        var host = server.address().address;
        var port = server.address().port;

        console.log('Expresso admin UI listening at http://%s:%s', host, port);
    });
}

function sanitizeMatrix(matrix) {
    if (matrix.config_dirty === undefined) {
        matrix.config_dirty = 0;
    }
}

function start(options) {
    if (options['config']) {
        config = options['config'];
    }
    
    if (options['matrix']) {
        matrix = options['matrix'];
    }
    sanitizeMatrix(matrix);
    
    if (options['aaa']) {
        aaa = options['aaa'];
    }
    
    if (options['expresso_views']) {
        view_path = options['expresso_views'];
    }
    
    createServer();
}

exports.start = start;