const express = require('express');
const app = express();

const fs = require('fs');
const hbs = require('hbs');
const path = require('path')
const bodyParser = require('body-parser');
const morganBody = require('morgan-body');


app.use(bodyParser.json());
app.set('view engine', 'html');
app.set('views', path.join(__dirname, 'views'));
app.use('/static', express.static(path.join(__dirname, 'static')));
app.engine('html', require('hbs').__express);
morganBody(app);

const session = require('express-session');
const randomize = require('randomatic');

app.use(session({
	name: 'session',
	secret: randomize('aA0', 69),
	resave: false,
	saveUninitialized: false,
	cookie: {secure: true}
}));

app.use(function(req, res, next) {
	if (req.session.archive === undefined) {
		req.session.archive = {
			'dumb': 'yes',
		  // formula: '[0.20 * a + 0.25 * e + 0.25 * p]', // depends on grade
		  // assignment: '',
		  // exam: '',
		  // paper: '',
		};
	}
	next();
});

app.get('/debug', (req, res) => {
	res.header('Content-Type', 'text/plain');
	return res.end(fs.readFileSync(__filename).toString());
});

app.get('/log', (req, res) => {
	res.header('Content-Type', 'text/plain');
	return res.end(fs.readFileSync(path.join(__dirname, '.log')).toString());
});

app.get('/', (req, res) => {
	return res.render('index');
});

function deepFreeze(obj) {
	var propNames = Object.getOwnPropertyNames(obj);
	for (let name of propNames) {
		let value = obj[name];
		obj[name] = value && typeof value === 'object' ? deepFreeze(value) : value;
	}
	return Object.freeze(obj);
}

function isObject(obj) {
	return obj !== null && typeof obj === 'object';
}

function merge(target, source) {
	for (let key in source) {
		if (isObject(target[key]) && isObject(source[key])) {
			merge(target[key], source[key]);
		} else {
			target[key] = source[key];
		}
	}
	return target;
}

function clone(target) {
	return merge({}, target);
}

const evaluate = require('static-eval');
const parse = require('esprima').parse;

app.post('/api/v2/', (req, res) => {
//	var archive = req.session.archive
	deepFreeze(Object);
	var student = clone(req.body);

	if (student.name.includes('Baker') || student.name.includes('Purvis')) {
		return res.json({
			'pass': 'n' + randomize('?', 10, {chars: 'o0'}) + 'pe'
		});
	}

	if (student.paper !== undefined) {
		let ast = parse(student.formula).body[0].expression;
		let weight = evaluate(ast, {
			a: student.assignment,
			e: student.exam,
			p: student.paper
		});

		return res.json({
			'pass': parseFloat(10.5) <= parseFloat(weight) ? 'yes' : 'no'
		});
	}
	return res.end();
});
app.listen(1337);