function convertFromUSD(value, currency) {
    switch(currency) {
        case 'USD': return value * 1;
        case 'GBP': return value * 0.6;
        case 'BTC': return value * 0.0023707918444761;
        default: return NaN;
    }
}

// Vacation database code
app.get('/vacations', function (req, res) {
    Vacation.find({available: true}, function (err, vacations) {
        var currency = req.session.currency || 'USD';
        var context = {
            currency: currency,
            vacations: vacations.map(function (vacation) {
                return {
                    sku: vacation.sku,
                    name: vacation.name,
                    description: vacation.description,
                    inSeason: vacation.inSeason,
                    price: convertFromUSD(vacation.priceInCents/100, currency),
                    qty: vacation.qty,
                }
            })
        };
        switch(currency) {
            case 'USD': context.currencyUSD = 'selected'; break;
            case 'GBP': context.currencyGBP = 'selected'; break;
            case 'BTC': context.currencyBTC = 'selected'; break;
        }
        res.render('vacations', context);
    });
});

var VacationInSeasonListener = require('./models/vacationInSeasonListener');

app.get('/notify-me-when-in-season', function (req, res) {
   res.render('notify-me-when-in-season', {sku: req.query.sku});
});

app.post('/notify-me-when-in-season', function (req, res) {
    VacationInSeasonListener.update(
        {email: req.body.email},
        {$push: {skus: req.body.sku}},
        {upsert: true},
        function (err) {
            if(err) {
                console.error(err.stack);
                req.session.flash = {
                    type: 'danger',
                    intro: 'Ooops!',
                    message: 'There was an error processing your request.',
                };
                return res.redirect(303, '/vacations');
            }
            req.session.flash = {
                type: 'success',
                intro: 'Thank you!',
                message: 'You will be notified when this vacation is in season.',
            };
            res.redirect(303, '/vacations');
        }
    );
});