// for now, we're mocking NewsletterSignup:
function NewsletterSignup() {
}
NewsletterSignup.prototype.save = function(cb) {
  cb();
};

var VALID_EMAIL_REGEX = /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)+$/;

app.post('/newsletter', function(req, res) {
  var name = req.body.name || '', email = req.body.email || '';

  // input validation
  if (!email.match(VALID_EMAIL_REGEX)) {
    if(req.xhr) return res.json({ error: 'Invalid email address. '});
    req.session.flash = {
      type: 'danger',
      intro: 'Validation error!',
      message: 'The email address you entered was not valid.'
    };
    return res.redirect(303, '/newsletter/archive');
  }

  new NewsletterSignup({ name: name, email: email }).save(function(err){
    if (err) {
      // couldn't save to database
      if(req.xhr) return res.json({ error: 'Database error.'});
      req.session.flash = {
        type: 'danger',
        intro: 'Database error!',
        message: 'There was a database error; please try again later.'
      };
      return res.redirect(303, '/newsletter/archive');
    }

    if(req.xhr) return res.json({ success: true });
    req.session.flash = {
      type: 'success',
      intro: 'Thank you!',
      message: 'You have now been signed up to the newsletter.'
    };
    return res.redirect(303, '/newsletter/archive');
  });
});
app.get('/newsletter/archive', function(req, res){
  res.render('newsletter/archive');
});