router.post('/register', [
	check('username')
	    .isLength({ min: 4 })
	    .withMessage('Please provide a username of at least four letters')
	    .trim(),
	check('email')
	    .isEmail()
	    .withMessage('Please ensure that your email address is properly formatted')
	    .trim()
	    .normalizeEmail(),
	check('password')
		.isLength({ min: 1 })
		.withMessage('Please provide a password.'),
	check('passwordconfirmation', 'Password confirmation field must have the same value as the password field')
        .exists()
        .custom((value, { req }) => value === req.body.password)
], (req, res, next) => {
	const errors = validationResult(req)
	const mappedErrors = errors.mapped()
	console.log('mappedErrors obj is:', mappedErrors)
	const mapErrors_noErrors = Object.keys(mappedErrors).length === 0
	console.log('is mappedErrors an empty object (b/c there are no errors)?', mapErrors_noErrors)



	    validationResult(req);

		// If there are no registration form validation errors we can move on to:
		// A - looking up registration request's user info by email to see if this account exists already.
		// B - if user obj does not exist, we can safely create one
		// C - if it does exist, let the visitor know so they can correct their actions

	    if(mapErrors_noErrors == true) {
    		console.log('notice: there are no errors from validation result');

	    	// A - Try to get user by email.  If its possible, we know that one is taken, so cant use it
	    	return Promise.try(() => {
	    	    // Here, we return the result of calling our own function. That return value is a Promise.
	    	    return User_fns.getUserByEmail(req.body.email);
	    	}).then((user) => {
	    		// B - if user obj does not exist, we can safely create one
	    		// an empty user object appears as empty array: []
	    		if (user === undefined || user.length == 0) {
	    		    // array empty or does not exist
	    		    console.log('user obj is empty or does not exist');
	    		    // safe to create user, b/c this one we searched for does not exist.
	    		    // - B1. hash pw.
	    		    console.log('pw avail?', req.body.password);
	    		    var password =  req.body.password;


			    	return Promise.try(() => {
			    		return User_fns.hashPassword(password);
			    	}).then((hashed_password) => {
			    		console.log('hashed_password available?', hashed_password)
				    	req.flash('success', 'Thanks for registering.')

			    		return User_fns.createUser(req.body.username, req.body.email, hashed_password)

    			    	res.render('pages/register', {
    		    	    data: req.body, // { message, email }
    		    	    errors: errors.mapped(),
    		    	    env: process.env.NODE_ENV
    		    		})
			    	})
	    		    // - B2. insert user into users table.

	    		        // passing in the request objects from form, and hashed_password

	    		    	// should even pass in some of their info, such as username, so its clear that it worked
	    		    // - B3. flash confirmation
	    		} else {
	    			console.log('User object exists already, so we will notify visitor', user)
	    			// the user object based on the email already exists
	    			req.flash('success', 'Sorry, a user with that email address already exists.  You may already have an account, or perhaps you mistyped your email address.')
	    			// flash some error message to the user.

			    	res.render('pages/register', {
		    	    data: req.body, // { message, email }
		    	    errors: errors.mapped(),
		    	    env: process.env.NODE_ENV
		    		})
	    		}


	    	});


	    } else {
	    	// This will push data to the template to make it highlight the error fields
	    	console.log('notice: there ARE errors from validation result');
	    	res.render('pages/register', {
	    	    data: req.body, // { message, email }
	    	    errors: errors.mapped(),
	    	    env: process.env.NODE_ENV
	    		})
	    }

	// The matchedData function returns the output of the sanitizers on our input.
	// i.e. this is the sanitized req.body
	const data = matchedData(req)
	console.log('Sanitized:', data)

});