<?php

if (!isset($_GET['action']))
    header('Location: .');

include_once ('includes/functions.php');

$action = $_GET['action'];

switch ($action) {
    case 'login':
        $error_location = 'login.php?error=';
        $success_location = 'pages/home.php';

        // If fields are empty, redirect to login with error state.
        if (empty($_POST['login_username']) || empty($_POST['login_password']))
            header('Location: ' . $error_location . 'empty');

        include_once ('fields/login_fields.php');
        // If field inputs are invalid, redirect to login with error state.
        foreach ($_POST as $field => $value) {
            if (!validate($value, $login_fields[$field]['validators']))
                header('Location: ' . $error_location . 'invalid');
        }

        $username = $_POST['login_username'];
        $password_hash = hash('sha256', $_POST['login_password']);

        // If username/password hash are incorrect, redirect to login with error state.
        if (!authorize($username, $password_hash))
            header('Location: ' . $error_location . 'incorrect');

        unset($_POST['login_username']);
        unset($_POST['login_password']);

        // auth() handles setting $_SESSION variables, user is now OK to proceed to home.php.
        header('Location: ' . $success_location);
    default:
        // code...
        break;
}

function validate($input, $validators)
{
    include_once ('includes/input_validation.php');

    foreach ($validators as $v) {
        switch ($v) {
            case 'no_spaces':
                if (!no_spaces($input))
                    return false;
                break;

            case 'no_digits':
                if (!no_digits($input))
                    return false;
                break;

            case 'no_backslash':
                if (!no_backslash($input))
                    return false;
                break;

            case 'no_special':
                if (!no_special($input))
                    return false;
                break;

            case 'only_digits':
                if (!only_digits($input))
                    return false;
                break;

            // TODO: Need to get x.
            case 'only_digits_x':
                if (!only_digits_x($input, 5))
                    return false;
                break;

            case 'only_letters':
                if (!only_letters($input))
                    return false;
                break;

            // TODO: Need to get x.
            case 'only_letters_x':
                if (!only_letters_x($input, 5))
                    return false;
                break;

            case 'valid_email':
                if (!valid_email($input))
                    return false;
                break;

            case 'valid_phone':
                if (!valid_phone($input))
                    return false;
                break;

            case 'pw_strength':
                if (!pw_strength($input))
                    return false;
                break;

            case 'check_sql':
                if (check_sql($input))
                    return false;
                break;
        }
    }

    return true;
}