<?php
if (!isset($_POST['data']) || !isset($_POST['filepath'])) {
    exit('ERROR');
}

if (!preg_match('`^[A-Za-z0-9\s\\\/_-]+$`', json_decode($_POST['filepath']))) {
    exit('WRONG FILE PATH');
}

$form_data = json_decode($_POST['data']);
$filepath = preg_replace('`(.*)json-forms`', '../json-forms', json_decode($_POST['filepath']));
$filepath = rtrim($filepath, DIRECTORY_SEPARATOR) . DIRECTORY_SEPARATOR;
$filepath = str_replace(array('/', '\\'), DIRECTORY_SEPARATOR, $filepath);
$output = array(
    'status' => '',
    'msg'    => ''
);

$json_error = '';
switch (json_last_error()) {
    case JSON_ERROR_NONE:
    break;
    case JSON_ERROR_DEPTH:
        $json_error = 'JSON error - Maximum stack depth exceeded';
    break;
    case JSON_ERROR_STATE_MISMATCH:
        $json_error =  'JSON error - Underflow or the modes mismatch';
    break;
    case JSON_ERROR_CTRL_CHAR:
        $json_error =  'JSON error - Unexpected control character found';
    break;
    case JSON_ERROR_SYNTAX:
        $json_error =  'JSON error - Syntax error, malformed JSON';
    break;
    case JSON_ERROR_UTF8:
        $json_error =  'JSON error - Malformed UTF-8 characters, possibly incorrectly encoded';
    break;
    default:
        $json_error =  'JSON error - Unknown error';
    break;
}

if (!empty($json_error)) {
    $output = array(
        'status' => 'danger',
        'msg'    => $json_error
    );
}

if (!is_writable($filepath)) {
    $output = array(
        'status' => 'danger',
        'msg'    => 'The target directory is not writable'
    );
}

// All ok
if ($output['status'] !== 'danger') {
    $form_id = $form_data->userForm->id;
    file_put_contents($filepath . $form_id . '.json', json_encode($form_data));
    $output = array(
        'status' => 'success',
        'msg'    => 'Your form has been saved to ' . str_replace('..' . DIRECTORY_SEPARATOR . 'json-forms' . DIRECTORY_SEPARATOR, '', $filepath) . $form_id . '.json'
    );;
}

echo json_encode($output);