<?php
/**
 * Snap JSON utils
 *
 * Standard: PSR-2
 * @link http://www.php-fig.org/psr/psr-2
 *
 * @package SnapLib
 * @copyright (c) 2019, Snapcreek LLC
 * @license	https://opensource.org/licenses/GPL-3.0 GNU Public License
 *
 */
defined('ABSPATH') || defined('DUPXABSPATH') || exit;

if (!interface_exists('JsonSerializable')) {
    define('SNAP_WP_JSON_SERIALIZE_COMPATIBLE', true);

    /**
     * JsonSerializable interface.
     *
     * Compatibility shim for PHP <5.4
     *
     * @link https://secure.php.net/jsonserializable
     *
     * @since 4.4.0
     */
    interface JsonSerializable
    {

        public function jsonSerialize();
    }
}

if (!class_exists('DupLiteSnapJsonU', false)) {


    class DupLiteSnapJsonU
    {

        /**
         * Encode a variable into JSON, with some sanity checks.
         *
         * @since 4.1.0
         *
         * @param mixed $data    Variable (usually an array or object) to encode as JSON.
         * @param int   $options Optional. Options to be passed to json_encode(). Default 0.
         * @param int   $depth   Optional. Maximum depth to walk through $data. Must be
         *                       greater than 0. Default 512.
         * @return string|false The JSON encoded string, or false if it cannot be encoded.
         */
        public static function wp_json_encode($data, $options = 0, $depth = 512)
        {
            if (function_exists('wp_json_encode')) {
                return wp_json_encode($data, $options, $depth);
            }

            /*
             * json_encode() has had extra params added over the years.
             * $options was added in 5.3, and $depth in 5.5.
             * We need to make sure we call it with the correct arguments.
             */
            if (version_compare(PHP_VERSION, '5.5', '>=')) {
                $args = array($data, $options, $depth);
            } elseif (version_compare(PHP_VERSION, '5.3', '>=')) {
                $args = array($data, $options);
            } else {
                $args = array($data);
            }

            // Prepare the data for JSON serialization.
            $args[0] = self::_wp_json_prepare_data($data);

            $json = @call_user_func_array('json_encode', $args);

            // If json_encode() was successful, no need to do more sanity checking.
            // ... unless we're in an old version of PHP, and json_encode() returned
            // a string containing 'null'. Then we need to do more sanity checking.
            if (false !== $json && ( version_compare(PHP_VERSION, '5.5', '>=') || false === strpos($json, 'null') )) {
                return $json;
            }

            try {
                $args[0] = self::_wp_json_sanity_check($data, $depth);
            }
            catch (Exception $e) {
                return false;
            }

            return call_user_func_array('json_encode', $args);
        }

        /**
         * wp_json_encode with pretty print if define exists
         *
         * @param mixed $data    Variable (usually an array or object) to encode as JSON.
         * @param int   $options Optional. Options to be passed to json_encode(). Default 0.
         * @param int   $depth   Optional. Maximum depth to walk through $data. Must be
         *                       greater than 0. Default 512.
         * @return string|false The JSON encoded string, or false if it cannot be encoded.
         */
        public static function wp_json_encode_pprint($data, $options = 0, $depth = 512)
        {
            if (defined('JSON_PRETTY_PRINT')) {
                return self::wp_json_encode($data, JSON_PRETTY_PRINT | $options, $depth);
            } else {
                return self::wp_json_encode($data, $options, $depth);
            }
        }

        /**
         * Prepares response data to be serialized to JSON.
         *
         * This supports the JsonSerializable interface for PHP 5.2-5.3 as well.
         *
         * @ignore
         * @since 4.4.0
         * @access private
         *
         * @param mixed $data Native representation.
         * @return bool|int|float|null|string|array Data ready for `json_encode()`.
         */
        private static function _wp_json_prepare_data($data)
        {
            if (!defined('SNAP_WP_JSON_SERIALIZE_COMPATIBLE') || SNAP_WP_JSON_SERIALIZE_COMPATIBLE === false || !defined('WP_JSON_SERIALIZE_COMPATIBLE') || WP_JSON_SERIALIZE_COMPATIBLE === false) {
                return $data;
            }

            switch (gettype($data)) {
                case 'boolean':
                case 'integer':
                case 'double':
                case 'string':
                case 'NULL':
                    // These values can be passed through.
                    return $data;

                case 'array':
                    // Arrays must be mapped in case they also return objects.
                    return array_map(array(__CLASS__, '_wp_json_prepare_data'), $data);

                case 'object':
                    // If this is an incomplete object (__PHP_Incomplete_Class), bail.
                    if (!is_object($data)) {
                        return null;
                    }

                    if ($data instanceof JsonSerializable) {
                        $data = $data->jsonSerialize();
                    } else {
                        $data = get_object_vars($data);
                    }

                    // Now, pass the array (or whatever was returned from jsonSerialize through).
                    return self::_wp_json_prepare_data($data);

                default:
                    return null;
            }
        }

        /**
         * Perform sanity checks on data that shall be encoded to JSON.
         *
         * @ignore
         * @since 4.1.0
         * @access private
         *
         * @see wp_json_encode()
         *
         * @param mixed $data  Variable (usually an array or object) to encode as JSON.
         * @param int   $depth Maximum depth to walk through $data. Must be greater than 0.
         * @return mixed The sanitized data that shall be encoded to JSON.
         */
        private static function _wp_json_sanity_check($data, $depth)
        {
            if ($depth < 0) {
                throw new Exception('Reached depth limit');
            }

            if (is_array($data)) {
                $output = array();
                foreach ($data as $id => $el) {
                    // Don't forget to sanitize the ID!
                    if (is_string($id)) {
                        $clean_id = self::_wp_json_convert_string($id);
                    } else {
                        $clean_id = $id;
                    }

                    // Check the element type, so that we're only recursing if we really have to.
                    if (is_array($el) || is_object($el)) {
                        $output[$clean_id] = self::_wp_json_sanity_check($el, $depth - 1);
                    } elseif (is_string($el)) {
                        $output[$clean_id] = self::_wp_json_convert_string($el);
                    } else {
                        $output[$clean_id] = $el;
                    }
                }
            } elseif (is_object($data)) {
                $output = new stdClass;
                foreach ($data as $id => $el) {
                    if (is_string($id)) {
                        $clean_id = self::_wp_json_convert_string($id);
                    } else {
                        $clean_id = $id;
                    }

                    if (is_array($el) || is_object($el)) {
                        $output->$clean_id = self::_wp_json_sanity_check($el, $depth - 1);
                    } elseif (is_string($el)) {
                        $output->$clean_id = self::_wp_json_convert_string($el);
                    } else {
                        $output->$clean_id = $el;
                    }
                }
            } elseif (is_string($data)) {
                return self::_wp_json_convert_string($data);
            } else {
                return $data;
            }

            return $output;
        }

        private static function _wp_json_convert_string($string)
        {
            static $use_mb = null;
            if (is_null($use_mb)) {
                $use_mb = function_exists('mb_convert_encoding');
            }

            if ($use_mb) {
                $encoding = mb_detect_encoding($string, mb_detect_order(), true);
                if ($encoding) {
                    return mb_convert_encoding($string, 'UTF-8', $encoding);
                } else {
                    return mb_convert_encoding($string, 'UTF-8', 'UTF-8');
                }
            } else {
                return self::wp_check_invalid_utf8($string, true);
            }
        }

        /**
         * Checks for invalid UTF8 in a string.
         *
         * @since 2.8.0
         *
         * @staticvar bool $utf8_pcre
         *
         * @param string  $string The text which is to be checked.
         * @param bool    $strip Optional. Whether to attempt to strip out invalid UTF8. Default is false.
         * @return string The checked text.
         */
        public static function wp_check_invalid_utf8($string, $strip = false)
        {
            $string = (string) $string;

            if (0 === strlen($string)) {
                return '';
            }

            // Check for support for utf8 in the installed PCRE library once and store the result in a static
            static $utf8_pcre = null;
            if (!isset($utf8_pcre)) {
                $utf8_pcre = @preg_match('/^./u', 'a');
            }
            // We can't demand utf8 in the PCRE installation, so just return the string in those cases
            if (!$utf8_pcre) {
                return $string;
            }

            // preg_match fails when it encounters invalid UTF8 in $string
            if (1 === @preg_match('/^./us', $string)) {
                return $string;
            }

            // Attempt to strip the bad chars if requested (not recommended)
            if ($strip && function_exists('iconv')) {
                return iconv('utf-8', 'utf-8', $string);
            }

            return '';
        }

        /**
         * @param mixed $val object to be encoded
         * @return string escaped json string
         */
        public static function json_encode_esc_attr($val)
        {
            return esc_attr(json_encode($val));
        }

        /**
         * this function return a json encoded string without quotes at the beginning and the end
         * 
         * @param string $string
         * @return string
         * @throws Exception
         */
        public static function getJsonWithoutQuotes($string)
        {
            if (!is_string($string)) {
                throw new Exception('the function getJsonStringWithoutQuotes take only strings');
            }

            return substr(self::wp_json_encode($string), 1, -1);
        }
    }
}
