<?php
namespace Luracast\Restler\Format;

use Luracast\Restler\Data\Object;
use Luracast\Restler\RestException;

/**
 * Javascript Object Notation Format
 *
 * @category   Framework
 * @package    Restler
 * @subpackage format
 * @author     R.Arul Kumaran <arul@luracast.com>
 * @copyright  2010 Luracast
 * @license    http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link       http://luracast.com/products/restler/
 * @version    3.0.0rc5
 */
class JsonFormat extends Format
{
    /**
     * @var boolean|null  shim for json_encode option JSON_PRETTY_PRINT set
     * it to null to use smart defaults
     */
    public static $prettyPrint = null;

    /**
     * @var boolean|null  shim for json_encode option JSON_UNESCAPED_SLASHES
     * set it to null to use smart defaults
     */
    public static $unEscapedSlashes = null;

    /**
     * @var boolean|null  shim for json_encode JSON_UNESCAPED_UNICODE set it
     * to null to use smart defaults
     */
    public static $unEscapedUnicode = null;

    /**
     * @var boolean|null  shim for json_decode JSON_BIGINT_AS_STRING set it to
     * null to
     * use smart defaults
     */
    public static $bigIntAsString = null;

    const MIME = 'application/json';
    const EXTENSION = 'json';

    public function encode($data, $humanReadable = false)
    {
        if (!is_null(self::$prettyPrint)) {
            $humanReadable = self::$prettyPrint;
        }
        if (is_null(self::$unEscapedSlashes)) {
            self::$unEscapedSlashes = $humanReadable;
        }
        if (is_null(self::$unEscapedUnicode)) {
            self::$unEscapedUnicode = $this->charset == 'utf-8';
        }
        $options = 0;
        if ((PHP_MAJOR_VERSION == 5 && PHP_MINOR_VERSION >= 4) // PHP >= 5.4
            || PHP_MAJOR_VERSION > 5 // PHP >= 6.0
        ) {
            if ($humanReadable) $options |= JSON_PRETTY_PRINT;
            if (self::$unEscapedSlashes) $options |= JSON_UNESCAPED_SLASHES;
            if (self::$bigIntAsString) $options |= JSON_BIGINT_AS_STRING;
            if (self::$unEscapedUnicode) $options |= JSON_UNESCAPED_UNICODE;
            return json_encode(
                Object::toArray($data, true), $options
            );
        }

        $result = json_encode(Object::toArray($data, true));
        if ($humanReadable) $result = $this->formatJson($result);
        if (self::$unEscapedUnicode) {
            $result = preg_replace_callback('/\\\u(\w\w\w\w)/',
                function($matches)
                {
                    if (function_exists('mb_convert_encoding'))
                	{
                		return mb_convert_encoding(pack('H*', $matches[1]), 'UTF-8', 'UTF-16BE');	
                	}
                	else
                	{
                		return iconv('UTF-16BE','UTF-8',pack('H*', $matches[1]));
                	}
                }
                , $result);
        }
        if (self::$unEscapedSlashes) $result = str_replace('\/', '/', $result);
        return $result;
    }

    public function decode($data)
    {
        $options = 0;
        if (self::$bigIntAsString) {
            if ((PHP_MAJOR_VERSION == 5 && PHP_MINOR_VERSION >= 4) // PHP >= 5.4
                || PHP_MAJOR_VERSION > 5 // PHP >= 6.0
            ) {
                $options |= JSON_BIGINT_AS_STRING;
            } else {
                $data = preg_replace(
                    '/:\s*(\-?\d+(\.\d+)?([e|E][\-|\+]\d+)?)/',
                    ': "$1"', $data
                );
            }
        }
        $decoded = json_decode($data, $options);
        if (function_exists('json_last_error')) {
            switch (json_last_error()) {
                case JSON_ERROR_NONE :
                    return Object::toArray($decoded);
                    break;
                case JSON_ERROR_DEPTH :
                    $message = 'maximum stack depth exceeded';
                    break;
                case JSON_ERROR_STATE_MISMATCH :
                    $message = 'underflow or the modes mismatch';
                    break;
                case JSON_ERROR_CTRL_CHAR :
                    $message = 'unexpected control character found';
                    break;
                case JSON_ERROR_SYNTAX :
                    $message = 'malformed JSON';
                    break;
                case JSON_ERROR_UTF8 :
                    $message = 'malformed UTF-8 characters, possibly ' .
                        'incorrectly encoded';
                    break;
                default :
                    $message = 'unknown error';
                    break;
            }
            throw new RestException (400, 'Error parsing JSON, ' . $message);
        } elseif (strlen($data) && $decoded === null || $decoded === $data) {
            throw new RestException (400, 'Error parsing JSON');
        }

        return Object::toArray($decoded);
    }

    /**
     * Pretty print JSON string
     *
     * @param  string $json
     *
     * @return string formatted json
     */
    private function formatJson($json)
    {
        $tab = '  ';
        $newJson = '';
        $indentLevel = 0;
        $inString = false;
        $len = strlen($json);
        for ($c = 0; $c < $len; $c++) {
            $char = $json [$c];
            switch ($char) {
                case '{' :
                case '[' :
                    if (!$inString) {
                        $newJson .= $char . "\n" .
                            str_repeat($tab, $indentLevel + 1);
                        $indentLevel++;
                    } else {
                        $newJson .= $char;
                    }
                    break;
                case '}' :
                case ']' :
                    if (!$inString) {
                        $indentLevel--;
                        $newJson .= "\n" .
                            str_repeat($tab, $indentLevel) . $char;
                    } else {
                        $newJson .= $char;
                    }
                    break;
                case ',' :
                    if (!$inString) {
                        $newJson .= ",\n" .
                            str_repeat($tab, $indentLevel);
                    } else {
                        $newJson .= $char;
                    }
                    break;
                case ':' :
                    if (!$inString) {
                        $newJson .= ': ';
                    } else {
                        $newJson .= $char;
                    }
                    break;
                case '"' :
                    if ($c == 0) {
                        $inString = true;
                    } elseif ($c > 0 && $json [$c - 1] != '\\') {
                        $inString = !$inString;
                    }
                default :
                    $newJson .= $char;
                    break;
            }
        }

        return $newJson;
    }
}