<?php
//
//  FPDI - Version 1.5.4
//
//    Copyright 2004-2015 Setasign - Jan Slabon
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//

class fpdi_bridge extends TCPDF
{
    /**
     * Array of Tpl-Data
     *
     * @var array
     */
    protected $_tpls = array();

    /**
     * Name-prefix of Templates used in Resources-Dictionary
     *
     * @var string A String defining the Prefix used as Template-Object-Names. Have to begin with an /
     */
    public $tplPrefix = "/TPL";

    /**
     * Current Object Id.
     *
     * @var integer
     */
    protected $_currentObjId;

    /**
     * Return XObjects Dictionary.
     *
     * Overwritten to add additional XObjects to the resources dictionary of TCPDF
     *
     * @return string
     */
    protected function _getxobjectdict()
    {
        $out = parent::_getxobjectdict();
        foreach ($this->_tpls as $tplIdx => $tpl) {
            $out .= sprintf('%s%d %d 0 R', $this->tplPrefix, $tplIdx, $tpl['n']);
        }

        return $out;
    }

    /**
     * Writes a PDF value to the resulting document.
     *
     * Prepares the value for encryption of imported data by FPDI
     *
     * @param array $value
     */
    protected function _prepareValue(&$value)
    {
        switch ($value[0]) {
            case pdf_parser::TYPE_STRING:
                if ($this->encrypted) {
                    $value[1] = $this->_unescape($value[1]);
                    $value[1] = $this->_encrypt_data($this->_currentObjId, $value[1]);
                    $value[1] = TCPDF_STATIC::_escape($value[1]);
                }
                break;

            case pdf_parser::TYPE_STREAM:
                if ($this->encrypted) {
                    $value[2][1] = $this->_encrypt_data($this->_currentObjId, $value[2][1]);
                    $value[1][1]['/Length'] = array(
                        pdf_parser::TYPE_NUMERIC,
                        strlen($value[2][1])
                    );
                }
                break;

            case pdf_parser::TYPE_HEX:
                if ($this->encrypted) {
                    $value[1] = $this->hex2str($value[1]);
                    $value[1] = $this->_encrypt_data($this->_currentObjId, $value[1]);

                    // remake hexstring of encrypted string
                    $value[1] = $this->str2hex($value[1]);
                }
                break;
        }
    }

    /**
     * Un-escapes a PDF string
     *
     * @param string $s
     * @return string
     */
    protected function _unescape($s)
    {
        $out = '';
        for ($count = 0, $n = strlen($s); $count < $n; $count++) {
            if ($s[$count] != '\\' || $count == $n-1) {
                $out .= $s[$count];
            } else {
                switch ($s[++$count]) {
                    case ')':
                    case '(':
                    case '\\':
                        $out .= $s[$count];
                        break;
                    case 'f':
                        $out .= chr(0x0C);
                        break;
                    case 'b':
                        $out .= chr(0x08);
                        break;
                    case 't':
                        $out .= chr(0x09);
                        break;
                    case 'r':
                        $out .= chr(0x0D);
                        break;
                    case 'n':
                        $out .= chr(0x0A);
                        break;
                    case "\r":
                        if ($count != $n-1 && $s[$count+1] == "\n")
                            $count++;
                        break;
                    case "\n":
                        break;
                    default:
                        // Octal-Values
                        if (ord($s[$count]) >= ord('0') &&
                            ord($s[$count]) <= ord('9')) {
                            $oct = ''. $s[$count];

                            if (ord($s[$count+1]) >= ord('0') &&
                                ord($s[$count+1]) <= ord('9')) {
                                $oct .= $s[++$count];

                                if (ord($s[$count+1]) >= ord('0') &&
                                    ord($s[$count+1]) <= ord('9')) {
                                    $oct .= $s[++$count];
                                }
                            }

                            $out .= chr(octdec($oct));
                        } else {
                            $out .= $s[$count];
                        }
                }
            }
        }
        return $out;
    }

    /**
     * Hexadecimal to string
     *
     * @param string $data
     * @return string
     */
    public function hex2str($data)
    {
        $data = preg_replace('/[^0-9A-Fa-f]/', '', rtrim($data, '>'));
        if ((strlen($data) % 2) == 1) {
            $data .= '0';
        }

        return pack('H*', $data);
    }

    /**
     * String to hexadecimal
     *
     * @param string $str
     * @return string
     */
    public function str2hex($str)
    {
        return current(unpack('H*', $str));
    }
}