<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Pdf

 * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id$

 */

/** Internally used classes */

require_once 'Zend/Pdf/Element/Array.php';

require_once 'Zend/Pdf/Element/String/Binary.php';

require_once 'Zend/Pdf/Element/Boolean.php';

require_once 'Zend/Pdf/Element/Dictionary.php';

require_once 'Zend/Pdf/Element/Name.php';

require_once 'Zend/Pdf/Element/Null.php';

require_once 'Zend/Pdf/Element/Numeric.php';

require_once 'Zend/Pdf/Element/Object.php';

require_once 'Zend/Pdf/Element/Object/Stream.php';

require_once 'Zend/Pdf/Element/Reference.php';

require_once 'Zend/Pdf/Element/String.php';

/**

 * PDF string parser

 *

 * @package    Zend_Pdf

 * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Pdf_StringParser

{

    /**

     * Source PDF

     *

     * @var string

     */

    public $data = '';

    /**

     * Current position in a data

     *

     * @var integer

     */

    public $offset = 0;

    /**

     * Current reference context

     *

     * @var Zend_Pdf_Element_Reference_Context

     */

    private $_context = null;

    /**

     * Array of elements of the currently parsed object/trailer

     *

     * @var array

     */

    private $_elements = array();

    /**

     * PDF objects factory.

     *

     * @var Zend_Pdf_ElementFactory_Interface

     */

    private $_objFactory = null;

    /**

     * Clean up resources.

     *

     * Clear current state to remove cyclic object references

     */

    public function cleanUp()

    {

        $this->_context = null;

        $this->_elements = array();

        $this->_objFactory = null;

    }

    /**

     * Character with code $chCode is white space

     *

     * @param integer $chCode

     * @return boolean

     */

    public static function isWhiteSpace($chCode)

    {

        if ($chCode == 0x00 || // null character

            $chCode == 0x09 || // Tab

            $chCode == 0x0A || // Line feed

            $chCode == 0x0C || // Form Feed

            $chCode == 0x0D || // Carriage return

            $chCode == 0x20    // Space

           ) {

            return true;

        } else {

            return false;

        }

    }

    /**

     * Character with code $chCode is a delimiter character

     *

     * @param integer $chCode

     * @return boolean

     */

    public static function isDelimiter($chCode )

    {

        if ($chCode == 0x28 || // '('

            $chCode == 0x29 || // ')'

            $chCode == 0x3C || // '<'

            $chCode == 0x3E || // '>'

            $chCode == 0x5B || // '['

            $chCode == 0x5D || // ']'

            $chCode == 0x7B || // '{'

            $chCode == 0x7D || // '}'

            $chCode == 0x2F || // '/'

            $chCode == 0x25    // '%'

           ) {

            return true;

        } else {

            return false;

        }

    }

    /**

     * Skip white space

     *

     * @param boolean $skipComment

     */

    public function skipWhiteSpace($skipComment = true)

    {

        if ($skipComment) {

            while (true) {

                $this->offset += strspn($this->data, "\x00\t\n\f\r ", $this->offset);

                if ($this->offset < strlen($this->data)  &&  $this->data[$this->offset] == '%') {

                    // Skip comment

                    $this->offset += strcspn($this->data, "\r\n", $this->offset);

                } else {

                    // Non white space character not equal to '%' is found

                    return;

                }

            }

        } else {

            $this->offset += strspn($this->data, "\x00\t\n\f\r ", $this->offset);

        }

//        /** Original (non-optimized) implementation. */

//

//        while ($this->offset < strlen($this->data)) {

//            if (strpos("\x00\t\n\f\r ", $this->data[$this->offset]) !== false) {

//                $this->offset++;

//            } else if (ord($this->data[$this->offset]) == 0x25 && $skipComment) { // '%'

//                $this->skipComment();

//            } else {

//                return;

//            }

//        }

    }

    /**

     * Skip comment

     */

    public function skipComment()

    {

        while ($this->offset < strlen($this->data))

        {

            if (ord($this->data[$this->offset]) != 0x0A || // Line feed

                ord($this->data[$this->offset]) != 0x0d    // Carriage return

               ) {

                $this->offset++;

            } else {

                return;

            }

        }

    }

    /**

     * Read comment line

     *

     * @return string

     */

    public function readComment()

    {

        $this->skipWhiteSpace(false);

        /** Check if it's a comment line */

        if ($this->data[$this->offset] != '%') {

            return '';

        }

        for ($start = $this->offset;

             $this->offset < strlen($this->data);

             $this->offset++) {

            if (ord($this->data[$this->offset]) == 0x0A || // Line feed

                ord($this->data[$this->offset]) == 0x0d    // Carriage return

               ) {

                break;

            }

        }

        return substr($this->data, $start, $this->offset-$start);

    }

    /**

     * Returns next lexeme from a pdf stream

     *

     * @return string

     */

    public function readLexeme()

    {

        // $this->skipWhiteSpace();

        while (true) {

            $this->offset += strspn($this->data, "\x00\t\n\f\r ", $this->offset);

            if ($this->offset < strlen($this->data)  &&  $this->data[$this->offset] == '%') {

                $this->offset += strcspn($this->data, "\r\n", $this->offset);

            } else {

                break;

            }

        }

        if ($this->offset >= strlen($this->data)) {

            return '';

        }

        if ( /* self::isDelimiter( ord($this->data[$start]) ) */

             strpos('()<>[]{}/%', $this->data[$this->offset]) !== false ) {

            switch (substr($this->data, $this->offset, 2)) {

                case '<<':

                    $this->offset += 2;

                    return '<<';

                    break;

                case '>>':

                    $this->offset += 2;

                    return '>>';

                    break;

                default:

                    return $this->data[$this->offset++];

                    break;

            }

        } else {

            $start = $this->offset;

            $compare = '';

            if( version_compare( phpversion(), '5.2.5' ) >= 0) {

                $compare = "()<>[]{}/%\x00\t\n\f\r ";

            } else {

                $compare = "()<>[]{}/%\x00\t\n\r ";

            }

            $this->offset += strcspn($this->data, $compare, $this->offset);

            return substr($this->data, $start, $this->offset - $start);

        }

    }

    /**

     * Read elemental object from a PDF stream

     *

     * @return Zend_Pdf_Element

     * @throws Zend_Pdf_Exception

     */

    public function readElement($nextLexeme = null)

    {

        if ($nextLexeme === null) {

            $nextLexeme = $this->readLexeme();

        }

        /**

         * Note: readElement() method is a public method and could be invoked from other classes.

         * If readElement() is used not by Zend_Pdf_StringParser::getObject() method, then we should not care

         * about _elements member management.

         */

        switch ($nextLexeme) {

            case '(':

                return ($this->_elements[] = $this->_readString());

            case '<':

                return ($this->_elements[] = $this->_readBinaryString());

            case '/':

                return ($this->_elements[] = new Zend_Pdf_Element_Name(

                                                    Zend_Pdf_Element_Name::unescape( $this->readLexeme() )

                                                                      ));

            case '[':

                return ($this->_elements[] = $this->_readArray());

            case '<<':

                return ($this->_elements[] = $this->_readDictionary());

            case ')':

                // fall through to next case

            case '>':

                // fall through to next case

            case ']':

                // fall through to next case

            case '>>':

                // fall through to next case

            case '{':

                // fall through to next case

            case '}':

                require_once 'Zend/Pdf/Exception.php';

                throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Offset - 0x%X.',

                                                $this->offset));

            default:

                if (strcasecmp($nextLexeme, 'true') == 0) {

                    return ($this->_elements[] = new Zend_Pdf_Element_Boolean(true));

                } else if (strcasecmp($nextLexeme, 'false') == 0) {

                    return ($this->_elements[] = new Zend_Pdf_Element_Boolean(false));

                } else if (strcasecmp($nextLexeme, 'null') == 0) {

                    return ($this->_elements[] = new Zend_Pdf_Element_Null());

                }

                $ref = $this->_readReference($nextLexeme);

                if ($ref !== null) {

                    return ($this->_elements[] = $ref);

                }

                return ($this->_elements[] = $this->_readNumeric($nextLexeme));

        }

    }

    /**

     * Read string PDF object

     * Also reads trailing ')' from a pdf stream

     *

     * @return Zend_Pdf_Element_String

     * @throws Zend_Pdf_Exception

     */

    private function _readString()

    {

        $start = $this->offset;

        $openedBrackets = 1;

        $this->offset += strcspn($this->data, '()\\', $this->offset);

        while ($this->offset < strlen($this->data)) {

            switch (ord( $this->data[$this->offset] )) {

                case 0x28: // '(' - opened bracket in the string, needs balanced pair.

                    $this->offset++;

                    $openedBrackets++;

                    break;

                case 0x29: // ')' - pair to the opened bracket

                    $this->offset++;

                    $openedBrackets--;

                    break;

                case 0x5C: // '\\' - escape sequence, skip next char from a check

                    $this->offset += 2;

            }

            if ($openedBrackets == 0) {

                break; // end of string

            }

            $this->offset += strcspn($this->data, '()\\', $this->offset);

        }

        if ($openedBrackets != 0) {

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Unexpected end of file while string reading. Offset - 0x%X. \')\' expected.', $start));

        }

        return new Zend_Pdf_Element_String(Zend_Pdf_Element_String::unescape( substr($this->data,

                                                                                     $start,

                                                                                     $this->offset - $start - 1) ));

    }

    /**

     * Read binary string PDF object

     * Also reads trailing '>' from a pdf stream

     *

     * @return Zend_Pdf_Element_String_Binary

     * @throws Zend_Pdf_Exception

     */

    private function _readBinaryString()

    {

        $start = $this->offset;

        $this->offset += strspn($this->data, "\x00\t\n\f\r 0123456789abcdefABCDEF", $this->offset);

        if ($this->offset >= strlen($this->data) - 1) {

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Unexpected end of file while reading binary string. Offset - 0x%X. \'>\' expected.', $start));

        }

        if ($this->data[$this->offset++] != '>') {

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Unexpected character while binary string reading. Offset - 0x%X.', $this->offset));

        }

        return new Zend_Pdf_Element_String_Binary(

                       Zend_Pdf_Element_String_Binary::unescape( substr($this->data,

                                                                        $start,

                                                                        $this->offset - $start - 1) ));

    }

    /**

     * Read array PDF object

     * Also reads trailing ']' from a pdf stream

     *

     * @return Zend_Pdf_Element_Array

     * @throws Zend_Pdf_Exception

     */