<?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) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

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

 * @version    $Id: Parser.php 23395 2010-11-19 15:30:47Z alexander $

 */

/** Internally used classes */

require_once 'Zend/Pdf/Element.php';

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

/** Zend_Pdf_StringParser */

require_once 'Zend/Pdf/StringParser.php';

/**

 * PDF file parser

 *

 * @package    Zend_Pdf

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

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

 */

class Zend_Pdf_Parser

{

    /**

     * String parser

     *

     * @var Zend_Pdf_StringParser

     */

    private $_stringParser;

    /**

     * Last PDF file trailer

     *

     * @var Zend_Pdf_Trailer_Keeper

     */

    private $_trailer;

    /**

     * PDF version specified in the file header

     *

     * @var string

     */

    private $_pdfVersion;

    /**

     * Get length of source PDF

     *

     * @return integer

     */

    public function getPDFLength()

    {

        return strlen($this->_stringParser->data);

    }

    /**

     * Get PDF String

     *

     * @return string

     */

    public function getPDFString()

    {

        return $this->_stringParser->data;

    }

    /**

     * PDF version specified in the file header

     *

     * @return string

     */

    public function getPDFVersion()

    {

        return $this->_pdfVersion;

    }

    /**

     * Load XReference table and referenced objects

     *

     * @param integer $offset

     * @throws Zend_Pdf_Exception

     * @return Zend_Pdf_Trailer_Keeper

     */

    private function _loadXRefTable($offset)

    {

        $this->_stringParser->offset = $offset;

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

        $refTable = new Zend_Pdf_Element_Reference_Table();

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

        $context  = new Zend_Pdf_Element_Reference_Context($this->_stringParser, $refTable);

        $this->_stringParser->setContext($context);

        $nextLexeme = $this->_stringParser->readLexeme();

        if ($nextLexeme == 'xref') {

            /**

             * Common cross-reference table

             */

            $this->_stringParser->skipWhiteSpace();

            while ( ($nextLexeme = $this->_stringParser->readLexeme()) != 'trailer' ) {

                if (!ctype_digit($nextLexeme)) {

                    require_once 'Zend/Pdf/Exception.php';

                    throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Offset - 0x%X. Cross-reference table subheader values must contain only digits.', $this->_stringParser->offset-strlen($nextLexeme)));

                }

                $objNum = (int)$nextLexeme;

                $refCount = $this->_stringParser->readLexeme();

                if (!ctype_digit($refCount)) {

                    require_once 'Zend/Pdf/Exception.php';

                    throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Offset - 0x%X. Cross-reference table subheader values must contain only digits.', $this->_stringParser->offset-strlen($refCount)));

                }

                $this->_stringParser->skipWhiteSpace();

                while ($refCount > 0) {

                    $objectOffset = substr($this->_stringParser->data, $this->_stringParser->offset, 10);

                    if (!ctype_digit($objectOffset)) {

                        require_once 'Zend/Pdf/Exception.php';

                        throw new Zend_Pdf_Exception(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Offset must contain only digits.', $this->_stringParser->offset));

                    }

                    // Force $objectOffset to be treated as decimal instead of octal number

                    for ($numStart = 0; $numStart < strlen($objectOffset)-1; $numStart++) {

                        if ($objectOffset[$numStart] != '0') {

                            break;

                        }

                    }

                    $objectOffset = substr($objectOffset, $numStart);

                    $this->_stringParser->offset += 10;

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

                        require_once 'Zend/Pdf/Exception.php';

                        throw new Zend_Pdf_Exception(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Value separator must be white space.', $this->_stringParser->offset));

                    }

                    $this->_stringParser->offset++;

                    $genNumber = substr($this->_stringParser->data, $this->_stringParser->offset, 5);

                    if (!ctype_digit($objectOffset)) {

                        require_once 'Zend/Pdf/Exception.php';

                        throw new Zend_Pdf_Exception(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Offset must contain only digits.', $this->_stringParser->offset));

                    }

                    // Force $objectOffset to be treated as decimal instead of octal number

                    for ($numStart = 0; $numStart < strlen($genNumber)-1; $numStart++) {

                        if ($genNumber[$numStart] != '0') {

                            break;

                        }

                    }

                    $genNumber = substr($genNumber, $numStart);

                    $this->_stringParser->offset += 5;

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

                        require_once 'Zend/Pdf/Exception.php';

                        throw new Zend_Pdf_Exception(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Value separator must be white space.', $this->_stringParser->offset));

                    }

                    $this->_stringParser->offset++;

                    $inUseKey = $this->_stringParser->data[$this->_stringParser->offset];

                    $this->_stringParser->offset++;

                    switch ($inUseKey) {

                        case 'f':

                            // free entry

                            unset( $this->_refTable[$objNum . ' ' . $genNumber . ' R'] );

                            $refTable->addReference($objNum . ' ' . $genNumber . ' R',

                                                    $objectOffset,

                                                    false);

                            break;

                        case 'n':

                            // in-use entry

                            $refTable->addReference($objNum . ' ' . $genNumber . ' R',

                                                    $objectOffset,

                                                    true);

                    }

                    if ( !Zend_Pdf_StringParser::isWhiteSpace(ord( $this->_stringParser->data[$this->_stringParser->offset] )) ) {

                        require_once 'Zend/Pdf/Exception.php';

                        throw new Zend_Pdf_Exception(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Value separator must be white space.', $this->_stringParser->offset));

                    }

                    $this->_stringParser->offset++;

                    if ( !Zend_Pdf_StringParser::isWhiteSpace(ord( $this->_stringParser->data[$this->_stringParser->offset] )) ) {

                        require_once 'Zend/Pdf/Exception.php';

                        throw new Zend_Pdf_Exception(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Value separator must be white space.', $this->_stringParser->offset));

                    }

                    $this->_stringParser->offset++;

                    $refCount--;

                    $objNum++;

                }

            }

            $trailerDictOffset = $this->_stringParser->offset;

            $trailerDict = $this->_stringParser->readElement();

            if (!$trailerDict instanceof Zend_Pdf_Element_Dictionary) {

                require_once 'Zend/Pdf/Exception.php';

                throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Offset - 0x%X.  Dictionary expected after \'trailer\' keyword.', $trailerDictOffset));

            }

        } else {

            $xrefStream = $this->_stringParser->getObject($offset, $context);

            if (!$xrefStream instanceof Zend_Pdf_Element_Object_Stream) {

                require_once 'Zend/Pdf/Exception.php';

                throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Offset - 0x%X.  Cross-reference stream expected.', $offset));

            }

            $trailerDict = $xrefStream->dictionary;

            if ($trailerDict->Type->value != 'XRef') {

                require_once 'Zend/Pdf/Exception.php';

                throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Offset - 0x%X.  Cross-reference stream object must have /Type property assigned to /XRef.', $offset));

            }

            if ($trailerDict->W === null  || $trailerDict->W->getType() != Zend_Pdf_Element::TYPE_ARRAY) {

                require_once 'Zend/Pdf/Exception.php';

                throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Offset - 0x%X. Cross reference stream dictionary doesn\'t have W entry or it\'s not an array.', $offset));

            }

            $entryField1Size = $trailerDict->W->items[0]->value;

            $entryField2Size = $trailerDict->W->items[1]->value;

            $entryField3Size = $trailerDict->W->items[2]->value;

            if ($entryField2Size == 0 || $entryField3Size == 0) {

                require_once 'Zend/Pdf/Exception.php';

                throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Offset - 0x%X. Wrong W dictionary entry. Only type field of stream entries has default value and could be zero length.', $offset));

            }

            $xrefStreamData = $xrefStream->value;

            if ($trailerDict->Index !== null) {

                if ($trailerDict->Index->getType() != Zend_Pdf_Element::TYPE_ARRAY) {

                    require_once 'Zend/Pdf/Exception.php';

                    throw new Zend_Pdf_Exception(sprintf('PDF file syntax error. Offset - 0x%X. Cross reference stream dictionary Index entry must be an array.', $offset));

                }

                $sections = count($trailerDict->Index->items)/2;

            } else {

                $sections = 1;

            }

            $streamOffset = 0;

            $size    = $entryField1Size + $entryField2Size + $entryField3Size;

            $entries = strlen($xrefStreamData)/$size;

            for ($count = 0; $count < $sections; $count++) {

                if ($trailerDict->Index !== null) {

                    $objNum  = $trailerDict->Index->items[$count*2    ]->value;

                    $entries = $trailerDict->Index->items[$count*2 + 1]->value;

                } else {

                    $objNum  = 0;

                    $entries = $trailerDict->Size->value;

                }

                for ($count2 = 0; $count2 < $entries; $count2++) {

                    if ($entryField1Size == 0) {

                        $type = 1;

                    } else if ($entryField1Size == 1) { // Optimyze one-byte field case

                        $type = ord($xrefStreamData[$streamOffset++]);

                    } else {

                        $type = Zend_Pdf_StringParser::parseIntFromStream($xrefStreamData, $streamOffset, $entryField1Size);

                        $streamOffset += $entryField1Size;

                    }

                    if ($entryField2Size == 1) { // Optimyze one-byte field case

                        $field2 = ord($xrefStreamData[$streamOffset++]);

                    } else {

                        $field2 = Zend_Pdf_StringParser::parseIntFromStream($xrefStreamData, $streamOffset, $entryField2Size);

                        $streamOffset += $entryField2Size;

                    }

                    if ($entryField3Size == 1) { // Optimyze one-byte field case

                        $field3 = ord($xrefStreamData[$streamOffset++]);

                    } else {

                        $field3 = Zend_Pdf_StringParser::parseIntFromStream($xrefStreamData, $streamOffset, $entryField3Size);

                        $streamOffset += $entryField3Size;

                    }

                    switch ($type) {

                        case 0:

                            // Free object

                            $refTable->addReference($objNum . ' ' . $field3 . ' R', $field2, false);

                            // Debug output:

                            // echo "Free object - $objNum $field3 R, next free - $field2\n";

                            break;

                        case 1:

                            // In use object

                            $refTable->addReference($objNum . ' ' . $field3 . ' R', $field2, true);

                            // Debug output:

                            // echo "In-use object - $objNum $field3 R, offset - $field2\n";

                            break;

                        case 2:

                            // Object in an object stream

                            // Debug output:

                            // echo "Compressed object - $objNum 0 R, object stream - $field2 0 R, offset - $field3\n";

                            break;

                    }

                    $objNum++;

                }

            }

            // $streamOffset . ' ' . strlen($xrefStreamData) . "\n";

            // "$entries\n";

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception('Cross-reference streams are not supported yet.');

        }

        require_once 'Zend/Pdf/Trailer/Keeper.php';

        $trailerObj = new Zend_Pdf_Trailer_Keeper($trailerDict, $context);

        if ($trailerDict->Prev instanceof Zend_Pdf_Element_Numeric ||

            $trailerDict->Prev instanceof Zend_Pdf_Element_Reference ) {

            $trailerObj->setPrev($this->_loadXRefTable($trailerDict->Prev->value));

            $context->getRefTable()->setParent($trailerObj->getPrev()->getRefTable());

        }

        /**

         * We set '/Prev' dictionary property to the current cross-reference section offset.

         * It doesn't correspond to the actual data, but is true when trailer will be used

         * as a trailer for next generated PDF section.

         */

        $trailerObj->Prev = new Zend_Pdf_Element_Numeric($offset);

        return $trailerObj;

    }

    /**

     * Get Trailer object

     *

     * @return Zend_Pdf_Trailer_Keeper

     */

    public function getTrailer()

    {

        return $this->_trailer;

    }

    /**

     * Object constructor

     *

     * Note: PHP duplicates string, which is sent by value, only of it's updated.

     * Thus we don't need to care about overhead

     *

     * @param mixed $source

     * @param Zend_Pdf_ElementFactory_Interface $factory

     * @param boolean $load

     * @throws Zend_Exception

     */

    public function __construct($source, Zend_Pdf_ElementFactory_Interface $factory, $load)

    {

        if ($load) {

            if (($pdfFile = @fopen($source, 'rb')) === false ) {

                require_once 'Zend/Pdf/Exception.php';

                throw new Zend_Pdf_Exception( "Can not open '$source' file for reading." );

            }

            $data = '';

            $byteCount = filesize($source);

            while ($byteCount > 0 && !feof($pdfFile)) {

                $nextBlock = fread($pdfFile, $byteCount);

                if ($nextBlock === false) {

                    require_once 'Zend/Pdf/Exception.php';

                    throw new Zend_Pdf_Exception( "Error occured while '$source' file reading." );

                }

                $data .= $nextBlock;

                $byteCount -= strlen($nextBlock);

            }

            if ($byteCount != 0) {

                require_once 'Zend/Pdf/Exception.php';

                throw new Zend_Pdf_Exception( "Error occured while '$source' file reading." );

            }

            fclose($pdfFile);

            $this->_stringParser = new Zend_Pdf_StringParser($data, $factory);

        } else {

            $this->_stringParser = new Zend_Pdf_StringParser($source, $factory);

        }

        $pdfVersionComment = $this->_stringParser->readComment();

        if (substr($pdfVersionComment, 0, 5) != '%PDF-') {

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception('File is not a PDF.');

        }

        $pdfVersion = substr($pdfVersionComment, 5);

        if (version_compare($pdfVersion, '0.9',  '<')  ||

            version_compare($pdfVersion, '1.61', '>=')

           ) {

            /**

             * @todo

             * To support PDF versions 1.5 (Acrobat 6) and PDF version 1.7 (Acrobat 7)

             * Stream compression filter must be implemented (for compressed object streams).

             * Cross reference streams must be implemented

             */

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception(sprintf('Unsupported PDF version. Zend_Pdf supports PDF 1.0-1.4. Current version - \'%f\'', $pdfVersion));

        }

        $this->_pdfVersion = $pdfVersion;

        $this->_stringParser->offset = strrpos($this->_stringParser->data, '%%EOF');