Proyectos de Subversion Moodle

<?php

/**

 * This file is part of FPDI

 *

 * @package   setasign\Fpdi

 * @copyright Copyright (c) 2023 Setasign GmbH & Co. KG (https://www.setasign.com)

 * @license   http://opensource.org/licenses/mit-license The MIT License

 */

namespace setasign\Fpdi\PdfParser;

use setasign\Fpdi\PdfParser\CrossReference\CrossReference;

use setasign\Fpdi\PdfParser\CrossReference\CrossReferenceException;

use setasign\Fpdi\PdfParser\Type\PdfArray;

use setasign\Fpdi\PdfParser\Type\PdfBoolean;

use setasign\Fpdi\PdfParser\Type\PdfDictionary;

use setasign\Fpdi\PdfParser\Type\PdfHexString;

use setasign\Fpdi\PdfParser\Type\PdfIndirectObject;

use setasign\Fpdi\PdfParser\Type\PdfIndirectObjectReference;

use setasign\Fpdi\PdfParser\Type\PdfName;

use setasign\Fpdi\PdfParser\Type\PdfNull;

use setasign\Fpdi\PdfParser\Type\PdfNumeric;

use setasign\Fpdi\PdfParser\Type\PdfStream;

use setasign\Fpdi\PdfParser\Type\PdfString;

use setasign\Fpdi\PdfParser\Type\PdfToken;

use setasign\Fpdi\PdfParser\Type\PdfType;

use setasign\Fpdi\PdfParser\Type\PdfTypeException;

/**

 * A PDF parser class

 */

class PdfParser

{

    /**

     * @var StreamReader

     */

    protected $streamReader;

    /**

     * @var Tokenizer

     */

    protected $tokenizer;

    /**

     * The file header.

     *

     * @var string

     */

    protected $fileHeader;

    /**

     * The offset to the file header.

     *

     * @var int

     */

    protected $fileHeaderOffset;

    /**

     * @var CrossReference|null

     */

    protected $xref;

    /**

     * All read objects.

     *

     * @var array

     */

    protected $objects = [];

    /**

     * PdfParser constructor.

     *

     * @param StreamReader $streamReader

     */

    public function __construct(StreamReader $streamReader)

    {

        $this->streamReader = $streamReader;

        $this->tokenizer = new Tokenizer($streamReader);

    }

    /**

     * Removes cycled references.

     *

     * @internal

     */

    public function cleanUp()

    {

        $this->xref = null;

    }

    /**

     * Get the stream reader instance.

     *

     * @return StreamReader

     */

    public function getStreamReader()

    {

        return $this->streamReader;

    }

    /**

     * Get the tokenizer instance.

     *

     * @return Tokenizer

     */

    public function getTokenizer()

    {

        return $this->tokenizer;

    }

    /**

     * Resolves the file header.

     *

     * @throws PdfParserException

     * @return int

     */

    protected function resolveFileHeader()

    {

        if ($this->fileHeader) {

            return $this->fileHeaderOffset;

        }

        $this->streamReader->reset(0);

        $maxIterations = 1000;

        while (true) {

            $buffer = $this->streamReader->getBuffer(false);

            $offset = \strpos($buffer, '%PDF-');

            if ($offset === false) {

                if (!$this->streamReader->increaseLength(100) || (--$maxIterations === 0)) {

                    throw new PdfParserException(

                        'Unable to find PDF file header.',

                        PdfParserException::FILE_HEADER_NOT_FOUND

                    );

                }

                continue;

            }

            break;

        }

        $this->fileHeaderOffset = $offset;

        $this->streamReader->setOffset($offset);

        $this->fileHeader = \trim($this->streamReader->readLine());

        return $this->fileHeaderOffset;

    }

    /**

     * Get the cross-reference instance.

     *

     * @return CrossReference

     * @throws CrossReferenceException

     * @throws PdfParserException

     */

    public function getCrossReference()

    {

        if ($this->xref === null) {

            $this->xref = new CrossReference($this, $this->resolveFileHeader());

        }

        return $this->xref;

    }

    /**

     * Get the PDF version.

     *

     * @return int[] An array of major and minor version.

     * @throws PdfParserException

     */

    public function getPdfVersion()

    {

        $this->resolveFileHeader();

        if (\preg_match('/%PDF-(\d)\.(\d)/', $this->fileHeader, $result) === 0) {

            throw new PdfParserException(

                'Unable to extract PDF version from file header.',

                PdfParserException::PDF_VERSION_NOT_FOUND

            );

        }

        list(, $major, $minor) = $result;

        $catalog = $this->getCatalog();

        if (isset($catalog->value['Version'])) {

            $versionParts = \explode(

                '.',

                PdfName::unescape(PdfType::resolve($catalog->value['Version'], $this)->value)

            );

            if (count($versionParts) === 2) {

                list($major, $minor) = $versionParts;

            }

        }

        return [(int) $major, (int) $minor];

    }

    /**

     * Get the catalog dictionary.

     *

     * @return PdfDictionary

     * @throws Type\PdfTypeException

     * @throws CrossReferenceException

     * @throws PdfParserException

     */

    public function getCatalog()

    {

        $trailer = $this->getCrossReference()->getTrailer();

        $catalog = PdfType::resolve(PdfDictionary::get($trailer, 'Root'), $this);

        return PdfDictionary::ensure($catalog);

    }

    /**

     * Get an indirect object by its object number.

     *

     * @param int $objectNumber

     * @param bool $cache

     * @return PdfIndirectObject

     * @throws CrossReferenceException

     * @throws PdfParserException

     */

    public function getIndirectObject($objectNumber, $cache = false)

    {

        $objectNumber = (int) $objectNumber;

        if (isset($this->objects[$objectNumber])) {

            return $this->objects[$objectNumber];

        }

        $object = $this->getCrossReference()->getIndirectObject($objectNumber);

        if ($cache) {

            $this->objects[$objectNumber] = $object;

        }

        return $object;

    }

    /**

     * Read a PDF value.

     *

     * @param null|bool|string $token

     * @param null|string $expectedType

     * @return false|PdfArray|PdfBoolean|PdfDictionary|PdfHexString|PdfIndirectObject|PdfIndirectObjectReference|PdfName|PdfNull|PdfNumeric|PdfStream|PdfString|PdfToken

     * @throws Type\PdfTypeException

     */

    public function readValue($token = null, $expectedType = null)

    {

        if ($token === null) {

            $token = $this->tokenizer->getNextToken();

        }

        if ($token === false) {

            if ($expectedType !== null) {

                throw new Type\PdfTypeException('Got unexpected token type.', Type\PdfTypeException::INVALID_DATA_TYPE);

            }

            return false;

        }

        switch ($token) {

            case '(':

                $this->ensureExpectedType($token, $expectedType);

                return $this->parsePdfString();

            case '<':

                if ($this->streamReader->getByte() === '<') {

                    $this->ensureExpectedType('<<', $expectedType);

                    $this->streamReader->addOffset(1);

                    return $this->parsePdfDictionary();

                }

                $this->ensureExpectedType($token, $expectedType);

                return $this->parsePdfHexString();

            case '/':

                $this->ensureExpectedType($token, $expectedType);

                return $this->parsePdfName();

            case '[':

                $this->ensureExpectedType($token, $expectedType);

                return $this->parsePdfArray();

            default:

                if (\is_numeric($token)) {

                    if (($token2 = $this->tokenizer->getNextToken()) !== false) {

                        if (\is_numeric($token2) && ($token3 = $this->tokenizer->getNextToken()) !== false) {

                            switch ($token3) {

                                case 'obj':

                                    if ($expectedType !== null && $expectedType !== PdfIndirectObject::class) {

                                        throw new Type\PdfTypeException(

                                            'Got unexpected token type.',

                                            Type\PdfTypeException::INVALID_DATA_TYPE

                                        );

                                    }

                                    return $this->parsePdfIndirectObject((int)$token, (int)$token2);

                                case 'R':

                                    if (

                                        $expectedType !== null &&

                                        $expectedType !== PdfIndirectObjectReference::class

                                    ) {

                                        throw new Type\PdfTypeException(

                                            'Got unexpected token type.',

                                            Type\PdfTypeException::INVALID_DATA_TYPE

                                        );

                                    }

                                    return PdfIndirectObjectReference::create((int)$token, (int)$token2);

                            }

                            $this->tokenizer->pushStack($token3);

                        }

                        $this->tokenizer->pushStack($token2);

                    }

                    if ($expectedType !== null && $expectedType !== PdfNumeric::class) {

                        throw new Type\PdfTypeException(

                            'Got unexpected token type.',

                            Type\PdfTypeException::INVALID_DATA_TYPE

                        );

                    }

                    return PdfNumeric::create($token + 0);

                }

                if ($token === 'true' || $token === 'false') {

                    $this->ensureExpectedType($token, $expectedType);

                    return PdfBoolean::create($token === 'true');

                }

                if ($token === 'null') {

                    $this->ensureExpectedType($token, $expectedType);

                    return new PdfNull();

                }

                if ($expectedType !== null && $expectedType !== PdfToken::class) {

                    throw new Type\PdfTypeException(

                        'Got unexpected token type.',

                        Type\PdfTypeException::INVALID_DATA_TYPE

                    );

                }

                $v = new PdfToken();

                $v->value = $token;

                return $v;

        }

    }

    /**

     * @return PdfString

     */

    protected function parsePdfString()

    {

        return PdfString::parse($this->streamReader);

    }

    /**

     * @return false|PdfHexString

     */

    protected function parsePdfHexString()

    {

        return PdfHexString::parse($this->streamReader);

    }

    /**

     * @return bool|PdfDictionary

     * @throws PdfTypeException

     */

    protected function parsePdfDictionary()

    {

        return PdfDictionary::parse($this->tokenizer, $this->streamReader, $this);

    }

    /**

     * @return PdfName

     */

    protected function parsePdfName()

    {

        return PdfName::parse($this->tokenizer, $this->streamReader);

    }

    /**

     * @return false|PdfArray

     * @throws PdfTypeException

     */

    protected function parsePdfArray()

    {

        return PdfArray::parse($this->tokenizer, $this);

    }

    /**

     * @param int $objectNumber

     * @param int $generationNumber

     * @return false|PdfIndirectObject

     * @throws Type\PdfTypeException

     */

    protected function parsePdfIndirectObject($objectNumber, $generationNumber)

    {

        return PdfIndirectObject::parse(

            $objectNumber,

            $generationNumber,

            $this,

            $this->tokenizer,

            $this->streamReader

        );

    }

    /**

     * Ensures that the token will evaluate to an expected object type (or not).

     *

     * @param string $token

     * @param string|null $expectedType

     * @return bool

     * @throws Type\PdfTypeException

     */

    protected function ensureExpectedType($token, $expectedType)

    {

        static $mapping = [

            '(' => PdfString::class,

            '<' => PdfHexString::class,

            '<<' => PdfDictionary::class,

            '/' => PdfName::class,

            '[' => PdfArray::class,

            'true' => PdfBoolean::class,

            'false' => PdfBoolean::class,

            'null' => PdfNull::class

        ];

        if ($expectedType === null || $mapping[$token] === $expectedType) {

            return true;

        }

        throw new Type\PdfTypeException('Got unexpected token type.', Type\PdfTypeException::INVALID_DATA_TYPE);

    }

}