<?php
/**
 * File containing the ezcMailPartParser class
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 *
 * @package Mail
 * @version //autogen//
 * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
 */

/**
 * Base class for all parser parts.
 *
 * Parse process
 * 1. Figure out the headers of the next part.
 * 2. Based on the headers, create the parser for the bodyPart corresponding to
 *    the headers.
 * 3. Parse the body line by line. In the case of a multipart or a digest recursively
 *    start this process. Note that in the case of RFC822 messages the body contains
 *    headers.
 * 4. call finish() on the partParser and retrieve the ezcMailPart
 *
 * Each parser part gets the header for that part through the constructor
 * and is responsible for parsing the body of that part.
 * Parsing of the body is done on a push basis trough the parseBody() method
 * which is called repeatedly by the parent part for each line in the message.
 *
 * When there are no more lines the parent part will call finish() and the mail
 * part corresponding to the part you are parsing should be returned.
 *
 * @todo case on headers
 * @package Mail
 * @version //autogen//
 * @access private
 */
abstract class ezcMailPartParser
{
    /**
     * Mail headers which can appear maximum one time in a mail message,
     * as defined by RFC 2822.
     *
     * @var array(string)
     */
    protected static $uniqueHeaders = array( 'bcc', 'cc', 'content-type',
                                             'content-disposition', 'from',
                                             'content-transfer-encoding',
                                             'return-path',
                                             'in-reply-to', 'references',
                                             'message-id', 'date', 'reply-to',
                                             'sender', 'subject', 'sender', 'to' );

    /**
     * The default is to parse text attachments into ezcMailTextPart objects.
     *
     * Setting this to true before calling the parser will parse text attachments
     * into ezcMailFile objects. Use the parser options for this:
     *
     * <code>
     * $parser = new ezcMailParser();
     * $parser->options->parseTextAttachmentsAsFiles = true;
     * // call $parser->parseMail( $set );
     * </code>
     *
     * @var bool
     */
    public static $parseTextAttachmentsAsFiles = false;

    /**
     * The name of the last header parsed.
     *
     * This variable is used when glueing together multi-line headers.
     *
     * @var string
     */
    private $lastParsedHeader = null;

    /**
     * Parse the body of a message line by line.
     *
     * This method is called by the parent part on a push basis. When there
     * are no more lines the parent part will call finish() to retrieve the
     * mailPart.
     *
     * @param string $line
     */
    abstract public function parseBody( $line );

    /**
     * Return the result of the parsed part.
     *
     * This method is called when all the lines of this part have been parsed.
     *
     * @return ezcMailPart
     */
    abstract public function finish();

    /**
     * Returns a part parser corresponding to the given $headers.
     *
     * @throws ezcBaseFileNotFoundException
     *         if a neccessary temporary file could not be openened.
     * @param ezcMailHeadersHolder $headers
     * @return ezcMailPartParser
     */
    static public function createPartParserForHeaders( ezcMailHeadersHolder $headers )
    {
        // default as specified by RFC2045 - #5.2
        $mainType = 'text';
        $subType = 'plain';

        // parse the Content-Type header
        if ( isset( $headers['Content-Type'] ) )
        {
            $matches = array();
            // matches "type/subtype; blahblahblah"
            preg_match_all( '/^(\S+)\/([^;]+)/',
                            $headers['Content-Type'], $matches, PREG_SET_ORDER );
            if ( count( $matches ) > 0 )
            {
                $mainType = strtolower( $matches[0][1] );
                $subType = strtolower( $matches[0][2] );
            }
        }
        $bodyParser = null;

        // create the correct type parser for this the detected type of part
        switch ( $mainType )
        {
            /* RFC 2045 defined types */
            case 'image':
            case 'audio':
            case 'video':
            case 'application':
                $bodyParser = new ezcMailFileParser( $mainType, $subType, $headers );
                break;

            case 'message':
                switch ( $subType )
                {
                    case "rfc822":
                        $bodyParser = new ezcMailRfc822DigestParser( $headers );
                        break;

                    case "delivery-status":
                        $bodyParser = new ezcMailDeliveryStatusParser( $headers );
                        break;

                    default:
                        $bodyParser = new ezcMailFileParser( $mainType, $subType, $headers );
                        break;
                }
                break;

            case 'text':
                // dev/core#940 Ensure that emails are not processed as .unknown attachments by checking
                // for Filename or name in the content-disposition and content-type headers.
                if ( (ezcMailPartParser::$parseTextAttachmentsAsFiles === true)                   &&
                     (preg_match('/\s*filename="?([^;"]*);?/i', $headers['Content-Disposition']) ||
                      preg_match( '/\s*name="?([^;"]*);?/i'   , $headers['Content-Type'])        )  )
                {
                    $bodyParser = new ezcMailFileParser( $mainType, $subType, $headers );
                }
                else
                {
                    $bodyParser = new ezcMailTextParser( $subType, $headers );
                }
                break;

            case 'multipart':
                switch ( $subType )
                {
                    case 'mixed':
                        $bodyParser = new ezcMailMultipartMixedParser( $headers );
                        break;
                    case 'alternative':
                        $bodyParser = new ezcMailMultipartAlternativeParser( $headers );
                        break;
                    case 'related':
                        $bodyParser = new ezcMailMultipartRelatedParser( $headers );
                        break;
                    case 'digest':
                        $bodyParser = new ezcMailMultipartDigestParser( $headers );
                        break;
                    case 'report':
                        $bodyParser = new ezcMailMultipartReportParser( $headers );
                        break;
                    default:
                        $bodyParser = new ezcMailMultipartMixedParser( $headers );
                        break;
                }
                break;

                /* extensions */
            default:
                // we treat the body as binary if no main content type is set
                // or if it is unknown
                $bodyParser = new ezcMailFileParser( $mainType, $subType, $headers );
                break;
        }
        return $bodyParser;
    }

    /**
     * Parses the header given by $line and adds to $headers.
     *
     * This method is usually used to parse the headers for a subpart. The
     * only exception is RFC822 parts since you know the type in advance.
     *
     * @todo deal with headers that are listed several times
     * @param string $line
     * @param ezcMailHeadersHolder $headers
     */
    protected function parseHeader( $line, ezcMailHeadersHolder $headers )
    {
        $matches = array();
        preg_match_all( "/^([\w_-]*):\s?(.*)/", $line, $matches, PREG_SET_ORDER );
        if ( count( $matches ) > 0 )
        {
            if ( !in_array( strtolower( $matches[0][1] ), self::$uniqueHeaders ) )
            {
                $arr = $headers[$matches[0][1]];
                $arr[0][] = str_replace( "\t", " ", trim( $matches[0][2] ) );
                $headers[$matches[0][1]] = $arr;
            }
            else
            {
                $headers[$matches[0][1]] = str_replace( "\t", " ", trim( $matches[0][2] ) );
            }
            $this->lastParsedHeader = $matches[0][1];
        }
        else if ( $this->lastParsedHeader !== null ) // take care of folding
        {
            if ( !in_array( strtolower( $this->lastParsedHeader ), self::$uniqueHeaders ) )
            {
                $arr = $headers[$this->lastParsedHeader];
                $arr[0][count( $arr[0] ) - 1] .= str_replace( "\t", " ", $line );
                $headers[$this->lastParsedHeader] = $arr;
            }
            else
            {
                $headers[$this->lastParsedHeader] .= str_replace( "\t", " ", $line );
            }
        }
        // else -invalid syntax, this should never happen.
    }

    /**
     * Scans through $headers and sets any specific header properties on $part.
     *
     * Currently we only have Content-Disposition on the ezcMailPart level.
     * All parser parts must call this method once.
     *
     * @param ezcMailHeadersHolder $headers
     * @param ezcMailPart $part
     */
    static public function parsePartHeaders( ezcMailHeadersHolder $headers, ezcMailPart $part )
    {
        if ( isset( $headers['Content-Disposition'] ) )
        {
            $part->contentDisposition = ezcMailRfc2231Implementation::parseContentDisposition( $headers['Content-Disposition'] );
        }
    }
}

?>
