<?php
/**
 * File containing the ezcMailMultipartRelated 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
 */

/**
 * ezcMailMultipartRelated is intended for mail parts consisting of
 * several inter-related body parts.
 *
 * A typical example is an HTML mail with embedded images.
 * When you want to refer to a related part you can use content id's
 * (cid). Set the 'Content-ID' header of the related part to a valid
 * unique url-addr-spec (specified by RFC 822) and refer to it through
 * the form cid:unique-string.
 *
 * Example:
 * This example shows how you can use ezcMailMultipartRelated to create an
 * HTML mail with an inline image.
 * <code>
 * $mail = new ezcMail();
 * $mail->from = new ezcMailAddress( 'sender@example.com', 'Adrian Ripburger' );
 * $mail->addTo( new ezcMailAddress( 'receiver@example.com', 'Maureen Corley' ) );
 * $mail->subject = "Example of an HTML email with attachments";
 * $htmlText = new ezcMailText( "<html>Image <img src='cid:image@12345' /></html>" );
 * $htmlText->subType = 'html';
 * $image = new ezcMailFile( "path_to_my_image.jpg" );
 * $image->contentId = 'image@12345';
 * $mail->body = new ezcMailMultipartRelated( $htmlText, $image );
 * </code>
 *
 * @package Mail
 * @version //autogen//
 */
class ezcMailMultipartRelated extends ezcMailMultipart
{
    /**
     * Constructs a new ezcMailMultipartRelated.
     *
     * The constructor accepts an arbitrary number of ezcMailParts or arrays with ezcMailparts.
     * Parts are added in the order provided and the first part will be recognized
     * as the main body. Parameters of the wrong type are ignored.
     *
     * @param ezcMailPart|array(ezcMailPart) $...
     */
    public function __construct()
    {
        $args = func_get_args();
        parent::__construct( $args );
    }

    /**
     * Sets the main part $part of this alternative multipart.
     *
     * @param ezcMailPart $part
     */
    public function setMainPart( ezcMailPart $part )
    {
        $this->parts[0] = $part;
    }

    /**
     * Adds $part to the list of parts and returns the Content-ID of the part.
     *
     * @param ezcMailPart $part
     * @return string
     */
    public function addRelatedPart( ezcMailPart $part  )
    {
        // it doesn't have a Content-ID, we must set one.
        $contentId = '';
        if ( $part->getHeader( 'Content-ID' ) == '' )
        {
            if ( $part instanceof ezcMailFile )
            {
                $part->contentId = ezcMailTools::generateContentId( basename( $part->fileName ) );
            }
            else
            {
                $part->setHeader( 'Content-ID', ezcMailTools::generateContentId( 'part' ) );
            }
        }
        $contentId = trim( $part->getHeader( 'Content-ID' ), '<>' );

        // Set the content ID property of the ezcMailFile if one was found
        if ( $part instanceof ezcMailFile )
        {
            $part->contentId = $contentId;
        }

        if ( count( $this->parts ) > 0 )
        {
            $this->parts[] = $part;
        }
        else
        {
            $this->parts[1] = $part;
        }
        return $contentId;
    }

    /**
     * Returns the main part of this multipart or null if there is no such part.
     *
     * @return array(ezcMailPart)
     */
    public function getMainPart()
    {
        if ( isset( $this->parts[0] ) )
        {
            return $this->parts[0];
        }
        return null;
    }

    /**
     * Returns the mail parts associated with this multipart.
     *
     * @return array(ezcMailPart)
     */
    public function getRelatedParts()
    {
        if ( is_null( $this->getMainPart() ) )
        {
            return array_slice( $this->parts, 0 );
        }
        return array_slice( $this->parts, 1 );
    }

    /**
     * Returns the part associated with the passed Content-ID.
     *
     * @param string $cid
     * @return ezcMailPart
     */
    public function getRelatedPartByID( $cid )
    {
        $parts = $this->getRelatedParts();
        foreach ( $parts as $part )
        {
            if ( ( $part->getHeader( 'Content-ID' ) !== '' ) &&
                ( $part->getHeader( 'Content-ID' ) == "<$cid>" ) )
            {
                return $part;
            }
        }
        return false;
    }

    /**
     * Returns "related".
     *
     * @return string
     */
    public function multipartType()
    {
        return "related";
    }

    /**
     * Substitutes links in all ezcMailText parts with the subType HTML in this multipart/alternative.
     *
     * This method will perform substitution of CID's and absolute and relative links as specified by
     * RFC 2557 for links that resolve to files. Links to other message parts must be resolved when
     * displaying the message.
     *
     * - provide methods for substitution of these as well (inclusive listing of which they are)
     * @todo Move to separate class.
     */
    private function resolveHtmlLinks()
    {
        // 1. Check that the main part is a html part
        // 2. Go through the related parts and build up a structure of available
        //    CIDS and locations
        // 3. Substitute in this message.
    }
}
?>
