//
// VMime library (http://www.vmime.org)
// Copyright (C) 2002 Vincent Richard <vincent@vmime.org>
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 3 of
// the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// Linking this library statically or dynamically with other modules is making
// a combined work based on this library.  Thus, the terms and conditions of
// the GNU General Public License cover the whole combination.
//

#include "vmime/attachmentHelper.hpp"

#include "vmime/bodyPartAttachment.hpp"
#include "vmime/parsedMessageAttachment.hpp"
#include "vmime/generatedMessageAttachment.hpp"

#include "vmime/disposition.hpp"
#include "vmime/emptyContentHandler.hpp"

#include <iterator>


namespace vmime {


// static
bool attachmentHelper::isBodyPartAnAttachment(
	const shared_ptr <const bodyPart>& part,
	const unsigned int options
) {

	// First, try with "Content-Disposition" field.
	// If not present, we will try with "Content-Type" field.
	shared_ptr <const contentDispositionField> cdf =
		part->getHeader()->findField <contentDispositionField>(fields::CONTENT_DISPOSITION);

	if (cdf) {

		const contentDisposition disp = *cdf->getValue <contentDisposition>();

		if (disp.getName() != contentDispositionTypes::INLINE) {
			return true;
		}

		if ((options & INLINE_OBJECTS) == 0) {

			// If the Content-Disposition is 'inline' and there is no
			// Content-Id or Content-Location field, it may be an attachment
			if (!part->getHeader()->hasField(vmime::fields::CONTENT_ID) &&
			    !part->getHeader()->hasField(vmime::fields::CONTENT_LOCATION)) {

				// If this is the root part, it might not be an attachment
				if (!part->getParentPart()) {
					return false;
				}

				return true;
			}

			return false;
		}
	}

	// Assume "attachment" if type is not "text/..." or "multipart/...".
	mediaType type;
	bool hasContentTypeName = false;

	shared_ptr <const contentTypeField> ctf =
		part->getHeader()->findField <contentTypeField>(fields::CONTENT_TYPE);

	if (ctf) {

		type = *ctf->getValue <mediaType>();

		if (ctf->hasParameter("name")) {
			hasContentTypeName = true;
		}

	} else {

		// If this is the root part and no Content-Type field is present,
		// then this may not be a MIME message, so do not assume it is
		// an attachment
		if (!part->getParentPart()) {
			return false;
		}

		// No "Content-type" field: assume "application/octet-stream".
		type = mediaType(
			mediaTypes::APPLICATION,
			mediaTypes::APPLICATION_OCTET_STREAM
		);
	}

	if (type.getType() != mediaTypes::TEXT &&
	    type.getType() != mediaTypes::MULTIPART) {

		// Compatibility with (obsolete) RFC-1341: if there is a "name" parameter
		// on the "Content-Type" field, then we assume it is an attachment
		if (hasContentTypeName) {
			return true;
		}

		if ((options & INLINE_OBJECTS) == 0) {

			// If a "Content-Id" field is present, it might be an
			// embedded object (MHTML messages)
			if (part->getHeader()->hasField(vmime::fields::CONTENT_ID)) {
				return false;
			}
		}

		return true;
	}

	return false;
}


// static
shared_ptr <const attachment> attachmentHelper::getBodyPartAttachment(
	const shared_ptr <const bodyPart>& part,
	const unsigned int options
) {

	if (!isBodyPartAnAttachment(part, options)) {
		return null;
	}

	mediaType type;

	shared_ptr <const contentTypeField> ctf =
		part->getHeader()->findField <contentTypeField>(fields::CONTENT_TYPE);

	if (ctf) {

		type = *ctf->getValue <mediaType>();

	} else {

		// No "Content-type" field: assume "application/octet-stream".
		type = mediaType(
			mediaTypes::APPLICATION,
			mediaTypes::APPLICATION_OCTET_STREAM
		);
	}

	if (type.getType() == mediaTypes::MESSAGE &&
	    type.getSubType() == mediaTypes::MESSAGE_RFC822) {

		return make_shared <generatedMessageAttachment>(part);

	} else {

		return make_shared <bodyPartAttachment>(part);
	}
}


// static
const std::vector <shared_ptr <const attachment> >
	attachmentHelper::findAttachmentsInMessage(
		const shared_ptr <const message>& msg,
		const unsigned int options
	) {

	return findAttachmentsInBodyPart(msg, options);
}


// static
const std::vector <shared_ptr <const attachment> >
	attachmentHelper::findAttachmentsInBodyPart(
		const shared_ptr <const bodyPart>& part,
		const unsigned int options
	) {

	std::vector <shared_ptr <const attachment> > atts;

	// Test this part
	if (isBodyPartAnAttachment(part, options)) {

		atts.push_back(getBodyPartAttachment(part, options));

	// Find in sub-parts
	} else {

		shared_ptr <const body> bdy = part->getBody();

		for (size_t i = 0 ; i < bdy->getPartCount() ; ++i) {

			std::vector <shared_ptr <const attachment> > partAtts =
				findAttachmentsInBodyPart(bdy->getPartAt(i), options);

			std::copy(partAtts.begin(), partAtts.end(), std::back_inserter(atts));
		}
	}

	return atts;
}


// static
void attachmentHelper::addAttachment(const shared_ptr <message>& msg, const shared_ptr <attachment>& att) {

	// We simply search for a "multipart/mixed" part. If no one exists,
	// create it in the root part. This (very simple) algorithm should
	// work in the most cases.

	vmime::mediaType mpMixed(
		vmime::mediaTypes::MULTIPART,
		vmime::mediaTypes::MULTIPART_MIXED
	);

	shared_ptr <bodyPart> part = findBodyPart(msg, mpMixed);

	if (!part) {  // create it

		if (msg->getBody()->getPartCount() != 0) {

			// Create a new container part for the parts that were in
			// the root part of the message
			shared_ptr <bodyPart> container = make_shared <bodyPart>();

			if (msg->getHeader()->hasField(fields::CONTENT_TYPE)) {

				container->getHeader()->ContentType()->setValue(
					msg->getHeader()->ContentType()->getValue()
				);
			}

			if (msg->getHeader()->hasField(fields::CONTENT_TRANSFER_ENCODING)) {

				container->getHeader()->ContentTransferEncoding()->setValue(
					msg->getHeader()->ContentTransferEncoding()->getValue()
				);
			}

			// Move parts from the root part to this new part
			const std::vector <shared_ptr <bodyPart> > partList =
				msg->getBody()->getPartList();

			msg->getBody()->removeAllParts();

			for (unsigned int i = 0 ; i < partList.size() ; ++i) {
				container->getBody()->appendPart(partList[i]);
			}

			msg->getBody()->appendPart(container);

		} else {

			// The message is a simple (RFC-822) message, and do not
			// contains any MIME part. Move the contents from the
			// root to a new child part.
			shared_ptr <bodyPart> child = make_shared <bodyPart>();

			if (msg->getHeader()->hasField(fields::CONTENT_TYPE)) {

				child->getHeader()->ContentType()->setValue(
					msg->getHeader()->ContentType()->getValue()
				);
			}

			if (msg->getHeader()->hasField(fields::CONTENT_TRANSFER_ENCODING)) {

				child->getHeader()->ContentTransferEncoding()->setValue(
					msg->getHeader()->ContentTransferEncoding()->getValue()
				);
			}

			child->getBody()->setContents(msg->getBody()->getContents());
			msg->getBody()->setContents(make_shared <emptyContentHandler>());

			msg->getBody()->appendPart(child);
		}

		// Set the root part to 'multipart/mixed'
		msg->getHeader()->ContentType()->setValue(mpMixed);

		msg->getHeader()->removeAllFields(vmime::fields::CONTENT_DISPOSITION);
		msg->getHeader()->removeAllFields(vmime::fields::CONTENT_TRANSFER_ENCODING);

		part = msg;
	}

	// Generate the attachment part
	att->generateIn(part);
}


// static
shared_ptr <bodyPart> attachmentHelper::findBodyPart(
	const shared_ptr <bodyPart>& part,
	const mediaType& type
) {

	if (part->getBody()->getContentType() == type) {
		return part;
	}

	// Try in sub-parts
	shared_ptr <body> bdy = part->getBody();

	for (size_t i = 0 ; i < bdy->getPartCount() ; ++i) {

		shared_ptr <bodyPart> found = findBodyPart(bdy->getPartAt(i), type);

		if (found) {
			return found;
		}
	}

	return null;
}


// static
void attachmentHelper::addAttachment(const shared_ptr <message>& msg, const shared_ptr <message>& amsg) {

	shared_ptr <attachment> att = make_shared <parsedMessageAttachment>(amsg);
	addAttachment(msg, att);
}


} // vmime