/*
    Copyright (C) 2012 Carl Hetherington <cth@carlh.net>

    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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

/** @file  src/asset.cc
 *  @brief Parent class for assets of DCPs made up of MXF files.
 */

#include <iostream>
#include <boost/filesystem.hpp>
#include <libxml++/nodes/element.h>
#include "AS_DCP.h"
#include "KM_prng.h"
#include "KM_util.h"
#include "mxf_asset.h"
#include "util.h"
#include "metadata.h"
#include "exceptions.h"
#include "kdm.h"
#include "raw_convert.h"

using std::string;
using std::list;
using std::pair;
using boost::shared_ptr;
using boost::dynamic_pointer_cast;
using namespace libdcp;

MXFAsset::MXFAsset (boost::filesystem::path directory, boost::filesystem::path file_name)
	: Asset (directory, file_name)
	, _progress (0)
	, _encryption_context (0)
	, _decryption_context (0)
	, _interop (false)
{

}

MXFAsset::~MXFAsset ()
{
	delete _encryption_context;
	delete _decryption_context;
}

void
MXFAsset::fill_writer_info (ASDCP::WriterInfo* writer_info)
{
	writer_info->ProductVersion = _metadata.product_version;
	writer_info->CompanyName = _metadata.company_name;
	writer_info->ProductName = _metadata.product_name.c_str();

	if (_interop) {
		writer_info->LabelSetType = ASDCP::LS_MXF_INTEROP;
	} else {
		writer_info->LabelSetType = ASDCP::LS_MXF_SMPTE;
	}
	unsigned int c;
	Kumu::hex2bin (_uuid.c_str(), writer_info->AssetUUID, Kumu::UUID_Length, &c);
	assert (c == Kumu::UUID_Length);

	if (_key) {
		Kumu::GenRandomUUID (writer_info->ContextID);
		writer_info->EncryptedEssence = true;

		unsigned int c;
		Kumu::hex2bin (_key_id.c_str(), writer_info->CryptographicKeyID, Kumu::UUID_Length, &c);
		assert (c == Kumu::UUID_Length);
	}
}

bool
MXFAsset::equals (shared_ptr<const Asset> other, EqualityOptions opt, boost::function<void (NoteType, string)> note) const
{
	if (!Asset::equals (other, opt, note)) {
		return false;
	}
	
	shared_ptr<const MXFAsset> other_mxf = dynamic_pointer_cast<const MXFAsset> (other);
	if (!other_mxf) {
		note (ERROR, "comparing an MXF asset with a non-MXF asset");
		return false;
	}
	
	if (_file_name != other_mxf->_file_name) {
		note (ERROR, "MXF names differ");
		if (!opt.mxf_names_can_differ) {
			return false;
		}
	}
	
	return true;
}

void
MXFAsset::write_to_cpl (xmlpp::Element* node) const
{
	pair<string, string> const attr = cpl_node_attribute ();
	xmlpp::Element* a = node->add_child (cpl_node_name ());
	if (!attr.first.empty ()) {
		a->set_attribute (attr.first, attr.second);
	}
	a->add_child ("Id")->add_child_text ("urn:uuid:" + _uuid);
	a->add_child ("AnnotationText")->add_child_text (_file_name.string ());
	a->add_child ("EditRate")->add_child_text (raw_convert<string> (_edit_rate) + " 1");
	a->add_child ("IntrinsicDuration")->add_child_text (raw_convert<string> (_intrinsic_duration));
	a->add_child ("EntryPoint")->add_child_text (raw_convert<string> (_entry_point));
	a->add_child ("Duration")->add_child_text (raw_convert<string> (_duration));
	if (!_key_id.empty ()) {
		a->add_child("KeyId")->add_child_text ("urn:uuid:" + _key_id);
	}
	a->add_child ("Hash")->add_child_text (digest ());
}

void
MXFAsset::set_key (Key key)
{
	_key = key;

	if (_key_id.empty ()) {
		/* No key ID so far; we now need one */
		_key_id = make_uuid ();
	}
	
	_decryption_context = new ASDCP::AESDecContext;
	if (ASDCP_FAILURE (_decryption_context->InitKey (_key->value ()))) {
		throw MiscError ("could not set up decryption context");
	}

	_encryption_context = new ASDCP::AESEncContext;
	if (ASDCP_FAILURE (_encryption_context->InitKey (_key->value ()))) {
		throw MiscError ("could not set up encryption context");
	}
	
	uint8_t cbc_buffer[ASDCP::CBC_BLOCK_SIZE];
	
	Kumu::FortunaRNG rng;
	if (ASDCP_FAILURE (_encryption_context->SetIVec (rng.FillRandom (cbc_buffer, ASDCP::CBC_BLOCK_SIZE)))) {
		throw MiscError ("could not set up CBC initialization vector");
	}
}