/*
    Copyright (C) 2012-2015 Carl Hetherington <cth@carlh.net>

    This file is part of libdcp.

    libdcp 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.

    libdcp 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 libdcp.  If not, see <http://www.gnu.org/licenses/>.

    In addition, as a special exception, the copyright holders give
    permission to link the code of portions of this program with the
    OpenSSL library under certain conditions as described in each
    individual source file, and distribute linked combinations
    including the two.

    You must obey the GNU General Public License in all respects
    for all of the code used other than OpenSSL.  If you modify
    file(s) with this exception, you may extend this exception to your
    version of the file(s), but you are not obligated to do so.  If you
    do not wish to do so, delete this exception statement from your
    version.  If you delete this exception statement from all source
    files in the program, then also delete it here.
*/

/** @file  src/dcp.cc
 *  @brief DCP class.
 */

#include "raw_convert.h"
#include "dcp.h"
#include "sound_asset.h"
#include "atmos_asset.h"
#include "picture_asset.h"
#include "interop_subtitle_asset.h"
#include "smpte_subtitle_asset.h"
#include "mono_picture_asset.h"
#include "stereo_picture_asset.h"
#include "reel_subtitle_asset.h"
#include "util.h"
#include "metadata.h"
#include "exceptions.h"
#include "cpl.h"
#include "certificate_chain.h"
#include "compose.hpp"
#include "decrypted_kdm.h"
#include "decrypted_kdm_key.h"
#include "dcp_assert.h"
#include "reel_asset.h"
#include "font_asset.h"
#include "pkl.h"
#include "asset_factory.h"
#include "verify.h"
#include <asdcp/AS_DCP.h>
#include <xmlsec/xmldsig.h>
#include <xmlsec/app.h>
#include <libxml++/libxml++.h>
#include <boost/filesystem.hpp>
#include <boost/algorithm/string.hpp>
#include <boost/foreach.hpp>

using std::string;
using std::list;
using std::vector;
using std::cout;
using std::make_pair;
using std::map;
using std::cerr;
using std::exception;
using boost::shared_ptr;
using boost::dynamic_pointer_cast;
using boost::optional;
using boost::algorithm::starts_with;
using namespace dcp;

static string const assetmap_interop_ns = "http://www.digicine.com/PROTO-ASDCP-AM-20040311#";
static string const assetmap_smpte_ns   = "http://www.smpte-ra.org/schemas/429-9/2007/AM";
static string const volindex_interop_ns = "http://www.digicine.com/PROTO-ASDCP-VL-20040311#";
static string const volindex_smpte_ns   = "http://www.smpte-ra.org/schemas/429-9/2007/AM";

DCP::DCP (boost::filesystem::path directory)
	: _directory (directory)
{
	if (!boost::filesystem::exists (directory)) {
		boost::filesystem::create_directories (directory);
	}

	_directory = boost::filesystem::canonical (_directory);
}

/** Read a DCP.  This method does not do any deep checking of the DCP's validity, but
 *  if it comes across any bad things it will do one of two things.
 *
 *  Errors that are so serious that they prevent the method from working will result
 *  in an exception being thrown.  For example, a missing ASSETMAP means that the DCP
 *  can't be read without a lot of guesswork, so this will throw.
 *
 *  Errors that are not fatal will be added to notes, if it's non-0.  For example,
 *  if the DCP contains a mixture of Interop and SMPTE elements this will result
 *  in a note being added to the list.
 */
void
DCP::read (list<dcp::VerificationNote>* notes, bool ignore_incorrect_picture_mxf_type)
{
	/* Read the ASSETMAP and PKL */

	if (boost::filesystem::exists (_directory / "ASSETMAP")) {
		_asset_map = _directory / "ASSETMAP";
	} else if (boost::filesystem::exists (_directory / "ASSETMAP.xml")) {
		_asset_map = _directory / "ASSETMAP.xml";
	} else {
		boost::throw_exception (ReadError(String::compose("Could not find ASSETMAP nor ASSETMAP.xml in '%1'", _directory.string())));
	}

	cxml::Document asset_map ("AssetMap");

	asset_map.read_file (_asset_map.get());
	if (asset_map.namespace_uri() == assetmap_interop_ns) {
		_standard = INTEROP;
	} else if (asset_map.namespace_uri() == assetmap_smpte_ns) {
		_standard = SMPTE;
	} else {
		boost::throw_exception (XMLError ("Unrecognised Assetmap namespace " + asset_map.namespace_uri()));
	}

	list<shared_ptr<cxml::Node> > asset_nodes = asset_map.node_child("AssetList")->node_children ("Asset");
	map<string, boost::filesystem::path> paths;
	list<boost::filesystem::path> pkl_paths;
	BOOST_FOREACH (shared_ptr<cxml::Node> i, asset_nodes) {
		if (i->node_child("ChunkList")->node_children("Chunk").size() != 1) {
			boost::throw_exception (XMLError ("unsupported asset chunk count"));
		}
		string p = i->node_child("ChunkList")->node_child("Chunk")->string_child ("Path");
		if (starts_with (p, "file://")) {
			p = p.substr (7);
		}
		switch (*_standard) {
		case INTEROP:
			if (i->optional_node_child("PackingList")) {
				pkl_paths.push_back (p);
			} else {
				paths.insert (make_pair (remove_urn_uuid (i->string_child ("Id")), p));
			}
			break;
		case SMPTE:
		{
			optional<string> pkl_bool = i->optional_string_child("PackingList");
			if (pkl_bool && *pkl_bool == "true") {
				pkl_paths.push_back (p);
			} else {
				paths.insert (make_pair (remove_urn_uuid (i->string_child ("Id")), p));
			}
			break;
		}
		}
	}

	if (pkl_paths.empty()) {
		boost::throw_exception (XMLError ("No packing lists found in asset map"));
	}

	BOOST_FOREACH (boost::filesystem::path i, pkl_paths) {
		_pkls.push_back (shared_ptr<PKL>(new PKL(_directory / i)));
	}

	/* Now we have:
	     paths - map of files in the DCP that are not PKLs; key is ID, value is path.
	     _pkls - PKL objects for each PKL.

	   Read all the assets from the asset map.
	 */

	/* Make a list of non-CPL/PKL assets so that we can resolve the references
	   from the CPLs.
	*/
	list<shared_ptr<Asset> > other_assets;

	for (map<string, boost::filesystem::path>::const_iterator i = paths.begin(); i != paths.end(); ++i) {
		boost::filesystem::path path = _directory / i->second;

		if (i->second.empty()) {
			/* I can't see how this is valid, but it's
			   been seen in the wild with a DCP that
			   claims to come from ClipsterDCI 5.10.0.5.
			*/
			if (notes) {
				notes->push_back (VerificationNote(VerificationNote::VERIFY_WARNING, VerificationNote::EMPTY_ASSET_PATH));
			}
			continue;
		}

		if (!boost::filesystem::exists(path)) {
			if (notes) {
				notes->push_back (VerificationNote(VerificationNote::VERIFY_ERROR, VerificationNote::MISSING_ASSET, path));
			}
			continue;
		}

		/* Find the <Type> for this asset from the PKL that contains the asset */
		optional<string> pkl_type;
		BOOST_FOREACH (shared_ptr<PKL> j, _pkls) {
			pkl_type = j->type(i->first);
			if (pkl_type) {
				break;
			}
		}

		DCP_ASSERT (pkl_type);

		if (*pkl_type == CPL::static_pkl_type(*_standard) || *pkl_type == InteropSubtitleAsset::static_pkl_type(*_standard)) {
			xmlpp::DomParser* p = new xmlpp::DomParser;
			try {
				p->parse_file (path.string());
			} catch (std::exception& e) {
				delete p;
				throw ReadError(String::compose("XML error in %1", path.string()), e.what());
			}

			string const root = p->get_document()->get_root_node()->get_name ();
			delete p;

			if (root == "CompositionPlaylist") {
				shared_ptr<CPL> cpl (new CPL (path));
				if (_standard && cpl->standard() && cpl->standard().get() != _standard.get() && notes) {
					notes->push_back (VerificationNote(VerificationNote::VERIFY_ERROR, VerificationNote::MISMATCHED_STANDARD));
				}
				_cpls.push_back (cpl);
			} else if (root == "DCSubtitle") {
				if (_standard && _standard.get() == SMPTE && notes) {
					notes->push_back (VerificationNote(VerificationNote::VERIFY_ERROR, VerificationNote::MISMATCHED_STANDARD));
				}
				other_assets.push_back (shared_ptr<InteropSubtitleAsset> (new InteropSubtitleAsset (path)));
			}
		} else if (
			*pkl_type == PictureAsset::static_pkl_type(*_standard) ||
			*pkl_type == SoundAsset::static_pkl_type(*_standard) ||
			*pkl_type == AtmosAsset::static_pkl_type(*_standard) ||
			*pkl_type == SMPTESubtitleAsset::static_pkl_type(*_standard)
			) {

			other_assets.push_back (asset_factory(path, ignore_incorrect_picture_mxf_type));
		} else if (*pkl_type == FontAsset::static_pkl_type(*_standard)) {
			other_assets.push_back (shared_ptr<FontAsset> (new FontAsset (i->first, path)));
		} else if (*pkl_type == "image/png") {
			/* It's an Interop PNG subtitle; let it go */
		} else {
			throw ReadError (String::compose("Unknown asset type %1 in PKL", *pkl_type));
		}
	}

	resolve_refs (other_assets);

	/* While we've got the ASSETMAP lets look and see if this DCP refers to things that are not in its ASSETMAP */
	if (notes) {
		BOOST_FOREACH (shared_ptr<CPL> i, cpls()) {
			BOOST_FOREACH (shared_ptr<const ReelMXF> j, i->reel_mxfs()) {
				if (!j->asset_ref().resolved() && paths.find(j->asset_ref().id()) == paths.end()) {
					notes->push_back (VerificationNote(VerificationNote::VERIFY_WARNING, VerificationNote::EXTERNAL_ASSET, j->asset_ref().id()));
				}
			}
		}
	}
}

void
DCP::resolve_refs (list<shared_ptr<Asset> > assets)
{
	BOOST_FOREACH (shared_ptr<CPL> i, cpls ()) {
		i->resolve_refs (assets);
	}
}

bool
DCP::equals (DCP const & other, EqualityOptions opt, NoteHandler note) const
{
	list<shared_ptr<CPL> > a = cpls ();
	list<shared_ptr<CPL> > b = other.cpls ();

	if (a.size() != b.size()) {
		note (DCP_ERROR, String::compose ("CPL counts differ: %1 vs %2", a.size(), b.size()));
		return false;
	}

	bool r = true;

	BOOST_FOREACH (shared_ptr<CPL> i, a) {
		list<shared_ptr<CPL> >::const_iterator j = b.begin ();
		while (j != b.end() && !(*j)->equals (i, opt, note)) {
			++j;
		}

		if (j == b.end ()) {
			r = false;
		}
	}

	return r;
}

void
DCP::add (boost::shared_ptr<CPL> cpl)
{
	_cpls.push_back (cpl);
}

bool
DCP::encrypted () const
{
	BOOST_FOREACH (shared_ptr<CPL> i, cpls ()) {
		if (i->encrypted ()) {
			return true;
		}
	}

	return false;
}

/** Add a KDM to decrypt this DCP.  This method must be called after DCP::read()
 *  or the KDM you specify will be ignored.
 *  @param kdm KDM to use.
 */
void
DCP::add (DecryptedKDM const & kdm)
{
	list<DecryptedKDMKey> keys = kdm.keys ();

	BOOST_FOREACH (shared_ptr<CPL> i, cpls ()) {
		BOOST_FOREACH (DecryptedKDMKey const & j, kdm.keys ()) {
			if (j.cpl_id() == i->id()) {
				i->add (kdm);
			}
		}
	}
}

/** Write the VOLINDEX file.
 *  @param standard DCP standard to use (INTEROP or SMPTE)
 */
void
DCP::write_volindex (Standard standard) const
{
	boost::filesystem::path p = _directory;
	switch (standard) {
	case INTEROP:
		p /= "VOLINDEX";
		break;
	case SMPTE:
		p /= "VOLINDEX.xml";
		break;
	default:
		DCP_ASSERT (false);
	}

	xmlpp::Document doc;
	xmlpp::Element* root;

	switch (standard) {
	case INTEROP:
		root = doc.create_root_node ("VolumeIndex", volindex_interop_ns);
		break;
	case SMPTE:
		root = doc.create_root_node ("VolumeIndex", volindex_smpte_ns);
		break;
	default:
		DCP_ASSERT (false);
	}

	root->add_child("Index")->add_child_text ("1");
	doc.write_to_file_formatted (p.string (), "UTF-8");
}

void
DCP::write_assetmap (Standard standard, string pkl_uuid, boost::filesystem::path pkl_path, XMLMetadata metadata) const
{
	boost::filesystem::path p = _directory;

	switch (standard) {
	case INTEROP:
		p /= "ASSETMAP";
		break;
	case SMPTE:
		p /= "ASSETMAP.xml";
		break;
	default:
		DCP_ASSERT (false);
	}

	xmlpp::Document doc;
	xmlpp::Element* root;

	switch (standard) {
	case INTEROP:
		root = doc.create_root_node ("AssetMap", assetmap_interop_ns);
		break;
	case SMPTE:
		root = doc.create_root_node ("AssetMap", assetmap_smpte_ns);
		break;
	default:
		DCP_ASSERT (false);
	}

	root->add_child("Id")->add_child_text ("urn:uuid:" + make_uuid());
	root->add_child("AnnotationText")->add_child_text (metadata.annotation_text);

	switch (standard) {
	case INTEROP:
		root->add_child("VolumeCount")->add_child_text ("1");
		root->add_child("IssueDate")->add_child_text (metadata.issue_date);
		root->add_child("Issuer")->add_child_text (metadata.issuer);
		root->add_child("Creator")->add_child_text (metadata.creator);
		break;
	case SMPTE:
		root->add_child("Creator")->add_child_text (metadata.creator);
		root->add_child("VolumeCount")->add_child_text ("1");
		root->add_child("IssueDate")->add_child_text (metadata.issue_date);
		root->add_child("Issuer")->add_child_text (metadata.issuer);
		break;
	default:
		DCP_ASSERT (false);
	}

	xmlpp::Node* asset_list = root->add_child ("AssetList");

	xmlpp::Node* asset = asset_list->add_child ("Asset");
	asset->add_child("Id")->add_child_text ("urn:uuid:" + pkl_uuid);
	asset->add_child("PackingList")->add_child_text ("true");
	xmlpp::Node* chunk_list = asset->add_child ("ChunkList");
	xmlpp::Node* chunk = chunk_list->add_child ("Chunk");
	chunk->add_child("Path")->add_child_text (pkl_path.filename().string());
	chunk->add_child("VolumeIndex")->add_child_text ("1");
	chunk->add_child("Offset")->add_child_text ("0");
	chunk->add_child("Length")->add_child_text (raw_convert<string> (boost::filesystem::file_size (pkl_path)));

	BOOST_FOREACH (shared_ptr<Asset> i, assets ()) {
		i->write_to_assetmap (asset_list, _directory);
	}

	doc.write_to_file_formatted (p.string (), "UTF-8");
	_asset_map = p;
}

/** Write all the XML files for this DCP.
 *  @param standand INTEROP or SMPTE.
 *  @param metadata Metadata to use for PKL and asset map files.
 *  @param signer Signer to use, or 0.
 */
void
DCP::write_xml (
	Standard standard,
	XMLMetadata metadata,
	shared_ptr<const CertificateChain> signer,
	NameFormat name_format
	)
{
	BOOST_FOREACH (shared_ptr<CPL> i, cpls ()) {
		NameFormat::Map values;
		values['t'] = "cpl";
		i->write_xml (_directory / (name_format.get(values, "_" + i->id() + ".xml")), standard, signer);
	}

	shared_ptr<PKL> pkl;

	if (_pkls.empty()) {
		pkl.reset (new PKL (standard, metadata.annotation_text, metadata.issue_date, metadata.issuer, metadata.creator));
		_pkls.push_back (pkl);
		BOOST_FOREACH (shared_ptr<Asset> i, assets ()) {
			i->add_to_pkl (pkl, _directory);
		}
        } else {
		pkl = _pkls.front ();
	}

	NameFormat::Map values;
	values['t'] = "pkl";
	boost::filesystem::path pkl_path = _directory / name_format.get(values, "_" + pkl->id() + ".xml");
	pkl->write (pkl_path, signer);

	write_volindex (standard);
	write_assetmap (standard, pkl->id(), pkl_path, metadata);
}

list<shared_ptr<CPL> >
DCP::cpls () const
{
	return _cpls;
}

/** @param ignore_unresolved true to silently ignore unresolved assets, otherwise
 *  an exception is thrown if they are found.
 *  @return All assets (including CPLs).
 */
list<shared_ptr<Asset> >
DCP::assets (bool ignore_unresolved) const
{
	list<shared_ptr<Asset> > assets;
	BOOST_FOREACH (shared_ptr<CPL> i, cpls ()) {
		assets.push_back (i);
		BOOST_FOREACH (shared_ptr<const ReelMXF> j, i->reel_mxfs()) {
			if (ignore_unresolved && !j->asset_ref().resolved()) {
				continue;
			}

			string const id = j->asset_ref().id();
			bool already_got = false;
			BOOST_FOREACH (shared_ptr<Asset> k, assets) {
				if (k->id() == id) {
					already_got = true;
				}
			}

			if (!already_got) {
				shared_ptr<Asset> o = j->asset_ref().asset();
				assets.push_back (o);
				/* More Interop special-casing */
				shared_ptr<InteropSubtitleAsset> sub = dynamic_pointer_cast<InteropSubtitleAsset> (o);
				if (sub) {
					sub->add_font_assets (assets);
				}
			}
		}
	}

	return assets;
}

/** Given a list of files that make up 1 or more DCPs, return the DCP directories */
vector<boost::filesystem::path>
DCP::directories_from_files (vector<boost::filesystem::path> files)
{
	vector<boost::filesystem::path> d;
	BOOST_FOREACH (boost::filesystem::path i, files) {
		if (i.filename() == "ASSETMAP" || i.filename() == "ASSETMAP.xml") {
			d.push_back (i.parent_path ());
		}
	}
	return d;
}