/********************************************************************************
 *                                                                              *
 * This file is part of IfcOpenShell.                                           *
 *                                                                              *
 * IfcOpenShell is free software: you can redistribute it and/or modify         *
 * it under the terms of the Lesser GNU General Public License as published by  *
 * the Free Software Foundation, either version 3.0 of the License, or          *
 * (at your option) any later version.                                          *
 *                                                                              *
 * IfcOpenShell 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                 *
 * Lesser GNU General Public License for more details.                          *
 *                                                                              *
 * You should have received a copy of the Lesser GNU General Public License     *
 * along with this program. If not, see <http://www.gnu.org/licenses/>.         *
 *                                                                              *
 ********************************************************************************/

/********************************************************************************
 *                                                                              *
 * This started as a brief example of how IfcOpenShell can be interfaced from   * 
 * within a C++ context, it has since then evolved into a fullfledged command   *
 * line application that is able to convert geometry in an IFC files into       *
 * several tesselated and topological output formats.                           *
 *                                                                              *
 ********************************************************************************/

#include <fstream>
#include <sstream>
#include <set>
#include <time.h>

#include <boost/program_options.hpp>

#include "../ifcgeom/IfcGeomObjects.h"

#include "../ifcconvert/ColladaSerializer.h"
#include "../ifcconvert/IgesSerializer.h"
#include "../ifcconvert/StepSerializer.h"
#include "../ifcconvert/WavefrontObjSerializer.h"

void printVersion() {
	std::cerr << "IfcOpenShell IfcConvert " << IFCOPENSHELL_VERSION << std::endl;
}

void printUsage(const boost::program_options::options_description& generic_options, const boost::program_options::options_description& geom_options) {
	printVersion();
	std::cerr << "Usage: IfcConvert [options] <input.ifc> [<output>]" << std::endl
	          << std::endl
	          << "Converts the geometry in an IFC file into one of the following formats:" << std::endl
	          << "  .obj   WaveFront OBJ  (a .mtl file is also created)" << std::endl;
#ifdef WITH_OPENCOLLADA	          
	std::cerr << "  .dae   Collada        Digital Assets Exchange" << std::endl;
#endif
	std::cerr << "  .stp   STEP           Standard for the Exchange of Product Data" << std::endl
	          << "  .igs   IGES           Initial Graphics Exchange Specification" << std::endl
	          << std::endl
	          << "Command line options" << std::endl << generic_options << std::endl
	          << "Advanced options" << std::endl << geom_options << std::endl;
}

std::string change_extension(const std::string& fn, const std::string& ext) {
	std::string::size_type dot = fn.find_last_of('.');
	if (dot != std::string::npos) {
		return fn.substr(0,dot+1) + ext;
	} else {
		return fn + "." + ext;
	}
}

static std::stringstream log_stream;
void write_log();

int main(int argc, char** argv) {
	boost::program_options::options_description generic_options;
	generic_options.add_options()
		("help", "display usage information")
		("version", "display version information")
		("verbose,v", "more verbose output");

	boost::program_options::options_description fileio_options;
	fileio_options.add_options()
		("input-file", boost::program_options::value<std::string>(), "input IFC file")
		("output-file", boost::program_options::value<std::string>(), "output geometry file");

	std::vector<std::string> ignore_types_vector;
	boost::program_options::options_description geom_options;
	geom_options.add_options()
		("weld-vertices", "Specifies whether vertices are welded, meaning that the coordinates "
						  "vector will only contain unique xyz-triplets. This results in a "
					      "manifold mesh which is useful for modelling applications, but might "
					      "result in unwanted shading artifacts in rendering applications.")
		("use-world-coords", "Specifies whether to apply the local placements of building elements "
						     "directly to the coordinates of the representation mesh rather than "
						     "to represent the local placement in the 4x3 matrix, which will in that "
						     "case be the identity matrix.")
		("convert-back-units", "Specifies whether to convert back geometrical output back to the "
							   "unit of measure in which it is defined in the IFC file. Default is "
							   "to use meters.")
		("sew-shells", "Specifies whether to sew the faces of IfcConnectedFaceSets together. This is a "
					   "potentially time consuming operation, but guarantees a consistent orientation "
					   "of surface normals, even if the faces are not properly oriented in the IFC file.")
		("merge-boolean-operands", "Specifies whether to merge all IfcOpeningElement operands into a single "
								   "operand before applying the subtraction operation. This may "
								   "introduce a performance improvement at the risk of failing, in "
								   "which case the subtraction is applied one-by-one.")
		("force-ccw-face-orientation", "Recompute topological face normals using Newell's Method to "
									   "guarantee that face vertices are defined in a Counter Clock "
									   "Wise order, even if the faces are not part of a closed shell.")
		("disable-opening-subtractions", "Specifies whether to disable the boolean subtraction of "
										 "IfcOpeningElement Representations from their RelatingElements.")
		("ignore-types", boost::program_options::value< std::vector<std::string> >(&ignore_types_vector)->multitoken(), 
			"A list of IFC datatype keywords that should not be included in the geometrical output. "
			"Defaults to IfcOpeningElement and IfcSpace");
	
	boost::program_options::options_description cmdline_options;
	cmdline_options.add(generic_options).add(fileio_options).add(geom_options);

	boost::program_options::positional_options_description positional_options;
	positional_options.add("input-file", 1);
	positional_options.add("output-file", 1);

	boost::program_options::variables_map vmap;
	try {
		boost::program_options::store(boost::program_options::command_line_parser(argc, argv).
				  options(cmdline_options).positional(positional_options).run(), vmap);
	} catch (const boost::program_options::unknown_option& e) {
		std::cerr << "[Error] Unknown option '" << e.get_option_name() << "'" << std::endl << std::endl;
		// Usage information will be emitted below
	}
	boost::program_options::notify(vmap);

	if (vmap.count("version")) {
		printVersion();
		return 1;
	} else if (vmap.count("help") || !vmap.count("input-file")) {
		printUsage(generic_options, geom_options);
		return 1;
	}

	const bool verbose = vmap.count("verbose") != 0;
	const bool weld_vertices = vmap.count("weld-vertices") != 0;
	const bool use_world_coords = vmap.count("use-world-coords") != 0;
	const bool convert_back_units = vmap.count("convert-back-units") != 0;
	const bool sew_shells = vmap.count("sew-shells") != 0;
	const bool merge_boolean_operands = vmap.count("merge-boolean-operands") != 0;
	const bool force_ccw_face_orientation = vmap.count("force-ccw-face-orientation") != 0;
	const bool disable_opening_subtractions = vmap.count("disable-opening-subtractions") != 0;

	// Gets the set ifc types to be ignored from the command line. 
	std::set<std::string> ignore_types;
	for (std::vector<std::string>::const_iterator it = ignore_types_vector.begin(); it != ignore_types_vector.end(); ++it) {
		std::string lowercase_type = *it;
		for (std::string::iterator c = lowercase_type.begin(); c != lowercase_type.end(); ++c) {
			*c = tolower(*c);
		}
		ignore_types.insert(lowercase_type);
	}
	// If none are specified these are the defaults to skip from output
	if (ignore_types_vector.empty()) {
		ignore_types.insert("ifcopeningelement");
		ignore_types.insert("ifcspace");
	}
	
	const std::string input_filename = vmap["input-file"].as<std::string>();
	// If no output filename is specified a Wavefront OBJ file will be output
	// to maintain backwards compatibility with the obsolete IfcObj executable.
	const std::string output_filename = vmap.count("output-file") == 1 
		? vmap["output-file"].as<std::string>()
		: change_extension(input_filename, "obj");
	
	if (output_filename.size() < 5) {
		printUsage(generic_options, geom_options);
		return 1;
	}

	IfcGeomObjects::Settings(IfcGeomObjects::USE_WORLD_COORDS, use_world_coords);
	IfcGeomObjects::Settings(IfcGeomObjects::WELD_VERTICES, weld_vertices);
	IfcGeomObjects::Settings(IfcGeomObjects::SEW_SHELLS, sew_shells);
	IfcGeomObjects::Settings(IfcGeomObjects::CONVERT_BACK_UNITS, convert_back_units);
	IfcGeomObjects::Settings(IfcGeomObjects::FASTER_BOOLEANS, merge_boolean_operands);
	IfcGeomObjects::Settings(IfcGeomObjects::FORCE_CCW_FACE_ORIENTATION, force_ccw_face_orientation);
	IfcGeomObjects::Settings(IfcGeomObjects::DISABLE_OPENING_SUBTRACTIONS, disable_opening_subtractions);

	std::string output_extension = output_filename.substr(output_filename.size()-4);
	for (std::string::iterator c = output_extension.begin(); c != output_extension.end(); ++c) {
		*c = tolower(*c);
	}

	Logger::SetOutput(&std::cout, &log_stream);
	Logger::Verbosity(verbose ? Logger::LOG_NOTICE : Logger::LOG_ERROR);

	GeometrySerializer* serializer;
	if (output_extension == ".obj") {
		const std::string mtl_filename = output_filename.substr(0,output_filename.size()-3) + "mtl";
		if (!use_world_coords) {
			Logger::Message(Logger::LOG_NOTICE, "Using world coords when writing WaveFront OBJ files");
			IfcGeomObjects::Settings(IfcGeomObjects::USE_WORLD_COORDS, true);
		}
		serializer = new WaveFrontOBJSerializer(output_filename, mtl_filename);
#ifdef WITH_OPENCOLLADA
	} else if (output_extension == ".dae") {
		serializer = new ColladaSerializer(output_filename);
#endif
	} else if (output_extension == ".stp") {
		serializer = new StepSerializer(output_filename);
	} else if (output_extension == ".igs") {
		// Not sure why this is needed, but it is.
		// See: http://tracker.dev.opencascade.org/view.php?id=23679
		IGESControl_Controller::Init();
		serializer = new IgesSerializer(output_filename);
	} else {
		Logger::Message(Logger::LOG_ERROR, "Unknown output filename extension");
		write_log();
		printUsage(generic_options, geom_options);
		return 1;
	}

	if (!serializer->ready()) {
		Logger::Message(Logger::LOG_ERROR, "Unable to open output file for writing");
		write_log();
		return 1;
	}

	if (!serializer->isTesselated()) {
		IfcGeomObjects::Settings(IfcGeomObjects::DISABLE_TRIANGULATION, true);
		if (weld_vertices) {
			Logger::Message(Logger::LOG_NOTICE, "Weld vertices setting ignored when writing STEP or IGES files");
		}
	}

	time_t start,end;
	time(&start);
	// Parse the file supplied in argv[1]. Returns true on succes.
	if ( ! IfcGeomObjects::Init(input_filename, &std::cout, &log_stream) ) {
		Logger::Message(Logger::LOG_ERROR, "Unable to parse .ifc file or no geometrical entities found");
		write_log();
		return 1;
	}

	if (convert_back_units) {
		serializer->setUnitNameAndMagnitude(IfcGeomObjects::GetUnitName(), IfcGeomObjects::GetUnitMagnitude());
	} else {
		serializer->setUnitNameAndMagnitude("METER", 1.0f);
	}

	serializer->writeHeader();

	std::set<std::string> materials;

	int old_progress = -1;
	Logger::Status("Creating geometry...");

	// The functions IfcGeomObjects::Get() and IfcGeomObjects::Next() wrap an iterator of all geometrical entities in the Ifc file.
	// IfcGeomObjects::Get() returns an IfcGeomObjects::IfcGeomObject (see IfcGeomObjects.h for definition)
	// IfcGeomObjects::Next() is used to poll whether more geometrical entities are available    
	do {
		const IfcGeomObjects::IfcObject* geom_object;
		
		if (serializer->isTesselated()) {
			geom_object = IfcGeomObjects::Get();
		} else {
			geom_object = IfcGeomObjects::GetShapeModel();
		}

		std::string lowercase_type = geom_object->type();
		for (std::string::iterator c = lowercase_type.begin(); c != lowercase_type.end(); ++c) {
			*c = tolower(*c);
		}
		if (ignore_types.find(lowercase_type) != ignore_types.end()) continue;

		if (serializer->isTesselated()) {
			serializer->writeTesselated(static_cast<const IfcGeomObjects::IfcGeomObject*>(geom_object));
		} else {
			serializer->writeShapeModel(static_cast<const IfcGeomObjects::IfcGeomShapeModelObject*>(geom_object));
		}

		const int progress = IfcGeomObjects::Progress() / 2;
		if ( old_progress!= progress ) Logger::ProgressBar(progress);
		old_progress = progress;
	
	} while ( IfcGeomObjects::Next() );

	serializer->finalize();
	delete serializer;

	Logger::Status("\rDone creating geometry                                ");

	write_log();

	time(&end);
	int dif = (int) difftime (end,start);	
	printf ("\nConversion took %d seconds\n", dif );
}

void write_log() {
	std::string log = log_stream.str();
	if (!log.empty()) {
		std::cerr << std::endl << "Log:" << std::endl;
		std::cerr << log << std::endl;
	}
}