/********************************************************************************
 *                                                                              *
 * 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 <boost/algorithm/string.hpp>

#include "../ifcgeom/IfcGeomIterator.h"

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

#include <IGESControl_Controller.hxx>

static std::string DEFAULT_EXTENSION = "obj";

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 Asset 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
	          << "  .xml   XML            Property definitions and decomposition tree" << std::endl
			  << "  .svg   SVG            Scalable Vector Graphics (2d floor plan)" << 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::string bounds;
	std::vector<std::string> entity_vector;
	boost::program_options::options_description geom_options;
	geom_options.add_options()
		("plan",
			"Specifies whether to include curves in the output result. Typically "
			"these are representations of type Plan or Axis. Excluded by default.")
		("model",
			"Specifies whether to include surfaces and solids in the output result. "
			"Typically these are representations of type Body or Facetation. "
			"Included by default.")
		("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 artefacts 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.")
		("disable-opening-subtractions", 
			"Specifies whether to disable the boolean subtraction of "
			"IfcOpeningElement Representations from their RelatingElements.")
		("bounds", boost::program_options::value<std::string>(&bounds),
			"Specifies the bounding rectangle, for example 512x512, to which the " 
			"output will be scaled. Only used when converting to SVG.")
		("include", 
			"Specifies that the entities listed after --entities are to be included")
		("exclude", 
			"Specifies that the entities listed after --entities are to be excluded")
		("entities", boost::program_options::value< std::vector<std::string> >(&entity_vector)->multitoken(), 
			"A list of entities that should be included in or excluded from the "
			"geometrical output, depending on whether --ignore or --include is "
			"specified. Defaults to IfcOpeningElement and IfcSpace to be excluded.");
	
	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
	} catch (...) {
		// Catch other errors such as invalid command line syntax
	}
	boost::program_options::notify(vmap);

	if (vmap.count("version")) {
		printVersion();
		return 0;
	} else if (vmap.count("help") || !vmap.count("input-file")) {
		printUsage(generic_options, geom_options);
		return vmap.count("help") ? 0 : 1;
	} else if (vmap.count("include") && vmap.count("exclude")) {
		std::cerr << "[Error] --include and --ignore can not be specified together" << std::endl;
		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 disable_opening_subtractions = vmap.count("disable-opening-subtractions") != 0;
	bool include_entities = vmap.count("include") != 0;
	const bool include_plan = vmap.count("plan") != 0;
	const bool include_model = vmap.count("model") != 0 || (!include_plan);
	boost::optional<int> bounding_width, bounding_height;
	if (vmap.count("bounds") == 1) {
		int w, h;
		if (sscanf(bounds.c_str(), "%ux%u", &w, &h) == 2) {
			bounding_width = w;
			bounding_height = h;
		} else {
			std::cerr << "[Error] Invalid use of --bounds" << std::endl;
			printUsage(generic_options, geom_options);
			return 1;
		}
	}

	// Gets the set ifc types to be ignored from the command line. 
	std::set<std::string> entities;
	for (std::vector<std::string>::const_iterator it = entity_vector.begin(); it != entity_vector.end(); ++it) {
		const std::string& mixed_case_type = *it;
		entities.insert(boost::to_lower_copy(mixed_case_type));
	}
	
	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, DEFAULT_EXTENSION);
	
	if (output_filename.size() < 5) {
		printUsage(generic_options, geom_options);
		return 1;
	}

	std::string output_extension = output_filename.substr(output_filename.size()-4);
	boost::to_lower(output_extension);

	// If no entities are specified these are the defaults to skip from output
	if (entity_vector.empty()) {
		if (output_extension == ".svg") {
			entities.insert("ifcspace");
			include_entities = true;
		} else {
			entities.insert("ifcopeningelement");
			entities.insert("ifcspace");
		}
	}

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

	if (output_extension == ".xml") {
		int exit_code = 1;
		try {
			XmlSerializer s(output_filename);
			IfcParse::IfcFile f;
			if (!f.Init(input_filename)) {
				Logger::Message(Logger::LOG_ERROR, "Unable to parse .ifc file");
			} else {
				s.setFile(&f);
				s.finalize();
				exit_code = 0;
			}
		} catch (...) {}
		write_log();
		return exit_code;
	}

	IfcGeom::IteratorSettings settings;

	settings.set(IfcGeom::IteratorSettings::APPLY_DEFAULT_MATERIALS,      true);
	settings.set(IfcGeom::IteratorSettings::USE_WORLD_COORDS,             use_world_coords);
	settings.set(IfcGeom::IteratorSettings::WELD_VERTICES,                weld_vertices);
	settings.set(IfcGeom::IteratorSettings::SEW_SHELLS,                   sew_shells);
	settings.set(IfcGeom::IteratorSettings::CONVERT_BACK_UNITS,           convert_back_units);
	settings.set(IfcGeom::IteratorSettings::FASTER_BOOLEANS,              merge_boolean_operands);
	settings.set(IfcGeom::IteratorSettings::DISABLE_OPENING_SUBTRACTIONS, disable_opening_subtractions);
	settings.set(IfcGeom::IteratorSettings::INCLUDE_CURVES,               include_plan);
	settings.set(IfcGeom::IteratorSettings::EXCLUDE_SOLIDS_AND_SURFACES,  !include_model);

	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");
			settings.set(IfcGeom::IteratorSettings::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 if (output_extension == ".svg") {
		settings.set(IfcGeom::IteratorSettings::DISABLE_TRIANGULATION, true);
		serializer = new SvgSerializer(output_filename);
		if (bounding_width && bounding_height) {
			((SvgSerializer*) serializer)->setBoundingRectangle(
				static_cast<double>(*bounding_width), 
				static_cast<double>(*bounding_height)
			);
		}
	} else {
		Logger::Message(Logger::LOG_ERROR, "Unknown output filename extension");
		write_log();
		printUsage(generic_options, geom_options);
		return 1;
	}

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

	IfcGeom::Iterator<double> context_iterator(settings, input_filename);

	try {
		if (include_entities) {
			context_iterator.includeEntities(entities);
		} else {
			context_iterator.excludeEntities(entities);
		}
	} catch (const IfcParse::IfcException& e) {
		std::cout << "[Error] " << e.what() << std::endl;
		return 1;
	}

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

	time_t start,end;
	time(&start);
	
	if (!context_iterator.initialize()) {
		Logger::Message(Logger::LOG_ERROR, "Unable to parse .ifc file or no geometrical entities found");
		write_log();
		return 1;
	}

	serializer->setFile(context_iterator.getFile());

	if (convert_back_units) {
		serializer->setUnitNameAndMagnitude(context_iterator.getUnitName(), static_cast<const float>(context_iterator.getUnitMagnitude()));
	} else {
		serializer->setUnitNameAndMagnitude("METER", 1.0f);
	}

	serializer->writeHeader();

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

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

	// The functions IfcGeom::Iterator::get() and IfcGeom::Iterator::next() 
	// wrap an iterator of all geometrical products in the Ifc file. 
	// IfcGeom::Iterator::get() returns an IfcGeom::TriangulationElement or 
	// -BRepElement pointer, based on current settings. (see IfcGeomIterator.h 
	// for definition) IfcGeom::Iterator::next() is used to poll whether more 
	// geometrical entities are available. None of these functions throw 
	// exceptions, neither for parsing errors or geometrical errors. Upon 
	// calling next() the entity to be returned has already been processed, a 
	// true return value guarantees that a successfully processed product is 
	// available. 
	do {
		const IfcGeom::Element<double>* geom_object = context_iterator.get();
		
		if (serializer->isTesselated()) {
			serializer->write(static_cast<const IfcGeom::TriangulationElement<double>*>(geom_object));
		} else {
			serializer->write(static_cast<const IfcGeom::BRepElement<double>*>(geom_object));
		}
		
		const int progress = context_iterator.progress() / 2;
		if (old_progress!= progress) Logger::ProgressBar(progress);
		old_progress = progress;
	
	} while (context_iterator.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 );

	return 0;
}

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