/***********************************************************************************************************************
 *
 * Copyright (c) 2010 - 2025 by Tech Soft 3D, Inc.
 * The information contained herein is confidential and proprietary to Tech Soft 3D, Inc., and considered a trade secret
 * as defined under civil and criminal statutes. Tech Soft 3D shall pursue its civil and criminal remedies in the event
 * of unauthorized use or misappropriation of its trade secrets. Use of this information by anyone other than authorized
 * employees of Tech Soft 3D, Inc. is granted only under a written non-disclosure agreement, expressly prescribing the
 * scope and manner of such use.
 *
 ***********************************************************************************************************************/

#define INITIALIZE_A3D_API
#include <A3DSDKIncludes.h>
#include <hoops_license.h>

#include "../common.hpp"

#include <iostream>
#include <map>

#include <glad/glad.h>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

#include "application/application.h"
#include "application/camera.h"
#include "application/render/mesh.h"
#include "application/render/shader.h"
#include "application/render/vao.h"
#include "model/exchange.h"
#include "utils/properties.h"
#include "utils/bounding_box.h"
#include "utils/geometry.h"

static auto const exchange_bin_dir = _T(HOOPS_BINARY_DIRECTORY);



/*! Check if the file is valid.
*	\param [in] file_path The path to the model file.
*	\return true if the file is valid, else false. */
bool is_file_valid(const std::string& file_path, bool read = true) {
	if (FILE* file = fopen(file_path.c_str(), read ? "r" : "w")) {
		fclose(file);
		return true;
	}
	else {
		return false;
	}
}

/*! Manage the input command line arguments.
*	If no model file provided, open the default one (_micro engine.prc).
*	If `--dump_model_tree` option used, dump the model tree.
*	Finally create the resulting tree dump in the given output file.
*	\param argc The number of arguments.
*	\param argv The argument values.
*	\return the file to open and the xml file (tree dump) to create. */
std::pair<std::string, std::string> manage_input_arguments(int argc, char** argv) {
	std::string filename = std::string(SAMPLES_DATA_DIRECTORY) + "/prc/_micro engine.prc";
	std::string xmlfile;
	if (argc < 2) {
		std::cout << "Using file: " << filename << std::endl;
	}
	else {
		bool dump_tree = false;
		for (auto i = 1; i < argc; ++i) {
			if(strcmp(argv[i], "--dump_model_tree") == 0) {
				dump_tree = true;
				continue;
			}
			if (!is_file_valid(argv[i], !dump_tree)) {
				std::cout << "Invalid file provided. ";
				dump_tree = false;
			}
			else {
				if (dump_tree)
				{
					xmlfile = argv[i];
					dump_tree = false;
				}
				else
				{
					filename = argv[i];
					std::cout << "Valid file provided. ";
				}
			}
		}
	}
	std::cout << "Using file: " << filename << std::endl;
	return { filename, xmlfile };
}

int main(int argc, char** argv)
{
	//--------------------------------------------------------------------------
	// Command line arguments
	//--------------------------------------------------------------------------

	// CAD file can be configured as a parameter,
	// if none is provided or the one provided does not exist,
	// we go back to the Micro Engine PRC file available in the package.

	// `--dump_model_tree` option and the output xml file are optional
	if (argc > 4)
	{
		std::cout << "Usage:" << std::endl << argv[0] << " [input CAD file] --dump_model_tree [output XML file]" << std::endl;
		return -1;
	}
	
	auto inputs = manage_input_arguments(argc, argv);
	std::string input_file = inputs.first;
	std::string model_tree_file = inputs.second;

	//--------------------------------------------------------------------------
	// Initialize HOOPS EXCHANGE
	//--------------------------------------------------------------------------
	A3DSDKHOOPSExchangeLoader loader(exchange_bin_dir, HOOPS_LICENSE);
	CHECK_RET(loader.m_eSDKStatus);

	//--------------------------------------------------------------------------
	// Initialize OpenGL window
	//--------------------------------------------------------------------------
	Application application;
	std::string displayTitle = "TS3D Mesh Viewer : ";
	displayTitle.append(input_file);

	application.launch(utils::properties::screen_width, utils::properties::screen_height, displayTitle);
	application.display();

	//--------------------------------------------------------------------------
	// Load the input file
	//--------------------------------------------------------------------------
	A3DAsmModelFile* model_file = nullptr;
	auto const load_status = model::exchange::load_model(input_file.c_str(), model_file);
	if (A3D_SUCCESS != load_status && A3D_LOAD_MISSING_COMPONENTS != load_status)
	{
		std::cout << "input_file = " << input_file << std::endl;
		std::cout << "ERROR::MODELFILE::FILE_NOT_SUCCESSFULLY_READ: " << load_status << std::endl;
		return -1;
	}

	std::cout << input_file << " loaded \n";

	//--------------------------------------------------------------------------
	// Dump Tree if asked
	//--------------------------------------------------------------------------
	if (!model_tree_file.empty())
		model::exchange::tree::print(model_file, input_file, model_tree_file);


	//--------------------------------------------------------------------------
	// Retrieve meshes from the model
	//--------------------------------------------------------------------------

	// Collect the leaves of the model: the parts with their associated graphical contexts (A3DMiscCascadedAttributes) and transformations
	std::vector<he::structure::Part> model_leaves;
	model::exchange::collect_leaves(model_file, model_leaves);

	// transfer mesh data
	std::vector<Mesh> meshs;
	std::vector<Mesh> transparent_meshs;
	utils::geometry::BoundingBox bounding_box;
	for (const auto& leaf : model_leaves)
	{
		// For each leaf, retrieve the representation items that contain the geometry (brep and polybrep only)
		std::vector<A3DRiRepresentationItem*> ri_list;
		leaf.ri_list(ri_list);

		for (const auto& context : leaf.get_contexts())
		{
			// Process the different contexts of the leaf (same geometry, with different graphic style and transformation)
			const auto& graphical_context_data = std::get<1>(context);

			if (graphical_context_data.m_bShow == A3D_FALSE || graphical_context_data.m_bRemoved == A3D_TRUE)
				continue;

			const auto& graphical_context = std::get<0>(context);
			const auto& transformations = std::get<2>(context);

			for (const auto ri : ri_list)
			{
				// For each representation item containing the geometry in the leaf, 
				// fill one buffer if the ri is unicolor, 
				// or multiple buffers, in case it contains multiple graphic styles (color, material, texture).
				// These buffers contain the vertices, the indices, the bounding box and the graphic style (color, material, texture).
				std::vector<utils::geometry::BufferData> buffer_data_array = model::exchange::geometry::prepare_render_buffer(ri, graphical_context);
				
				if (buffer_data_array.empty())
					continue;

				for (const auto& buffer_data : buffer_data_array)
				{
					// Add the bounding box for the camera
					bounding_box.add_boxes(buffer_data.mesh_box, transformations);

					// Add the computed information in the list of meshs
					utils::properties::style::Graphics graphics = buffer_data.graphics;
					auto& container = graphics.has_transparency() ? transparent_meshs : meshs;

					for (const auto& placement : transformations)
					{
						container.emplace_back(buffer_data, placement, graphics);
					}
				}
			}
		}
	}
	
	if (meshs.empty())
	{
		std::cout << "ERROR::MODELFILE::NO_MESH_FOUND: " << load_status << std::endl;
		return 1;
	}

	//--------------------------------------------------------------------------
	// Sort meshes
	//--------------------------------------------------------------------------
	Mesh::sort_by_style(meshs);

	//--------------------------------------------------------------------------
	// Camera and shader setting
	//--------------------------------------------------------------------------
	application.compute_camera(bounding_box);

	Shader shader_program("default.vert", "default.frag");

	//--------------------------------------------------------------------------
	// Drawing loop
	//--------------------------------------------------------------------------
	bool first_style = true;
	while (!application.should_close())
	{
		glm::vec3 translation = (application.camera.up + application.camera.right - application.camera.front) * (application.camera.max_bbx_length * 0.5f);
		glm::vec3 light_pos = application.camera.position + translation;
		shader_program.add_light_properties(light_pos);
		shader_program.update_projection_matrix(application.compute_projection_matrix());
		shader_program.update_view_matrix(application.compute_view_matrix());

		shader_program.set_vec3("view_position", application.camera.position);
		application.clear();
		first_style = true;
		application.set_blending(false);
		for (auto& model : meshs)
		{
			shader_program.update_mesh_style(model.style, first_style);
			shader_program.update_model_matrix(model.placement);
			model.draw();
		}
		if (transparent_meshs.size())
		{
			std::map<float, Mesh> sorted;

			application.set_blending(true);

			for (const auto& model : transparent_meshs)
			{
				float d1 = glm::length(application.camera.position - model.box.min);
				float d2 = glm::length(application.camera.position - model.box.max);
				sorted[d1 < d2 ? d1 : d2] = model;
			}
			for (auto it = sorted.rbegin(); it != sorted.rend(); ++it)
			{
				shader_program.update_mesh_style(it->second.style, first_style);
				shader_program.update_model_matrix(it->second.placement);
				it->second.draw();
			}
		}
		application.display();
	}
	return 0;
}