/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#include <fstream>
#include <string>
#include <ryml.hpp>
#include <ryml_std.hpp>

#include "EngineConfiguration.hpp"
#include "IO/AppFolders.hpp"

namespace OpenVulkano
{
	namespace
	{
		const char *NUM_THREADS_STR                    = "num_threads";
		const char *FRAMEBUFFER_CLEAR_COLOR_STR        = "framebuffer_clear_color";
		const char *PREFER_FRAMEBUFFER_FORMAT_SRGB_STR = "prefer_framebuffer_format_srgb";
	}

	EngineConfiguration::EngineConfiguration()
	{
		const std::string filePath = AppFolders::GetAppConfigHomeDir().string() + "/EngineConfig.yml";
		std::ifstream file(filePath);
		if (!file.is_open())
		{
			return;
		}
	
		file.seekg(0, std::ios::end);
		size_t size = file.tellg();
		std::string buffer(size, ' ');
		file.seekg(0);
		file.read(buffer.data(), size); 

		ryml::Tree tree = ryml::parse_in_arena(ryml::to_csubstr(buffer));
		ryml::NodeRef root = tree.rootref();

		if (root.has_child(NUM_THREADS_STR) && root[NUM_THREADS_STR].val().is_integer())
		{
			root[NUM_THREADS_STR] >> m_numThreads;
		}

		if (root.has_child(FRAMEBUFFER_CLEAR_COLOR_STR) && root[FRAMEBUFFER_CLEAR_COLOR_STR].is_seq() && root[FRAMEBUFFER_CLEAR_COLOR_STR].num_children() == 4)
		{
			auto clearColorNode = root[FRAMEBUFFER_CLEAR_COLOR_STR];
			for (size_t i = 0; i < 4; ++i)
			{
				clearColorNode[i] >> m_frameBufferClearColor[i];
			}
		}

		if (root.has_child(PREFER_FRAMEBUFFER_FORMAT_SRGB_STR))
		{
			root[PREFER_FRAMEBUFFER_FORMAT_SRGB_STR] >> m_preferFramebufferFormatSRGB;
		}
	}

	EngineConfiguration* EngineConfiguration::GetEngineConfiguration()
	{
		static EngineConfiguration config;
		return &config;
	}
}