#include "Entrypoint/Common.hpp"
#include "Entrypoint/DirectX11.hpp"
#include "Entrypoint/DirectX12.hpp"
#include "Entrypoint/Metal.hpp"
#include "Entrypoint/OpenGL2.hpp"
#include "Entrypoint/OpenGL3.hpp"
#include "Entrypoint/Vulkan.hpp"
#include "Model/GlobalStates.hpp"
#include "UI/Localization.hpp"
#include "UI/States.hpp"
#include "UI/UI.hpp"
#include "Utils/I18n.hpp"
#include "Utils/Sigslot.hpp"

#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <IconsFontAwesome.h>
#include <imgui.h>
#include <argparse/argparse.hpp>
#include <iostream>
#include <memory>
#include <stdexcept>
#include <string>
#include <string_view>

using namespace std::literals::string_literals;
using namespace std::literals::string_view_literals;

static std::unique_ptr<RenderingBackend> CreateDefaultBackend() {
#if PLATFORM_WIN32
#	if BUILD_CORE_WITH_DX12_BACKEND
	try {
		auto backend = std::make_unique<DirectX12Backend>();
		return backend;
	} catch (const std::exception&) {
	}
#	elif BUILD_CORE_WITH_DX11_BACKEND
	try {
		auto backend = std::make_unique<DirectX11Backend>();
		return backend;
	} catch (const std::exception&) {
	}
#	elif BUILD_CORE_WITH_VULKAN_BACKEND
	try {
		auto backend = std::make_unique<VulkanBackend>();
		return backend;
	} catch (const std::exception&) {
	}
#	elif BUILD_CORE_WITH_OPENGL3_BACKEND
	try {
		auto backend = std::make_unique<OpenGL3Backend>();
		return backend;
	} catch (const std::exception&) {
	}
#	elif BUILD_CORE_WITH_OPENGL2_BACKEND
	try {
		auto backend = std::make_unique<OpenGL2Backend>();
		return backend;
	} catch (const std::exception&) {
	}
#	endif
#elif PLATFORM_MACOS
	// We currently only support using metal on macos
	backend = std::make_unique<MetalBackend>();
#elif PLATFORM_LINUX
#	if BUILD_CORE_WITH_VULKAN_BACKEND
	try {
		auto backend = std::make_unique<VulkanBackend>();
		return backend;
	} catch (const std::exception&) {
	}
#	elif BUILD_CORE_WITH_OPENGL3_BACKEND
	try {
		auto backend = std::make_unique<OpenGL3Backend>();
		return backend;
	} catch (const std::exception&) {
	}
#	elif BUILD_CORE_WITH_OPENGL2_BACKEND
	try {
		auto backend = std::make_unique<OpenGL2Backend>();
		return backend;
	} catch (const std::exception&) {
	}
#	endif
#endif

	return nullptr;
}

static std::unique_ptr<RenderingBackend> CreateBackend(std::string_view option) {
	if (option == "default") {
		return CreateDefaultBackend();
	} else if (option == "opengl2") {
		return std::make_unique<OpenGL2Backend>();
	} else if (option == "opengl3") {
		return std::make_unique<OpenGL3Backend>();
	} else if (option == "vulkan") {
		return std::make_unique<VulkanBackend>();
	} else if (option == "dx11") {
		return std::make_unique<DirectX11Backend>();
	} else if (option == "dx12") {
		return std::make_unique<DirectX12Backend>();
	} else if (option == "metal") {
		return std::make_unique<MetalBackend>();
	} else {
		std::string message;
		message += "Unknown backend '";
		message += option;
		message += "'.\n";
		throw std::runtime_error(message);
		return nullptr;
	}
}

int main(int argc, char* argv[]) {
	argparse::ArgumentParser parser;
	parser.add_argument("--rendering-backend")
		.help("Which rendering backend to use. If equals 'default', the preferred API for each platform will be used")
		.default_value("default"s);

	try {
		parser.parse_args(argc, argv);
	} catch (const std::runtime_error& error) {
		std::cout << error.what() << '\n';
		std::cout << parser;
		return -1;
	}

	auto backendOption = parser.get<std::string>("--rendering-backend");
	auto backend = CreateBackend(backendOption);

	ImGui::GetIO().IniFilename = nullptr;
	ImGui::GetIO().LogFilename = nullptr;
	ImGui::StyleColorsLight();

	// Includes latin alphabet, although for some reason smaller than if rendered using 18 point NotoSans regular
	ImGui::GetIO().Fonts->AddFontFromFileTTF("fonts/NotoSansSC-Regular.otf", 18, nullptr, ImGui::GetIO().Fonts->GetGlyphRangesChineseSimplifiedCommon());

	ImWchar iconRanges[] = { ICON_MIN_FA, ICON_MAX_FA };
	ImFontConfig config;
	config.MergeMode = true;
	ImGui::GetIO().Fonts->AddFontFromFileTTF("fonts/FontAwesome5-Solid.otf", 14, &config, iconRanges);

	I18n::OnReload.Connect([]() { LocaleStrings::Instance = std::make_unique<LocaleStrings>(); });
	// Do i18n initialization after linking reload signals, so that when SetLanguage() is called, the locale strings will be initialized (without us writing the code another time outside the slot)
	I18n::Init();
	I18n::SetLanguage("zh_CN");

	GlobalStates::Init();
	UIState::Init();

	auto window = backend->GetWindow();
	while (!glfwWindowShouldClose(window)) {
		backend->BeginFrame();
		UI::MainWindow();
		ImGui::ShowDemoWindow();
		backend->EndFrame();
	}

	UIState::Shutdown();
	GlobalStates::Shutdown();

	return 0;
}