// =============================================
//  Aster: context.h
//  Copyright (c) 2020-2024 Anish Bhobe
// =============================================

#pragma once

#include "global.h"
#include <utility>
#include <vector>

/**
 * @class Context
 *
 * @brief Vulkan context to handle device initialization logic.
 *
 * Handles the required hardware interactions.
 */
class Context final {
public:
	Context(const std::string_view &_app_name, const Version &_app_version, const b8 _enable_validation = true) :
			enable_validation_layers{ _enable_validation } {
		init(_app_name, _app_version);
	}

	Context(const std::string_view &_app_name, const Version &_app_version, const std::vector<const char *> &_additional_device_extensions, const b8 _enable_validation = true) :
			enable_validation_layers{ _enable_validation } {
		device_extensions.reserve(device_extensions.size() + _additional_device_extensions.size());
		device_extensions.insert(device_extensions.end(), _additional_device_extensions.begin(), _additional_device_extensions.end());

		init(_app_name, _app_version);
	}

	Context(const std::string_view &_app_name, const Version &_app_version, const std::vector<const char *> &_additional_device_extensions, const std::vector<const char *> &_additional_validation_layers) {
		device_extensions.reserve(device_extensions.size() + _additional_device_extensions.size());
		device_extensions.insert(device_extensions.end(), _additional_device_extensions.begin(), _additional_device_extensions.end());

		validation_layers.reserve(validation_layers.size() + _additional_validation_layers.size());
		validation_layers.insert(validation_layers.end(), _additional_validation_layers.begin(), _additional_validation_layers.end());

		init(_app_name, _app_version);
	}

	Context(const Context &_other) = delete;

	Context(Context &&_other) noexcept :
			enable_validation_layers{ _other.enable_validation_layers }, validation_layers{ std::move(_other.validation_layers) }, device_extensions{ std::move(_other.device_extensions) }, instance{ std::exchange(_other.instance, nullptr) }, debug_messenger{ std::exchange(_other.debug_messenger, nullptr) } {}

	Context &operator=(const Context &_other) = delete;

	Context &operator=(Context &&_other) noexcept {
		if (this == &_other)
			return *this;
		enable_validation_layers = _other.enable_validation_layers;
		validation_layers = std::move(_other.validation_layers);
		device_extensions = std::move(_other.device_extensions);
		instance = std::exchange(_other.instance, nullptr);
		debug_messenger = std::exchange(_other.debug_messenger, nullptr);
		return *this;
	}

	~Context();

	// Fields
	bool enable_validation_layers{ true };

	std::vector<const char *> validation_layers = {
		"VK_LAYER_KHRONOS_validation",
	};

	std::vector<const char *> device_extensions = {
		VK_KHR_SWAPCHAIN_EXTENSION_NAME,
		VK_KHR_MULTIVIEW_EXTENSION_NAME,
	};

	vk::raii::Context raii_context;
	vk::raii::Instance instance{ nullptr };
	vk::raii::DebugUtilsMessengerEXT debug_messenger{ nullptr };

private:
	void init(const std::string_view &_app_name, const Version &_app_version);

	static VKAPI_ATTR b32 VKAPI_CALL debug_callback(VkDebugUtilsMessageSeverityFlagBitsEXT _message_severity,
			VkDebugUtilsMessageTypeFlagsEXT _message_type,
			const VkDebugUtilsMessengerCallbackDataEXT *_callback_data,
			void *_user_data);
};