#include "SDL3/SDL_vulkan.h"
#include "materialsystem/materialsystem.h"
#include "tier0/platform.h"
#include "tier1/utlstring.h"
#include "tier1/utlvector.h"
#define VK_NO_PROTOTYPES
#include "vulkan/vulkan_core.h"
#include "vulkan_state.h"
#include "igamewindow.h"


#define REQUIRED_EXTENSION(ext) ext##_EXTENSION_NAME,
#define OPTIONAL_EXTENSION(ext) ext##_EXTENSION_NAME,
const char *g_vkDeviceExtensions[] = {
#include "device_extensions.h"
};
#undef REQUIRED_EXTENSION
#undef OPTIONAL_EXTENSION



class CVkRenderContext: public IRenderContext
{
public:
	virtual void Init() override;
	virtual void Frame( float fDeltaTime ) override;
	virtual void Shutdown() override;

	virtual IVertexBuffer *CreateVertexBuffer( uint32_t nSize ) override;
	virtual IIndexBuffer *CreateIndexBuffer( uint32_t nSize ) override;
	virtual IImage *CreateRenderTarget( uint32_t x, uint32_t y, EImageFormat eFormat, EMultisampleType eMultisampleType ) override;
	virtual IImage *CreateStorageImage( uint32_t x, uint32_t y, EImageFormat eFormat, EMultisampleType eMultisampleType ) override;

	virtual void DestroyBuffer( IBuffer *pBuffer ) override;
	virtual void DestroyImage( IImage *pImage ) override;
private:
	IBuffer *CreateBuffer( uint32_t nSize, VkBufferUsageFlags2 eUsage );
	IBuffer *CreateBufferAligned( uint32_t nSize, uint32_t nAlignment, VkBufferUsageFlags2 eUsage );
	
	VkPhysicalDevice SelectPhysicalDevice( CUtlVector<VkPhysicalDevice> physicalDevices );

	void CreateSwapchain();
	void DestroySwapchain();
};

//-----------------------------------------------------------------------------
// Creates vertex buffer. Wrapper over CreateBuffer 
//-----------------------------------------------------------------------------
IVertexBuffer *CVkRenderContext::CreateVertexBuffer( uint32_t nSize )
{
	return (IVertexBuffer*)CreateBuffer(nSize, VK_BUFFER_USAGE_2_VERTEX_BUFFER_BIT);
}

//-----------------------------------------------------------------------------
// Creates index buffer. Wrapper over CreateBuffer 
//-----------------------------------------------------------------------------
IIndexBuffer *CVkRenderContext::CreateIndexBuffer( uint32_t nSize )
{
	return (IIndexBuffer*)CreateBuffer(nSize, VK_BUFFER_USAGE_2_INDEX_BUFFER_BIT);
}

//-----------------------------------------------------------------------------
// Creates basic vulkan buffer
//-----------------------------------------------------------------------------
IBuffer *CreateBuffer( uint32_t nSize, VkBufferUsageFlags2 eUsage )
{

}

//-----------------------------------------------------------------------------
// Creates vulkan buffer aligned to the nAlignment
// Useful for everything eg: ray tracing, which requires them to be aligned 
// to the groupBaseAlignment.
//-----------------------------------------------------------------------------
IBuffer *CreateBufferAligned( uint32_t nSize, uint32_t nAlignment, VkBufferUsageFlags2 eUsage )
{

}


IImage *CVkRenderContext::CreateRenderTarget( uint32_t x, uint32_t y, EImageFormat eFormat, EMultisampleType eMultisampleType )
{

}

IImage *CVkRenderContext::CreateStorageImage( uint32_t x, uint32_t y, EImageFormat eFormat, EMultisampleType eMultisampleType )
{

}


void CVkRenderContext::DestroyBuffer( IBuffer *pBuffer )
{

}

void CVkRenderContext::DestroyImage( IImage *pImage )
{

}

CVkRenderContext s_vkRenderContext;
IRenderContext *g_pVkRenderContext = &s_vkRenderContext;


uint32_t g_iDrawFamily;
uint32_t g_iPresentFamily;

VkInstance g_vkInstance;
VkPhysicalDevice g_vkPhysicalDevice;
VkDevice g_vkDevice;
VkSwapchainKHR g_vkSwapchain;


void CVkRenderContext::Init()
{
	VkResult r;

	int nExtensionCount;
	CUtlVector<const char *> extensions = {};

	uint32_t nPhysicalDevicesCount;
	CUtlVector<VkPhysicalDevice> physicalDevices;
	
	uint32_t nNumQueueFamilies = 0;
	CUtlVector<VkQueueFamilyProperties> queueFamilyProperties;
	
	VkApplicationInfo stApplicationInfo = {};
	VkInstanceCreateInfo stInstanceCreateInfo = {};

	VkDeviceQueueCreateInfo stDeviceQueueCreateInfo = {};
	VkDeviceCreateInfo stDeviceCreateInfo = {};
	
	float fPriority = 1.0;

	r = volkInitialize();
	VULKAN_RESULT_PRINT(r, volkInitialize)

	// Get extensions required by game window
	nExtensionCount = gamewindow->GetVulkanInstanceExtensionCount();
	extensions.Resize(nExtensionCount);
	V_memcpy(extensions.GetData(), gamewindow->GetVulkanInstanceExtensions(), extensions.GetSize()*sizeof(const char*));

	// Create instance
	stApplicationInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
	stApplicationInfo.apiVersion = VK_API_VERSION_1_4;
	stApplicationInfo.pApplicationName = "funny";
	stApplicationInfo.pEngineName = "funny";

	stInstanceCreateInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
	stInstanceCreateInfo.pApplicationInfo = &stApplicationInfo;
	stInstanceCreateInfo.enabledExtensionCount = extensions.GetSize();
	stInstanceCreateInfo.ppEnabledExtensionNames = extensions.GetData();

	r = vkCreateInstance(&stInstanceCreateInfo, NULL, &g_vkInstance);
	VULKAN_RESULT_PRINT(r, vkCreateInstance)
	
	// volk requires to load instance this way
	volkLoadInstance(g_vkInstance);


	// Get amount of physical devices
	r = vkEnumeratePhysicalDevices(g_vkInstance, &nPhysicalDevicesCount, NULL);
	VULKAN_RESULT_PRINT(r, vkEnumeratePhysicalDevices)
	physicalDevices.Resize(nPhysicalDevicesCount);

	// Read all physical devices
	r = vkEnumeratePhysicalDevices(g_vkInstance, &nPhysicalDevicesCount, physicalDevices.GetData());
	VULKAN_RESULT_PRINT(r, vkEnumeratePhysicalDevices)

	g_vkPhysicalDevice = SelectPhysicalDevice(physicalDevices);


	// Get all queues
	vkGetPhysicalDeviceQueueFamilyProperties(g_vkPhysicalDevice, &nNumQueueFamilies, NULL);
	queueFamilyProperties.Resize(nNumQueueFamilies);

	uint32_t i = 0;
	vkGetPhysicalDeviceQueueFamilyProperties(g_vkPhysicalDevice, &nNumQueueFamilies, queueFamilyProperties.GetData());

	for (auto &family: queueFamilyProperties)
	{
		if (family.queueFlags & VK_QUEUE_GRAPHICS_BIT)
		{
			g_iDrawFamily = i;
			g_iPresentFamily = i;
		}
		i++;
	}


	// Create device
	stDeviceQueueCreateInfo.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
	stDeviceQueueCreateInfo.queueCount = 1;
	stDeviceQueueCreateInfo.pQueuePriorities = &fPriority;
	stDeviceQueueCreateInfo.queueFamilyIndex = g_iDrawFamily;

	stDeviceCreateInfo.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
	stDeviceCreateInfo.queueCreateInfoCount = 1;
	stDeviceCreateInfo.pQueueCreateInfos = &stDeviceQueueCreateInfo;
	vkCreateDevice(g_vkPhysicalDevice, &stDeviceCreateInfo, NULL, &g_vkDevice);

	CreateSwapchain();
}

void CVkRenderContext::Frame( float fDeltaTime )
{

}

void CVkRenderContext::CreateSwapchain()
{
	CUtlVector<VkSurfaceFormatKHR> surfaceFormats;
	
	gamewindow->CreateVulkanSurface(g_vkInstance);

	VkSwapchainCreateInfoKHR stSwapchainCreateInfo = {};
	stSwapchainCreateInfo.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
	stSwapchainCreateInfo.surface = (VkSurfaceKHR)gamewindow->GetVulkanSurface();

	vkCreateSwapchainKHR(g_vkDevice, &stSwapchainCreateInfo, NULL, &g_vkSwapchain);

}

void CVkRenderContext::DestroySwapchain()
{
	vkDestroySwapchainKHR(g_vkDevice, g_vkSwapchain, NULL);
	gamewindow->DestroyVulkanSurface(g_vkInstance);
}

//-----------------------------------------------------------------------------
// TODO: Move to the rendering context
//-----------------------------------------------------------------------------
void CVkRenderContext::Shutdown()
{
	vkDestroyInstance(g_vkInstance, NULL);
}


//-----------------------------------------------------------------------------
// Selects best device to be used in rendering.
// We want to get the best perfomance out of the GPU, so we need to select the
// best driver.
//-----------------------------------------------------------------------------
VkPhysicalDevice CVkRenderContext::SelectPhysicalDevice( CUtlVector<VkPhysicalDevice> physicalDevices )
{
	uint32_t uMaxScore = 0;
	VkPhysicalDevice selectedDevice = 0;
	VkResult r;

	for (auto &device: physicalDevices)
	{
		uint32_t nExtensionCount;
		CUtlVector<VkExtensionProperties> extensions;
		VkPhysicalDeviceFeatures stPhysicalDeviceFeatures;
		VkPhysicalDeviceProperties stPhysicalDeviceProperties;
		uint32_t uScore = 0;

		r = vkEnumerateDeviceExtensionProperties(device, NULL, &nExtensionCount, NULL);
		VULKAN_RESULT_PRINT(r, vkEnumeratePhysicalDevices)
		extensions.Resize(nExtensionCount);
		
		r = vkEnumerateDeviceExtensionProperties(device, NULL, &nExtensionCount, extensions.GetData());
		VULKAN_RESULT_PRINT(r, vkEnumeratePhysicalDevices)

		vkGetPhysicalDeviceProperties(device, &stPhysicalDeviceProperties);
		vkGetPhysicalDeviceFeatures(device, &stPhysicalDeviceFeatures);

		if (stPhysicalDeviceProperties.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU)
			uScore += 1000;
		if (stPhysicalDeviceProperties.deviceType == VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU)
			uScore += 500;

		if (uScore >= uMaxScore)
		{
			selectedDevice = device;
			uMaxScore = uScore;
		}
	}

	return selectedDevice;
}