#ifndef OPENCLHELPER_H
#define OPENCLHELPER_H

#define CL_HPP_MINIMUM_OPENCL_VERSION 120
#define CL_HPP_TARGET_OPENCL_VERSION 120

#include <QObject>
#include <QFile>

#include "logger/Logger.h"
#include "lib/CL/cl2.hpp"

#define caseReturnString(x) case x: \
		return #x

/*************************************************************************************************/
/**
 * @brief The OpenCLHelper class
 * @note This class can not be broken to .h and .cpp files, because of the way opencl works,
 * if we include it in 2 places it complains about duplicated defenition
 * @author Mohsen Emami revised by Hessamoddin Hediyehloo(H-4nd-H)
 * @date 2019/8/5(1398/5/14)
 */
/*************************************************************************************************/
class OpenClHelper : public QObject
{
	Q_OBJECT

private:
	inline std::vector<cl::Platform> getAllAvailablePlatform();

	inline std::vector<cl::Platform> getAmdAndNvidiaPlatforms();

	inline std::vector<cl::Platform> filterNoneAmdAndNoneNvidiaPlatforms(
		std::vector<cl::Platform> platforms);

	inline void ThrowIfNoPlatformAvailable(const std::vector<cl::Platform>& platforms);

	inline std::vector<cl::Device> getAllAvailableDevicesForValidPlatforms(
		const std::vector<cl::Platform>& platforms);

	inline std::vector<cl::Device> getAllAvailableDevicesForGivenPlatforms(
		const cl::Platform& platform);

	inline void ThrowIfNoDeviceAvailable(const std::vector<cl::Device>& devices);

	inline QString getErrorString(int error);

	inline QString getKernelFullPath(QString kernelPath, QString kernelName);

	inline std::string readKernelSourceCode(QString kernelPath);

	inline cl::Program createProgramFromKernelCode(const cl::Context& context,
												   std::string kernelSource);

	inline cl::Kernel createKernelFromProgram(const cl::Program& program, QString kernelName);

public:
	inline cl::Context& getContext();
	inline cl::Device getFirstDeviceByContext(const cl::Context& context);
	inline cl::Kernel createKernel(const cl::Context& context,
								   const QString kernelPath,
								   const QString KernelName);

	inline cl::Buffer* allocateClBuffer(const cl::Context& context,
										quint64 size,
										bool read);

	inline cl::Image* allocateClImage(const cl::Context& context,
									  cl::ImageFormat clFrameFormat,
									  QList<quint64> dimensions, bool read);

	inline cl::CommandQueue createCommandQueue(const cl::Context& context,
											   const cl_command_queue_properties properties);
	template<typename ... Ts>
	inline cl::KernelFunctor<Ts...> createKernelFunctor(const cl::Kernel& kernel);

	template<typename ... Ts>
	inline void runKernelFunctor(cl::KernelFunctor<Ts...>& kernelFunctor,
								 cl::EnqueueArgs args,
								 Ts... ts);
};

/*************************************************************************************************/
/**
 * @brief Returns the name of error
 * @param error The error to get th ename of
 * @return The error name
 */
/*************************************************************************************************/
QString OpenClHelper::getErrorString(int error)
{
	switch(error)
	{
		caseReturnString(CL_SUCCESS);
		caseReturnString(CL_DEVICE_NOT_FOUND);
		caseReturnString(CL_DEVICE_NOT_AVAILABLE);
		caseReturnString(CL_COMPILER_NOT_AVAILABLE);
		caseReturnString(CL_MEM_OBJECT_ALLOCATION_FAILURE);
		caseReturnString(CL_OUT_OF_RESOURCES);
		caseReturnString(CL_OUT_OF_HOST_MEMORY);
		caseReturnString(CL_PROFILING_INFO_NOT_AVAILABLE);
		caseReturnString(CL_MEM_COPY_OVERLAP);
		caseReturnString(CL_IMAGE_FORMAT_MISMATCH);
		caseReturnString(CL_IMAGE_FORMAT_NOT_SUPPORTED);
		caseReturnString(CL_BUILD_PROGRAM_FAILURE);
		caseReturnString(CL_MAP_FAILURE);
		caseReturnString(CL_MISALIGNED_SUB_BUFFER_OFFSET);
		caseReturnString(CL_COMPILE_PROGRAM_FAILURE);
		caseReturnString(CL_LINKER_NOT_AVAILABLE);
		caseReturnString(CL_LINK_PROGRAM_FAILURE);
		caseReturnString(CL_DEVICE_PARTITION_FAILED);
		caseReturnString(CL_KERNEL_ARG_INFO_NOT_AVAILABLE);
		caseReturnString(CL_INVALID_VALUE);
		caseReturnString(CL_INVALID_DEVICE_TYPE);
		caseReturnString(CL_INVALID_PLATFORM);
		caseReturnString(CL_INVALID_DEVICE);
		caseReturnString(CL_INVALID_CONTEXT);
		caseReturnString(CL_INVALID_QUEUE_PROPERTIES);
		caseReturnString(CL_INVALID_COMMAND_QUEUE);
		caseReturnString(CL_INVALID_HOST_PTR);
		caseReturnString(CL_INVALID_MEM_OBJECT);
		caseReturnString(CL_INVALID_IMAGE_FORMAT_DESCRIPTOR);
		caseReturnString(CL_INVALID_IMAGE_SIZE);
		caseReturnString(CL_INVALID_SAMPLER);
		caseReturnString(CL_INVALID_BINARY);
		caseReturnString(CL_INVALID_BUILD_OPTIONS);
		caseReturnString(CL_INVALID_PROGRAM);
		caseReturnString(CL_INVALID_PROGRAM_EXECUTABLE);
		caseReturnString(CL_INVALID_KERNEL_NAME);
		caseReturnString(CL_INVALID_KERNEL_DEFINITION);
		caseReturnString(CL_INVALID_KERNEL);
		caseReturnString(CL_INVALID_ARG_INDEX);
		caseReturnString(CL_INVALID_ARG_VALUE);
		caseReturnString(CL_INVALID_ARG_SIZE);
		caseReturnString(CL_INVALID_KERNEL_ARGS);
		caseReturnString(CL_INVALID_WORK_DIMENSION);
		caseReturnString(CL_INVALID_WORK_GROUP_SIZE);
		caseReturnString(CL_INVALID_WORK_ITEM_SIZE);
		caseReturnString(CL_INVALID_GLOBAL_OFFSET);
		caseReturnString(CL_INVALID_EVENT_WAIT_LIST);
		caseReturnString(CL_INVALID_EVENT);
		caseReturnString(CL_INVALID_OPERATION);
		caseReturnString(CL_INVALID_GL_OBJECT);
		caseReturnString(CL_INVALID_BUFFER_SIZE);
		caseReturnString(CL_INVALID_MIP_LEVEL);
		caseReturnString(CL_INVALID_GLOBAL_WORK_SIZE);
		caseReturnString(CL_INVALID_PROPERTY);
		caseReturnString(CL_INVALID_IMAGE_DESCRIPTOR);
		caseReturnString(CL_INVALID_COMPILER_OPTIONS);
		caseReturnString(CL_INVALID_LINKER_OPTIONS);
		caseReturnString(CL_INVALID_DEVICE_PARTITION_COUNT);

		default:
			return "Unknown OpenCL error code";
	}
}

/*************************************************************************************************/
/**
 * @brief Return the full file path for the kernel
 * @param kernelPath Directory of kernel
 * @param kernelName Kernel name
 * @return Full kernel path
 */
/*************************************************************************************************/
QString OpenClHelper::getKernelFullPath(QString kernelPath, QString kernelName)
{
	return QDir(kernelPath).filePath(kernelName + ".cl");
}

/*************************************************************************************************/
/**
 * @brief Read kernel source file from the given path
 * @param kernelPath Kernel file path
 * @return Kernel source code
 */
/*************************************************************************************************/
std::string OpenClHelper::readKernelSourceCode(QString kernelPath)
{
	QFile kernelFile(kernelPath);

	if(!kernelFile.open(QIODevice::ReadOnly | QIODevice::Text))
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLKernelError,
							  "Can not open kernel file @ " + kernelPath,
							  this->metaObject()->className());
	}

	auto kernelSource = kernelFile.readAll().toStdString();

	kernelFile.close();

	return kernelSource;
}

/*************************************************************************************************/
/**
 * @brief Compile the rkernel code and create a ne wprogram object
 * @param context OpenCL object
 * @param kernelSource Kernel source code
 * @return Created program object
 */
/*************************************************************************************************/
cl::Program OpenClHelper::createProgramFromKernelCode(const cl::Context& context,
													  std::string kernelSource)
{
	cl_int err = 0;

	cl::Program program(context, kernelSource, true, &err);

	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLKernelError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return program;
}

/*************************************************************************************************/
/**
 * @brief Create kernel object from openCl program object
 * @param program OpenCL program object
 * @param kernelName Name of the kernel
 * @return OpenCl kernel
 */
/*************************************************************************************************/
cl::Kernel OpenClHelper::createKernelFromProgram(const cl::Program& program, QString kernelName)
{
	cl_int err;

	cl::Kernel kernel(program, kernelName.toStdString().c_str(), &err);

	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLKernelError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return kernel;
}

/*************************************************************************************************/
/**
 * @brief Checks to see if platform list is empty or not, throws exception if empty
 * @param platforms List of platforms
 */
/*************************************************************************************************/
void OpenClHelper::ThrowIfNoPlatformAvailable(const std::vector<cl::Platform>& platforms)
{
	if(platforms.size() > 0)
	{
		return;
	}

	throw LoggerException(ESeverityLevel::Alert,
						  ELogID::CLPlatformError,
						  "No valid platform was found",
						  this->metaObject()->className());
}

/*************************************************************************************************/
/**
 * @brief Checks to see if device list is empty or not, throws exception if empty
 * @param devices List of devices
 */
/*************************************************************************************************/
void OpenClHelper::ThrowIfNoDeviceAvailable(const std::vector<cl::Device>& devices)
{
	if(devices.size() > 0)
	{
		return;
	}

	throw LoggerException(ESeverityLevel::Alert,
						  ELogID::CLDeviceError,
						  "No valid device was found",
						  this->metaObject()->className());
}

/*************************************************************************************************/
/**
 * @brief Return all available opencl platforms
 * @return Availaable opencl platforms
 */
/*************************************************************************************************/
std::vector<cl::Platform> OpenClHelper::getAllAvailablePlatform()
{
	std::vector<cl::Platform> availablePlatforms;

	cl_int err = cl::Platform::get(&availablePlatforms);
	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLPlatformError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return availablePlatforms;
}

/*************************************************************************************************/
/**
 * @brief Remove none amd and none nvidia paltforsm from a given list of platforms
 * @param platforms List of available platforms
 * @return Platform list containing only nvidia and amd
 */
/*************************************************************************************************/
std::vector<cl::Platform> OpenClHelper::filterNoneAmdAndNoneNvidiaPlatforms(
	std::vector<cl::Platform> platforms)
{
	std::vector<cl::Platform> AmdNvidiaPlatforms;
	for(auto it = platforms.begin(); it != platforms.end(); it++)
	{
		cl::string currentPlatformName = it->getInfo<CL_PLATFORM_NAME>();

		Logger::log(ESeverityLevel::Debug, ELogID::CLPlatformInfo,
					"Platform Name: " + QString::fromStdString(currentPlatformName),
					this->metaObject()->className());

		if(!(it->getInfo<CL_PLATFORM_NAME>().find("NVIDIA") == cl::string::npos) ||
		   !(it->getInfo<CL_PLATFORM_NAME>().find("AMD") == cl::string::npos))
		{
			AmdNvidiaPlatforms.push_back(*it);
		}
	}

	return AmdNvidiaPlatforms;
}

/*************************************************************************************************/
/**
 * @brief gets available nvidia or amd platforms on host machine
 * @return platforms The list of available nvidia nd amd platforms
 */
/*************************************************************************************************/
std::vector<cl::Platform> OpenClHelper::getAmdAndNvidiaPlatforms()
{
	auto availablePlatform = getAllAvailablePlatform();

	availablePlatform = filterNoneAmdAndNoneNvidiaPlatforms(availablePlatform);

	ThrowIfNoPlatformAvailable(availablePlatform);

	return availablePlatform;
}

/*************************************************************************************************/
/**
 * @brief get the opencl devices for all provided platforms
 * @param platforms The list of nvidia and amd platforms \sa getPlatforms
 * @return devices List of available devices for provided platforms
 */
/*************************************************************************************************/
std::vector<cl::Device> OpenClHelper::getAllAvailableDevicesForValidPlatforms(
	const std::vector<cl::Platform>& platforms)
{
	std::vector<cl::Device> availableDevices;
	for(auto platform = platforms.begin(); platform != platforms.end(); platform++)
	{
		auto temp = getAllAvailableDevicesForGivenPlatforms(*platform);

		for(auto device = temp.begin(); device != temp.end(); device++)
		{
			availableDevices.push_back(*device);
			cl::string currentDeviceName = device->getInfo<CL_DEVICE_NAME>();

			Logger::log(ESeverityLevel::Debug, ELogID::CLDeviceInfo,
						"Device Name: " + QString::fromStdString(currentDeviceName),
						this->metaObject()->className());
		}
	}

	return availableDevices;
}

std::vector<cl::Device> OpenClHelper::getAllAvailableDevicesForGivenPlatforms(
	const cl::Platform& platform)
{
	std::vector<cl::Device> availableDevices;
	cl_int err = platform.getDevices(CL_DEVICE_TYPE_GPU, &availableDevices);

	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLDeviceError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return availableDevices;
}

/*************************************************************************************************/
/**
 * @brief get context of opencl
 * @return context Actual opencl context
 */
/*************************************************************************************************/
cl::Context& OpenClHelper::getContext()
{
	static cl::Context* internalContext = nullptr;
	if(internalContext)
	{
		return *internalContext;
	}

	auto platforms = getAmdAndNvidiaPlatforms();

	auto devices = getAllAvailableDevicesForValidPlatforms(platforms);

	cl_int err;
	internalContext = new cl::Context(devices, Q_NULLPTR, Q_NULLPTR, Q_NULLPTR, &err);

	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLContextError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return *internalContext;
}

/*************************************************************************************************/
/**
 * @brief Creates and compiles the given kernel
 * @param context OpenCl contex \sa getContext
 * @param kernelPath The folder directory for kernel
 * @param kernelName The kernel file name without .cl extension
 * @return kernel The newly created kernel instance
 */
/*************************************************************************************************/
cl::Kernel OpenClHelper::createKernel(const cl::Context& context,
									  const QString kernelPath,
									  const QString kernelName)
{
	auto kernelFullPath = getKernelFullPath(kernelPath, kernelName);

	auto kernelSource = readKernelSourceCode(kernelFullPath);

	auto program = createProgramFromKernelCode(context, kernelSource);

	return createKernelFromProgram(program, kernelName);
}

/*************************************************************************************************/
/**
 * @brief allocate a cl buffer
 * @param context OpenCL context \sa getContext
 * @param size Number of bytes to allocate
 * @param read Should the buffer be allocated with read access or write access
 * @return buffer The allocated buffer pointer
 */
/*************************************************************************************************/
cl::Buffer* OpenClHelper::allocateClBuffer(const cl::Context& context,
										   quint64 size, bool read = true)
{
	cl_mem_flags clMemFlags = read ? CL_MEM_READ_ONLY : CL_MEM_WRITE_ONLY;

	cl_int err;
	auto buffer = new cl::Buffer(context, clMemFlags, size, Q_NULLPTR, &err);
	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLBufferError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return buffer;
}

/*************************************************************************************************/
/**
 * @brief Allocate proper CL image based on input
 * @param context OpenCL context \sa getContext
 * @param clFrameFormat Frame format for image
 * @param dimensions List containing size for each image dimension, can be 1D, 2D or 3D
 * @return image Actual allocated image
 */
/*************************************************************************************************/
cl::Image* OpenClHelper::allocateClImage(const cl::Context& context,
										 cl::ImageFormat clFrameFormat,
										 QList<quint64> dimensions,
										 bool read)
{
	cl_mem_flags clMemFlags = CL_MEM_READ_WRITE;

	cl::Image* image = Q_NULLPTR;

	cl_int err = 0;

	switch(dimensions.size())
	{
		case 1:
			image = new cl::Image1D(context,
									clMemFlags,
									clFrameFormat,
									dimensions[0],
									&err);
			break;

		case 2:
			image = new cl::Image2D(context,
									clMemFlags,
									clFrameFormat,
									dimensions[0],
									dimensions[1],
									0,
									&err);
			break;

		case 3:
			image = new cl::Image3D(context,
									clMemFlags,
									clFrameFormat,
									dimensions[0],
									dimensions[1],
									dimensions[2],
									0,
									0,
									&err);
			break;

		default:
			throw LoggerException(ESeverityLevel::Alert,
								  ELogID::CLFrameError,
								  "Invalid dimension size",
								  this->metaObject()->className());
	}

	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLFrameError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return image;
}

/*************************************************************************************************/
/**
 * @brief Creates a functor for given kernel
 * @param kernel The kernel to build functor for
 * @return functor The created functor
 */
/*************************************************************************************************/
template<typename ... Ts>
cl::KernelFunctor<Ts...> OpenClHelper::createKernelFunctor(const cl::Kernel& kernel)
{
	auto kernelName = QString::fromStdString(kernel.getInfo<CL_KERNEL_FUNCTION_NAME>());

	cl_int err;

	cl::KernelFunctor<Ts...> functor(kernel.getInfo<CL_KERNEL_PROGRAM>(), kernelName, &err);

	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLKernelFunctorError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return functor;
}

/*************************************************************************************************/
/**
 * @brief Create an OpenCl commandQueue
 * @param context OpenCL context \sa getContext
 * @param properties Properties to build queue upon them
 * @return queue The newly created queue
 */
/*************************************************************************************************/
cl::CommandQueue OpenClHelper::createCommandQueue(const cl::Context& context,
												  const cl_command_queue_properties properties)
{
	cl_int err;
	cl::CommandQueue commandQueue(context, properties, &err);

	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLCommandQueueCreationError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return commandQueue;
}

/*************************************************************************************************/
/**
 * @brief Returns the first device of context
 * @param context OpenCl context \sa getContext
 * @param device First device of context
 * @return success or failure
 */
/*************************************************************************************************/
cl::Device OpenClHelper::getFirstDeviceByContext(const cl::Context& context)
{
	std::vector<cl::Device> devices;
	auto err = context.getInfo<std::vector<cl::Device> >(CL_CONTEXT_DEVICES, &devices);

	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLDeviceError,
							  getErrorString(err),
							  this->metaObject()->className());
	}

	return devices[0];
}

/*************************************************************************************************/
/**
 * @brief Run the kernel functor \sa createKernelFunctor
 * @param kernelFunctor Functor to run
 * @param args Arg structure for functor
 * @param ts actual arg for functor
 * @return success or failure
 */
/*************************************************************************************************/
template<typename ... Ts>
void OpenClHelper::runKernelFunctor(cl::KernelFunctor<Ts...>& kernelFunctor,
									cl::EnqueueArgs args,
									Ts... ts)
{
	cl_int err;
	kernelFunctor(args, ts ..., err);

	if(err != CL_SUCCESS)
	{
		throw LoggerException(ESeverityLevel::Alert,
							  ELogID::CLKernelRunError,
							  getErrorString(err),
							  this->metaObject()->className());
	}
}

#endif