#include "jim-nvenc.h"
#include <util/platform.h>
#include <util/threading.h>

static void *nvenc_lib = NULL;
static pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER;
NV_ENCODE_API_FUNCTION_LIST nv = {NV_ENCODE_API_FUNCTION_LIST_VER};
NV_CREATE_INSTANCE_FUNC nv_create_instance = NULL;

#define error(format, ...) \
	blog(LOG_ERROR, "[jim-nvenc] " format, ##__VA_ARGS__)

static inline bool nv_failed(NVENCSTATUS err, const char *func, const char *call)
{
	if (err == NV_ENC_SUCCESS)
		return false;

	error("%s: %s failed: %d (%s)", func, call, (int)err,
			nv_error_name(err));
	return true;
}

#define NV_FAILED(x) nv_failed(x, __FUNCTION__, #x)

bool load_nvenc_lib(void)
{
	if (sizeof(void*) == 8) {
		nvenc_lib = os_dlopen("nvEncodeAPI64.dll");
	} else {
		nvenc_lib = os_dlopen("nvEncodeAPI.dll");
	}

	return !!nvenc_lib;
}

static void *load_nv_func(const char *func)
{
	void *func_ptr = os_dlsym(nvenc_lib, func);
	if (!func_ptr) {
		error("Could not load function: %s", func);
	}
	return func_ptr;
}

typedef NVENCSTATUS (NVENCAPI *NV_MAX_VER_FUNC)(uint32_t*);

const char *nv_error_name(NVENCSTATUS err)
{
#define RETURN_CASE(x) \
	case x: return #x

	switch (err) {
	RETURN_CASE(NV_ENC_SUCCESS);
	RETURN_CASE(NV_ENC_ERR_NO_ENCODE_DEVICE);
	RETURN_CASE(NV_ENC_ERR_UNSUPPORTED_DEVICE);
	RETURN_CASE(NV_ENC_ERR_INVALID_ENCODERDEVICE);
	RETURN_CASE(NV_ENC_ERR_INVALID_DEVICE);
	RETURN_CASE(NV_ENC_ERR_DEVICE_NOT_EXIST);
	RETURN_CASE(NV_ENC_ERR_INVALID_PTR);
	RETURN_CASE(NV_ENC_ERR_INVALID_EVENT);
	RETURN_CASE(NV_ENC_ERR_INVALID_PARAM);
	RETURN_CASE(NV_ENC_ERR_INVALID_CALL);
	RETURN_CASE(NV_ENC_ERR_OUT_OF_MEMORY);
	RETURN_CASE(NV_ENC_ERR_ENCODER_NOT_INITIALIZED);
	RETURN_CASE(NV_ENC_ERR_UNSUPPORTED_PARAM);
	RETURN_CASE(NV_ENC_ERR_LOCK_BUSY);
	RETURN_CASE(NV_ENC_ERR_NOT_ENOUGH_BUFFER);
	RETURN_CASE(NV_ENC_ERR_INVALID_VERSION);
	RETURN_CASE(NV_ENC_ERR_MAP_FAILED);
	RETURN_CASE(NV_ENC_ERR_NEED_MORE_INPUT);
	RETURN_CASE(NV_ENC_ERR_ENCODER_BUSY);
	RETURN_CASE(NV_ENC_ERR_EVENT_NOT_REGISTERD);
	RETURN_CASE(NV_ENC_ERR_GENERIC);
	RETURN_CASE(NV_ENC_ERR_INCOMPATIBLE_CLIENT_KEY);
	RETURN_CASE(NV_ENC_ERR_UNIMPLEMENTED);
	RETURN_CASE(NV_ENC_ERR_RESOURCE_REGISTER_FAILED);
	RETURN_CASE(NV_ENC_ERR_RESOURCE_NOT_REGISTERED);
	RETURN_CASE(NV_ENC_ERR_RESOURCE_NOT_MAPPED);
	}
#undef RETURN_CASE

	return "Unknown Error";
}

static inline bool init_nvenc_internal(void)
{
	static bool initialized = false;
	static bool success = false;

	if (initialized)
		return success;
	initialized = true;

	NV_MAX_VER_FUNC nv_max_ver = (NV_MAX_VER_FUNC)
		load_nv_func("NvEncodeAPIGetMaxSupportedVersion");
	if (!nv_max_ver) {
		return false;
	}

	uint32_t ver = 0;
	if (NV_FAILED(nv_max_ver(&ver))) {
		return false;
	}

	uint32_t cur_ver =
		(NVENCAPI_MAJOR_VERSION << 4) | NVENCAPI_MINOR_VERSION;
	if (cur_ver > ver) {
		error("Current driver version does not support this NVENC "
				"version, please upgrade your driver");
		return false;
	}

	nv_create_instance = (NV_CREATE_INSTANCE_FUNC)
		load_nv_func("NvEncodeAPICreateInstance");
	if (!nv_create_instance) {
		return false;
	}

	if (NV_FAILED(nv_create_instance(&nv))) {
		return false;
	}

	success = true;
	return true;
}

bool init_nvenc(void)
{
	bool success;

	pthread_mutex_lock(&init_mutex);
	success = init_nvenc_internal();
	pthread_mutex_unlock(&init_mutex);

	return success;
}

extern struct obs_encoder_info nvenc_info;

void jim_nvenc_load(void)
{
	pthread_mutex_init(&init_mutex, NULL);
	obs_register_encoder(&nvenc_info);
}

void jim_nvenc_unload(void)
{
	pthread_mutex_destroy(&init_mutex);
}