#include <iostream>
#include <vector>
#include <onnxruntime_cxx_api.h>
#include "node.h"

using namespace Napi;

#define SESSION_INSTANCE_METHOD(method) InstanceMethod<&OrtSession::method>(#method, static_cast<napi_property_attributes>(napi_writable | napi_configurable))

static ONNXTensorElementDataType getDataTypeFromString(const std::string &name)
{
	static const std::map<std::string, ONNXTensorElementDataType> dataTypeNameMap = {
		{"float32", ONNX_TENSOR_ELEMENT_DATA_TYPE_FLOAT},
		{"float", ONNX_TENSOR_ELEMENT_DATA_TYPE_FLOAT},
		{"float64", ONNX_TENSOR_ELEMENT_DATA_TYPE_DOUBLE},
		{"double", ONNX_TENSOR_ELEMENT_DATA_TYPE_DOUBLE},
		{"int8", ONNX_TENSOR_ELEMENT_DATA_TYPE_INT8},
		{"uint8", ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT8},
		{"int16", ONNX_TENSOR_ELEMENT_DATA_TYPE_INT16},
		{"uint16", ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT16},
		{"int32", ONNX_TENSOR_ELEMENT_DATA_TYPE_INT32},
		{"uint32", ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT32},
		{"int64", ONNX_TENSOR_ELEMENT_DATA_TYPE_INT64},
		{"uint64", ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT64},
	};
	auto it = dataTypeNameMap.find(name);
	return (it == dataTypeNameMap.end()) ? ONNX_TENSOR_ELEMENT_DATA_TYPE_UNDEFINED : it->second;
}

static size_t getDataTypeSize(ONNXTensorElementDataType type)
{
	static const std::map<ONNXTensorElementDataType, size_t> dataTypeSizeMap = {
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_FLOAT, 4},
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_DOUBLE, 8},
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_INT8, 1},
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT8, 1},
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_INT16, 2},
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT16, 2},
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_INT32, 4},
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT32, 4},
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_INT64, 8},
		{ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT64, 8},
	};
	auto it = dataTypeSizeMap.find(type);
	return (it == dataTypeSizeMap.end()) ? 0 : it->second;
}

static void *dataFromTypedArray(const Napi::Value &val, size_t &bytes)
{
	auto arr = val.As<TypedArray>();
	auto data = static_cast<uint8_t *>(arr.ArrayBuffer().Data());
	bytes = arr.ByteLength();
	return static_cast<void *>(data + arr.ByteOffset());
}

class OrtSessionNodeInfo {
  public:
	inline OrtSessionNodeInfo(const std::string &name, const Ort::TypeInfo &typeInfo)
		: name_(name), shape_(typeInfo.GetTensorTypeAndShapeInfo().GetShape()), type_(typeInfo.GetTensorTypeAndShapeInfo().GetElementType()) {}

	inline const std::string &GetName() const { return name_; }
	inline const std::vector<int64_t> &GetShape() const { return shape_; }
	inline ONNXTensorElementDataType GetType() const { return type_; }
	inline size_t GetElementSize() const { return getDataTypeSize(type_); }
	size_t GetElementCount() const
	{
		if (!shape_.size()) return 0;
		size_t result = 1;
		for (auto dim : shape_) {
			if (dim <= 0) continue;
			result *= dim;
		}
		return result;
	}
	inline size_t GetElementBytes() const { return GetElementSize() * GetElementCount(); }

  private:
	std::string name_;
	std::vector<int64_t> shape_;
	ONNXTensorElementDataType type_;
};

class OrtSessionRunWorker : public AsyncWorker {
  public:
	OrtSessionRunWorker(std::shared_ptr<Ort::Session> session, const Napi::Function &callback)
		: Napi::AsyncWorker(callback), session_(session) {}
	~OrtSessionRunWorker() {}

	void Execute()
	{
		if (!HasError()) {
			try {
				Ort::RunOptions runOption;
				session_->Run(runOption, &inputNames_[0], &inputValues_[0], inputNames_.size(), &outputNames_[0], &outputValues_[0], outputNames_.size());
			}
			catch (std::exception &err) {
				SetError(err.what());
			}
		}
	}

	void OnOK()
	{
		if (HasError()) {
			Callback().Call({Error::New(Env(), errorMessage_.c_str()).Value(), Env().Undefined()});
		}
		else {
			auto result = Object::New(Env());
			for (int i = 0; i < outputNames_.size(); ++i) {
				size_t bytes = outputElementBytes_[i];
				Ort::Value &value = outputValues_[i];
				auto buffer = ArrayBuffer::New(Env(), value.GetTensorMutableRawData(), bytes);
				result.Set(String::New(Env(), outputNames_[i]), buffer);
			}
			Callback().Call({Env().Undefined(), result});
		}
	}

	inline void AddInput(const Ort::MemoryInfo &memoryInfo, const std::string &name, ONNXTensorElementDataType type, const std::vector<int64_t> &shape, void *data, size_t dataByteLen)
	{
		try {
			inputNames_.push_back(name.c_str());
			inputValues_.push_back(Ort::Value::CreateTensor(memoryInfo, data, dataByteLen, &shape[0], shape.size(), type));
		}
		catch (std::exception &err) {
			SetError(err.what());
		}
	}

	inline void AddOutput(const std::string &name, size_t elementBytes)
	{
		outputNames_.push_back(name.c_str());
		outputValues_.push_back(Ort::Value{nullptr});
		outputElementBytes_.push_back(elementBytes);
	}

	inline void SetError(const std::string &what) { errorMessage_ = what; }

	inline bool HasError() { return errorMessage_.size() > 0; }

  public:
	std::shared_ptr<Ort::Session> session_;
	std::vector<const char *> inputNames_;
	std::vector<Ort::Value> inputValues_;
	std::vector<const char *> outputNames_;
	std::vector<Ort::Value> outputValues_;
	std::vector<size_t> outputElementBytes_;
	std::string errorMessage_;
};

class OrtSession : public ObjectWrap<OrtSession> {
  public:
	static Napi::Object Init(Napi::Env env, Napi::Object exports)
	{
		Function func = DefineClass(env, "OrtSession", {
														   SESSION_INSTANCE_METHOD(GetInputsInfo),
														   SESSION_INSTANCE_METHOD(GetOutputsInfo),
														   SESSION_INSTANCE_METHOD(Run),
													   });
		FunctionReference *constructor = new FunctionReference();
		*constructor = Napi::Persistent(func);
		exports.Set("OrtSession", func);
		env.SetInstanceData<FunctionReference>(constructor);
		return exports;
	}

	OrtSession(const CallbackInfo &info)
		: ObjectWrap(info)
	{
		try {
			if (info[0].IsString()) session_ = std::make_shared<Ort::Session>(env, info[0].As<String>().Utf8Value().c_str(), sessionOptions);
			else if (info[0].IsTypedArray()) {
				size_t bufferBytes;
				auto buffer = dataFromTypedArray(info[0], bufferBytes);
				session_ = std::make_shared<Ort::Session>(env, buffer, bufferBytes, sessionOptions);
			}
			else session_ = nullptr;

			if (session_ != nullptr) {
				Ort::AllocatorWithDefaultOptions allocator;
				for (int i = 0; i < session_->GetInputCount(); ++i) {
					std::string name = session_->GetInputNameAllocated(i, allocator).get();
					auto typeInfo = session_->GetInputTypeInfo(i);
					inputs_.emplace(name, std::make_shared<OrtSessionNodeInfo>(name, typeInfo));
				}
				for (int i = 0; i < session_->GetOutputCount(); ++i) {
					std::string name = session_->GetOutputNameAllocated(i, allocator).get();
					auto typeInfo = session_->GetOutputTypeInfo(i);
					outputs_.emplace(name, std::make_shared<OrtSessionNodeInfo>(name, typeInfo));
				}
			}
		}
		catch (std::exception &e) {
			Error::New(info.Env(), e.what()).ThrowAsJavaScriptException();
		}
	}

	~OrtSession() {}

	Napi::Value GetInputsInfo(const Napi::CallbackInfo &info) { return BuildNodeInfoToJavascript(info.Env(), inputs_); }

	Napi::Value GetOutputsInfo(const Napi::CallbackInfo &info) { return BuildNodeInfoToJavascript(info.Env(), outputs_); }

	Napi::Value Run(const Napi::CallbackInfo &info)
	{
		auto worker = new OrtSessionRunWorker(session_, info[1].As<Function>());
		auto inputArgument = info[0].As<Object>();
		auto memoryInfo = Ort::MemoryInfo::CreateCpu(OrtDeviceAllocator, OrtMemTypeDefault);
		for (auto it = inputArgument.begin(); it != inputArgument.end(); ++it) {
			auto name = (*it).first.As<String>().Utf8Value();
			auto input = GetInput(name);
			if (!input) worker->SetError(std::string("input name #" + name + " not exists"));
			else {
				auto inputOption = static_cast<Napi::Value>((*it).second).As<Object>();
				if (!inputOption.Has("data") || !inputOption.Get("data").IsTypedArray()) worker->SetError((std::string("data is required in inputs #" + name)));
				else {
					auto type = inputOption.Has("type") ? getDataTypeFromString(inputOption.Get("type").As<String>().Utf8Value()) : input->GetType();
					size_t dataByteLen;
					void *data = dataFromTypedArray(inputOption.Get("data"), dataByteLen);
					auto shape = inputOption.Has("shape") ? GetShapeFromJavascript(inputOption.Get("shape").As<Array>()) : input->GetShape();
					worker->AddInput(memoryInfo, input->GetName(), type, shape, data, dataByteLen);
				}
			}
		}
		for (auto &it : outputs_) {
			worker->AddOutput(it.second->GetName(), it.second->GetElementBytes());
		}
		worker->Queue();

		return info.Env().Undefined();
	}

  private:
	static std::vector<int64_t> GetShapeFromJavascript(Napi::Array arr)
	{
		std::vector<int64_t> res(arr.Length());
		for (int i = 0; i < res.size(); ++i) res[i] = arr.Get(i).As<Number>().Int32Value();
		return res;
	}

	inline std::shared_ptr<OrtSessionNodeInfo> GetInput(const std::string &name) const
	{
		auto it = inputs_.find(name);
		return (it == inputs_.end()) ? nullptr : it->second;
	}

	inline std::shared_ptr<OrtSessionNodeInfo> GetOutput(const std::string &name) const
	{
		auto it = outputs_.find(name);
		return (it == outputs_.end()) ? nullptr : it->second;
	}

	Napi::Value BuildNodeInfoToJavascript(Napi::Env env, const std::map<std::string, std::shared_ptr<OrtSessionNodeInfo>> &nodes)
	{
		auto result = Object::New(env);
		for (auto it : nodes) {
			auto &node = *it.second;
			auto item = Object::New(env);
			item.Set(String::New(env, "name"), String::New(env, node.GetName()));
			item.Set(String::New(env, "type"), Number::New(env, node.GetType()));
			auto &shapeVec = node.GetShape();
			auto shape = Array::New(env, shapeVec.size());
			for (int i = 0; i < shapeVec.size(); ++i) shape.Set(i, Number::New(env, shapeVec[i]));
			item.Set(String::New(env, "shape"), shape);
			result.Set(String::New(env, node.GetName()), item);
		}

		return result;
	}

  private:
	Ort::Env env;
	Ort::SessionOptions sessionOptions;
	std::shared_ptr<Ort::Session> session_;
	std::map<std::string, std::shared_ptr<OrtSessionNodeInfo>> inputs_;
	std::map<std::string, std::shared_ptr<OrtSessionNodeInfo>> outputs_;
};

void InstallOrtAPI(Napi::Env env, Napi::Object exports)
{
	OrtSession::Init(env, exports);
}

#ifdef USE_ONNXRUNTIME
static Object Init(Env env, Object exports)
{
	InstallOrtAPI(env, exports);
	return exports;
}
NODE_API_MODULE(addon, Init)

#endif