#include <iostream>
#include <array>
#include <vector>
#include <memory>
#include <unistd.h>
#include <cassert>
#include <type_traits>

#include <hidapi/hidapi.h>

using Packet = std::vector<uint8_t>;
static_assert(sizeof (uint8_t) == sizeof (unsigned char)); // unsigned char is used in the HID API library

class HIDException {
private:
	std::wstring message;
public:

	HIDException(std::wstring message) : message(message) {
	}

	virtual ~HIDException() {
	}

	const std::wstring getMessage() const {
		return message;
	}

};

class HIDDevice {
private:
	std::shared_ptr<hid_device> handle;

public:

	HIDDevice(unsigned short vendorId, unsigned short productId, const wchar_t *serialNumber) {
		int initError = hid_init(); // TODO: move to HIDContext class?
		if (initError) throw HIDException(L"Unable to init HID API.");
		handle.reset(hid_open(vendorId, productId, serialNumber), hid_close);
		if (handle == nullptr) throw HIDException(L"Unable to open HID device. Are you root? Is mouse present?");
	}

	virtual ~HIDDevice() {
		hid_exit(); // TODO: move to HIDContext class?
	}

	const std::wstring getManufacturerName() const {
		std::array<wchar_t, 200 > buffer;
		int error = hid_get_manufacturer_string(handle.get(), buffer.data(), buffer.size());
		if (error) throw HIDException(L"Unable to get manufacturer name.");
		return buffer.data();
	}

	const std::wstring getProductName() const {
		std::array<wchar_t, 200 > buffer;
		int error = hid_get_product_string(handle.get(), buffer.data(), buffer.size());
		if (error) throw HIDException(L"Unable to get product name.");
		return buffer.data();
	}

	const std::wstring getSerialNumber() const {
		std::array<wchar_t, 200 > buffer;
		int error = hid_get_serial_number_string(handle.get(), buffer.data(), buffer.size());
		if (error) throw HIDException(L"Unable to get serial number.");
		return buffer.data();
	}

	void sendFeatureReport(Packet data) {
		int written = hid_send_feature_report(handle.get(), data.data(), data.size());
		if (written < 0) throw HIDException(L"Unable to send feature report.");
	}

};

enum class Frequency : uint8_t {
	Hz_0125 = 8,
	Hz_0250 = 4,
	Hz_0500 = 2,
	Hz_1000 = 1
};

using FrequencyType = std::underlying_type<Frequency>::type;

class CadMouseConfig {
private:
	bool liftOffDetection = true;
	bool smartScrolling = false;
	Frequency frequency = Frequency::Hz_1000;
public:

	void setFrequency(Frequency frequency) {
		this->frequency = frequency;
	}

	void setLiftOffDetection(bool liftOffDetection) {
		this->liftOffDetection = liftOffDetection;
	}

	void setSmartScrolling(bool smartScrolling) {
		this->smartScrolling = smartScrolling;
	}

	Packet serialize() {
		Packet data;
		data.reserve(32);

		data.push_back(0x10); // report ID
		data.push_back(0x00); // option

		data.push_back(0x1c); // speed

		data.push_back(liftOffDetection ? 0x00 : 0x1f);

		if (smartScrolling) {
			data.push_back(0x00);
			data.push_back(0x00);
			data.push_back(0x00);
			data.push_back(0x01);
		} else {
			data.push_back(0x01);
			data.push_back(0xff);
			data.push_back(0x00);
			data.push_back(0x00);
		}

		for (int i = 0; i < 8; i++) data.push_back(0x00); // constant padding or magic

		// magic constants or unknown fields
		data.push_back(0x00);
		data.push_back(0x03);
		data.push_back(0x00);
		data.push_back(0x0a);
		data.push_back(0x0b);
		data.push_back(0x0c);
		data.push_back(0x0c);
		data.push_back(0x0e);
		data.push_back(0x0d);
		data.push_back(0x2f);
		data.push_back(0x00);
		data.push_back(0x1e);

		data.push_back(0x00);
		data.push_back(0x00);
		data.push_back(0x00);
		data.push_back(static_cast<FrequencyType> (frequency));

		return data;
	}

};

int main(int argc, char** argv) {
	try {

		std::wcout << L"cadMousePro" << std::endl;
		HIDDevice mouse(0x256f, 0xc652, nullptr);
		std::wcout << L"mouse opened" << std::endl;
		std::wcout << L"manufacturer:  " << mouse.getManufacturerName() << std::endl;
		std::wcout << L"product:       " << mouse.getProductName() << std::endl;
		// std::wcout << L"serial number: " << mouse.getSerialNumber() << std::endl; // throws exception

		CadMouseConfig config;

		mouse.sendFeatureReport(config.serialize());

		return 0;
	} catch (const HIDException& e) {
		std::wcout << L"HIDException: " << e.getMessage() << std::endl;
		return 1;
	}
}