// Standard C++
#include <array>
#include <iomanip>
#include <iostream>
#include <string>
#include <thread>

// Asio
#include <asio.hpp>

using namespace std;

int
main()
{
	asio::io_context context;

	try {
		const auto baudrate = 57600;
		const auto databits = 8;

		asio::serial_port port(context);

		auto send = [&](string_view cmd) {
			asio::write(port, asio::buffer(cmd));
		};

		port.open("/dev/cuaU0");
		if ( !port.is_open() ) {
			cerr << "Kann Port nicht öffnen...\n";
			return EXIT_FAILURE;
		}

		port.set_option(asio::serial_port::baud_rate(baudrate));
		port.set_option(asio::serial_port::parity(asio::serial_port::parity::none));
		port.set_option(asio::serial_port::character_size(databits));
		port.set_option(asio::serial_port::stop_bits(asio::serial_port::stop_bits::one));
		port.set_option(asio::serial_port::flow_control(asio::serial_port::flow_control::none));

		send("<GETSERIAL>>");

		jthread thread([&context, &port]() {
			array<char, 1000> buffer{};

			function<void()> readFromPort = [&]() {
				port.async_read_some(asio::buffer(buffer, buffer.size()), [&](std::error_code error, size_t length) {
					if ( !error ) {
						cout << "Daten: " << length << ": ";
						for ( size_t i = 0; i != length; ++i ) {
							auto chr = static_cast<unsigned char>(buffer.at(i));

							if ( isprint(chr) ) {
								cout << static_cast<char>(chr);
							}
							else {
								cout << '<' << hex << setw(2) << setfill('0') << static_cast<unsigned>(chr) << dec << '>';
							}
						}
						cout << '\n';

						readFromPort();
					}
					else {
						if ( error != asio::error::operation_not_supported ) {
							cerr << "Fehler: " << error.message() << '\n';
						}
					}
				});
			};

			readFromPort();
			context.run();
		});

		for ( string line; getline(cin, line); ) {
			if ( line == "ser?" ) {
				send("<GETSERIAL>>");
			}
			if ( line == "ver?" ) {
				send("<GETVER>>");
			}
			if ( line == "date?" ) {
				send("<GETDATETIME>>");
			}
			if ( line == "hb!" ) {
				send("<HEARTBEAT1>>");
			}

			if ( line == "quit" ) {
				break;
			}
		}

		port.cancel();
		context.stop();
		port.close();
	}
	catch ( asio::system_error& e ) {
		cerr << e.what() << '\n';
	}
}