twitchirc/Project1/irc.cpp

#include <string>
#include <vector>
#include <istream>
#include <sstream>
#include <iostream>
#include <deque>
#include <optional>

#include "irc.h"

#include <SDL.h> // for SDL_GetTicks();


enum class ircommand parse_command(const std::string& command) {
	if (!command.compare("PRIVMSG")) {
		return ircommand::PRIVMSG;
	}
	if (!command.compare("JOIN")) {
		return ircommand::JOIN;
	}
	if (!command.compare("QUIT")) {
		return ircommand::QUIT;
	}
	if (!command.compare("PING")) {
		return ircommand::PING;
	}

	return ircommand::UNKNOWN;
}


/*
	https://datatracker.ietf.org/doc/html/rfc1459.html#section-2.3.1
*/
std::optional<msg> 
parse_chat_message(const std::string &message) 
{
// :nightbot!nightbot@nightbot.tmi.twitch.tv PRIVMSG #ironmouse :If you would like to support ironmouse donations are not required but greatly appreciated: https://www.streamlabs.com/ironmouse

	struct msg m {};
	int start = 0;
	int end = 0;

	if (message[0] == ':') {
		// prefix

		// parse user from prefix
		start = message.find("!", start);
		end = message.find("@", start);
		if (start != std::string::npos && end != std::string::npos && start < end) {
			start++;
			m.user = message.substr(start, end - start);
			end = message.find(" ", end);
		} else {
			start = 1;
			end = message.find(" ", start);
			m.user = message.substr(start, end - start);
		}
	}

	// command
	start = message.find_first_not_of(" ", end);
	end = message.find(" ", start);
	if (start == std::string::npos || end == std::string::npos) {
		return {};
	}
	auto command = message.substr(start, end - start);
	m.cmd = parse_command(command);

	if (m.cmd == ircommand::PRIVMSG) {
		// channel
		start = message.find("#");
		end = message.find(" ", start);
		start++;
		m.channel = message.substr(start, end - start);
	}

	start = message.find(":", end); // end of command params
	start++;


	// message
	m.message = message.substr(start, message.size()  - start);
	m.complete_message = message;

	return m;
}


void parse_chat_messages(const std::string& messages, 
	std::deque<msg> &message_queue) {
	// parse some input from server

	int start = 0;

	std::vector<std::string> tokens{};
	std::istringstream iss(messages);
	std::string s;
	while (std::getline(iss, s)) {
		auto msg = parse_chat_message(s);
		msg->received_at = SDL_GetTicks();
		if (msg) {
			message_queue.push_back(*msg);
		}
	}
}