presence.cpp

#include <array>
#include <cstdio>
#include <cstring>
#include <discord_rpc.h>
#include <iostream>
#include <memory>
#include <stdexcept>
#include <string>
#include <thread>

/*
 * Utility functions
 */

std::string exec(const char* cmd) {
    std::array<char, 128> buffer;
    std::string result;
    std::shared_ptr<FILE> pipe(popen(cmd, "r"), pclose);
    if (!pipe) throw std::runtime_error("popen() failed!");
    while (!feof(pipe.get())) {
        if (fgets(buffer.data(), 128, pipe.get()) != nullptr)
            result += buffer.data();
    }
    return result;
}

std::string formatSong(std::string songName, std::string songArtist) {

    if (songArtist == (std::string)"") {
        return songName;
    }
	std::string sep = " - ";
	return songName + sep + songArtist;
}

/*
 * Discord Callbacks
 */

void handleDiscordReady(const DiscordUser* user) {
    std::cout << "Connected to " << user->username << std::endl;
}

void handleDiscordError(int _errorCode, const char* message) {
    std::cout << "Errored with error: " << message << std::endl;
}

void InitDiscord() {
   DiscordEventHandlers handlers;
   memset(&handlers, 0, sizeof(handlers));
   handlers.ready = handleDiscordReady;
   handlers.errored = handleDiscordError;
   handlers.disconnected = handleDiscordError;
   Discord_Initialize("503540314506657792", &handlers, 1, NULL);
}

/*
 * End Discord Callbacks
 */

void presenceLoop() {
    std::string current_song;
	long start_time;
    while (true) {
		std::string song_name = exec("playerctl metadata xesam:title");
		std::string artist = exec("playerctl metadata xesam:artist");
        std::string song = formatSong(song_name, artist);
		if (current_song != song) {
            DiscordRichPresence discordPresence;
            memset(&discordPresence, 0, sizeof(discordPresence));
            std::cout << "NEW SONG! Updating presence.." << std::endl;
            discordPresence.details = song.c_str();
            discordPresence.largeImageKey = "smiley";
            discordPresence.largeImageText = "Dank tunes";
            Discord_UpdatePresence(&discordPresence);
			current_song = song;
		}
        std::this_thread::sleep_for(std::chrono::seconds(3));
        std::cout << "Polling..." << std::endl;
    }
}

int main() {
    std::cout << "Preparing to start Discord handlers..." << std::endl;

    InitDiscord();

    presenceLoop();
}