#include <sys/types.h>
#include <sys/socket.h>
#include <iostream>

#include <netdb.h>  // use getprotobyname
#include <arpa/inet.h>  // use inet_pton
#include <cerrno>   // for errorno
#include <cstring>  // for errorstring
#include <netinet/in.h>

// how many connections will wait in queue?
#define CONNECTION_QUEUE_COUNT 10

#define SERVER_IP_ADDRESS "127.0.0.1" // bind to localhost
#define SERVER_PORT 6666 // port to bind to

/**
    Obtains tcp socket via socket()
    @author Filip Sivák <sivakfil@fel.cvut.cz>
    @throws int 1, if socket fails
 */
int getTcpSocket() {
    int sock;
    sock = socket(PF_INET, SOCK_STREAM, getprotobyname("tcp")->p_proto);
    if( sock < 0 ) throw 1;
    return sock;
}


/**
    Obtains sockaddr_in via inet_pton
    @author: Filip Sivák <sivakfil@fel.cvut.cz>
 */
struct sockaddr_in getAddress(const char address, int port) {
    struct sockaddr_in ip4;

    ip4.sin_family = AF_INET;
    ip4.sin_port = htons( port ); // hostByteOrder --> networkByteOrder
    ip4.sin_addr.s_addr = inet_addr( &address );
    return ip4;
}

/**
    Binds given socket to given address
    You should obtain address by getAddress()
    @throws 2 if error occurs during bind
    @author Filip Sivák<sivakfil@fel.cvut.cz>
*/
void doBind(int socket, struct sockaddr_in address) {
    int binded = 0;
    binded = bind(socket, (struct sockaddr *)&address, sizeof address);
    if(binded != 0) {
        throw 2;
    }
}

/**
    Accepts incoming connections
    @param sockaddr_storage *incoming_addr - pointer to incoming address
                     that will be set
    @throw error no. 3 on error
    @returns socket file descriptor of incoming connection
 */
int  doAccept(int socket, struct sockaddr_storage *incoming_addr) {
    int accepted;

    socklen_t addrSize;
    addrSize = sizeof incoming_addr;

    accepted = accept(socket, (struct sockaddr *) incoming_addr, &addrSize);
    if(accepted == -1) {
        throw 3;
    }else {
        return accepted;
    }
}

int main(void) {
    try {
        int socket = getTcpSocket();
        std::cout << "Yo! I have a socket for you: " << socket << "\n";

        struct sockaddr_in socketAddress;
        const char *addr = SERVER_IP_ADDRESS;
        socketAddress = getAddress(*addr, SERVER_PORT);

        doBind( socket, socketAddress );

        std::cout << "Yo! I have binded your socket esse!\n";

        int listenError = listen( socket, CONNECTION_QUEUE_COUNT );
        if(listenError == -1) throw 4;

        std::cout << "Yo Homie! I'm listening. Taalk to me! \n";

        struct sockaddr_storage incoming_addr;
        int socketIncoming = doAccept(socket, &incoming_addr);

        std::cout << "Hi Hi Hi mr.: " << socketIncoming << "! \n";

    }catch(int errorNo) {
        std::cout << "-----------------------\n";
        std::cout << "Error with no: " << errorNo << " occured!\n";
        std::cout << "Error: " << std::strerror(errno) << " \n";
    }

    return 0;
}