// Standard C++ headers
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <string>

// Socket headers
#include <sys/socket.h>
#include <netinet/ip.h>
#include <arpa/inet.h>

// UNIX system headers
#include <errno.h>

using namespace std;

const int SERVER_PORT=0;
const int MAX_PENDING=5;
const int MAX_LINE=256;

void handle_error(int eno, char const *msg)
{
    if(eno == 0)
        cerr << msg << endl;
    else
        cerr << msg << ": "<< strerror(eno) << endl;
    exit(errno);
}

int main(int argc, char *argv[])
{
    int nread;
    socklen_t len;
    sockaddr_in sin;
    sockaddr *sin_p = (sockaddr *)&sin;
    sin.sin_family = AF_INET;                   // IP version 4
    sin.sin_port = htons(SERVER_PORT);
    sin.sin_addr.s_addr = htonl(INADDR_ANY);    // Listen on all IP addresses
    int rstat;

    cout << ntohs(sin.sin_port) << endl;

    // Create socket
    int s = socket(AF_INET, SOCK_STREAM, 0);
    if(s == -1)
        handle_error(errno, "simplex_server - socket");

    // Bind socket to local address
    rstat = bind(s, sin_p, sizeof(sin));
    if(rstat == -1)
        handle_error(errno, "simplex_server - bind");

    rstat = listen(s, MAX_PENDING);
    if(rstat == -1)
        handle_error(errno, "simplex_server - listen");

    // Allocate a memory buffer for received messages
    char *buf = new char[MAX_LINE];

    // Wait for connections
    while(true) {
        // Upon return the sin structure will contain the address of the
        // connecting socket.  Note that a new socket is returned.
        len = sizeof(sin);
        int new_s = accept(s, sin_p, &len);
        if(new_s == -1)
            handle_error(errno, "simplex_server - accept");

		  // Display IP addr and Port
		  len = sizeof(sin);
		  rstat = getpeername(new_s, sin_p, &len);
		  if (rstat == -1)
				handle_error(errno, "simplex_server - address and port");
		  // h_addr contains the memory address of the IP address (?!?)
		  // The IP addresses are in network byte order
		  char *dst = new char[INET_ADDRSTRLEN];
		  const char *rmem = inet_ntop(AF_INET, &sin.sin_addr, dst, INET_ADDRSTRLEN);
		  if(rmem == NULL)
				handle_error(errno, "simplex_client - inet_ntop");
		  cout << "Client IP Address: " << dst << endl;
		  cout << "Client IP Port: " << ntohs(sin.sin_port) << endl;

        // Receive and print messages as long as client is connected.
        while(true) {
            nread = recv(new_s, buf, MAX_LINE, 0);
            if(nread == -1)
                handle_error(0, "simplex_server - recv");
            if (nread == 0) break;  // client has disconnected
            cout << buf << flush;
        }
        close(new_s);
    }
    close(s);
    delete [] buf;

    return 0;
}