// this is the client.
// compile with CC client.cpp -o client
// the server must already be running before you run the client
// and you must know the server's port number, e.g. 21000
// if the client and server are on the same computer, just say
//          client 21000
// otherwise, say something like
//          client rabbit.eng.miami.edu 21000
// (the client must be told where the server is)

// the only useful things in this file are the "connection" and
// "event" objects, and of course the sample main()


#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <netdb.h>
#include <sys/param.h>
#include <sys/select.h>
#include <sys/time.h>
#include <string>
#include <iostream>

extern int errno;

string is(int n)
{ char s[20];
  sprintf(s, "%d", n);
  return s; }

const string timeout = "timeout";
const string disconnection = "disconnection";
const string keyboard = "keyboard";
const string server = "server";

struct event
{ string what;
  string data; 
  event(string a, string c)
  { what=a; data=c; } };

struct connection
{ int port;
  string hostname, ip;
  int main_socket;

  connection(string hostname, int port);
  event wait(double maxtime=-1);
  void send(string s);
  void disconnect(); };

connection::connection(string hn, int p)
{ hostname=hn;
  port=p;
  hostent * record = gethostbyname(hostname.c_str());
  if (record==NULL) 
  { herror("gethostbyname failed"); 
    exit(1); }
  in_addr * addressptr = (in_addr *) record->h_addr;
  ip=inet_ntoa(* addressptr);
  main_socket = socket(AF_INET, SOCK_STREAM, 0);
  if (main_socket<0)
  { perror("socket creation");
    exit(1); }
  sockaddr_in server_info;
  server_info.sin_len = sizeof(server_info);
  server_info.sin_family = AF_INET;
  server_info.sin_addr = * addressptr;
  server_info.sin_port = htons(port);
  int r = connect(main_socket, (sockaddr *) &server_info, sizeof(server_info));
  if (r<0)
  { perror("connect");
    exit(1); } }

void connection::send(string s)
{ write(main_socket, s.c_str(), s.length()); }

event connection::wait(double maxtime)
{ while (1)
  { fd_set fds;
    FD_ZERO(&fds);
    FD_SET(main_socket, &fds);
    FD_SET(0, &fds);
    timeval maxwait;
    maxwait.tv_sec=(int)maxtime;
    maxwait.tv_usec=(int)((maxtime-(int)maxtime)*1000000);
    int r3;
    if (maxtime<0)
      r3 = select(main_socket+1, &fds, NULL, NULL, NULL);
    else
      r3 = select(main_socket+1, &fds, NULL, NULL, &maxwait);
    if (r3<0)
    { perror("select");
      sleep(2);
      continue; }
    else if (r3==0)
      return event(timeout, timeout);
    else if (FD_ISSET(main_socket, &fds))
    { char s[1000];
      int n=read(main_socket, s, 999);
      if (n<=0)
      { close(main_socket);
        return event(disconnection, ""); }
      else
      { s[n]=0;
        return event(server, s); } }
    else if (FD_ISSET(0, &fds))
    { char s[1000];
      int n=read(0, s, 999);
      while (n>0 && s[n-1]<' ')
        n-=1;
      s[n]=0;
      return event(keyboard, s); } } }

void connection::disconnect()
{ if (main_socket>=0)
    close(main_socket);
  main_socket=-1; }
 
void main(int argc, char *argv[])
{ char * server = "127.0.0.1";
  int port;
  if (argc>=3)
  { server=argv[1];
    port=atol(argv[2]); }
  else
    port=atol(argv[1]);
  connection con(server, port);
  while (true)
  { event e = con.wait();
    if (e.what==disconnection)
    { cout << "I've been disconnected\n";
      exit(1); }
    else if (e.what==server)
      cout << "received from the server: " << e.data << "\n";
    else if (e.what==keyboard)
      con.send(e.data);
    else
      cout << e.what << " '" << e.data << "'\n"; } }