#include <winsock2.h>
#include <iostream.h>
#include <string.h>
#include "addr.h"

//---------------------------------------------------------------------------
char *reverse(char* str)
{
   char *s = strdup(str);
   int   i=0, l=strlen(str)-1;
   while( s[i] ){
      str[l-i] = s[i];
      i++;
   }
   delete s;
   return str;
}
//---------------------------------------------------------------------------

#define DEFPORT "5555"

int main(int argc, char* argv[])
{
   SOCKET      s;
   SOCKADDR_IN local, peer;
   int         peerlen;
   char        buf[256];

   init();

   if( argc < 2 ){
      cout<<"Default port "<<DEFPORT<<" is used"<<endl;
      set_address(NULL, DEFPORT, "udp", &local);
   }
   else{
      cout<<"Port "<<argv[1]<<" is used"<<endl;
      set_address(NULL, argv[1], "udp", &local);
   }
   print_address(local);

   if( (s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == INVALID_SOCKET ){
      cerr<<"failed to create socket\n";
      return 2;
   }

   if( bind(s, (SOCKADDR*)&local, sizeof(local)) ){
      cerr<<"Failed to bind the socket"<<endl;
      return 3;
   }

   while(1){
      peerlen = sizeof(peer);
      if( recvfrom(s, buf, sizeof(buf), 0, (SOCKADDR*)&peer, &peerlen) < 0 ){
         cerr<<"Error reading from socket"<<endl;
         return 4;
      }
      cout<<"Packet '"<<buf<<"' from: \n";
      print_address(peer);
      if( sendto(s, reverse(buf), sizeof(buf), 0, (SOCKADDR*)&peer, peerlen) < 0 ){
         cerr<<"Error writing into socket"<<endl;
         return 5;
      }
   }

   return 0;
}
//---------------------------------------------------------------------------