#include <iostream>          // For cout and cerr
#include <cstdlib>           // For atoi()
#include "cls_sockets.h" // For UDPSocket and SocketException

const int ECHOMAX = 255;     // Longest string to echo

int main(int argc, char *argv[]) {

  if (argc != 2) {                  // Test for correct number of parameters
    cerr << "Usage: " << argv[0] << " <Server Port>" << endl;
    exit(1);
  }

  unsigned short echoServPort = atoi(argv[1]);     // First arg:  local port

  try {
    UDPSocket sock(echoServPort);                
  
    char echoBuffer[ECHOMAX];         // Buffer for echo string
    int recvMsgSize;                  // Size of received message
    string sourceAddress;             // Address of datagram source
    unsigned short sourcePort;        // Port of datagram source

		for (;;) {  // Run forever
      // Block until receive message from a client
      recvMsgSize = sock.recvFrom(echoBuffer, ECHOMAX, sourceAddress, sourcePort);
  
      cout << "Received packet from " << sourceAddress << ":" << sourcePort << endl;
  
      sock.sendTo(echoBuffer, recvMsgSize, sourceAddress, sourcePort);
    }
  } catch (SocketException &e) {
    cerr << e.what() << endl;
    exit(1);
  }
  // NOT REACHED

  return 0;
}