#include <iostream>
#include <string>
#include <netdb.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <sstream>
#include <string.h>
#include <unistd.h>

using namespace std;

//  nc -u -v -4 mirkwood.cs.edinboro.edu 10000

const string MYPORT {"10000"};
const string HOSTNAME{"mirkwood.cs.edinboro.edu"};

const size_t BUFFER_SIZE{1000};

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

     srand(time(nullptr));
     char buffer[BUFFER_SIZE];     

     int theSocket;

     addrinfo *res;
     addrinfo hints;

     memset(&hints, 0, sizeof(hints));

     hints.ai_family = AF_INET;
     hints.ai_socktype = SOCK_DGRAM;

     int errCode;

     errCode = getaddrinfo(HOSTNAME.c_str(), MYPORT.c_str() , &hints, &res);

     if (errCode != 0) {
        cout << "Get Address Error: " << gai_strerror(errCode) << endl;
        return 1;
     } 

     theSocket = socket(AF_INET, SOCK_DGRAM, 0);

     if(theSocket == -1) {
        perror("Socket failed: ");
        exit(1);
     }

     sockaddr * ptr = reinterpret_cast<sockaddr *>(res->ai_addr);
     
     if( -1 == bind(theSocket, ptr, sizeof(sockaddr_in))) {
         perror("Bind failed: ");
     }

     freeaddrinfo(res);

     bool done{false};
     socklen_t len;
     size_t bytes;

     cout << argv[0] << " started" << endl;
     // should fix this  to use information from getaddrinfo
     cout << "Connect with  nc -u -v -4 147.64.242.52 10000" << endl;
     cout << "\tinteger input will roll a die" << endl;
     cout << "\tquit  will cause the server to exit " << endl;
     cout << endl;

     while (not done) {
         cout << endl;

         len = sizeof(sockaddr_in);
         sockaddr_in clientAddress;

         memset(&buffer, 0, BUFFER_SIZE);

         bytes = recvfrom(theSocket, buffer, BUFFER_SIZE, 0,
                   reinterpret_cast<struct sockaddr *>(&clientAddress), &len);


         char nbuffer[100];
         inet_ntop(AF_INET, 
                   reinterpret_cast<void *> (&clientAddress.sin_addr), 
                   nbuffer, 100);
         int port = ntohs(clientAddress.sin_port);

         cout << "Got " << bytes << " bytes from "  
              << nbuffer << ":" << port  << "." << endl;

         if (bytes > 0) {
             buffer[bytes-1] = 0;
             stringstream s(buffer);

             int number;
             if (s >> number) {

                 int value{0};
                 if (number > 0) {
                    value = rand() % number+1;
                 } 
                 // should return an error message for 0 and negative

                 cout << "The bytes were the number " 
                      << number << ", returning " << value  << "." << endl;

                 // create a result to send back
                 stringstream out;
                 out << "The result of d" << number << " is " << value << endl;

                 // just so I dont' have to do a out.str().c_str()
                 string copy = out.str();

                 memset(&buffer, 0, BUFFER_SIZE);
                 size_t size = min(BUFFER_SIZE, copy.size()+1);
                 strncpy(buffer, copy.c_str(), BUFFER_SIZE-1);
                 bytes= sendto(theSocket, buffer, size, 0, 
                   reinterpret_cast<struct sockaddr*>(&clientAddress), len);
            } else {
                s.clear();
                string word;
                s >> word;
                cout << "The bytes were the word " << word << endl;
                if (word == "quit") {
                    done = true;
                } else {

                   bytes= sendto(theSocket, buffer, bytes, 0, 
                   reinterpret_cast<struct sockaddr *>(&clientAddress), len);
                }
            }
         }
     }

     close(theSocket);

     return 0;
}