#include <cstdlib>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock.h>
 
#define BACKLOG_MAX 5
#define BUFFER_SIZE 128
#define EXIT_CALL_STRING "#quit"

using namespace std;



 
int local_socket = 0;
int remote_socket = 0;
 
int remote_length = 0;
int message_length = 0;
 
unsigned short local_port = 0;
unsigned short remote_port = 0;
 
char message[BUFFER_SIZE];
 
struct sockaddr_in local_address;
struct sockaddr_in remote_address;
 
WSADATA wsa_data;
 
/* Exibe uma mensagem de erro e termina o programa */
void msg_err_exit(char *msg)
{
    fprintf(stderr, msg);
    system("PAUSE");
    exit(EXIT_FAILURE);
}
 
int main(int argc, char **argv)
{
    // inicia o Winsock 2.0 (DLL), Only for Windows
    if (WSAStartup(MAKEWORD(2, 0), &wsa_data) != 0)
        msg_err_exit("WSAStartup() failed\n");
 
    // criando o socket local para o servidor
    local_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (local_socket == INVALID_SOCKET)
    {
        WSACleanup();
        msg_err_exit("socket() failed\n");
    }
 
    printf("Porta local: ");
    scanf("%d", &local_port);
    fflush(stdin);
 
    // zera a estrutura local_address
    memset(&local_address, 0, sizeof(local_address));
 
    // internet address family
    local_address.sin_family = AF_INET;
 
    // porta local
    local_address.sin_port = htons(local_port);
 
    // endereco
    local_address.sin_addr.s_addr = htonl(INADDR_ANY); // inet_addr("127.0.0.1")
 
    // interligando o socket com o endereço (local)
    if (bind(local_socket, (struct sockaddr *) &local_address, sizeof(local_address)) == SOCKET_ERROR)
    {
        WSACleanup();
        closesocket(local_socket);
        msg_err_exit("bind() failed\n");
    }
 
    // coloca o socket para escutar as conexoes
    if (listen(local_socket, BACKLOG_MAX) == SOCKET_ERROR)
    {
        WSACleanup();
        closesocket(local_socket);
        msg_err_exit("listen() failed\n");
    }
 
    remote_length = sizeof(remote_address);
 
    printf("aguardando alguma conexao...\n");
    remote_socket = accept(local_socket, (struct sockaddr *) &remote_address, &remote_length);
    if(remote_socket == INVALID_SOCKET)
    {
        WSACleanup();
        closesocket(local_socket);
        msg_err_exit("accept() failed\n");
    }
 
    printf("conexao estabelecida com %s\n", inet_ntoa(remote_address.sin_addr));
    printf("aguardando mensagens...\n");
    do
    {
        // limpa o buffer
        memset(&message, 0, BUFFER_SIZE);
 
        // recebe a mensagem do cliente
        message_length = recv(remote_socket, message, BUFFER_SIZE, 0);
        if(message_length == SOCKET_ERROR)
            msg_err_exit("recv() failed\n");
 
        // exibe a mensagem na tela
        printf("%s: %s\n", inet_ntoa(remote_address.sin_addr), message);
    }
    while(strcmp(message, EXIT_CALL_STRING)); // sai quando receber um "#quit" do cliente
 
    printf("encerrando\n");
    WSACleanup();
    closesocket(local_socket);
    closesocket(remote_socket);
 
    system("PAUSE");
    return 0;
}