#include <iostream>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/epoll.h>
#include <unistd.h>
#include <signal.h>
#include <strings.h>

#include <list>
#include <string>

#include <boost/foreach.hpp>
#include <boost/typeof/typeof.hpp>

using namespace std;

void signal_handler(int sig);

const char *host_ip = "127.0.0.1";
const int host_port = 6000;
bool b_is_running = true;

int main()
try {
 int server_socket = socket(AF_INET, SOCK_STREAM, 0);
 if (server_socket == -1) {
 cerr << "create socket error" << endl;
 return 1;
 }

 struct sockaddr_in server_addr;
 bzero(&server_addr, sizeof(server_addr));
 server_addr.sin_family = AF_INET;
 server_addr.sin_addr.s_addr = inet_addr(host_ip);
 server_addr.sin_port = htons(host_port);

 if (bind(server_socket, (const struct sockaddr*)&server_addr, 
 sizeof(server_addr)) == -1) {
 cerr << "bind error" << endl;
 close(server_socket);
 return 1;
 }
 cout << "binding at " << host_port << endl;

 listen(server_socket, 10);

 cout << "--Start--" << endl;

 signal(SIGKILL, signal_handler);

 int epoll_fds = epoll_create(10);

 struct epoll_event ev;
 bzero(&ev, sizeof(ev));

 ev.events = EPOLLIN | EPOLLHUP;
 ev.data.fd = server_socket;
 epoll_ctl(epoll_fds, EPOLL_CTL_ADD, server_socket, &ev);

 const int buffer_size = 1024;
 char buffer[buffer_size] = {0};

 while (b_is_running) {
 struct epoll_event evs[10];
 int nfds = epoll_wait(epoll_fds, evs, 10, 0);
 if (nfds > 0) {
 for (int i = 0; i < nfds; ++i) {
 if (evs[i].data.fd == server_socket) {
 struct sockaddr client_addr;
 socklen_t client_addr_len;

 int client_socket = accept(server_socket, &client_addr, &client_addr_len);
 if (client_socket == -1) {
 cerr << "accept error." << endl;
 } else {
 cout << "accept connect: " << client_socket << endl;
 struct epoll_event ev;
 bzero(&ev, sizeof(ev));
 ev.events = EPOLLIN;
 ev.data.fd = client_socket;

 epoll_ctl(epoll_fds, EPOLL_CTL_ADD, client_socket, &ev);

 string echo("Login Success!\n");
 write(client_socket, echo.c_str(), echo.length());
 }
 } else {
 int this_fds = evs[i].data.fd;
 if (evs[i].events & EPOLLIN) {
 bzero(buffer, buffer_size);
 int rsize = read(this_fds, buffer, buffer_size);
 string echo("ECHO:");
 echo += buffer;
 write(this_fds, echo.c_str(), echo.length());

 } else if (evs[i].events & EPOLLHUP) {
 cout << "client hup: " << this_fds << endl;
 epoll_ctl(epoll_fds, EPOLL_CTL_DEL, this_fds, NULL);
 close(this_fds);
 }
 }
 }
 }
 }

 close(server_socket);
 cout << "--End--" << endl;
 return 0;
} catch (...) {
 cerr << "Exception ocurr." << endl;
}

void signal_handler(int sig)
{
 b_is_running = false; 
 cout << "Ctrl+C" << endl;
}