#include <iostream>
#include <sys/types.h>
#include <sys/socket.h>
#include <strings.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <netdb.h>
#include <string>

using namespace std;

//const unsigned serv_port = 5100;
const unsigned MAXBUFLEN = 512;


int main(int argc, char **argv) {
	int sockfd, rv, flag;
	ssize_t n;
	char buf[MAXBUFLEN];
	struct addrinfo hints, *res, *ressave;

	if (argc != 3) {
		cout << "echo_client server_name_or_ip port" << endl;
		exit(1);
	}

	cout << argv[1] << " " << argv[2] << endl;

	bzero(&hints, sizeof(struct addrinfo));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;

	if ((rv = getaddrinfo(argv[1], argv[2], &hints, &res)) != 0) {
		cout << "getaddrinfo wrong: " << gai_strerror(rv) << endl;
		exit(1);
	}

	ressave = res;
	flag = 0;
	do {
		sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
		if (sockfd < 0) 
			continue;
		if (connect(sockfd, res->ai_addr, res->ai_addrlen) == 0) {
			flag = 1;
			break;
		}
		close(sockfd);
	} while ((res = res->ai_next) != NULL);
	freeaddrinfo(ressave);

	if (flag == 0) {
		fprintf(stderr, "cannot connect\n");
		exit(1);
	}
	string oneline;

	/* Does this program have problems? Yes.
	 * The client may be blocked forever after the server crashes or closes
	 * the connection. FOREVER: until user types a line. Otherwise, the client 
	 * program is blocked on getline().
	 */ 		 
	while (getline(cin, oneline)) {
		if (oneline == "quit") {
			close(sockfd);
			break;
		} else {
			write(sockfd, oneline.c_str(), oneline.length());
			// we assume we obtain everything we need
			// in reality, we should make sure to read certain amount
			// of bytes, oneline.length()
			n = read(sockfd, buf, MAXBUFLEN);

			// check if error or closed
			if (n <= 0) {
				if (n == 0) {
					cout << "server closed" << endl;
				} else {
					cout << "something wrong" << endl;
				}
				close(sockfd);
				exit(0);
			}

			// print out echo string
			buf[n] = '\0';
			cout << buf << endl;
		}
	}
}