#include <winsock2.h>
#include <io.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#pragma comment(lib,"ws2_32")
#define BUFSIZE			8192
#define DEFAULT_PORT	5320

enum {CMD_NAME,DST_IP,DST_PORT};
void InitWinSocket();
void ParseCmdLine(int*port ,unsigned long *ip,int argc,char*argv[]);
void CreateTcpSocket(SOCKET* sock);
void ConnectToServer(SOCKET sock,unsigned long dst_ip,int port);
void CommunicateWithServer(SOCKET sock);
void ReceiveFromServer(void* s);
int	ReadFromKeyBoardAndSandToServer(SOCKET sock);

int main(int argc, char *argv[]){
	SOCKET sock;
	int port;
	unsigned long dst_ip;

	InitWinSocket();
	ParseCmdLine(&port,&dst_ip,argc,argv);
	CreateTcpSocket(&sock);

	ConnectToServer(sock,dst_ip,port);
	CommunicateWithServer(sock);

	closesocket(sock);
	WSACleanup(); 

	return 0;
}

void CommunicateWithServer(SOCKET sock){
	char buf[BUFSIZE];

	CreateThread(NULL,0,
		(LPTHREAD_START_ROUTINE)(ReceiveFromServer),
		&(sock),0,NULL);
	ReadFromKeyBoardAndSandToServer(sock);
	strcpy(buf,"quit");
	send(sock,buf,strlen(buf),0);
}
	
void ReceiveFromServer(void* s){
	int len;
	SOCKET sock;
	char buf[BUFSIZE];

	sock=*((SOCKET*)s);
	while((len=recv(sock,buf,BUFSIZE-1,0))>=0){
		buf[len]='\0';
		printf("%s",buf);
		fflush(stdout);
	}
}
	
int	ReadFromKeyBoardAndSandToServer(SOCKET sock){
	int len;
	char cmd[BUFSIZE];
	char buf[BUFSIZE];
	while(true){
		if((len=_read(0,buf,BUFSIZE-1))>0){
			buf[len]='\0';
			sscanf(buf,"%s",cmd);
			if(strcmp(cmd,"quit")==0)	break;
			if(send(sock,buf,len,0)<0)	break;
		}
	}
	return 0;
}
	
void InitWinSocket(){
	WSADATA wsaData;

	if (WSAStartup(MAKEWORD(2,1),&wsaData) != 0){
	fprintf(stderr,"WSAStartup failed: %d\n",GetLastError());
	exit(EXIT_FAILURE);
  }
}

void ParseCmdLine(int*port ,unsigned long *ip,int argc,char*argv[]){
	if(argc != 2 && argc!=3){
		fprintf(stderr," Usag: %s hostname [port]\n",argv[0]);
		exit(EXIT_FAILURE);
	}

	if((*ip=inet_addr(argv[DST_IP]))==INADDR_NONE){
		struct hostent* he;
		if((he=gethostbyname(argv[DST_IP]))==NULL){
			fprintf(stderr,"gethostbyname error\n");
			exit(EXIT_FAILURE);

		}
		memcpy((char*)ip,(char*)he->h_addr,he->h_length);
	}
	*ip=ntohl(*ip);
	if(argc==3){
		if((*port=(atoi(argv[DST_PORT])))==0){
			struct servent *se;
			if((se=getservbyname(argv[DST_PORT],"TCP"))!=NULL)
				*port=(int)ntohs((u_short)se->s_port);
			else{
				fprintf(stderr,"getservbynmame error\n");
				exit(EXIT_FAILURE);
			}
		}
	}else *port=DEFAULT_PORT;

}	

void CreateTcpSocket(SOCKET* sock){
	if((*sock=socket(AF_INET,SOCK_STREAM,0))<0){
		perror("socket");
		exit(EXIT_FAILURE);
	}
}

void ConnectToServer(SOCKET sock,unsigned long dst_ip,int port){
	struct sockaddr_in server;
	memset((char*)&server,0,sizeof(server));
	server.sin_family=AF_INET;
	server.sin_addr.s_addr=htonl(dst_ip);
	server.sin_port=htons(port);

	if(connect(sock,(struct sockaddr*)&server,sizeof(server))<0){
		perror("connect");
		exit(EXIT_FAILURE);
	}
}