/******************************************************************************
*  this program is developed by bhavani prasad sangannagari                   *
*  standard routines for socket interface are copied from comer               *

* 1. allows user to modify default port and host
* 2. client repeats the main menu after each response until user selects quit.*                              *
*                                                                             *
****************************************************************************/  

/****************************************************************************
* main threads ()                                                              *
* implements comment 1 and passes to TCPlib routine                            *
*********************************************************************************/

#include<stdio.h>
#include<stdlib.h>
#include<stdarg.h>
#include<winsock.h>
#include<iostream.h>
#include<process.h>
#include<conio.h>
#define BUFSIZE   100
#define LINELEN 128
#define WSVERS     MAKEWORD(2, 0)


void TCPlib(const char *, const char *);
SOCKET connectTCP(const char *, const char *);
SOCKET connectsock(const char *, const char *, const char *);
void errexit(const char *format, ...);

void list(SOCKET);  // to list out all the books
void search(SOCKET); // to search the book
void checkout(SOCKET);// to check out a book
void quit(SOCKET);    //  to quit the client
void readip(SOCKET);  // to read the data from the server


void main(int argc, char *argv[])
{
	const char *host = "localhost";
	const char *service = "2003";

	WSADATA wsadata;
	 
	switch (argc) {
	case 1:
		host = "localhost";
		break;
	case 3:
		service = argv[2];
		
	case 2:
		host = argv[1];
		break;
	default:
		fprintf(stderr, "usage: TCP [host [port]]\n");
		exit(1);
	}


  if (WSAStartup(WSVERS, &wsadata) != 0)
	   errexit("WSAStartup  failed\n");
  TCPlib(host,service);
  WSACleanup();
  exit(0);
}
/****************************************************************************
* TCPlib()                                                                      *
* performs sorts the users requests to different functions and repeats the main *
* menu                                                                          *
*********************************************************************************/
void TCPlib(const char *host, const char *service)
{
	char c;
	SOCKET s;
	
//	int cc, outchars, inchars;

	s = connectTCP(host, service);
	while(1) {

	printf("\n**************************************************");
    printf("\n***************** MEMORIAL LIBRARY *****************");
	printf("\n**************************************************");

	printf("\n       ENTER    1:  LIST OF ALL THE BOOKS AVAILABLE");
    printf("\n                2:  TO SEARCH FOR A BOOK           ");
	printf("\n                3:  TO CHECK OUT A BOOK            ");
	printf("\n                4:  QUIT                           ");
    printf("\n  Your Choice  : ");

	switch(c = _getche()) {

	case '1':  list(s);
		break;
	case '2':  search(s);
		break;
	case '3':  checkout(s);
		break;
	case '4':  quit(s);
		       return;
	default:  printf("\n          INVALID OPTION SELECTED :  PLEASE SELECT AGAIN");
	}
	}

	closesocket(s);
}

/****************************************************************************
* list() 
* intimates the server of the particular user requests and passes control to   *
* readip() to read server response                                             *
*********************************************************************************/

void list(SOCKET s) {
	int rc;
	rc = send(s,  "1", 1,0);
	if (rc < 0)
		{
			fprintf(stderr, "Error sending message to server %d\n", GetLastError());
			closesocket(s);
			exit(1);
		}

	readip(s);	
	return;
}
/****************************************************************************
* search()
* intimates the server of the particular user requests to search the book by *
* ISBN or booktitle                                                          *
* readip() to read server response                                           *
******************************************************************************/
void search(SOCKET s) {
	int rc;
	char c,sendbuf[BUFSIZE],temp[20];
	memset(sendbuf,0,sizeof sendbuf);
	memset(temp,0,sizeof temp);
	while(1) {

		printf("\n       ENTER    1:  TO SEARCH BOOK BY ISBN");
		printf("\n                2:  TO SEARCH BOOK BY BOOK TITLE");
		printf("\n                3:  TO  QUIT SEARCH BOOK");
		printf("\n  Your Choice  : ");
		switch(c = _getche()) {

		 case '1': memset(sendbuf,0,sizeof sendbuf);
			      printf("\n  ENTER ISBN ");
                  scanf("%s",temp);
				  flushall();
				  strcat(sendbuf,"21");
				  strcat(sendbuf,temp);
				  strcat(sendbuf,"#");
			      rc = send(s, sendbuf,sizeof sendbuf,0);
				  if (rc < 0)
					{
					fprintf(stderr, "Error sending message to server %d\n", GetLastError());
					closesocket(s);
					exit(1);
					}
			      readip(s);
			  break;
		case '2': memset(sendbuf,0,sizeof sendbuf);
			      printf("\n  ENTER THE BOOK TITLE");
                  gets(temp);
				  strcat(sendbuf,"22");
				  strcat(sendbuf,temp);
				  strcat(sendbuf,"#");
			      rc = send(s, sendbuf,sizeof sendbuf,0);
	              if (rc < 0)
					{
						fprintf(stderr, "Error sending message to server %d\n", GetLastError());
						closesocket(s);
						exit(1);
					}
				  readip(s);
			  break;
		 case '3': return;

		default:  printf("\nenter proper value");
		} // end switch
	} //end while
}
/****************************************************************************
* checkout()
* takes the particular ISBN from user and sends to server then calls readip() *
* for reading input															  *
*******************************************************************************/
void checkout(SOCKET s) {
	
	int rc;
	char c,sendbuf[BUFSIZE],temp[20];
	memset(sendbuf,0,sizeof sendbuf);
	memset(temp,0,sizeof temp);
    while(1) {

		printf("\n       ENTER    1:  TO CHECKOUT A BOOK BY ISBN");
		printf("\n                2:  TO  QUIT CHECKOUT");
		printf("\n  Your Choice  : ");
		switch(c = _getche()) {

		 case '1':memset(sendbuf,0,sizeof sendbuf);
			      printf("\n  ENTER ISBN ");
                  scanf("%s",temp);
				  flushall();
				  strcat(sendbuf,"31");
				  strcat(sendbuf,temp);
				  strcat(sendbuf,"#");
			      rc = send(s, sendbuf,sizeof sendbuf,0);
				  if (rc < 0)
					{
					fprintf(stderr, "Error sending message to server %d\n", GetLastError());
					closesocket(s);
					exit(1);
					}
				  printf("\n See your server window and wait for a while");
			      readip(s);
			  break;
		 case '2': return;
         default:  printf("\nenter proper value");
		}//end switch
	} // end while
}
/****************************************************************************
* quit()															         *
* intimates the server that this client is quiting before quiting            *
******************************************************************************/
void quit(SOCKET s) {
	
	int rc;
    rc = send(s,  "4", 1,0);
	if (rc < 0)
		{
			fprintf(stderr, "Error sending message to server %d\n", GetLastError());
			closesocket(s);
			exit(1);
		}
	closesocket(s);
	return;
}

/****************************************************************************
* readip()                                                                   *
* reads input from the server until server sends 1 to indicate end of data   *
******************************************************************************/
void readip(SOCKET s) {
    
	char recvbuf[BUFSIZE];
	int rc;
   
	memset(&recvbuf, 0, sizeof(recvbuf));
	
	printf("\nBook Tit Author L Name Author F Name,ISBN ,Copy Avail,Copies Checked Out, copies still avail\n");
	while(1) {
		rc = recv(s,recvbuf,BUFSIZE,0);// receive message from server
		if (strlen(recvbuf)== 1)
			break;
		if(rc<0)
		{
			fprintf(stderr, "Error in recieving from server: %d\n",GetLastError());
			closesocket(s);
			exit(1);
		}

		printf("%s",recvbuf);
		memset(recvbuf,0,sizeof recvbuf);
		}
	
	return;
}

SOCKET connectsock(const char *host, const char *service, const char *transport) 
{

	struct hostent *phe;
	struct servent *pse;
	struct protoent *ppe;
	struct sockaddr_in sin;
	int s,type;

	memset(&sin, 0, sizeof(sin));
	sin.sin_family = AF_INET;

	/*map service name to prot number*/
    if ( pse = getservbyname(service,transport))
		sin.sin_port = pse->s_port;
	else if ((sin.sin_port = htons((u_short) atoi(service))) == 0)
		errexit("cant get \"%s\" host entry\n", service);

	/*map host name to IP address , allowing for dotted decimal */
	if( phe = gethostbyname(host))
           memcpy(&sin.sin_addr,phe->h_addr,phe->h_length);
	else if ((sin.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE)
		errexit("cant get \"%s\" host entry\n", host);

	/*map protocol name to protocol number */
	if ((ppe = getprotobyname(transport)) == 0)
		errexit("cant get \"%s\" protocol entry \n", transport);

	/*use protocol to choose a sockettype */
	if (strcmp(transport, "udp") == 0)
		type = SOCK_DGRAM;
	else
		type = SOCK_STREAM;

	/*allocate a socket */
	s = socket(PF_INET, type, ppe->p_proto);

	if (s == INVALID_SOCKET)
		errexit("cant create socket: %d\n", GetLastError());

	/* connect the socket */
	if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) == SOCKET_ERROR)
		errexit("cant connect to %s.%s: %d\n", host, service,GetLastError());

	return s;

}

SOCKET connectTCP(const char *host, const char *service) {



	return connectsock(host,service,"tcp");

}

void errexit(const char *format, ...)
{
	va_list args;
    
	va_start(args, format);
	vfprintf(stderr, format, args);
	va_end(args);
	WSACleanup();
	exit(1);
}