#include <stdio.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <errno.h>
#define MAX 100
#define SA struct sockaddr
#include <net/if.h>
#include <sys/ioctl.h>
//added for nonblock
#define BACKLOG 10
#include <fcntl.h>




// Returns hostname for the local computer
void checkHostName(int hostname)
{
    if (hostname == -1)
    {
        perror("gethostname");
        exit(1);
    }
}

// Returns host information corresponding to host name
void checkHostEntry(struct hostent * hostentry)
{
    if (hostentry == NULL)
    {
        perror("gethostbyname");
        exit(1);
    }
}

// Converts space-delimited IPv4 addresses
// to dotted-decimal format
void checkIPbuffer(char *IPbuffer)
{
    if (NULL == IPbuffer)
    {
        perror("inet_ntoa");
        exit(1);
    }
}



// Function for server side chat
void servfunc(int sockfd, char *ip, int cliport)
{
	char buff[100];
	int n;
	bzero(buff, 100);
	read(sockfd, buff, sizeof(buff));
	printf("Message recieve from %s\n", ip);
	printf("Sender's Port: %d\n", cliport);
	printf("Message: %s\n", buff);

//chat back and forth with client
/*
    char buff[100];
    int n;
    // infinite loop for chat
    for (;;) {
        bzero(buff, MAX);

        // read the message from client and copy it in buffer
        read(sockfd, buff, sizeof(buff));
        // print buffer which contains the client contents
     	printf("Type 'exit' to exit chat\n");
	printf("Message recieve from %s\n", ip);
	printf("Sender's Port: %d\n", cliport);
	printf("Message: %s\n", buff);
	printf("Message: ");
        bzero(buff, MAX);
        n = 0;
        // copy server message in the buffer
        while ((buff[n++] = getchar()) != '\n')
            ;

        // and send that buffer to client
        write(sockfd, buff, sizeof(buff));

        // if msg contains "Exit" then server exit and chat ended.
        if (strncmp("close", buff, 4) == 0) {
            printf("Server Exit...\n");
            break;
        }
    }
*/
}




//Function for client side chat
void clifunc(int clifd, int portnum)
{
//chat back and forth with server
/*
	char buff[100];
    int n;
    for (;;) {
        bzero(buff, sizeof(buff));
	printf("Type 'exit' to exit chat\n");
        printf("Message : ");
        n = 0;
        while ((buff[n++] = getchar()) != '\n')
            ;
        write(clifd, buff, sizeof(buff));
	printf("Message sent to port no: %d\n", portnum);
        bzero(buff, sizeof(buff));
        read(clifd, buff, sizeof(buff));
        printf("From Port %d: %s\n", portnum, buff);
        if ((strncmp(buff, "exit", 4)) == 0) {
            printf("Client Exit...\n");
            break;
        }
    }
*/

//write not working

	char buff2[100];
	int o = 0;
	bzero(buff2, sizeof(buff2));
	printf("Enter the message: ");
	while((buff2[o++] = getchar()) != '\n')
		;
	write(clifd, buff2, sizeof(buff2));
	bzero(buff2, sizeof(buff2));
	printf("Message sent to port: %d\n", portnum);

/*
//one message
	//send cant take spaces
	char buff2[100];
	int o;

		printf("Enter the message : ");

		char msgtoserver[MAX];
		scanf("%s",msgtoserver);
		send(clifd, msgtoserver, strlen(msgtoserver), 0);
		bzero(buff2, sizeof(buff2));
*/

}

//for unblock
int guard(int n, char* err){ if ( n == -1) { perror(err); exit(1); } return n;}

int main(int argc, char *argv[]){
int sockfd, connfd, len;
struct sockaddr_in servaddr, cli;
int portnum;
int choice;
int done = 0;


//for myip
char hostbuffer[256];
char *IPbuffer;
struct hostent *host_entry;
int hostname;

int connectyorn = 0;

int inputport;
char *destination;

int ready = 0;

int portnumber;

//int myport;
unsigned int myport;

//for send clientside
struct sockaddr_in cliaddr, cliaddr2;
int clifd;



if(argc < 2){

sockfd = guard(socket(AF_INET, SOCK_STREAM, 0), "could not create");
sockfd = socket(AF_INET, SOCK_STREAM, 0);
int flags = guard(fcntl(sockfd, F_GETFL), "could not get flags");
guard(fcntl(sockfd, F_SETFL, flags | O_NONBLOCK), "could not set to nonblocking");
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = htons(0);
guard(bind(sockfd, (SA*)&servaddr, sizeof(servaddr)), "could not bind");
int length = sizeof(servaddr);
getsockname(sockfd, (SA*)&servaddr, &length);
myport = ntohs(servaddr.sin_port);
printf("My port: %u \n", myport);
guard(listen(sockfd, 100), "could not listen");



while(done != 9999){
//added for unblock socket
socklen_t addr_size;
addr_size = sizeof(struct sockaddr_in);
int clientfd = accept(sockfd, (SA*)&cli,&addr_size);
if(clientfd == -1){
	if(errno == EWOULDBLOCK){
	printf("No pending connections.\n");
	sleep(1);
	}
	/*
	else{
	printf("error accepting connection");
	//exit(1);
	}
	*/
}
else{
//for single msg recieve
	/*
		char buff[MAX];
		bzero(buff, MAX);

		// read the message from client and copy it in buffer
		read(clientfd, buff, sizeof(buff));
		//to get ip
		char ip[INET_ADDRSTRLEN];
		inet_ntop(AF_INET, &(cli.sin_addr),ip , INET_ADDRSTRLEN);
		//printf("Message recieve from: %s\n", inet_ntoa(servaddr.sin_addr));
		printf("Message recieve from: %s\n", ip);
		printf("Sender's Port: %d\n", ntohs(cli.sin_port));
		printf("Message: %s\n", buff);
*/
	char *ip = inet_ntoa(cli.sin_addr);
	int cliport = ntohs(cli.sin_port);
	servfunc(clientfd, ip, cliport);
	close(sockfd);

}


printf("1.help\n");
printf("2.myip\n");
printf("3.myport\n");
printf("4.connect <destination> <port no>\n");
printf("5.list\n");
printf("6.terminate <connection id.>\n");
printf("7.send <connection id.> <message>\n");
printf("8.exit\n");
printf("9.Refresh\n");

scanf("%d", &choice);

switch(choice){
case 1: printf("2. myip: Display IP address of the process.\n");
	printf("3. myport: Display the port on which the process is listening for incoming connections.\n");
	printf("4. connect: Connect to specified <destination> at the specified <port no>\n");
	printf("5. list: Display a numbered list of all the connections the process is part of.\n");
	printf("6. terminate: Terminate the connection listed under the specified number when LIST is used to display all connections.\n");
	printf("7. send: Send message to the host of the connect that is designated by the number 3 when command 'list' is used.\n");
	printf("8. exit: Close all connections and terminate the process.\n");
	break;
case 2:
    // To retrieve hostname
    hostname = gethostname(hostbuffer, sizeof(hostbuffer));
    checkHostName(hostname);

    // To retrieve host information
    host_entry = gethostbyname(hostbuffer);
    checkHostEntry(host_entry);

    // To convert an Internet network
    // address into ASCII string
    IPbuffer = inet_ntoa(*((struct in_addr*)
                           host_entry->h_addr_list[0]));
  checkIPbuffer(IPbuffer);
    //printf("Hostname: %s\n", hostbuffer);
    printf("Host IP: %s\n", IPbuffer);
	break;
case 3:
	printf("My port: %u \n", myport);
	break;
case 4:

printf("connect <destination> <port no>\n");
//	printf("Input destination: ");
	//char *destination;
//	scanf("%s", destination);
	printf("Input port no: ");

	scanf("%d", &inputport);

	portnum = inputport;


	// socket create and varification
	clifd = socket(AF_INET, SOCK_STREAM, 0);
	if (clifd == -1) {
		printf("socket creation failed...\n");
		exit(0);
	}
	else
		printf("Socket successfully created..\n");


	bzero(&servaddr, sizeof(servaddr));


	// assign IP, PORT
	cliaddr.sin_family = AF_INET;
	//127.0.0.1
//	servaddr.sin_addr.s_addr = inet_addr(destination);
 	cliaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
	cliaddr.sin_port = htons(portnum);

	//added
	cliaddr2.sin_family = AF_INET;
 	cliaddr2.sin_addr.s_addr = inet_addr("127.0.0.1");
	cliaddr2.sin_port = htons(myport);
	//cant bind to myport to get correct port number on clifunc
	if(bind(clifd, (SA*)&cliaddr2, sizeof(struct sockaddr_in)) == 0 ){
	printf("Binded\n");
	}
	else{
	printf("Unable to Bind\n");
	}

	// connect the client socket to server socket
	if (connect(clifd, (SA*)&cliaddr, sizeof(cliaddr)) != 0) {
		printf("connection with the server failed...\n");
		//exit(0);
	}
	else{
		printf("connected to the server..\n");
	connectyorn = 1;
	ready = 1;
	}
	break;
case 5: printf("list");
	break;
case 6: printf("terminate");
	break;
case 7:
	if(connectyorn == 1){
	 // function for chat
	clifunc(clifd, portnum);

	// close the socket
	close(clifd);
	}
	else
	printf("Not connected to server\n");
	break;
case 8: printf("Closing program\n");
	done = 9999;
	break;
case 9:
	break;
}


}
}
else{

portnum = atoi(argv[1]);

struct sockaddr_in cliaddr, cliaddr2;
int clifd;


	// socket create and varification
	clifd = socket(AF_INET, SOCK_STREAM, 0);
	if (clifd == -1) {
		printf("socket creation failed...\n");
		exit(0);
	}
	else
		printf("Socket successfully created..\n");
	//bzero(&servaddr, sizeof(servaddr));
	//assign port and ip
	cliaddr.sin_family = AF_INET;
	cliaddr.sin_addr.s_addr = INADDR_ANY;
	cliaddr.sin_port = htons(portnum);

	cliaddr.sin_addr.s_addr = inet_addr("127.0.0.1");

	//explicity assign port by binding client with port
	cliaddr2.sin_family = AF_INET;
	cliaddr2.sin_addr.s_addr = INADDR_ANY;
	cliaddr2.sin_port = htons(0);

	cliaddr2.sin_addr.s_addr = inet_addr("127.0.0.1");


	if(bind(clifd, (SA*)&cliaddr2, sizeof(struct sockaddr_in)) == 0 ){
	printf("Binded\n");
	}
	else{
	printf("Unable to Bind\n");
	}

	int length = sizeof(cliaddr2);
	getsockname(clifd, (SA*)&cliaddr2, &length);
	myport = ntohs(cliaddr2.sin_port);
	printf("My port: %u \n", myport);



	// connect the client socket to server socket
	if (connect(clifd, (SA*)&cliaddr, sizeof(cliaddr)) != 0) {
		printf("connection with the server failed...\n");
		exit(0);
	}
	else{
		printf("connected to the server..\n");
	// function for chat
	clifunc(clifd, portnum);
	// close the socket
	close(clifd);
	}

}


}