#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/wait.h>
#include <signal.h>
#include "tools.h"

#define SERVERPORT 3018	// the port users will be connecting to
#define PORT_MY_ID_LAST_3_DIG 294
#define PORT_PEER_UDP_BASE 5100
#define PORT_OFFSET_PER_PEER 100
#define MY_UDP_PORT(Peer_Num) (PORT_PEER_UDP_BASE+PORT_OFFSET_PER_PEER*Peer_Num+PORT_MY_ID_LAST_3_DIG)
#define TEMP_BUF_SIZE 100
#define BACKLOG 2

struct SGROUP_Info{
	char name[6];//the name of the peer
	char c_port_num[6];// port number stored in characters
	unsigned int i_port_num;// port number stored in integer
};
typedef struct SGROUP_Info SGROUP_Info;

SGROUP_Info g_info[4];
char* peerName[4] = {"peer1","peer2","peer3","peer4"};
char groupNum;
char InBuf1[TEMP_BUF_SIZE];
char InBuf2[TEMP_BUF_SIZE];
char OutBuf1[TEMP_BUF_SIZE];
char OutBuf2[TEMP_BUF_SIZE];
int peerID=1;
/**************************************************
* void Store_Group_member(char *buf,int id)
* function: store the name and TCP port number of received data.
* parameter:
* buf: the buffer that stored the information
* id: the order of the received data
***************************************************/
void Store_Group_member(char *buf,int id)
{
	int i,j;
	char tmpStr[8];
	
	getStrSegment(buf, tmpStr,2);
	strcpy(g_info[id].name,tmpStr);
	getStrSegment(buf, tmpStr,3);
	strcpy(g_info[id].c_port_num,tmpStr);
	g_info[id].i_port_num=a5toi(g_info[id].c_port_num);
}
/***************************************************
* int CheckGroupsize(int pID,char* buf)
* function: check the group size , the data hidden in the received data buffer.
* return value:
*	the group size
* param
* buf: the pointer of the received buffer
****************************************************/
int CheckGroupsize(int pID,char* buf)
{
	int i,j;
	char tmpStr[8];

	getStrSegment(buf, tmpStr,2);//get group size

	switch(tmpStr[0]){
	case '0':return 0;
	case '1':return 1;
	case '2':return 2;
	case '3':return 3;
	case '4':return 4;
	default:
		printf("get group size error\n");
		return 99;
		break;
	}
}
/****************************************************
* void strcatName(void)
* function:append the sender's name to the string
*****************************************************/
void strcatName(void)
{
	memset(OutBuf1, '\0',TEMP_BUF_SIZE); 
	strcat(OutBuf1,peerName[peerID-1]);

}
/****************************************************
* void strcatGroupSize(int size)
* function:append the group's size to the string
* param:
*	size: the group size
*****************************************************/
void strcatGroupSize(int size)
{
	strcat(OutBuf1," ");
	memset(OutBuf2, '\0',TEMP_BUF_SIZE); 
	itostr(OutBuf2, size) ;
	OutBuf2[1]='\0';
	strcat(OutBuf1, OutBuf2);
}
/****************************************************
* void strcatGroupNumber(void)
* function:append the group number to the string
*****************************************************/
void strcatGroupNumber(void)
{
	int num;
	
	num = strlen(OutBuf1);
	OutBuf1[num] = groupNum;
	OutBuf1[num+1] = '\0';

}
/****************************************************
* void send_ackr(void)
* function:send ack to the designated socket
*****************************************************/
void send_ack(int fd)
{
	if (send(fd, "ack", 3, 0) == -1){
               perror("send");
               exit(1);
	}
}
/****************************************************
* void rcv_ack(int fd)
* function:wait a ack from the designated port
*****************************************************/
void rcv_ack(int fd)
{	
	int numbytes;
	if ((numbytes=recv(fd, OutBuf1, 19, 0)) == -1) {
	        perror("ack");
	        exit(1);
	}
}
/****************************************************
* void sendDataToGroupPeer(int pID,int size)
* function:send the group information to peers belong to the same group
* para:
* pid, peer ID
* size, group size
*****************************************************/
void sendDataToGroupPeer(int pID,int size)
{
	int sockfd, numbytes;  
	int i,j;
	int stop = 0;
	struct hostent *he;
	int newSize = size -1;
	struct sockaddr_in their_addr; // connector's address information 
	
	/*****************************************
	*                    Open a new TCP socket
	*****************************************/
	if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
		perror("socket");
		exit(1);
	}
	if ((he=gethostbyname("localhost")) == NULL) {  
		perror("gethostbyname");
		exit(1);
	}
	their_addr.sin_family = AF_INET;
	their_addr.sin_port = htons(g_info[0].i_port_num);
	their_addr.sin_addr =  *((struct in_addr *)he->h_addr);
	memset(&(their_addr.sin_zero), '\0', 8); 
	if (connect(sockfd, (struct sockaddr *)&their_addr,
	                                          sizeof(struct sockaddr)) == -1) {
	    perror("connect");
	    exit(1);
	}
	/*****************************************
       * 			send message 1
       ******************************************/
	strcatName();
	strcatGroupSize(newSize);

	if (send(sockfd, OutBuf1, strlen(OutBuf1), 0) == -1)
                perror("send");
 	rcv_ack(sockfd);
 	
 	/*****************************************
       * 			send message 2
       ******************************************/
	strcatName();
	strcat(OutBuf1," welcome to group");
	strcatGroupNumber();
	if (send(sockfd, OutBuf1, strlen(OutBuf1), 0) == -1)
		perror("send");
	rcv_ack(sockfd);
	
	/*****************************************
	*			send rest message
	******************************************/
	if(newSize>1){
		for(i=0; i<newSize-1;i++){
			//provider name
			memset(OutBuf1, '\0',TEMP_BUF_SIZE); 
			strcat(OutBuf1,peerName[pID-1]);
			strcat(OutBuf1," ");
			strcat(OutBuf1, g_info[i+1].name);
			//peer port num
			strcat(OutBuf1," ");
			strcat(OutBuf1, g_info[i+1].c_port_num);
			if (send(sockfd, OutBuf1, strlen(OutBuf1), 0) == -1)
                		perror("send");
	          	rcv_ack(sockfd);
		}
	}
	close(sockfd);
} 

int main(int argc, char *argv[])
{
	int UDP_sockfd;
	int TCP_sockfd;
	int new_fd;
	
	struct sockaddr_in my_UDP_addr;	// my address information
	struct sockaddr_in my_TCP_addr;	// my address information
	struct sockaddr_in their_addr; // connector's address information
	int len = sizeof(struct sockaddr_in);;
	struct hostent *he;
	int numbytes;
	int g_size;
	int i,j;
	socklen_t sin_size;

	/* get the host info */
	if ((he=gethostbyname("localhost")) == NULL) {  
		perror("gethostbyname");
		exit(1);
	}
	/* fork 4 peers*/
	while(peerID<4){
		if( fork() == 0 )
			peerID++;
		else
			break;
		
	}

	/* Create a TCP socket and get a port number from the kernel*/
	if ((TCP_sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
		perror("TCPsocket");
		exit(1);
	}

	my_TCP_addr.sin_family = AF_INET;		 // host byte order
	my_TCP_addr.sin_port = INADDR_ANY;
	my_TCP_addr.sin_addr = *((struct in_addr *)he->h_addr); // automatically fill with my IP
	memset(&(my_TCP_addr.sin_zero), '\0', 8); // zero the rest of the struct

	/*bind TCP port assigned by kernel*/
	if (bind(TCP_sockfd, (struct sockaddr *)&my_TCP_addr,
		sizeof(struct sockaddr)) == -1) {
		perror("bind");
		exit(1);
	}

	/*get the socket info assigned by kernel*/
	if(getsockname(TCP_sockfd,(struct sockaddr *)&my_TCP_addr,&len )<0){
		perror("getsockname");
		exit(1);
	}

	/*open the UDP*/
	if ((UDP_sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
		perror("UDPsocket");
		exit(1);
	}

	/*create a UDP socket and bind a dedicated port*/
	
	my_UDP_addr.sin_family = AF_INET;		 // host byte order
	my_UDP_addr.sin_port = htons(MY_UDP_PORT(peerID-1));	 // short, network byte order
	my_UDP_addr.sin_addr.s_addr = INADDR_ANY; // automatically fill with my IP
	memset(&(my_UDP_addr.sin_zero), '\0', 8); // zero the rest of the struct
	
	if (bind(UDP_sockfd, (struct sockaddr *)&my_UDP_addr,
		sizeof(struct sockaddr)) == -1) {
		perror("bind");
		exit(1);
	}
	/* Try to send the registration data*/

	/*a) peer name*/
	memset(OutBuf1, '\0',TEMP_BUF_SIZE); 
	strcat(OutBuf1,peerName[peerID-1]);
	
	/*b). TCP port number*/
	
	strcat(OutBuf1," ");
	memset(OutBuf2, '\0',TEMP_BUF_SIZE); 
	itostr(OutBuf2, my_TCP_addr.sin_port) ;
	OutBuf2[5]='\0';
	
	strcat(OutBuf1, OutBuf2);
	
	/*c). IP Address*/
	strcat(OutBuf1," ");
	strcat(OutBuf1,inet_ntoa(my_TCP_addr.sin_addr));
	
	/*d). group number*/
	 srand ( time(NULL)+peerID);
	if(rand()%2){
		groupNum = '1';
	}else{
		groupNum = '2';
	}
	strcat(OutBuf1," ");
	
	memset(OutBuf2, '\0',TEMP_BUF_SIZE); 

	memcpy(OutBuf2,&groupNum,1);
	OutBuf2[1]='\0';
	strcat(OutBuf1, OutBuf2);
	
	
	their_addr.sin_family = AF_INET;	 // host byte order
	their_addr.sin_port = htons(SERVERPORT); // short, network byte order
	their_addr.sin_addr = *((struct in_addr *)he->h_addr);
	memset(&(their_addr.sin_zero), '\0', 8);  // zero the rest of the struct
	
	/*send the registration data to boot strap server*/
	if ((numbytes = sendto(UDP_sockfd, OutBuf1, strlen(OutBuf1), 0,
			 (struct sockaddr *)&their_addr, sizeof(struct sockaddr))) == -1) {
		perror("sendto");
		exit(1);
	}
	close(UDP_sockfd);

	/*listen on the TCP port*/
	if (listen(TCP_sockfd, BACKLOG) == -1) {
		perror("listen");
		exit(1);
	}
	sin_size = sizeof(struct sockaddr_in);
	
	if ((new_fd = accept(TCP_sockfd, (struct sockaddr *)&their_addr,
                                                       &sin_size)) == -1) {
            perror("accept");
    
        }
	memset(OutBuf2, '\0',TEMP_BUF_SIZE); 
	
	/*received a group information*/
	 if ((numbytes=recv(new_fd, OutBuf2, TEMP_BUF_SIZE-1, 0)) == -1) {
	        perror("recv");
	        exit(1);
	    }

	OutBuf2[numbytes] = '\0';  
	
    	g_size=CheckGroupsize(peerID,OutBuf2);
	send_ack(new_fd);
	
	//receive welcome message
	 if ((numbytes=recv(new_fd, OutBuf2, TEMP_BUF_SIZE-1, 0)) == -1) {
	        perror("recv");
	        exit(1);
	  }
	OutBuf2[numbytes] = '\0';
	send_ack(new_fd);
	
   	if(g_size == 1){// show the message and terminate
		printf("Peer%d joined group %c\n",peerID,groupNum);
		close(TCP_sockfd);
		close(new_fd); 
		exit(1);
		
   	}else{// receiving the rest group data
	    	for(i = 0 ;i< g_size -1;i++){
	    	    memset(InBuf1, '\0',TEMP_BUF_SIZE); 
		    if ((numbytes=recv(new_fd, InBuf1, TEMP_BUF_SIZE-1, 0)) == -1) {
		        perror("recv");
		        exit(1);
		    }

		    InBuf1[numbytes] = '\0';

		    Store_Group_member(InBuf1,i);
		    send_ack(new_fd);
	    	}
        close(new_fd);  // parent doesn't need this
        }
   	printf("Peer%d joined group %c\n",peerID,groupNum);
        sendDataToGroupPeer(peerID,g_size);
        close(TCP_sockfd);
	 close(new_fd); 
        exit(1);

}