/*
 
    C socket server example, handles multiple clients using threads */
 
 
 
#include<stdio.h> 
 
#include<string.h> //strlen 
 
#include<stdlib.h> //strlen 
 
#include<sys/socket.h> 
 
#include<arpa/inet.h> //inet_addr 
 
#include<unistd.h> 
 
#//write 
 
#include<pthread.h>
 
#include "daq.h"
 
#define PORT 9930
 
//the thread function 
 
 
 
 
 
 
 
void *connection_handler(void *);
 
 
 
int is_connected = 0; 
 
int ncalls=0;
 
extern int ctrl_c;
 
 
 
int writesock(int sock, int id , char *msg, int len ){
 
    int hdr[2];
 
    hdr[0]= id;
 
    hdr[1]= len + 8;
 
    write(sock , hdr , 8);
 
    return write(sock , msg , len);
 
}
 
 
 
 
 
int main(int argc , char *argv[]) {
 
    int socket_desc , client_sock , c , *new_sock=NULL;
 
    struct sockaddr_in server , client;
 
 
 
    if (argc >1) return daq_main(argc, argv);
 
     
 
    //Create socket
 
    socket_desc = socket(AF_INET , SOCK_STREAM , 0);
 
    if (socket_desc == -1)
 
    {
 
        printf("Could not create socket");  
    }
 
     
 
    //Prepare the sockaddr_in structure
 
    server.sin_family = AF_INET;
 
    server.sin_addr.s_addr = INADDR_ANY;
 
    server.sin_port = htons( PORT );
 
     
 
    //Bind
 
    if( bind(socket_desc,(struct sockaddr *)&server , sizeof(server)) < 0)
 
    {
 
        //print the error message
 
        return 1;
 
    }
 
     
 
    //Listen
 
    listen(socket_desc , 3);
 
     
 
    //Accept and incoming connection
 
    puts("Waiting for incoming connections...");  
    c = sizeof(struct sockaddr_in);
 
     
 
     
 
    //Accept and incoming connection
 
    puts("Waiting for incoming connections...");  
    c = sizeof(struct sockaddr_in);
 
    while( (client_sock = accept(socket_desc, (struct sockaddr *)&client, (socklen_t*)&c)) )
 
    {
 
        puts("Connection accepted");  
         
 
        pthread_t sniffer_thread;
 
 
 
        if (is_connected){
 
            char message[0xFF]="Only one client can connect. Disconnect it first!";
 
            writesock
(client_sock 
, 0, message 
, strlen(message
)); 
            close (client_sock);
 
            continue;
 
        }
 
        *new_sock = client_sock;
 
        if( pthread_create( &sniffer_thread , NULL , connection_handler , (void*) new_sock) < 0)
 
        {
 
            perror("could not create thread");  
            return 1;
 
        }
 
 
 
         
 
        //Now join the thread , so that we dont terminate before the thread
 
        //pthread_join( sniffer_thread , NULL);
 
        
 
        puts("Handler assigned");  
        
 
    }
 
     
 
    if (client_sock < 0)
 
    {
 
        return 1;
 
    }
 
     
 
    return 0;
 
}
 
 
 
 
 
 
 
void *daq_handler(void *rdata){
 
 
 
 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
 
 //Get the socket descriptor
 
 int sock = *(int*)rdata;
 
 int *idata = (int *)rdata; 
 
 
 
 char * settings = (char *) (idata+2);
 
 daq_init(settings);
 
 settings +=12;
 
 int bufsize = 0;  
 
 char * data = NULL;
 
 
 
 //for(int i =0;i<5;i++) printf("%d %d\n",i, idata[i]);
 
 while (1){
 
    int nb = daq_run ( settings, &data, &bufsize );
 
    int error = 0;
 
    socklen_t len = sizeof (error);
 
    int retval = getsockopt (sock, SOL_SOCKET, SO_ERROR, &error, &len);
 
    if (retval!=0 || error!=0) break;
 
    writesock(sock , 1, data , nb );
 
    if (ctrl_c) break;
 
    //break;
 
 }
 
 if (data
!=NULL
)  free(data
);  
 fprintf(stderr
, "Exiting thread %d\n", sock 
) ;  
 return NULL;
 
}
 
 
 
/*
 
 * This will handle connection for each client
 
 * */
 
 
 
void *connection_handler(void *socket_desc) {
 
    //Get the socket descriptor
 
    int sock = *(int*)socket_desc;
 
    int read_size;
 
    char *message , client_message[2000];
 
    is_connected = 1;
 
    //Send some messages to the client
 
    message = "Info from connection handler\n";
 
    writesock
(sock 
, 0, message 
, strlen(message
)); 
          
 
    //Receive a message from client
 
    pthread_t daq_thread = 0;
 
 
 
    while( (read_size = recv(sock , client_message , 2000 , 0)) > 0 )
 
    {
 
        //Send the message back to client
 
        int * hdr = (int *) client_message;
 
        printf("Received %d bytes RECID = %d LEN %d\n",read_size
, hdr
[0], hdr
[1]);  
        switch (hdr[0]){
 
           case 0:
 
             ctrl_c = 0;
 
             hdr[0]= sock;
 
             if( pthread_create( &daq_thread , NULL , daq_handler , (void*) &client_message) < 0)
 
             {
 
               perror("could not create daq thread");  
              }
 
              break;
 
           case 1:
 
             ctrl_c = 1;
 
             sleep(1);
 
             if (daq_thread) {
 
                pthread_cancel(daq_thread);
 
                daq_thread = 0;
 
             }
 
 
 
             break;
 
           default: break;
 
 
 
        }
 
    }
 
     
 
    if(read_size == 0)
 
    {
 
        puts("Client disconnected");  
    }
 
    else if(read_size == -1)
 
    {
 
        
 
    }
 
    if (daq_thread) {
 
      pthread_cancel(daq_thread);
 
      daq_thread = 0;
 
    }
 
 
 
         
 
    //Free the socket pointer
 
    socket_desc = 0;
 
    is_connected = 0;
 
     
 
    return 0;
 
}