/* (C) Spiros Ioannou 1999 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#include <time.h>
#include <signal.h>
#include <errno.h>

#include <sys/types.h>
#include <sys/wait.h>

#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
 

int serve_client(int);


int
serve_client(int Asd)
{
  fd_set inout_fds;
  char buff[1024];
  char outbuff[1024];
  int  r,i,s;
  FILE *pfp;

  for (;;) {
    FD_ZERO(&inout_fds);
    FD_SET(Asd, &inout_fds);
    i=0;
    do {
      s = select(64, &inout_fds, (fd_set *) 0,
		 (fd_set *) 0, (struct timeval *) 0);
    } while (s == EINTR && i++<10);
    buff[0] = 0;
    outbuff[0] = 0;

    if (FD_ISSET(Asd, &inout_fds)) {
      r = read(Asd, buff, 1024);
      buff[r] = 0;
      /* chop */
      if (r > 2 && buff[r - 1] == '\n') {
	buff[r-1] = 0;
#ifdef DEBUG
	printf("serve_client[%d]:read:#%s#\n", getpid(), buff);
#endif
      }
      if (r <= 0) {
	shutdown(Asd, 2);
	close(Asd);
#ifdef DEBUG
	printf("serve_child:socket closed,returning\n");
#endif
	return 1;
      }
      else {
	/* parse input here */
	if (!strcmp(buff, "daemon_stop")) {
#ifdef DEBUG
	  printf("\nserve_child:exiting\n");
#endif
	  return (0);
	}
	else if (!strcmp(buff, "quit")) {
	  shutdown(Asd, 2);
	  close(Asd);
	  return 2;
	}
	else if (!strcmp(buff, "calc_checksums")) {
#ifdef DEBUG
	  printf("serve_child:calculating checksums\n");
#endif
	  if ((pfp=popen("md5sum *","r"))!=NULL) {
	    while (fgets(buff,1024,pfp))
	      if (write(Asd,buff,strlen(buff))<=0) {
		pclose(pfp);
		break;
	      }
	    pclose(pfp);
	    //disconnect client
	    shutdown(Asd, 2);
	    close(Asd);
	  }
	  else {
	    perror("statusd:popen");
	  }
	}
	else {
	  sprintf(outbuff, "%s:invalid command\n", buff);
	  write(Asd, outbuff, strlen(outbuff));
	}
      }
    }
    else
      printf("serve_client:select interrupted(?)\n");
  }
}

int
main(int argc, char **argv)
{
  int  one = 1,r, i;
  struct sockaddr_in sa;
  int  Asd, len, lsd;
  fd_set inout_fds;
  char buff[1024];
  int  port;

  if (argc != 2) {
    fprintf(stderr, "statusd version 0.1\n");
    fprintf(stderr, "Usage: statusd <port>\n");
    exit(0);
  }

  port = atoi(argv[1]);


  if ((lsd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
    perror("socket");
    exit(1);
  }
  setsockopt(lsd, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof(one));
  sa.sin_family = AF_INET;
  sa.sin_port = htons((u_short) port);
  sa.sin_addr.s_addr = htonl(INADDR_ANY);

  if (bind(lsd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
    perror("bind");
    exit(2);
  }

  if (listen(lsd, 1) < 0) {
    perror("listen");
    exit(3);
  }
  len = sizeof(sa);
  printf("statusd:listening on port %d\n",port);



  for (;;) {

    FD_ZERO(&inout_fds);
    FD_SET(lsd, &inout_fds);

    do {
      i = select(64, &inout_fds,(fd_set *)0,(fd_set *)0,(struct timeval *)0);
    } while (i == EINTR);

    if (i < 0) {
      perror("statusd:select");
      exit(4);
    }

    if (FD_ISSET(lsd, &inout_fds)) {
      if ((Asd = accept(lsd, (struct sockaddr *) &sa, &len)) < 0) {
	perror("accept");
	exit(5);
      }
      printf("\nstatusd:accepted connection from %s [port:%d]\n",
	     inet_ntoa(sa.sin_addr) , 
	     ntohs(sa.sin_port));

      // show some help 
      strcpy(buff, "\navailable commands\n------------------\n");
      strcat(buff, "calc_checksums \t\t\t//calculate them\n");
      strcat(buff, "quit \t\t\t\t//close current connection\n");
      strcat(buff, "daemon_stop \t\t\t//stop the daemon\n\n");
      write(Asd, buff, strlen(buff));

      if ((r=serve_client(Asd))==0) {
	printf("statusd:process %d shuting down by request\n", getpid());
	exit(6);
      }
      else if (r==1) {
	Asd=-1;
	printf("statusd:client disconnected\n");
      }
      else if (r==2) {
	Asd=-1;
	printf("statusd:client requested disconnect\n");
      }
    }

  }

  return -1;
}