/* Abandon
*  All
*  Hope
*  Ye
*  Who
*  Enter
*  Here
*/

#include "smallsh.h" /*include file for example*/
#include <sys/types.h>
#include <unistd.h>
#include <signal.h>

/*program buffers, shared resources, and work pointers*/
static char inpbuf[MAXBUF], tokbuf[2*MAXBUF],
*ptr = inpbuf, *tok = tokbuf;

//Job list structure
struct procnode
{
  pid_t procid;
  int job;
  int status;
  char command[MAXBUF];
  struct procnode *prevjob;
  struct procnode *nextjob;
  struct procnode *prevcom;
  struct procnode *nextcom;
};
struct procnode *proclist;

//signal handling
struct sigaction sigact;

void signal_handler(sig)
int sig;
{
  //if(sig == SIGINT)
  //TODO: Kill currently running foreground process in shell
}

void sigproc(void)
{
  sigact.sa_handler = signal_handler;
  sigemptyset(&sigact.sa_mask); 
  sigdelset(&sigact.sa_mask, SIGKILL);
  sigdelset(&sigact.sa_mask, SIGINT);
  sigact.sa_flags = 0;
  sigaction(SIGINT, &sigact, (struct sigaction *)NULL);
}

userin(p) /*print prompt and read a line*/
char *p;
{

  int c, count;

  /*initialization for later routines*/
  ptr = inpbuf;
  tok = tokbuf;

  /*display prompt*/
  printf("%s ",p);

  for(count = 0;;)
  {
    if((c = getchar()) == EOF)
      return(EOF);

    if(count<MAXBUF)
      inpbuf[count++] = c;

    if(c == '\n' && count <MAXBUF)
    {
      inpbuf[count] = '\0';
      return(count);
    }

    /*if line too long restart*/
    if(c == '\n')
    {
      printf("smallsh:input line too long\n");
      count = 0;
      printf("%s",p);
    }
  }
}

gettok(outptr) /*get token and place into tokbuf*/
char **outptr;
{
  int type;

*outptr = tok;

/*strip white space*/
for(;*ptr == ' ' || *ptr == '\t'; ptr++)
  ;

*tok++ = *ptr;

  switch(*ptr++)
  {
    case '\n':
      type = EOL; break;
    case '&':
      type = AMPERSAND; break;
    case ';':
      type = SEMICOLON; break;
    case '#':
      type = POUND; break;
    default:
      type = ARG;
      while(inarg(*ptr))
        *tok++ = *ptr++;
  }

*tok++ = '\0';
return(type);
}

static char special[]=
{' ', '\t', '&', ':', '\n', '\0'};

inarg(c) /*are we in an ordinary argument*/
char c;
{
  char *wrk;

  for(wrk = special;*wrk != '\0';wrk++)
    if(c == *wrk)
      return(0);

    return(1);
}

#include "smallsh.h"

procline() /*process input line*/
{
  char *arg[MAXARG+1]; /*pointer array for runcommand*/
  int toktype; /*type of token in command*/
  int narg; /*number of arguments so far*/
  int type; /*FOREGROUND or BACKGROUND*/

  for(narg = 0;;)
  {
    /*loop FOREVER*/

    /*take action according to token type*/

    switch(toktype = gettok(&arg[narg]))
    {
      case ARG:

      if(narg<MAXARG)
        narg++;
      break;

      case EOL:
      case SEMICOLON:
      case AMPERSAND:
      case POUND:

        type = (toktype == AMPERSAND) ?
        BACKGROUND : FOREGROUND;

        if(narg!=0)
        {
          arg[narg] = NULL;
          runcommand(arg, type);
        }

        if((toktype == EOL)||(toktype=POUND))
          return;

        narg = 0;
        break;
    }
  }
}


#include "smallsh.h"
#include <stdlib.h>

/*execute a command with optional wait*/
runcommand(cline,where, proclist)
char **cline;
int where;
struct procnode *proclist;
{
  int pid, exitstat, ret;
  
  if(strcasecmp(cline, "jobs")==0) //Have no idea if this is going to work
  {
    jobs(proclist); //No harm in trying
  }

  if((pid = fork()) <0)
  {
    perror("smallsh");
    return(-1);
  }
  
  if(pid == 0)
  {
    /*child*/
    execvp(*cline, cline);
    perror(*cline);
    exit(127);
  }

  /*code for parent*/
  /*if background process print pid and exit*/

  if(where == BACKGROUND)
  {
    printf("[Process id %d]\n", pid);
    return(0);
  }

  /*wait until process pid exists*/

  while( (ret=wait(&exitstat)) != pid && ret != -1)
    ;

  return(ret == -1 ? -1 : exitstat);
}

#include "smallsh.h"
jobs(proclist)
struct procnode *proclist;
{
  printf("HIDER");
}

#include "smallsh.h"

char *prompt = "Command>"; /*prompt*/

main()
{
  sigproc();
  while(userin(prompt) != EOF)
    procline();
}