/*
 Author: Jose Romeo Vela        Date: March 24, 2002
 email: jrvela@aristasol.com
 http://www.aristasol.com/

 This software is licensed under GNU's GPL. For details see http://www.gnu.org/ 

 Copyright (c) 2002, Jose Romeo Vela

==============================================================================
Modifications:
   4/9/2002 jrv 
      Show the -b option in the Usage message
      
      Added validation to the load_mem function to avoid out of bound memory
      loading.

      Added a new function begin_pc to process the -b option.

  4/13/2002 jrv2
     Added comments.
     Introduced the save_pc variable to save the -b option just in
     case that the -l option attempts to overrid it. 

  4/15/2002 jrv3
     Fixed a bug introduced with jrv2. Added the option_b variable to solve
     the issue.
  5/17/2002 jrv4
     Standard input and standard output can now be used as input and output
     for cinc programs. This allows the programmer to type or pipe data
     to a cinc program when it is executed.

     If -i is ommited then use standard input (stdin)
     If -o is ommited then use standard outout (stdout)

     Depricated option -r, instead introduced option -n.
*/


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

#include "config.h"


void pusage(void){
  /* Display usage information */
  printf("\nUsage: cinc [-vrhd] [-l <file>] [-i <file>] [-o <file>] [-b <address>]\n");
}

void phelp(void)
{
  pusage();
  printf(" -v   Version\n");
  printf(" -r   Depricated option ignored, see -n\n");
  printf(" -n   Don't Run Program\n");
  printf(" -d   Dump Memory\n");
  printf(" -h   Help\n");
  printf(" -l   Load program\n");
  printf(" -b   Begin Address\n");
  printf(" -i   IN file\n");
  printf(" -o   OUT file\n");
  printf("Cardiac opeation codes:\n");
  printf("          code   abbr  Meaning\n");
  printf("           0     INP   Input\n");
  printf("           1     CLA   Clear and Add\n");
  printf("           2     ADD   Add\n");
  printf("           3     TAC   Test Accumulator Contents\n");
  printf("           4     SFT   Shift\n");
  printf("           5     OUT   Output\n");
  printf("           6     STO   Store\n");
  printf("           7     SUB   Subtract\n");
  printf("           8     JMP   Jump\n");
  printf("           9     HRS   Halt and Reset\n\n");
 

  
}



int begin_pc(char * optarg, struct cardiac_s * cardiac)
{
  /* the begin option is a way to tell cinc what memory address to 
     set the program counter.
  */

  int rc = 0;
  int addr = 0;

  
  sscanf(optarg,"%d",&addr);

  /* Validate the address */  
  if ((addr >= 0) && (addr < MAXRAM)) {
    cardiac->pc = addr;
  } else { /* Out of bounds */
    rc = 2;
  }
  return(rc);

}

int load_mem(char * filename,struct cardiac_s * cardiac)
{
  /* This option loads a cardiac machine code program to memory */
  int rc = 0;
  int addr = 0;
  int cont = 0;
  int scan_rc;
  int set_pc;


  FILE *load;

  load = NULL;
  load = fopen(filename,"r"); 
  if (load == NULL) {
    rc = 1;
    return(rc);
  }
  
  set_pc = TRUE;


  while ( (scan_rc = fscanf(load,"%2d:%4d",&addr,&cont)) > 0 ) {
    if ( set_pc) {
      /* by default the program counter will be set to the first address
	 given in the load file. This can be overriden by the -b option */
      cardiac->pc=addr;
      set_pc = FALSE;
    }
    

    if (addr > 0 && addr < MAXRAM) {
      cardiac->ram[addr] = cont;
    } else { /* out of bounds attempt */
      rc = 2; 
      return(rc);
    }
  }

  fclose(load); 

  return(rc);
    
    
}

int setopts(int argc, char *argv[], struct cardiac_s * cardiac)
{
  int rc = 0;
  int opt;
  int exit_code;
  int save_pc;
  int option_b = FALSE;
  /* jrv4 aded two new variables */
  int option_i = FALSE;
  int option_o = FALSE;

  

  tty = NULL;
  cardiac->running=TRUE;
  
  while ((opt = getopt(argc,argv,"vrnhdi:o:l:b:")) != -1) {
    switch (opt) {
    case 'v' :
      printf("cinc v %s - CARDIAC emulator\n",VERSION);
      cardiac->running=FALSE;
      break;
    case 'r' : /* depricated option ignore it */
      break;
    case 'n' :
      cardiac->running=FALSE;
      break;
    case 'd' :
      cardiac->dump=TRUE;
      break;
    case 'b' :
      exit_code = 0;
      exit_code = begin_pc(optarg,cardiac);
      if (exit_code) rc = 20+exit_code;
      save_pc = cardiac->pc;
      option_b = TRUE;
      break;
    case 'l' :
      exit_code = 0;
      exit_code = load_mem(optarg,cardiac); 
      if (exit_code) rc = 10+exit_code;
      break;

    case 'i':
      cardiac->IN=fopen(optarg,"r");
      if (cardiac->IN==NULL) rc=32;
      option_i = TRUE;
      break;

    case 'o':
      cardiac->OUT=fopen(optarg,"w");
      if (cardiac->OUT==NULL) rc=43;
      option_o = TRUE;
      break;

    case '?':
      cardiac->running=FALSE;
      printf("\nFor help, try: cinc -h\n");
      rc = 0;
      break;
    case 'h':
      cardiac->running=FALSE;
      phelp();
      rc = 0;
      break;   
    }

  }

  /* jrv4 code to default to stdin and stdout */
  if ( ! option_i ) {
    tty = fopen("/dev/tty","w");
    cardiac->IN = stdin;
  }

  if ( ! option_o ) {
    cardiac->OUT = stdout;
  }

  if (option_b && (save_pc != cardiac->pc)) 
    { /* the -b option has precedence over the -l option, thus pc 
	 needs to be reset to the value specified in the b option.
       */
      cardiac->pc=save_pc;
    }

  /*Note: more option validation must be implemented in future version.*/
  /*      For the time being there may be conflicting options.    */


  return(rc);
}