/*
 * GNU Typist  - interactive typing tutor program for UNIX systems
 * 
 * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003  
 * 					Simon Baldwin (simonb@sco.com)
 * Copyright (C) 2003  GNU Typist Development Team <bug-gtypist@gnu.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
#include "config.h"
#include "script.h"
#ifdef HAVE_LIBCURSES
#include <curses.h>
#else
#include <ncurses.h>
#endif
#include "error.h"

#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "gettext.h"
#define _(String) gettext (String)

int global_line_counter = 0;
struct label_entry *global_label_list[NLHASH];

// Nobody bothers to free this string at exit.
char *__last_label = NULL;

void __update_last_label (const char *label)
{
  if (__last_label)
     free (__last_label);
  __last_label = strdup (label);
  if (!__last_label)
  {
     perror ("strdup");
     fatal_error (_("internal error: strdup"), label);
  }
}

/*
  label hashing function - returns an index for the lists
*/
int 
hash_label( char *label ) {
  char	*p;				/* pointer through string */
  int	csum = 0;			/* sum of characters */
  
  /* hash by summing the characters and taking modulo of the
     number of hash lists defined */
  for ( p = label; *p != ASCII_NULL; p++ )
    csum += *p;
  return ( csum % NLHASH );
}

static int line_is_empty (const char *line)
{
   while (*line)
   {
      if (!isspace (*line))
         return 0;

      line ++;
   }

   return 1;
}

/*
  get the next non-comment, non-blank line from the script file
  and check its basic format
*/
void get_script_line( FILE *script, char *line )
{
  /* get lines until not empty/comment, or eof found */
  fgets(line, MAX_SCR_LINE, script);
  global_line_counter++;
  while (! feof (script) && 
	   (line_is_empty (line) ||
	    SCR_COMMAND (line) == C_COMMENT ||
	    SCR_COMMAND (line) == C_ALT_COMMENT)) 
    {
      fgets(line, MAX_SCR_LINE, script);
      global_line_counter++;
    }

  /* if a line was read then check it */
  if ( ! feof( script )) 
    {
      /* Get rid of trailing spaces and newline */
      while( *line && isspace( line[strlen( line )-1] ) )
        line [strlen (line) - 1] = ASCII_NULL;

      if ( strlen( line ) < MIN_SCR_LINE )
	fatal_error( _("data shortage"), line );
      if ( SCR_SEP( line ) != C_SEP )
	fatal_error( _("missing ':'"), line );
      if ( SCR_COMMAND( line ) != C_LABEL 
	   && SCR_COMMAND( line ) != C_GOTO 
	   && SCR_COMMAND( line ) != C_YGOTO
	   && SCR_COMMAND( line ) != C_NGOTO
	   && strlen( SCR_DATA( line )) > COLS )
	fatal_error( _("line too long for screen"), line );
    }

  if (SCR_COMMAND (line) == '*')
     __update_last_label (SCR_DATA (line));
}

/*
  buffer up the complete data from a command; used for [Dd], [Pp] and M
*/
char *buffer_command( FILE *script, char *line ) {
  int	total_chars = 0;		/* character counter */
  char	*data = NULL;			/* data string */

  /* get the complete exercise into a single string */
  do 
    {
      
      /* allocate space for the extra data */
      if ( total_chars == 0 )
	data = (char*)malloc( strlen(SCR_DATA( line )) +
			      strlen(STRING_NL) + 1 );
      else
	data = (char*)realloc( data, strlen( data ) +
			       strlen(SCR_DATA( line )) +
			       strlen(STRING_NL) + 1 );
      if ( data == NULL )
	fatal_error( _("internal error: malloc"), line );
      
      /* store the data in the allocated area */
      if ( total_chars == 0 )
	strcpy( data, "" );
      strcat( data, SCR_DATA( line ) );
      strcat( data, STRING_NL );
      total_chars = strlen( data );
      
      /* and get the next script line */
      get_script_line( script, line );
    } 
  while ( SCR_COMMAND( line ) == C_CONT && ! feof( script ));

  /* return our (malloced) data */
  return( data );
}

/*
  search out a label from the file, and set the file pointer to
  that location

  It also updates __last_label for the returns into menu from lessons.
*/
void 
seek_label( FILE *script, char *label, char *ref_line ) {
  struct label_entry	*check_label;	/* pointer through list */
  int	hash;				/* hash index */
  char	err[MAX_SCR_LINE];		/* error message string */

  if (!label)
     do_exit (script);
  
  __update_last_label (label);
		  
  /* find the right hash list for the label */
  hash = hash_label( label );
  
  /* search the linked list for the label */
  for ( check_label = global_label_list[ hash ]; check_label != NULL;
	check_label = check_label->next ) 
    {
      
      /* see if this is our label */
      if ( strcmp( check_label->label, label ) == 0 )
	break;
    }

  /* see if the label was not found in the file */
  if ( check_label == NULL ) 
    {
      sprintf( err, _("label '%s' not found"), label );
      fatal_error( err, ref_line );
    }

  /* move to the label position in the file */
  if ( fseek( script, check_label->offset, SEEK_SET ) == -1 )
    fatal_error( _("internal error: fseek"), ref_line );
  global_line_counter = check_label->line_count;
}

/*
  exit from the program (implied on eof)
*/
void 
do_exit( FILE *script ) 
{
  /* close up all files, reset the screen stuff, and exit */
  fclose( script );
  /* if ( cl_colour && has_colors() )*/
  wbkgdset( stdscr, 0 );
  clear(); refresh(); endwin();
  printf( _("Happy Typing!\n\n") );
  exit( 0 );
}