/* vi_mode.c -- A vi emulation mode for Bash.

   Derived from code written by Jeff Sparkes (jeff1@????).
 */


/* **************************************************************** */
/*								    */
/*			VI Emulation Mode			    */
/*								    */
/* **************************************************************** */

/* Last string searched for from `/' or `?'. */
static char *vi_last_search = (char *)NULL;
static int vi_histpos;

/* Non-zero means enter insertion mode. */
int vi_doing_insert = 0;

/* *** UNCLEAN *** */
/* Command keys which do movement for xxx_to commands. */
static char *vi_motion = " hl^$0ftFt;,%wbeWBE|";

/* Keymap used for vi replace characters.  Created dynamically since
   rarely used. */
static Keymap vi_replace_map = (Keymap)NULL;

/* The number of characters inserted in the last replace operation. */
static vi_replace_count = 0;

/* Yank the nth arg from the previous line into this line at point. */
rl_vi_yank_arg (count)
     int count;
{
  rl_yank_nth_arg (count, 0);
}

/* Search again for the last thing searched for. */
rl_vi_search_again (ignore, key)
     int ignore, key;
{
  switch (key)
    {
    case 'n':
      rl_vi_dosearch (vi_last_search, -1);
      break;

    case 'N':
      rl_vi_dosearch (vi_last_search, 1);
      break;
    }
}

/* Do a vi style search. */
rl_vi_search (count, key)
     int count, key;
{
  int dir, c, save_pos;
  char *p;

  switch (key)
    {
    case '?':
      dir = 1;
      break;

    case '/':
      dir = -1;
      break;

    default:
      ding ();
      return;
    }

  vi_histpos = where_history ();
  maybe_save_line ();
  save_pos = rl_point;

  /* Reuse the line input buffer to read the search string. */
  the_line[0] = 0;
  rl_end = rl_point = 0;
  p = (char *)alloca (2 + (rl_prompt ? strlen (rl_prompt) : 0));

  sprintf (p, "%s%c", rl_prompt ? rl_prompt : "", key);

  rl_message (p, 0, 0);

  while (c = rl_read_key ())
    {
      switch (c)
	{
	case CTRL('H'):
	case RUBOUT:
	  if (rl_point == 0)
	    {
	      maybe_unsave_line ();
	      rl_clear_message ();
	      rl_point = save_pos;
	      return;
	    }

	case CTRL('W'):
	case CTRL('U'):
	  rl_dispatch (c, keymap);
	  break;

	case ESC:
	case RETURN:
	case NEWLINE:
	  goto dosearch;
	  break;

	case CTRL('C'):
	  maybe_unsave_line ();
	  rl_clear_message ();
	  rl_point = 0;
	  ding ();
	  return;

	default:
	  rl_insert (1, c);
	  break;
	}
      rl_redisplay ();
    }
 dosearch:
  if (vi_last_search)
    free (vi_last_search);

  vi_last_search = savestring (the_line);
  rl_vi_dosearch (the_line, dir);
}

rl_vi_dosearch (string, dir)
     char *string;
     int dir;
{
  int old, save = vi_histpos;
  HIST_ENTRY *h;

  if (string == 0 || *string == 0 || vi_histpos < 0)
    {
      ding ();
      return;
    }

  if ((save = history_search_pos (string, dir, vi_histpos + dir)) == -1)
    {
      maybe_unsave_line ();
      rl_clear_message ();
      rl_point = 0;
      ding ();
      return;
    }

  vi_histpos = save;

  old = where_history ();
  history_set_pos (vi_histpos);
  h = current_history ();
  history_set_pos (old);

  strcpy (the_line, h->line);
  rl_undo_list = (UNDO_LIST *)h->data;
  rl_end = strlen (the_line);
  rl_point = 0;
  rl_clear_message ();
}

/* Completion, from vi's point of view. */
rl_vi_complete (ignore, key)
     int ignore, key;
{
  if ((rl_point < rl_end) && (!whitespace (the_line[rl_point])))
    {
      if (!whitespace (the_line[rl_point + 1]))
	rl_vi_end_word (1, 'E');
      rl_point++;
    }

  if (key == '*')
    rl_complete_internal ('*');
  else
    rl_complete (0, key);

  rl_vi_insertion_mode ();
}

/* Previous word in vi mode. */
rl_vi_prev_word (count, key)
     int count, key;
{
  if (count < 0)
    {
      rl_vi_next_word (-count, key);
      return;
    }

  if (uppercase_p (key))
    rl_vi_bWord (count);
  else
    rl_vi_bword (count);
}

/* Next word in vi mode. */
rl_vi_next_word (count, key)
     int count;
{
  if (count < 0)
    {
      rl_vi_prev_word (-count, key);
      return;
    }

  if (uppercase_p (key))
    rl_vi_fWord (count);
  else
    rl_vi_fword (count);
}

/* Move to the end of the ?next? word. */
rl_vi_end_word (count, key)
     int count, key;
{
  if (count < 0)
    {
      ding ();
      return;
    }

  if (uppercase_p (key))
    rl_vi_eWord (count);
  else
    rl_vi_eword (count);
}

/* Move forward a word the way that 'W' does. */
/* Move forward a word the way that 'W' does. */
rl_vi_fWord (count)
     int count;
{
  while (count-- && rl_point < (rl_end - 1))
    {
      /* Skip until whitespace. */
      while (!whitespace (the_line[rl_point]) && rl_point < rl_end)
        rl_point++;

      /* Now skip whitespace. */
      while (whitespace (the_line[rl_point]) && rl_point < rl_end)
        rl_point++;
    }
}

rl_vi_bWord (count)
     int count;
{
  while (count-- && rl_point > 0)
    {
      /* If we are at the start of a word, move back to whitespace so
         we will go back to the start of the previous word. */
      if (!whitespace (the_line[rl_point]) &&
          whitespace (the_line[rl_point - 1]))
        rl_point--;

      while (rl_point > 0 && whitespace (the_line[rl_point]))
        rl_point--;

      if (rl_point > 0)
        {
          while (--rl_point >= 0 && !whitespace (the_line[rl_point]));
          rl_point++;
        }
    }
}

rl_vi_eWord (count)
     int count;
{
  while (count-- && rl_point < (rl_end - 1))
    {
      /* Move to white space. */
      while (++rl_point < rl_end && whitespace (the_line[rl_point]))
        ;

      if (rl_point && rl_point < rl_end)
        {
          /* Skip whitespace. */
          while (rl_point < rl_end && whitespace (the_line[rl_point]))
            rl_point++;

          /* Skip until whitespace. */
          while (rl_point < rl_end && !whitespace (the_line[rl_point]))
            rl_point++;

          /* Move back to the last character of the word. */
          rl_point--;
        }
    }
}

rl_vi_fword (count)
     int count;
{
  while (count-- && rl_point < (rl_end - 1))
    {
      /* Move to white space (really non-identifer). */
      if (isident (the_line[rl_point]))
        {
          while (isident (the_line[rl_point]) && rl_point < rl_end)
            rl_point++;
        }
      else /* if (!whitespace (the_line[rl_point])) */
        {
          while (!isident (the_line[rl_point]) &&
                 !whitespace (the_line[rl_point]) && rl_point < rl_end)
            rl_point++;
        }

      /* Move past whitespace. */
      while (whitespace (the_line[rl_point]) && rl_point < rl_end)
        rl_point++;
    }
}

rl_vi_bword (count)
     int count;
{
  while (count-- && rl_point > 0)
    {
      int last_is_ident;

      /* If we are at the start of a word, move back to a non-identifier
         so we will go back to the start of the previous word. */
      if (isident (the_line[rl_point]) && !isident (the_line[rl_point - 1]))
        rl_point--;

      /* If this character and the previous character are `opposite', move
         back so we don't get messed up by the rl_point++ down there in
         the while loop.  Without this code, words like `l;' screw up the
         function. */
      last_is_ident = isident (the_line[rl_point - 1]);
      if ((isident (the_line[rl_point]) && !last_is_ident) ||
          (!isident (the_line[rl_point]) && last_is_ident))
        rl_point--;

      while (rl_point > 0 && whitespace (the_line[rl_point]))
        rl_point--;

      if (rl_point > 0)
        {
          if (isident (the_line[rl_point]))
            while (--rl_point >= 0 && isident (the_line[rl_point]));
          else
            while (--rl_point >= 0 && !isident (the_line[rl_point]) &&
                   !whitespace (the_line[rl_point]));
          rl_point++;
        }
    }
}

rl_vi_eword (count)
     int count;
{
  while (count-- && rl_point < rl_end - 1)
    {
      while (++rl_point < rl_end && whitespace (the_line[rl_point]))
        ;

      if (rl_point < rl_end)
        {
          if (isident (the_line[rl_point]))
            while (++rl_point < rl_end && isident (the_line[rl_point]));
          else
            while (++rl_point < rl_end && !isident (the_line[rl_point])
                   && !whitespace (the_line[rl_point]));
          rl_point--;
        }
    }
}

rl_vi_insert_beg ()
{
  rl_beg_of_line ();
  rl_vi_insertion_mode ();
  return 0;
}

rl_vi_append_mode ()
{
  if (rl_point < rl_end)
    rl_point += 1;
  rl_vi_insertion_mode ();
  return 0;
}

rl_vi_append_eol ()
{
  rl_end_of_line ();
  rl_vi_append_mode ();
  return 0;
}

/* What to do in the case of C-d. */
rl_vi_eof_maybe (count, c)
     int count, c;
{
  rl_newline (1, '\n');
}

/* Insertion mode stuff. */

/* Switching from one mode to the other really just involves
   switching keymaps. */
rl_vi_insertion_mode ()
{
  keymap = vi_insertion_keymap;
}

rl_vi_movement_mode ()
{
  if (rl_point > 0)
    rl_backward (1);

  keymap = vi_movement_keymap;
  vi_done_inserting ();
}

vi_done_inserting ()
{
  if (vi_doing_insert)
    {
      rl_end_undo_group ();
      vi_doing_insert = 0;
    }
}

rl_vi_arg_digit (count, c)
     int count, c;
{
  if (c == '0' && rl_numeric_arg == 1 && !rl_explicit_arg)
    rl_beg_of_line ();
  else
    rl_digit_argument (count, c);
}

/* Doesn't take an arg count in vi */
rl_vi_change_case (ignore1, ignore2)
     int ignore1, ignore2;
{
  char c = 0;

  /* Don't try this on an empty line. */
  if (rl_point >= rl_end - 1)
    return;

  if (uppercase_p (the_line[rl_point]))
    c = to_lower (the_line[rl_point]);
  else if (lowercase_p (the_line[rl_point]))
    c = to_upper (the_line[rl_point]);

  /* Vi is kind of strange here. */
  if (c)
    {
      rl_begin_undo_group ();
      rl_delete (1, c);
      rl_insert (1, c);
      rl_end_undo_group ();
      rl_vi_check ();
    }
  else
    rl_forward (1);
}

rl_vi_put (count, key)
     int count, key;
{
  if (!uppercase_p (key) && (rl_point + 1 <= rl_end))
    rl_forward (1);

  rl_yank ();
  rl_backward (1);
}

rl_vi_check ()
{
  if (rl_point && rl_point == rl_end)
    rl_point--;
}

rl_vi_column (count)
{
  if (count > rl_end)
    rl_end_of_line ();
  else
    rl_point = count - 1;
}

int
rl_vi_domove (key, nextkey)
     int key, *nextkey;
{
  int c, save;

  rl_mark = rl_point;
  c = rl_read_key ();
  *nextkey = c;

  if (!member (c, vi_motion))
    {
      if (digit (c))
	{
	  save = rl_numeric_arg;
	  rl_digit_loop1 ();
	  rl_numeric_arg *= save;
	}
      else if ((key == 'd' && c == 'd') ||
	       (key == 'c' && c == 'c'))
	{
	  rl_mark = rl_end;
	  rl_beg_of_line ();
	  return (0);
	}
      else
	return (-1);
    }

  rl_dispatch (c, keymap);

  /* No change in position means the command failed. */
  if (rl_mark == rl_point)
    return (-1);

  if ((c == 'w' || c == 'W') && rl_point < rl_end)
    rl_point--;

  if (rl_mark < rl_point)
    exchange (rl_point, rl_mark);

  return (0);
}

/* A simplified loop for vi. Don't dispatch key at end.
   Don't recognize minus sign? */
rl_digit_loop1 ()
{
  int key, c;

  while (1)
    {
      rl_message ("(arg: %d) ", arg_sign * rl_numeric_arg, 0);
      key = c = rl_read_key ();

      if (keymap[c].type == ISFUNC &&
	  keymap[c].function == rl_universal_argument)
	{
	  rl_numeric_arg *= 4;
	  continue;
	}

      c = UNMETA (c);
      if (numeric (c))
	{
	  if (rl_explicit_arg)
	    rl_numeric_arg = (rl_numeric_arg * 10) + (c - '0');
	  else
	    rl_numeric_arg = (c - '0');
	  rl_explicit_arg = 1;
	}
      else
	{
	  rl_clear_message ();
	  rl_stuff_char (key);
	  break;
	}
    }
}

rl_vi_delete_to (count, key)
     int count, key;
{
  int c;

  if (uppercase_p (key))
    rl_stuff_char ('$');

  if (rl_vi_domove (key, &c))
    {
      ding ();
      return;
    }

  if ((c != '|') && (c != 'h') && rl_mark < rl_end)
    rl_mark++;

  rl_kill_text (rl_point, rl_mark);
}

rl_vi_change_to (count, key)
     int count, key;
{
  int c;

  if (uppercase_p (key))
    rl_stuff_char ('$');

  if (rl_vi_domove (key, &c))
    {
      ding ();
      return;
    }

  if ((c != '|') && (c != 'h') && rl_mark < rl_end)
    rl_mark++;

  rl_begin_undo_group ();
  vi_doing_insert = 1;
  rl_kill_text (rl_point, rl_mark);
  rl_vi_insertion_mode ();
}

rl_vi_yank_to (count, key)
     int count, key;
{
  int c, save = rl_point;

  if (uppercase_p (key))
    rl_stuff_char ('$');

  if (rl_vi_domove (key, &c))
    {
      ding ();
      return;
    }

  rl_begin_undo_group ();
  rl_kill_text (rl_point, rl_mark);
  rl_end_undo_group ();
  rl_do_undo ();
  rl_point = save;
}

rl_vi_delete (count)
{
  int end;

  if (rl_end == 0)
    {
      ding ();
      return;
    }

  end = rl_point + count;

  if (end >= rl_end)
    end = rl_end;

  rl_kill_text (rl_point, end);
  
  if (rl_point > 0 && rl_point == rl_end)
    rl_backward (1);
}

/* Turn the current line into a comment in shell history.
   A K*rn shell style function. */
rl_vi_comment ()
{
  rl_beg_of_line ();
  rl_insert_text (": ");	/* `#' doesn't work in interactive mode */
  rl_redisplay ();
  rl_newline (1, '\010');
}

rl_vi_first_print ()
{
  rl_back_to_indent ();
}

rl_back_to_indent (ignore1, ignore2)
     int ignore1, ignore2;
{
  rl_beg_of_line ();
  while (rl_point < rl_end && whitespace (the_line[rl_point]))
    rl_point++;
}

/* NOTE: it is necessary that opposite directions are inverses */
#define	FTO	 1		/* forward to */
#define BTO	-1		/* backward to */
#define FFIND	 2		/* forward find */
#define BFIND	-2		/* backward find */

rl_vi_char_search (count, key)
     int count, key;
{
  static char target;
  static int orig_dir, dir;
  int pos;

  if (key == ';' || key == ',')
    dir = (key == ';' ? orig_dir : -orig_dir);
  else
    {
      target = rl_getc (in_stream);

      switch (key)
	{
	case 't':
	  orig_dir = dir = FTO;
	  break;

	case 'T':
	  orig_dir = dir = BTO;
	  break;

	case 'f':
	  orig_dir = dir = FFIND;
	  break;

	case 'F':
	  orig_dir = dir = BFIND;
	  break;
	}
    }

  pos = rl_point;

  if (dir < 0)
    {
      pos--;
      do
	{
	  if (the_line[pos] == target)
	    {
	      if (dir == BTO)
		rl_point = pos + 1;
	      else
		rl_point = pos;
	      return;
	    }
	}
      while (pos--);

      if (pos < 0)
	{
	  ding ();
	  return;
	}
    }
  else
    {			/* dir > 0 */
      pos++;
      do
	{
	  if (the_line[pos] == target)
	    {
	      if (dir == FTO)
		rl_point = pos - 1;
	      else
		rl_point = pos;
	      return;
	    }
	}
      while (++pos < rl_end);

      if (pos >= (rl_end - 1))
	ding ();
    }
}

/* Match brackets */
rl_vi_match ()
{
  int count = 1, brack, pos;

  pos = rl_point;
  if ((brack = rl_vi_bracktype (the_line[rl_point])) == 0)
    {
      while ((brack = rl_vi_bracktype (the_line[rl_point])) == 0 &&
	     rl_point < rl_end - 1)
	rl_forward (1);

      if (brack <= 0)
	{
	  rl_point = pos;
	  ding ();
	  return;
	}
    }

  pos = rl_point;

  if (brack < 0)
    {
      while (count)
	{
	  if (--pos >= 0)
	    {
	      int b = rl_vi_bracktype (the_line[pos]);
	      if (b == -brack)
		count--;
	      else if (b == brack)
		count++;
	    }
	  else
	    {
	      ding ();
	      return;
	    }
	}
    }
  else
    {			/* brack > 0 */
      while (count)
	{
	  if (++pos < rl_end)
	    {
	      int b = rl_vi_bracktype (the_line[pos]);
	      if (b == -brack)
		count--;
	      else if (b == brack)
		count++;
	    }
	  else
	    {
	      ding ();
	      return;
	    }
	}
    }
  rl_point = pos;
}

int
rl_vi_bracktype (c)
     int c;
{
  switch (c)
    {
    case '(': return  1;
    case ')': return -1;
    case '[': return  2;
    case ']': return -2;
    case '{': return  3;
    case '}': return -3;
    default:  return  0;
    }
}

rl_vi_change_char ()
{
  int c;

  c = rl_getc (in_stream);

  switch (c)
    {
    case '\033':
    case CTRL('C'):
      return;

    default:
      rl_begin_undo_group ();
      rl_delete (1, c);
      rl_insert (1, c);
      rl_end_undo_group ();
      break;
    }
}

rl_vi_subst (count, key)
     int count, key;
{
  rl_begin_undo_group ();
  vi_doing_insert = 1;

  if (uppercase_p (key))
    {
      rl_beg_of_line ();
      rl_kill_line (1);
    }
  else
    rl_delete (count, key);

  rl_vi_insertion_mode ();
}

rl_vi_overstrike (count, key)
     int count, key;
{
  int i;

  if (vi_doing_insert == 0)
    {
      vi_doing_insert = 1;
      rl_begin_undo_group ();
    }

  for (i = 0; i < count; i++)
    {
      vi_replace_count++;
      rl_begin_undo_group ();

      if (rl_point < rl_end)
	{
	  rl_delete (1, key);
	  rl_insert (1, key);
	}
      else
	rl_insert (1, key);

      rl_end_undo_group ();
    }
}

rl_vi_overstrike_delete (count)
     int count;
{
  int i, s;

  for (i = 0; i < count; i++)
    {
      if (vi_replace_count == 0)
	{
	  ding ();
	  break;
	}
      s = rl_point;

      if (rl_do_undo ())
	vi_replace_count--;

      if (rl_point == s)
	rl_backward (1);
    }

  if (vi_replace_count == 0 && vi_doing_insert)
    {
      rl_end_undo_group ();
      rl_do_undo ();
      vi_doing_insert = 0;
    }
}

rl_vi_replace ()
{
  int i;

  vi_replace_count = 0;

  vi_replace_map = rl_make_bare_keymap ();

  for (i = ' '; i < 127; i++)
    vi_replace_map[i].function = rl_vi_overstrike;

  vi_replace_map[RUBOUT].function = rl_vi_overstrike_delete;
  vi_replace_map[ESC].function = rl_vi_movement_mode;
  vi_replace_map[RETURN].function = rl_newline;
  vi_replace_map[NEWLINE].function = rl_newline;
  keymap = vi_replace_map;
}

/*
 * Try to complete the word we are standing on or the word that ends with
 * the previous character. A space matches everything.
 * Word delimiters are space and ;.
 */
rl_vi_possible_completions()
{
  int save_pos = rl_point;

  if (!index (" ;", the_line[rl_point]))
    {
      while (!index(" ;", the_line[++rl_point]))
	;
    }
  else if (the_line[rl_point-1] == ';')
    {
      ding ();
      return (0);
    }

  rl_possible_completions ();
  rl_point = save_pos;

  return (0);
}