/* search.c - code for non-incremental searching in emacs and vi modes. */

/* Copyright (C) 1992 Free Software Foundation, Inc.

   This file is part of the Readline Library (the Library), a set of
   routines for providing Emacs style line input to programs that ask
   for it.

   The Library 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, or (at your option)
   any later version.

   The Library 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.

   The GNU General Public License is often shipped with GNU software, and
   is generally kept in a file called COPYING or LICENSE.  If you do not
   have a copy of the license, write to the Free Software Foundation,
   59 Temple Place, Suite 330, Boston, MA 02111 USA. */
#define READLINE_LIBRARY

#if defined (HAVE_CONFIG_H)
#  include <config.h>
#endif

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

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif

#if defined (HAVE_STDLIB_H)
#  include <stdlib.h>
#else
#  include "ansi_stdlib.h"
#endif

#include "rldefs.h"
#include "rlmbutil.h"

#include "readline.h"
#include "history.h"

#include "rlprivate.h"
#include "xmalloc.h"

#ifdef abs
#  undef abs
#endif
#define abs(x)		(((x) >= 0) ? (x) : -(x))

extern HIST_ENTRY *_rl_saved_line_for_history;

/* Functions imported from the rest of the library. */
extern int _rl_free_history_entry PARAMS((HIST_ENTRY *));

static char *noninc_search_string = (char *) NULL;
static int noninc_history_pos;

static char *prev_line_found = (char *) NULL;

static int rl_history_search_len;
static int rl_history_search_pos;
static char *history_search_string;
static int history_string_size;

static void make_history_line_current PARAMS((HIST_ENTRY *));
static int noninc_search_from_pos PARAMS((char *, int, int));
static void noninc_dosearch PARAMS((char *, int));
static void noninc_search PARAMS((int, int));
static int rl_history_search_internal PARAMS((int, int));
static void rl_history_search_reinit PARAMS((void));

/* Make the data from the history entry ENTRY be the contents of the
   current line.  This doesn't do anything with rl_point; the caller
   must set it. */
static void
make_history_line_current (entry)
     HIST_ENTRY *entry;
{
#if 0
  rl_replace_line (entry->line, 1);
  rl_undo_list = (UNDO_LIST *)entry->data;
#else
  _rl_replace_text (entry->line, 0, rl_end);
  _rl_fix_point (1);
#endif

  if (_rl_saved_line_for_history)
    _rl_free_history_entry (_rl_saved_line_for_history);
  _rl_saved_line_for_history = (HIST_ENTRY *)NULL;
}

/* Search the history list for STRING starting at absolute history position
   POS.  If STRING begins with `^', the search must match STRING at the
   beginning of a history line, otherwise a full substring match is performed
   for STRING.  DIR < 0 means to search backwards through the history list,
   DIR >= 0 means to search forward. */
static int
noninc_search_from_pos (string, pos, dir)
     char *string;
     int pos, dir;
{
  int ret, old;

  if (pos < 0)
    return -1;

  old = where_history ();
  if (history_set_pos (pos) == 0)
    return -1;

  RL_SETSTATE(RL_STATE_SEARCH);
  if (*string == '^')
    ret = history_search_prefix (string + 1, dir);
  else
    ret = history_search (string, dir);
  RL_UNSETSTATE(RL_STATE_SEARCH);

  if (ret != -1)
    ret = where_history ();

  history_set_pos (old);
  return (ret);
}

/* Search for a line in the history containing STRING.  If DIR is < 0, the
   search is backwards through previous entries, else through subsequent
   entries. */
static void
noninc_dosearch (string, dir)
     char *string;
     int dir;
{
  int oldpos, pos;
  HIST_ENTRY *entry;

  if (string == 0 || *string == '\0' || noninc_history_pos < 0)
    {
      rl_ding ();
      return;
    }

  pos = noninc_search_from_pos (string, noninc_history_pos + dir, dir);
  if (pos == -1)
    {
      /* Search failed, current history position unchanged. */
      rl_maybe_unsave_line ();
      rl_clear_message ();
      rl_point = 0;
      rl_ding ();
      return;
    }

  noninc_history_pos = pos;

  oldpos = where_history ();
  history_set_pos (noninc_history_pos);
  entry = current_history ();
#if defined (VI_MODE)
  if (rl_editing_mode != vi_mode)
#endif
  history_set_pos (oldpos);

  make_history_line_current (entry);

  rl_point = 0;
  rl_mark = rl_end;

  rl_clear_message ();
}

/* Search non-interactively through the history list.  DIR < 0 means to
   search backwards through the history of previous commands; otherwise
   the search is for commands subsequent to the current position in the
   history list.  PCHAR is the character to use for prompting when reading
   the search string; if not specified (0), it defaults to `:'. */
static void
noninc_search (dir, pchar)
     int dir;
     int pchar;
{
  int saved_point, saved_mark, c;
  char *p;
#if defined (HANDLE_MULTIBYTE)
  char mb[MB_LEN_MAX];
#endif

  rl_maybe_save_line ();
  saved_point = rl_point;
  saved_mark = rl_mark;

  /* Clear the undo list, since reading the search string should create its
     own undo list, and the whole list will end up being freed when we
     finish reading the search string. */
  rl_undo_list = 0;

  /* Use the line buffer to read the search string. */
  rl_line_buffer[0] = 0;
  rl_end = rl_point = 0;

  p = _rl_make_prompt_for_search (pchar ? pchar : ':');
  rl_message (p, 0, 0);
  free (p);

#define SEARCH_RETURN rl_restore_prompt (); RL_UNSETSTATE(RL_STATE_NSEARCH); return

  RL_SETSTATE(RL_STATE_NSEARCH);
  /* Read the search string. */
  while (1)
    {
      RL_SETSTATE(RL_STATE_MOREINPUT);
      c = rl_read_key ();
      RL_UNSETSTATE(RL_STATE_MOREINPUT);

#if defined (HANDLE_MULTIBYTE)
      if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
	c = _rl_read_mbstring (c, mb, MB_LEN_MAX);
#endif

      if (c == 0)
	break;

      switch (c)
	{
	case CTRL('H'):
	case RUBOUT:
	  if (rl_point == 0)
	    {
	      rl_maybe_unsave_line ();
	      rl_clear_message ();
	      rl_point = saved_point;
	      rl_mark = saved_mark;
	      SEARCH_RETURN;
	    }
	  _rl_rubout_char (1, c);
	  break;

	case CTRL('W'):
	  rl_unix_word_rubout (1, c);
	  break;

	case CTRL('U'):
	  rl_unix_line_discard (1, c);
	  break;

	case RETURN:
	case NEWLINE:
	  goto dosearch;
	  /* NOTREACHED */
	  break;

	case CTRL('C'):
	case CTRL('G'):
	  rl_maybe_unsave_line ();
	  rl_clear_message ();
	  rl_point = saved_point;
	  rl_mark = saved_mark;
	  rl_ding ();
	  SEARCH_RETURN;

	default:
#if defined (HANDLE_MULTIBYTE)
	  if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
	    rl_insert_text (mb);
	  else
#endif
	    _rl_insert_char (1, c);
	  break;
	}
      (*rl_redisplay_function) ();
    }

 dosearch:
  rl_mark = saved_mark;

  /* If rl_point == 0, we want to re-use the previous search string and
     start from the saved history position.  If there's no previous search
     string, punt. */
  if (rl_point == 0)
    {
      if (!noninc_search_string)
	{
	  rl_ding ();
	  SEARCH_RETURN;
	}
    }
  else
    {
      /* We want to start the search from the current history position. */
      noninc_history_pos = where_history ();
      FREE (noninc_search_string);
      noninc_search_string = savestring (rl_line_buffer);
    }

  rl_restore_prompt ();
  noninc_dosearch (noninc_search_string, dir);
  RL_UNSETSTATE(RL_STATE_NSEARCH);
}

/* Search forward through the history list for a string.  If the vi-mode
   code calls this, KEY will be `?'. */
int
rl_noninc_forward_search (count, key)
     int count, key;
{
  noninc_search (1, (key == '?') ? '?' : 0);
  return 0;
}

/* Reverse search the history list for a string.  If the vi-mode code
   calls this, KEY will be `/'. */
int
rl_noninc_reverse_search (count, key)
     int count, key;
{
  noninc_search (-1, (key == '/') ? '/' : 0);
  return 0;
}

/* Search forward through the history list for the last string searched
   for.  If there is no saved search string, abort. */
int
rl_noninc_forward_search_again (count, key)
     int count, key;
{
  if (!noninc_search_string)
    {
      rl_ding ();
      return (-1);
    }
  noninc_dosearch (noninc_search_string, 1);
  return 0;
}

/* Reverse search in the history list for the last string searched
   for.  If there is no saved search string, abort. */
int
rl_noninc_reverse_search_again (count, key)
     int count, key;
{
  if (!noninc_search_string)
    {
      rl_ding ();
      return (-1);
    }
  noninc_dosearch (noninc_search_string, -1);
  return 0;
}

static int
rl_history_search_internal (count, dir)
     int count, dir;
{
  HIST_ENTRY *temp;
  int ret, oldpos;

  rl_maybe_save_line ();
  temp = (HIST_ENTRY *)NULL;

  /* Search COUNT times through the history for a line whose prefix
     matches history_search_string.  When this loop finishes, TEMP,
     if non-null, is the history line to copy into the line buffer. */
  while (count)
    {
      ret = noninc_search_from_pos (history_search_string, rl_history_search_pos + dir, dir);
      if (ret == -1)
	break;

      /* Get the history entry we found. */
      rl_history_search_pos = ret;
      oldpos = where_history ();
      history_set_pos (rl_history_search_pos);
      temp = current_history ();
      history_set_pos (oldpos);

      /* Don't find multiple instances of the same line. */
      if (prev_line_found && STREQ (prev_line_found, temp->line))
        continue;
      prev_line_found = temp->line;
      count--;
    }

  /* If we didn't find anything at all, return. */
  if (temp == 0)
    {
      rl_maybe_unsave_line ();
      rl_ding ();
      /* If you don't want the saved history line (last match) to show up
         in the line buffer after the search fails, change the #if 0 to
         #if 1 */
#if 0
      if (rl_point > rl_history_search_len)
        {
          rl_point = rl_end = rl_history_search_len;
          rl_line_buffer[rl_end] = '\0';
          rl_mark = 0;
        }
#else
      rl_point = rl_history_search_len;	/* rl_maybe_unsave_line changes it */
      rl_mark = rl_end;
#endif
      return 1;
    }

  /* Copy the line we found into the current line buffer. */
  make_history_line_current (temp);

  rl_point = rl_history_search_len;
  rl_mark = rl_end;

  return 0;
}

static void
rl_history_search_reinit ()
{
  rl_history_search_pos = where_history ();
  rl_history_search_len = rl_point;
  prev_line_found = (char *)NULL;
  if (rl_point)
    {
      if (rl_history_search_len >= history_string_size - 2)
	{
	  history_string_size = rl_history_search_len + 2;
	  history_search_string = (char *)xrealloc (history_search_string, history_string_size);
	}
      history_search_string[0] = '^';
      strncpy (history_search_string + 1, rl_line_buffer, rl_point);
      history_search_string[rl_point + 1] = '\0';
    }
  _rl_free_saved_history_line ();
}

/* Search forward in the history for the string of characters
   from the start of the line to rl_point.  This is a non-incremental
   search. */
int
rl_history_search_forward (count, ignore)
     int count, ignore;
{
  if (count == 0)
    return (0);

  if (rl_last_func != rl_history_search_forward &&
      rl_last_func != rl_history_search_backward)
    rl_history_search_reinit ();

  if (rl_history_search_len == 0)
    return (rl_get_next_history (count, ignore));
  return (rl_history_search_internal (abs (count), (count > 0) ? 1 : -1));
}

/* Search backward through the history for the string of characters
   from the start of the line to rl_point.  This is a non-incremental
   search. */
int
rl_history_search_backward (count, ignore)
     int count, ignore;
{
  if (count == 0)
    return (0);

  if (rl_last_func != rl_history_search_forward &&
      rl_last_func != rl_history_search_backward)
    rl_history_search_reinit ();

  if (rl_history_search_len == 0)
    return (rl_get_previous_history (count, ignore));
  return (rl_history_search_internal (abs (count), (count > 0) ? -1 : 1));
}