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

/* Copyright (C) 1992-2024 Free Software Foundation, Inc.

   This file is part of the GNU Readline Library (Readline), a library
   for reading lines of text with interactive input and history editing.      

   Readline 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 3 of the License, or
   (at your option) any later version.

   Readline 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 Readline.  If not, see <http://www.gnu.org/licenses/>.
*/

#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 "histlib.h"

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

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

_rl_search_cxt *_rl_nscxt = 0;

static HIST_ENTRY *_rl_saved_line_for_search;

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 int _rl_history_search_flags;

static char *history_search_string;
static size_t history_string_size;

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

static _rl_search_cxt *_rl_nsearch_init (int, int);
static void _rl_nsearch_abort (_rl_search_cxt *);
static int _rl_nsearch_dispatch (_rl_search_cxt *, int);

void
_rl_free_saved_search_line (void)
{
  if (_rl_saved_line_for_search)
    _rl_free_saved_line (_rl_saved_line_for_search);
  _rl_saved_line_for_search = (HIST_ENTRY *)NULL;
}

static inline void
_rl_unsave_saved_search_line (void)
{
  if (_rl_saved_line_for_search)
    _rl_unsave_line (_rl_saved_line_for_search);
  _rl_saved_line_for_search = (HIST_ENTRY *)NULL;
}

/* Make the data from the history entry at offset NEWPOS be the contents of
   the current line, which is at offset CURPOS. We use the same strategy
   as incremental search.
   This doesn't do anything with rl_point beyond bounds checking; the caller
   must set it to any desired value. */
static void
make_history_line_current (int curpos, int newpos)
{
  if (newpos < curpos)
    rl_get_previous_history (curpos - newpos, 0);
  else
    rl_get_next_history (newpos - curpos, 0);

  _rl_fix_point (1);

#if defined (VI_MODE)
  if (rl_editing_mode == vi_mode)
    /* POSIX.2 says that the `U' command doesn't affect the copy of any
       command lines to the edit line.  We're going to implement that by
       making the undo list start after the matching line is copied to the
       current editing buffer. */
    rl_free_undo_list ();
#endif
}

/* 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 (char *string, int pos, int dir, int flags, int *ncp)
{
  int ret, old, sflags;
  char *s;

  if (pos < 0)
    return -1;

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

  RL_SETSTATE(RL_STATE_SEARCH);
  /* These functions return the match offset in the line; history_offset gives
     the matching line in the history list */

  sflags = 0;		/* Non-anchored search */
  s = string;
  if (*s == '^')
    {
      sflags |= ANCHORED_SEARCH;
      s++;
    }

  if (flags & SF_PATTERN)
    ret = _hs_history_patsearch (s, dir, dir, sflags);
  else
    {
      if (_rl_search_case_fold)
	sflags |= CASEFOLD_SEARCH;
      ret = _hs_history_search (s, dir, dir, sflags);
    }
  RL_UNSETSTATE(RL_STATE_SEARCH);

  if (ncp)
    *ncp = ret;		/* caller will catch -1 to indicate no-op */

  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. Leaves noninc_history_pos set to the offset of the found history
   entry, if successful. Returns 1 if the search was successful, 0 otherwise. */
static int
noninc_dosearch (char *string, int dir, int flags)
{
  int oldpos, pos, ind;

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

  pos = noninc_search_from_pos (string, noninc_history_pos + dir, dir, flags, &ind);
  if (pos == -1)
    {
      /* Search failed, current history position unchanged. */
      rl_clear_message ();
      rl_point = 0;		/* caller will fix it up if needed */
      rl_ding ();
      return 0;
    }

  oldpos = where_history ();
  noninc_history_pos = pos;
  make_history_line_current (oldpos, noninc_history_pos);

#if defined (VI_MODE)
  if (rl_editing_mode == vi_mode)
    history_set_pos (noninc_history_pos);	/* XXX */
#endif

  if (_rl_enable_active_region && ((flags & SF_PATTERN) == 0) && ind >= 0 && ind < rl_end)
    {
      rl_point = ind;
      rl_mark = ind + strlen (string);
      if (rl_mark > rl_end)
	rl_mark = rl_end;	/* can't happen? */
      rl_activate_mark ();
    }
  else
    {  
      rl_point = 0;
      rl_mark = rl_end;
    }

  rl_clear_message ();
  return 1;
}

static _rl_search_cxt *
_rl_nsearch_init (int dir, int pchar)
{
  _rl_search_cxt *cxt;
  char *p;

  cxt = _rl_scxt_alloc (RL_SEARCH_NSEARCH, 0);
  if (dir < 0)
    cxt->sflags |= SF_REVERSE;		/* not strictly needed */
#if defined (VI_MODE)
  if (VI_COMMAND_MODE() && (pchar == '?' || pchar == '/'))
    cxt->sflags |= SF_PATTERN;
#endif

  cxt->direction = dir;
  cxt->history_pos = cxt->save_line;

  _rl_saved_line_for_search = _rl_alloc_saved_line ();

  /* 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 : ':');
  cxt->sflags |= SF_FREEPMT;
  rl_message ("%s", p);
  xfree (p);

  RL_SETSTATE(RL_STATE_NSEARCH);

  _rl_nscxt = cxt;

  return cxt;
}

int
_rl_nsearch_cleanup (_rl_search_cxt *cxt, int r)
{
  _rl_scxt_dispose (cxt, 0);
  _rl_nscxt = 0;

  RL_UNSETSTATE(RL_STATE_NSEARCH);

  return (r != 1);
}

static void
_rl_nsearch_abort (_rl_search_cxt *cxt)
{
  _rl_unsave_saved_search_line ();
  rl_point = cxt->save_point;
  rl_mark = cxt->save_mark;
  if (cxt->sflags & SF_FREEPMT)
    rl_restore_prompt ();		/* _rl_make_prompt_for_search saved it */
  cxt->sflags &= ~SF_FREEPMT;
  rl_clear_message ();
  _rl_fix_point (1);

  RL_UNSETSTATE (RL_STATE_NSEARCH);
}

int
_rl_nsearch_sigcleanup (_rl_search_cxt *cxt, int r)
{
  if (cxt->sflags & SF_FREEPMT)
    rl_restore_prompt ();		/* _rl_make_prompt_for_search saved it */
  cxt->sflags &= ~SF_FREEPMT;
  return (_rl_nsearch_cleanup (cxt, r));
}

/* Process just-read character C according to search context CXT.  Return -1
   if the caller should abort the search, 0 if we should break out of the
   loop, and 1 if we should continue to read characters. */
static int
_rl_nsearch_dispatch (_rl_search_cxt *cxt, int c)
{
  int n;

  if (c < 0)
    c = CTRL ('C');  

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

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

    case CTRL('Q'):
    case CTRL('V'):
      n = rl_quoted_insert (1, c);
      if (n < 0)
	{
	  _rl_nsearch_abort (cxt);
	  return -1;
	}
      cxt->lastc = (rl_point > 0) ? rl_line_buffer[rl_point - 1] : rl_line_buffer[0];
      break;

    case RETURN:
    case NEWLINE:
      return 0;

    case CTRL('H'):
    case RUBOUT:
      if (rl_point == 0)
	{
	  _rl_nsearch_abort (cxt);
	  return -1;
	}
      _rl_rubout_char (1, c);
      break;

    case CTRL('C'):
    case CTRL('G'):
      rl_ding ();
      _rl_nsearch_abort (cxt);
      return -1;

    case ESC:
      /* XXX - experimental code to allow users to bracketed-paste into the
	 search string. Similar code is in isearch.c:_rl_isearch_dispatch().
	 The difference here is that the bracketed paste sometimes doesn't
	 paste everything, so checking for the prefix and the suffix in the
	 input queue doesn't work well. We just have to check to see if the
	 number of chars in the input queue is enough for the bracketed paste
	 prefix and hope for the best. */
      if (_rl_enable_bracketed_paste && ((n = _rl_nchars_available ()) >= (BRACK_PASTE_SLEN-1)))
	{
	  if (_rl_read_bracketed_paste_prefix (c) == 1)
	    rl_bracketed_paste_begin (1, c);
	  else
	    {
	      c = rl_read_key ();	/* get the ESC that got pushed back */
	      _rl_insert_char (1, c);
	    }
        }
      else
        _rl_insert_char (1, c);
     break;

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

  (*rl_redisplay_function) ();
  rl_deactivate_mark ();
  return 1;
}

/* Perform one search according to CXT, using NONINC_SEARCH_STRING, which
   we determine, via a call to noninc_dosearch().
   Return -1 if the search should be aborted, any other value means to clean
   up using _rl_nsearch_cleanup ().
   If the search is not successful, we will restore the original line, so
   make sure we restore rl_point.
   Returns 1 if the search was successful, 0 otherwise. */
static int
_rl_nsearch_dosearch (_rl_search_cxt *cxt)
{
  int r;

  rl_mark = cxt->save_mark;

  /* We're committed to using the contents of rl_line_buffer as the search
     string, whatever they are. We no longer need the undo list generated
     by reading the search string. The old undo list will be restored
     by _rl_unsave_saved_search_line(). */
  rl_free_undo_list ();

  /* 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 == 0)
	{
	  _rl_unsave_saved_search_line ();	/* XXX */
	  rl_ding ();
	  if (cxt->sflags & SF_FREEPMT)
	    rl_restore_prompt ();
	  cxt->sflags &= ~SF_FREEPMT;
	  RL_UNSETSTATE (RL_STATE_NSEARCH);
	  return -1;
	}
    }
  else
    {
      /* We want to start the search from the current history position. */
      noninc_history_pos = cxt->save_line;
      FREE (noninc_search_string);
      noninc_search_string = savestring (rl_line_buffer);

      /* We don't want the subsequent undo list generated by the search
	 matching a history line to include the contents of the search string,
	 so we need to clear rl_line_buffer here. If we don't want that,
	 change the #if 1 to an #if 0 below. */
#if 1
      rl_line_buffer[rl_point = rl_end = 0] = '\0';
#endif
    }

  if (cxt->sflags & SF_FREEPMT)
    rl_restore_prompt ();
  cxt->sflags &= ~SF_FREEPMT;

  /* We are finished using the line buffer to read the search string, restore
     the original contents without doing a redisplay. */
  _rl_unsave_saved_search_line ();		/* XXX */

  r = noninc_dosearch (noninc_search_string, cxt->direction, cxt->sflags&SF_PATTERN);
  if (r == 0)	/* search failed, we will restore the original line */
    rl_point = cxt->save_point;
  return r;
}

/* 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 int
noninc_search (int dir, int pchar)
{
  _rl_search_cxt *cxt;
  int c, r;

  cxt = _rl_nsearch_init (dir, pchar);

  if (RL_ISSTATE (RL_STATE_CALLBACK))
    return (0);

  /* Read the search string. */
  r = 0;
  while (1)
    {
      c = _rl_search_getchar (cxt);

      if (c < 0)
	{
	  _rl_nsearch_abort (cxt);
	  return 1;
	}
	  
      if (c == 0)
	break;

      r = _rl_nsearch_dispatch (cxt, c);
      if (r < 0)
        return 1;
      else if (r == 0)
	break;        
    }

  r = _rl_nsearch_dosearch (cxt);
  return ((r >= 0) ? _rl_nsearch_cleanup (cxt, r) : (r != 1));
}

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

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

/* Search forward through the history list for the last string searched
   for.  If there is no saved search string, abort.  If the vi-mode code
   calls this, KEY will be `N'. */
int
rl_noninc_forward_search_again (int count, int key)
{
  int r, flags;

  if (!noninc_search_string)
    {
      rl_ding ();
      return (1);
    }

  flags = 0;
#if defined (VI_MODE)
  if (VI_COMMAND_MODE() && key == 'N')
    flags = SF_PATTERN;
#endif

  r = noninc_dosearch (noninc_search_string, 1, flags);
  return (r != 1);
}

/* Reverse search in the history list for the last string searched
   for.  If there is no saved search string, abort.  If the vi-mode code
   calls this, KEY will be `n'. */
int
rl_noninc_reverse_search_again (int count, int key)
{
  int r, flags;

  if (!noninc_search_string)
    {
      rl_ding ();
      return (1);
    }

  flags = 0;
#if defined (VI_MODE)
  if (VI_COMMAND_MODE() && key == 'n')
    flags = SF_PATTERN;
#endif

  r = noninc_dosearch (noninc_search_string, -1, flags);
  return (r != 1);
}

#if defined (READLINE_CALLBACKS)
int
_rl_nsearch_callback (_rl_search_cxt *cxt)
{
  int c, r;

  c = _rl_search_getchar (cxt);
  if (c <= 0)
    {
      if (c < 0)
        _rl_nsearch_abort (cxt);
      return 1;
    }
  r = _rl_nsearch_dispatch (cxt, c);
  if (r != 0)
    return 1;

  r = _rl_nsearch_dosearch (cxt);
  return ((r >= 0) ? _rl_nsearch_cleanup (cxt, r) : (r != 1));
}
#endif

/* The strategy is to find the line to move to (COUNT occurrences of
   HISTORY_SEARCH_STRING in direction DIR), then use the same mechanism that
   incremental search uses to move to it. That's wrapped up in
   make_history_line_current(). */    
static int
rl_history_search_internal (int count, int dir)
{
  HIST_ENTRY *temp;
  int ret, oldpos, newcol;
  char *t;

  oldpos = where_history ();	/* where are we now? */
  temp = (HIST_ENTRY *)NULL;

  /* Search COUNT times through the history for a line matching
     history_search_string.  If history_search_string[0] == '^', the
     line must match from the start; otherwise any substring can match.
     When this loop finishes, TEMP, if non-null, is the history line to
     copy into the line buffer. */
  while (count)
    {
      RL_CHECK_SIGNALS ();
      ret = noninc_search_from_pos (history_search_string, _rl_history_search_pos + dir, dir, 0, &newcol);
      if (ret == -1)
	break;

      /* Get the history entry we found. */
      _rl_history_search_pos = ret;
      history_set_pos (_rl_history_search_pos);
      temp = current_history ();	/* will never be NULL after successful search */
      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 without changing history offset */
  if (temp == 0)
    {
      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_unsave_line changes it */
      rl_mark = rl_end;				/* XXX */
#endif
      return 1;
    }

  /* Copy the line we found into the current line buffer. */
  make_history_line_current (oldpos, _rl_history_search_pos);

  /* decide where to put rl_point -- need to change this for pattern search */
  if (_rl_history_search_flags & ANCHORED_SEARCH)
    rl_point = _rl_history_search_len;	/* easy case */
  else
    {
#if 0
      t = strstr (rl_line_buffer, history_search_string);	/* XXX */
      rl_point = t ? (int)(t - rl_line_buffer) + _rl_history_search_len : rl_end;
#else
      rl_point = (newcol >= 0) ? newcol : rl_end;
#endif
    }
  rl_mark = rl_end;

  return 0;
}

static void
rl_history_search_reinit (int flags)
{
  int sind;

  _rl_history_search_pos = where_history ();
  _rl_history_search_len = rl_point;
  _rl_history_search_flags = flags;

  prev_line_found = (char *)NULL;
  if (rl_point)
    {
      /* Allocate enough space for anchored and non-anchored searches */
      if (_rl_history_search_len + 2 >= history_string_size)
	{
	  history_string_size = _rl_history_search_len + 2;
	  history_search_string = (char *)xrealloc (history_search_string, history_string_size);
	}
      sind = 0;
      if (flags & ANCHORED_SEARCH)
	history_search_string[sind++] = '^';
      strncpy (history_search_string + sind, rl_line_buffer, rl_point);
      history_search_string[rl_point + sind] = '\0';
    }
  _rl_free_saved_search_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.  The search is anchored to the beginning of the history line. */
int
rl_history_search_forward (int count, int 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 (ANCHORED_SEARCH);

  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 (int count, int 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 (ANCHORED_SEARCH);

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

/* 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.  The search succeeds if the search string is present anywhere
   in the history line. */
int
rl_history_substr_search_forward (int count, int ignore)
{
  if (count == 0)
    return (0);

  if (rl_last_func != rl_history_substr_search_forward &&
      rl_last_func != rl_history_substr_search_backward)
    rl_history_search_reinit (NON_ANCHORED_SEARCH);

  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_substr_search_backward (int count, int ignore)
{
  if (count == 0)
    return (0);

  if (rl_last_func != rl_history_substr_search_forward &&
      rl_last_func != rl_history_substr_search_backward)
    rl_history_search_reinit (NON_ANCHORED_SEARCH);

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