/*      $OpenBSD: vi.c,v 1.29 2023/03/08 04:43:05 guenther Exp $        */
/*      $NetBSD: vi.c,v 1.33 2011/02/17 16:44:48 joerg Exp $    */

/*-
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Christos Zoulas of Cornell University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "config.h"

/*
 * vi.c: Vi mode commands.
 */
#include <sys/wait.h>
#include <ctype.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "el.h"
#include "common.h"
#include "emacs.h"
#include "fcns.h"
#include "vi.h"

static el_action_t      cv_action(EditLine *, wint_t);
static el_action_t      cv_paste(EditLine *, wint_t);

/* cv_action():
 *      Handle vi actions.
 */
static el_action_t
cv_action(EditLine *el, wint_t c)
{

        if (el->el_chared.c_vcmd.action != NOP) {
                /* 'cc', 'dd' and (possibly) friends */
                if (c != (wint_t)el->el_chared.c_vcmd.action)
                        return CC_ERROR;

                if (!(c & YANK))
                        cv_undo(el);
                cv_yank(el, el->el_line.buffer,
                    (int)(el->el_line.lastchar - el->el_line.buffer));
                el->el_chared.c_vcmd.action = NOP;
                el->el_chared.c_vcmd.pos = 0;
                if (!(c & YANK)) {
                        el->el_line.lastchar = el->el_line.buffer;
                        el->el_line.cursor = el->el_line.buffer;
                }
                if (c & INSERT)
                        el->el_map.current = el->el_map.key;

                return CC_REFRESH;
        }
        el->el_chared.c_vcmd.pos = el->el_line.cursor;
        el->el_chared.c_vcmd.action = c;
        return CC_ARGHACK;
}

/* cv_paste():
 *      Paste previous deletion before or after the cursor
 */
static el_action_t
cv_paste(EditLine *el, wint_t c)
{
        c_kill_t *k = &el->el_chared.c_kill;
        size_t len = (size_t)(k->last - k->buf);

        if (k->buf == NULL || len == 0)
                return CC_ERROR;
#ifdef DEBUG_PASTE
        (void) fprintf(el->el_errfile, "Paste: \"%.*ls\"\n", (int)len,
            k->buf);
#endif

        cv_undo(el);

        if (!c && el->el_line.cursor < el->el_line.lastchar)
                el->el_line.cursor++;

        c_insert(el, (int)len);
        if (el->el_line.cursor + len > el->el_line.lastchar)
                return CC_ERROR;
        (void) memcpy(el->el_line.cursor, k->buf, len *
            sizeof(*el->el_line.cursor));

        return CC_REFRESH;
}


/* vi_paste_next():
 *      Vi paste previous deletion to the right of the cursor
 *      [p]
 */
protected el_action_t
vi_paste_next(EditLine *el, wint_t c __attribute__((__unused__)))
{

        return cv_paste(el, 0);
}


/* vi_paste_prev():
 *      Vi paste previous deletion to the left of the cursor
 *      [P]
 */
protected el_action_t
vi_paste_prev(EditLine *el, wint_t c __attribute__((__unused__)))
{

        return cv_paste(el, 1);
}


/* vi_prev_big_word():
 *      Vi move to the previous space delimited word
 *      [B]
 */
protected el_action_t
vi_prev_big_word(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_line.cursor == el->el_line.buffer)
                return CC_ERROR;

        el->el_line.cursor = cv_prev_word(el->el_line.cursor,
            el->el_line.buffer,
            el->el_state.argument,
            cv__isWord);

        if (el->el_chared.c_vcmd.action != NOP) {
                cv_delfini(el);
                return CC_REFRESH;
        }
        return CC_CURSOR;
}


/* vi_prev_word():
 *      Vi move to the previous word
 *      [b]
 */
protected el_action_t
vi_prev_word(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_line.cursor == el->el_line.buffer)
                return CC_ERROR;

        el->el_line.cursor = cv_prev_word(el->el_line.cursor,
            el->el_line.buffer,
            el->el_state.argument,
            cv__isword);

        if (el->el_chared.c_vcmd.action != NOP) {
                cv_delfini(el);
                return CC_REFRESH;
        }
        return CC_CURSOR;
}


/* vi_next_big_word():
 *      Vi move to the next space delimited word
 *      [W]
 */
protected el_action_t
vi_next_big_word(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_line.cursor >= el->el_line.lastchar - 1)
                return CC_ERROR;

        el->el_line.cursor = cv_next_word(el, el->el_line.cursor,
            el->el_line.lastchar, el->el_state.argument, cv__isWord);

        if (el->el_map.type == MAP_VI)
                if (el->el_chared.c_vcmd.action != NOP) {
                        cv_delfini(el);
                        return CC_REFRESH;
                }
        return CC_CURSOR;
}


/* vi_next_word():
 *      Vi move to the next word
 *      [w]
 */
protected el_action_t
vi_next_word(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_line.cursor >= el->el_line.lastchar - 1)
                return CC_ERROR;

        el->el_line.cursor = cv_next_word(el, el->el_line.cursor,
            el->el_line.lastchar, el->el_state.argument, cv__isword);

        if (el->el_map.type == MAP_VI)
                if (el->el_chared.c_vcmd.action != NOP) {
                        cv_delfini(el);
                        return CC_REFRESH;
                }
        return CC_CURSOR;
}


/* vi_change_case():
 *      Vi change case of character under the cursor and advance one character
 *      [~]
 */
protected el_action_t
vi_change_case(EditLine *el, wint_t c)
{
        int i;

        if (el->el_line.cursor >= el->el_line.lastchar)
                return CC_ERROR;
        cv_undo(el);
        for (i = 0; i < el->el_state.argument; i++) {

                c = *el->el_line.cursor;
                if (iswupper(c))
                        *el->el_line.cursor = towlower(c);
                else if (iswlower(c))
                        *el->el_line.cursor = towupper(c);

                if (++el->el_line.cursor >= el->el_line.lastchar) {
                        el->el_line.cursor--;
                        re_fastaddc(el);
                        break;
                }
                re_fastaddc(el);
        }
        return CC_NORM;
}


/* vi_change_meta():
 *      Vi change prefix command
 *      [c]
 */
protected el_action_t
vi_change_meta(EditLine *el, wint_t c __attribute__((__unused__)))
{

        /*
         * Delete with insert == change: first we delete and then we leave in
         * insert mode.
         */
        return cv_action(el, DELETE | INSERT);
}


/* vi_insert_at_bol():
 *      Vi enter insert mode at the beginning of line
 *      [I]
 */
protected el_action_t
vi_insert_at_bol(EditLine *el, wint_t c __attribute__((__unused__)))
{

        el->el_line.cursor = el->el_line.buffer;
        cv_undo(el);
        el->el_map.current = el->el_map.key;
        return CC_CURSOR;
}


/* vi_replace_char():
 *      Vi replace character under the cursor with the next character typed
 *      [r]
 */
protected el_action_t
vi_replace_char(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_line.cursor >= el->el_line.lastchar)
                return CC_ERROR;

        el->el_map.current = el->el_map.key;
        el->el_state.inputmode = MODE_REPLACE_1;
        cv_undo(el);
        return CC_ARGHACK;
}


/* vi_replace_mode():
 *      Vi enter replace mode
 *      [R]
 */
protected el_action_t
vi_replace_mode(EditLine *el, wint_t c __attribute__((__unused__)))
{

        el->el_map.current = el->el_map.key;
        el->el_state.inputmode = MODE_REPLACE;
        cv_undo(el);
        return CC_NORM;
}


/* vi_substitute_char():
 *      Vi replace character under the cursor and enter insert mode
 *      [s]
 */
protected el_action_t
vi_substitute_char(EditLine *el, wint_t c __attribute__((__unused__)))
{

        c_delafter(el, el->el_state.argument);
        el->el_map.current = el->el_map.key;
        return CC_REFRESH;
}


/* vi_substitute_line():
 *      Vi substitute entire line
 *      [S]
 */
protected el_action_t
vi_substitute_line(EditLine *el, wint_t c __attribute__((__unused__)))
{

        cv_undo(el);
        cv_yank(el, el->el_line.buffer,
            (int)(el->el_line.lastchar - el->el_line.buffer));
        (void) em_kill_line(el, 0);
        el->el_map.current = el->el_map.key;
        return CC_REFRESH;
}


/* vi_change_to_eol():
 *      Vi change to end of line
 *      [C]
 */
protected el_action_t
vi_change_to_eol(EditLine *el, wint_t c __attribute__((__unused__)))
{

        cv_undo(el);
        cv_yank(el, el->el_line.cursor,
            (int)(el->el_line.lastchar - el->el_line.cursor));
        (void) ed_kill_line(el, 0);
        el->el_map.current = el->el_map.key;
        return CC_REFRESH;
}


/* vi_insert():
 *      Vi enter insert mode
 *      [i]
 */
protected el_action_t
vi_insert(EditLine *el, wint_t c __attribute__((__unused__)))
{

        el->el_map.current = el->el_map.key;
        cv_undo(el);
        return CC_NORM;
}


/* vi_add():
 *      Vi enter insert mode after the cursor
 *      [a]
 */
protected el_action_t
vi_add(EditLine *el, wint_t c __attribute__((__unused__)))
{
        int ret;

        el->el_map.current = el->el_map.key;
        if (el->el_line.cursor < el->el_line.lastchar) {
                el->el_line.cursor++;
                if (el->el_line.cursor > el->el_line.lastchar)
                        el->el_line.cursor = el->el_line.lastchar;
                ret = CC_CURSOR;
        } else
                ret = CC_NORM;

        cv_undo(el);

        return ret;
}


/* vi_add_at_eol():
 *      Vi enter insert mode at end of line
 *      [A]
 */
protected el_action_t
vi_add_at_eol(EditLine *el, wint_t c __attribute__((__unused__)))
{

        el->el_map.current = el->el_map.key;
        el->el_line.cursor = el->el_line.lastchar;
        cv_undo(el);
        return CC_CURSOR;
}


/* vi_delete_meta():
 *      Vi delete prefix command
 *      [d]
 */
protected el_action_t
vi_delete_meta(EditLine *el, wint_t c __attribute__((__unused__)))
{

        return cv_action(el, DELETE);
}


/* vi_end_big_word():
 *      Vi move to the end of the current space delimited word
 *      [E]
 */
protected el_action_t
vi_end_big_word(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_line.cursor == el->el_line.lastchar)
                return CC_ERROR;

        el->el_line.cursor = cv__endword(el->el_line.cursor,
            el->el_line.lastchar, el->el_state.argument, cv__isWord);

        if (el->el_chared.c_vcmd.action != NOP) {
                el->el_line.cursor++;
                cv_delfini(el);
                return CC_REFRESH;
        }
        return CC_CURSOR;
}


/* vi_end_word():
 *      Vi move to the end of the current word
 *      [e]
 */
protected el_action_t
vi_end_word(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_line.cursor == el->el_line.lastchar)
                return CC_ERROR;

        el->el_line.cursor = cv__endword(el->el_line.cursor,
            el->el_line.lastchar, el->el_state.argument, cv__isword);

        if (el->el_chared.c_vcmd.action != NOP) {
                el->el_line.cursor++;
                cv_delfini(el);
                return CC_REFRESH;
        }
        return CC_CURSOR;
}


/* vi_undo():
 *      Vi undo last change
 *      [u]
 */
protected el_action_t
vi_undo(EditLine *el, wint_t c __attribute__((__unused__)))
{
        c_undo_t un = el->el_chared.c_undo;

        if (un.len == -1)
                return CC_ERROR;

        /* switch line buffer and undo buffer */
        el->el_chared.c_undo.buf = el->el_line.buffer;
        el->el_chared.c_undo.len = el->el_line.lastchar - el->el_line.buffer;
        el->el_chared.c_undo.cursor =
            (int)(el->el_line.cursor - el->el_line.buffer);
        el->el_line.limit = un.buf + (el->el_line.limit - el->el_line.buffer);
        el->el_line.buffer = un.buf;
        el->el_line.cursor = un.buf + un.cursor;
        el->el_line.lastchar = un.buf + un.len;

        return CC_REFRESH;
}


/* vi_command_mode():
 *      Vi enter command mode (use alternative key bindings)
 *      [<ESC>]
 */
protected el_action_t
vi_command_mode(EditLine *el, wint_t c __attribute__((__unused__)))
{

        /* [Esc] cancels pending action */
        el->el_chared.c_vcmd.action = NOP;
        el->el_chared.c_vcmd.pos = 0;

        el->el_state.doingarg = 0;

        el->el_state.inputmode = MODE_INSERT;
        el->el_map.current = el->el_map.alt;
#ifdef VI_MOVE
        if (el->el_line.cursor > el->el_line.buffer)
                el->el_line.cursor--;
#endif
        return CC_CURSOR;
}


/* vi_zero():
 *      Vi move to the beginning of line
 *      [0]
 */
protected el_action_t
vi_zero(EditLine *el, wint_t c)
{

        if (el->el_state.doingarg)
                return ed_argument_digit(el, c);

        el->el_line.cursor = el->el_line.buffer;
        if (el->el_chared.c_vcmd.action != NOP) {
                cv_delfini(el);
                return CC_REFRESH;
        }
        return CC_CURSOR;
}


/* vi_delete_prev_char():
 *      Vi move to previous character (backspace)
 *      [^H] in insert mode only
 */
protected el_action_t
vi_delete_prev_char(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_line.cursor <= el->el_line.buffer)
                return CC_ERROR;

        c_delbefore1(el);
        el->el_line.cursor--;
        return CC_REFRESH;
}


/* vi_list_or_eof():
 *      Vi list choices for completion or indicate end of file if empty line
 *      [^D]
 */
protected el_action_t
vi_list_or_eof(EditLine *el, wint_t c)
{

        if (el->el_line.cursor == el->el_line.lastchar) {
                if (el->el_line.cursor == el->el_line.buffer) {
                        terminal_writec(el, c); /* then do a EOF */
                        return CC_EOF;
                } else {
                        /*
                         * Here we could list completions, but it is an
                         * error right now
                         */
                        terminal_beep(el);
                        return CC_ERROR;
                }
        } else {
#ifdef notyet
                re_goto_bottom(el);
                *el->el_line.lastchar = '\0';   /* just in case */
                return CC_LIST_CHOICES;
#else
                /*
                 * Just complain for now.
                 */
                terminal_beep(el);
                return CC_ERROR;
#endif
        }
}


/* vi_kill_line_prev():
 *      Vi cut from beginning of line to cursor
 *      [^U]
 */
protected el_action_t
vi_kill_line_prev(EditLine *el, wint_t c __attribute__((__unused__)))
{
        wchar_t *kp, *cp;

        cp = el->el_line.buffer;
        kp = el->el_chared.c_kill.buf;
        while (cp < el->el_line.cursor)
                *kp++ = *cp++;  /* copy it */
        el->el_chared.c_kill.last = kp;
        c_delbefore(el, (int)(el->el_line.cursor - el->el_line.buffer));
        el->el_line.cursor = el->el_line.buffer;        /* zap! */
        return CC_REFRESH;
}


/* vi_search_prev():
 *      Vi search history previous
 *      [?]
 */
protected el_action_t
vi_search_prev(EditLine *el, wint_t c __attribute__((__unused__)))
{

        return cv_search(el, ED_SEARCH_PREV_HISTORY);
}


/* vi_search_next():
 *      Vi search history next
 *      [/]
 */
protected el_action_t
vi_search_next(EditLine *el, wint_t c __attribute__((__unused__)))
{

        return cv_search(el, ED_SEARCH_NEXT_HISTORY);
}


/* vi_repeat_search_next():
 *      Vi repeat current search in the same search direction
 *      [n]
 */
protected el_action_t
vi_repeat_search_next(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_search.patlen == 0)
                return CC_ERROR;
        else
                return cv_repeat_srch(el, el->el_search.patdir);
}


/* vi_repeat_search_prev():
 *      Vi repeat current search in the opposite search direction
 *      [N]
 */
protected el_action_t
vi_repeat_search_prev(EditLine *el, wint_t c __attribute__((__unused__)))
{

        if (el->el_search.patlen == 0)
                return CC_ERROR;
        else
                return (cv_repeat_srch(el,
                    el->el_search.patdir == ED_SEARCH_PREV_HISTORY ?
                    ED_SEARCH_NEXT_HISTORY : ED_SEARCH_PREV_HISTORY));
}


/* vi_next_char():
 *      Vi move to the character specified next
 *      [f]
 */
protected el_action_t
vi_next_char(EditLine *el, wint_t c __attribute__((__unused__)))
{
        return cv_csearch(el, CHAR_FWD, -1, el->el_state.argument, 0);
}


/* vi_prev_char():
 *      Vi move to the character specified previous
 *      [F]
 */
protected el_action_t
vi_prev_char(EditLine *el, wint_t c __attribute__((__unused__)))
{
        return cv_csearch(el, CHAR_BACK, -1, el->el_state.argument, 0);
}


/* vi_to_next_char():
 *      Vi move up to the character specified next
 *      [t]
 */
protected el_action_t
vi_to_next_char(EditLine *el, wint_t c __attribute__((__unused__)))
{
        return cv_csearch(el, CHAR_FWD, -1, el->el_state.argument, 1);
}


/* vi_to_prev_char():
 *      Vi move up to the character specified previous
 *      [T]
 */
protected el_action_t
vi_to_prev_char(EditLine *el, wint_t c __attribute__((__unused__)))
{
        return cv_csearch(el, CHAR_BACK, -1, el->el_state.argument, 1);
}


/* vi_repeat_next_char():
 *      Vi repeat current character search in the same search direction
 *      [;]
 */
protected el_action_t
vi_repeat_next_char(EditLine *el, wint_t c __attribute__((__unused__)))
{

        return cv_csearch(el, el->el_search.chadir, el->el_search.chacha,
                el->el_state.argument, el->el_search.chatflg);
}


/* vi_repeat_prev_char():
 *      Vi repeat current character search in the opposite search direction
 *      [,]
 */
protected el_action_t
vi_repeat_prev_char(EditLine *el, wint_t c __attribute__((__unused__)))
{
        el_action_t r;
        int dir = el->el_search.chadir;

        r = cv_csearch(el, -dir, el->el_search.chacha,
                el->el_state.argument, el->el_search.chatflg);
        el->el_search.chadir = dir;
        return r;
}


/* vi_match():
 *      Vi go to matching () {} or []
 *      [%]
 */
protected el_action_t
vi_match(EditLine *el, wint_t c __attribute__((__unused__)))
{
        const wchar_t match_chars[] = L"()[]{}";
        wchar_t *cp;
        size_t delta, i, count;
        wchar_t o_ch, c_ch;

        *el->el_line.lastchar = '\0';           /* just in case */

        i = wcscspn(el->el_line.cursor, match_chars);
        o_ch = el->el_line.cursor[i];
        if (o_ch == 0)
                return CC_ERROR;
        delta = wcschr(match_chars, o_ch) - match_chars;
        c_ch = match_chars[delta ^ 1];
        count = 1;
        delta = 1 - (delta & 1) * 2;

        for (cp = &el->el_line.cursor[i]; count; ) {
                cp += delta;
                if (cp < el->el_line.buffer || cp >= el->el_line.lastchar)
                        return CC_ERROR;
                if (*cp == o_ch)
                        count++;
                else if (*cp == c_ch)
                        count--;
        }

        el->el_line.cursor = cp;

        if (el->el_chared.c_vcmd.action != NOP) {
                /* NB posix says char under cursor should NOT be deleted
                   for -ve delta - this is different to netbsd vi. */
                if (delta > 0)
                        el->el_line.cursor++;
                cv_delfini(el);
                return CC_REFRESH;
        }
        return CC_CURSOR;
}

/* vi_undo_line():
 *      Vi undo all changes to line
 *      [U]
 */
protected el_action_t
vi_undo_line(EditLine *el, wint_t c __attribute__((__unused__)))
{

        cv_undo(el);
        return hist_get(el);
}

/* vi_to_column():
 *      Vi go to specified column
 *      [|]
 * NB netbsd vi goes to screen column 'n', posix says nth character
 */
protected el_action_t
vi_to_column(EditLine *el, wint_t c __attribute__((__unused__)))
{

        el->el_line.cursor = el->el_line.buffer;
        el->el_state.argument--;
        return ed_next_char(el, 0);
}

/* vi_yank_end():
 *      Vi yank to end of line
 *      [Y]
 */
protected el_action_t
vi_yank_end(EditLine *el, wint_t c __attribute__((__unused__)))
{

        cv_yank(el, el->el_line.cursor,
            (int)(el->el_line.lastchar - el->el_line.cursor));
        return CC_REFRESH;
}

/* vi_yank():
 *      Vi yank
 *      [y]
 */
protected el_action_t
vi_yank(EditLine *el, wint_t c __attribute__((__unused__)))
{

        return cv_action(el, YANK);
}

/* vi_comment_out():
 *      Vi comment out current command
 *      [#]
 */
protected el_action_t
vi_comment_out(EditLine *el, wint_t c __attribute__((__unused__)))
{

        el->el_line.cursor = el->el_line.buffer;
        c_insert(el, 1);
        *el->el_line.cursor = '#';
        re_refresh(el);
        return ed_newline(el, 0);
}

/* vi_alias():
 *      Vi include shell alias
 *      [@]
 * NB: posix implies that we should enter insert mode, however
 * this is against historical precedent...
 */
#ifdef __weak_reference
__weakref_visible char *my_get_alias_text(const char *)
    __weak_reference(get_alias_text);
#endif
protected el_action_t
vi_alias(EditLine *el, wint_t c __attribute__((__unused__)))
{
#ifdef __weak_reference
        char alias_name[3];
        char *alias_text;

        if (my_get_alias_text == 0) {
                return CC_ERROR;
        }

        alias_name[0] = '_';
        alias_name[2] = 0;
        if (el_getc(el, &alias_name[1]) != 1)
                return CC_ERROR;

        alias_text = my_get_alias_text(alias_name);
        if (alias_text != NULL)
                el_wpush(el, ct_decode_string(alias_text, &el->el_scratch));
        return CC_NORM;
#else
        return CC_ERROR;
#endif
}

/* vi_to_history_line():
 *      Vi go to specified history file line.
 *      [G]
 */
protected el_action_t
vi_to_history_line(EditLine *el, wint_t c __attribute__((__unused__)))
{
        int sv_event_no = el->el_history.eventno;
        el_action_t rval;


        if (el->el_history.eventno == 0) {
                 (void) wcsncpy(el->el_history.buf, el->el_line.buffer,
                     EL_BUFSIZ);
                 el->el_history.last = el->el_history.buf +
                         (el->el_line.lastchar - el->el_line.buffer);
        }

        /* Lack of a 'count' means oldest, not 1 */
        if (!el->el_state.doingarg) {
                el->el_history.eventno = 0x7fffffff;
                hist_get(el);
        } else {
                /* This is brain dead, all the rest of this code counts
                 * upwards going into the past.  Here we need count in the
                 * other direction (to match the output of fc -l).
                 * I could change the world, but this seems to suffice.
                 */
                el->el_history.eventno = 1;
                if (hist_get(el) == CC_ERROR)
                        return CC_ERROR;
                el->el_history.eventno = 1 + el->el_history.ev.num
                                        - el->el_state.argument;
                if (el->el_history.eventno < 0) {
                        el->el_history.eventno = sv_event_no;
                        return CC_ERROR;
                }
        }
        rval = hist_get(el);
        if (rval == CC_ERROR)
                el->el_history.eventno = sv_event_no;
        return rval;
}

/* vi_histedit():
 *      Vi edit history line with vi
 *      [v]
 */
protected el_action_t
vi_histedit(EditLine *el, wint_t c __attribute__((__unused__)))
{
        int fd;
        pid_t pid;
        ssize_t st;
        int status;
        char tempfile[] = "/tmp/histedit.XXXXXXXXXX";
        char *cp;
        size_t len;
        wchar_t *line;

        if (el->el_state.doingarg) {
                if (vi_to_history_line(el, 0) == CC_ERROR)
                        return CC_ERROR;
        }

        fd = mkstemp(tempfile);
        if (fd == -1)
                return CC_ERROR;
        len = (size_t)(el->el_line.lastchar - el->el_line.buffer);
#define TMP_BUFSIZ (EL_BUFSIZ * MB_LEN_MAX)
        cp = malloc(TMP_BUFSIZ);
        if (cp == NULL) {
                close(fd);
                unlink(tempfile);
                return CC_ERROR;
        }
        line = reallocarray(NULL, len + 1, sizeof(*line));
        if (line == NULL) {
                close(fd);
                unlink(tempfile);
                free(cp);
                return CC_ERROR;
        }
        wcsncpy(line, el->el_line.buffer, len);
        line[len] = '\0';
        wcstombs(cp, line, TMP_BUFSIZ - 1);
        cp[TMP_BUFSIZ - 1] = '\0';
        len = strlen(cp);
        write(fd, cp, len);
        write(fd, "\n", 1);
        pid = fork();
        switch (pid) {
        case -1:
                close(fd);
                unlink(tempfile);
                free(cp);
                free(line);
                return CC_ERROR;
        case 0:
                close(fd);
                execlp("vi", "vi", tempfile, (char *)NULL);
                exit(0);
                /*NOTREACHED*/
        default:
                while (waitpid(pid, &status, 0) != pid)
                        continue;
                lseek(fd, (off_t)0, SEEK_SET);
                st = read(fd, cp, TMP_BUFSIZ - 1);
                if (st > 0) {
                        cp[st] = '\0';
                        len = (size_t)(el->el_line.limit - el->el_line.buffer);
                        len = mbstowcs(el->el_line.buffer, cp, len);
                        if (len > 0 && el->el_line.buffer[len - 1] == '\n')
                                --len;
                }
                else
                        len = 0;
                el->el_line.cursor = el->el_line.buffer;
                el->el_line.lastchar = el->el_line.buffer + len;
                free(cp);
                free(line);
                break;
        }

        close(fd);
        unlink(tempfile);
        /* return CC_REFRESH; */
        return ed_newline(el, 0);
}

/* vi_history_word():
 *      Vi append word from previous input line
 *      [_]
 * Who knows where this one came from!
 * '_' in vi means 'entire current line', so 'cc' is a synonym for 'c_'
 */
protected el_action_t
vi_history_word(EditLine *el, wint_t c __attribute__((__unused__)))
{
        const wchar_t *wp = HIST_FIRST(el);
        const wchar_t *wep, *wsp;
        int len;
        wchar_t *cp;
        const wchar_t *lim;

        if (wp == NULL)
                return CC_ERROR;

        wep = wsp = NULL;
        do {
                while (iswspace(*wp))
                        wp++;
                if (*wp == 0)
                        break;
                wsp = wp;
                while (*wp && !iswspace(*wp))
                        wp++;
                wep = wp;
        } while ((!el->el_state.doingarg || --el->el_state.argument > 0)
            && *wp != 0);

        if (wsp == NULL || (el->el_state.doingarg && el->el_state.argument != 0))
                return CC_ERROR;

        cv_undo(el);
        len = (int)(wep - wsp);
        if (el->el_line.cursor < el->el_line.lastchar)
                el->el_line.cursor++;
        c_insert(el, len + 1);
        cp = el->el_line.cursor;
        lim = el->el_line.limit;
        if (cp < lim)
                *cp++ = ' ';
        while (wsp < wep && cp < lim)
                *cp++ = *wsp++;
        el->el_line.cursor = cp;

        el->el_map.current = el->el_map.key;
        return CC_REFRESH;
}

/* vi_redo():
 *      Vi redo last non-motion command
 *      [.]
 */
protected el_action_t
vi_redo(EditLine *el, wint_t c __attribute__((__unused__)))
{
        c_redo_t *r = &el->el_chared.c_redo;

        if (!el->el_state.doingarg && r->count) {
                el->el_state.doingarg = 1;
                el->el_state.argument = r->count;
        }

        el->el_chared.c_vcmd.pos = el->el_line.cursor;
        el->el_chared.c_vcmd.action = r->action;
        if (r->pos != r->buf) {
                if (r->pos + 1 > r->lim)
                        /* sanity */
                        r->pos = r->lim - 1;
                r->pos[0] = 0;
                el_wpush(el, r->buf);
        }

        el->el_state.thiscmd = r->cmd;
        el->el_state.thisch = r->ch;
        return (*el->el_map.func[r->cmd])(el, r->ch);
}