/*      $OpenBSD: v_itxt.c,v 1.8 2014/11/12 04:28:41 bentley Exp $      */

/*-
 * Copyright (c) 1992, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *      Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/time.h>

#include <bitstring.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../common/common.h"
#include "vi.h"

/*
 * !!!
 * Repeated input in the historic vi is mostly wrong and this isn't very
 * backward compatible.  For example, if the user entered "3Aab\ncd" in
 * the historic vi, the "ab" was repeated 3 times, and the "\ncd" was then
 * appended to the result.  There was also a hack which I don't remember
 * right now, where "3o" would open 3 lines and then let the user fill them
 * in, to make screen movements on 300 baud modems more tolerable.  I don't
 * think it's going to be missed.
 *
 * !!!
 * There's a problem with the way that we do logging for change commands with
 * implied motions (e.g. A, I, O, cc, etc.).  Since the main vi loop logs the
 * starting cursor position before the change command "moves" the cursor, the
 * cursor position to which we return on undo will be where the user entered
 * the change command, not the start of the change.  Several of the following
 * routines re-log the cursor to make this work correctly.  Historic vi tried
 * to do the same thing, and mostly got it right.  (The only spectacular way
 * it fails is if the user entered 'o' from anywhere but the last character of
 * the line, the undo returned the cursor to the start of the line.  If the
 * user was on the last character of the line, the cursor returned to that
 * position.)  We also check for mapped keys waiting, i.e. if we're in the
 * middle of a map, don't bother logging the cursor.
 */
#define LOG_CORRECT {                                                   \
        if (!MAPPED_KEYS_WAITING(sp))                                   \
                (void)log_cursor(sp);                                   \
}

static u_int32_t set_txt_std(SCR *, VICMD *, u_int32_t);

/*
 * v_iA -- [count]A
 *      Append text to the end of the line.
 *
 * PUBLIC: int v_iA(SCR *, VICMD *);
 */
int
v_iA(SCR *sp, VICMD *vp)
{
        size_t len;

        if (!db_get(sp, vp->m_start.lno, 0, NULL, &len))
                sp->cno = len == 0 ? 0 : len - 1;

        LOG_CORRECT;

        return (v_ia(sp, vp));
}

/*
 * v_ia -- [count]a
 *         [count]A
 *      Append text to the cursor position.
 *
 * PUBLIC: int v_ia(SCR *, VICMD *);
 */
int
v_ia(SCR *sp, VICMD *vp)
{
        size_t len;
        u_int32_t flags;
        int isempty;
        char *p;

        flags = set_txt_std(sp, vp, 0);
        sp->showmode = SM_APPEND;
        sp->lno = vp->m_start.lno;

        /* Move the cursor one column to the right and repaint the screen. */
        if (db_eget(sp, sp->lno, &p, &len, &isempty)) {
                if (!isempty)
                        return (1);
                len = 0;
                LF_SET(TXT_APPENDEOL);
        } else if (len) {
                if (len == sp->cno + 1) {
                        sp->cno = len;
                        LF_SET(TXT_APPENDEOL);
                } else
                        ++sp->cno;
        } else
                LF_SET(TXT_APPENDEOL);

        return (v_txt(sp, vp, NULL, p, len,
            0, OOBLNO, F_ISSET(vp, VC_C1SET) ? vp->count : 1, flags));
}

/*
 * v_iI -- [count]I
 *      Insert text at the first nonblank.
 *
 * PUBLIC: int v_iI(SCR *, VICMD *);
 */
int
v_iI(SCR *sp, VICMD *vp)
{
        sp->cno = 0;
        if (nonblank(sp, vp->m_start.lno, &sp->cno))
                return (1);

        LOG_CORRECT;

        return (v_ii(sp, vp));
}

/*
 * v_ii -- [count]i
 *         [count]I
 *      Insert text at the cursor position.
 *
 * PUBLIC: int v_ii(SCR *, VICMD *);
 */
int
v_ii(SCR *sp, VICMD *vp)
{
        size_t len;
        u_int32_t flags;
        int isempty;
        char *p;

        flags = set_txt_std(sp, vp, 0);
        sp->showmode = SM_INSERT;
        sp->lno = vp->m_start.lno;

        if (db_eget(sp, sp->lno, &p, &len, &isempty)) {
                if (!isempty)
                        return (1);
                len = 0;
        }

        if (len == 0)
                LF_SET(TXT_APPENDEOL);
        return (v_txt(sp, vp, NULL, p, len,
            0, OOBLNO, F_ISSET(vp, VC_C1SET) ? vp->count : 1, flags));
}

enum which { o_cmd, O_cmd };
static int io(SCR *, VICMD *, enum which);

/*
 * v_iO -- [count]O
 *      Insert text above this line.
 *
 * PUBLIC: int v_iO(SCR *, VICMD *);
 */
int
v_iO(SCR *sp, VICMD *vp)
{
        return (io(sp, vp, O_cmd));
}

/*
 * v_io -- [count]o
 *      Insert text after this line.
 *
 * PUBLIC: int v_io(SCR *, VICMD *);
 */
int
v_io(SCR *sp, VICMD *vp)
{
        return (io(sp, vp, o_cmd));
}

static int
io(SCR *sp, VICMD *vp, enum which cmd)
{
        recno_t ai_line, lno;
        size_t len;
        u_int32_t flags;
        char *p;

        flags = set_txt_std(sp, vp, TXT_ADDNEWLINE | TXT_APPENDEOL);
        sp->showmode = SM_INSERT;

        if (sp->lno == 1) {
                if (db_last(sp, &lno))
                        return (1);
                if (lno != 0)
                        goto insert;
                p = NULL;
                len = 0;
                ai_line = OOBLNO;
        } else {
insert:         p = "";
                sp->cno = 0;
                LOG_CORRECT;

                if (cmd == O_cmd) {
                        if (db_insert(sp, sp->lno, p, 0))
                                return (1);
                        if (db_get(sp, sp->lno, DBG_FATAL, &p, &len))
                                return (1);
                        ai_line = sp->lno + 1;
                } else {
                        if (db_append(sp, 1, sp->lno, p, 0))
                                return (1);
                        if (db_get(sp, ++sp->lno, DBG_FATAL, &p, &len))
                                return (1);
                        ai_line = sp->lno - 1;
                }
        }
        return (v_txt(sp, vp, NULL, p, len,
            0, ai_line, F_ISSET(vp, VC_C1SET) ? vp->count : 1, flags));
}

/*
 * v_change -- [buffer][count]c[count]motion
 *             [buffer][count]C
 *             [buffer][count]S
 *      Change command.
 *
 * PUBLIC: int v_change(SCR *, VICMD *);
 */
int
v_change(SCR *sp, VICMD *vp)
{
        size_t blen, len;
        u_int32_t flags;
        int isempty, lmode, rval;
        char *bp, *p;

        /*
         * 'c' can be combined with motion commands that set the resulting
         * cursor position, i.e. "cG".  Clear the VM_RCM flags and make the
         * resulting cursor position stick, inserting text has its own rules
         * for cursor positioning.
         */
        F_CLR(vp, VM_RCM_MASK);
        F_SET(vp, VM_RCM_SET);

        /*
         * Find out if the file is empty, it's easier to handle it as a
         * special case.
         */
        if (vp->m_start.lno == vp->m_stop.lno &&
            db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
                if (!isempty)
                        return (1);
                return (v_ia(sp, vp));
        }

        flags = set_txt_std(sp, vp, 0);
        sp->showmode = SM_CHANGE;

        /*
         * Move the cursor to the start of the change.  Note, if autoindent
         * is turned on, the cc command in line mode changes from the first
         * *non-blank* character of the line, not the first character.  And,
         * to make it just a bit more exciting, the initial space is handled
         * as auto-indent characters.
         */
        lmode = F_ISSET(vp, VM_LMODE) ? CUT_LINEMODE : 0;
        if (lmode) {
                vp->m_start.cno = 0;
                if (O_ISSET(sp, O_AUTOINDENT)) {
                        if (nonblank(sp, vp->m_start.lno, &vp->m_start.cno))
                                return (1);
                        LF_SET(TXT_AICHARS);
                }
        }
        sp->lno = vp->m_start.lno;
        sp->cno = vp->m_start.cno;

        LOG_CORRECT;

        /*
         * If not in line mode and changing within a single line, copy the
         * text and overwrite it.
         */
        if (!lmode && vp->m_start.lno == vp->m_stop.lno) {
                /*
                 * !!!
                 * Historic practice, c did not cut into the numeric buffers,
                 * only the unnamed one.
                 */
                if (cut(sp,
                    F_ISSET(vp, VC_BUFFER) ? &vp->buffer : NULL,
                    &vp->m_start, &vp->m_stop, lmode))
                        return (1);
                if (len == 0)
                        LF_SET(TXT_APPENDEOL);
                LF_SET(TXT_EMARK | TXT_OVERWRITE);
                return (v_txt(sp, vp, &vp->m_stop, p, len,
                    0, OOBLNO, F_ISSET(vp, VC_C1SET) ? vp->count : 1, flags));
        }

        /*
         * It's trickier if in line mode or changing over multiple lines.  If
         * we're in line mode delete all of the lines and insert a replacement
         * line which the user edits.  If there was leading whitespace in the
         * first line being changed, we copy it and use it as the replacement.
         * If we're not in line mode, we delete the text and start inserting.
         *
         * !!!
         * Copy the text.  Historic practice, c did not cut into the numeric
         * buffers, only the unnamed one.
         */
        if (cut(sp,
            F_ISSET(vp, VC_BUFFER) ? &vp->buffer : NULL,
            &vp->m_start, &vp->m_stop, lmode))
                return (1);

        /* If replacing entire lines and there's leading text. */
        if (lmode && vp->m_start.cno) {
                /*
                 * Get a copy of the first line changed, and copy out the
                 * leading text.
                 */
                if (db_get(sp, vp->m_start.lno, DBG_FATAL, &p, &len))
                        return (1);
                GET_SPACE_RET(sp, bp, blen, vp->m_start.cno);
                memmove(bp, p, vp->m_start.cno);
        } else
                bp = NULL;

        /* Delete the text. */
        if (del(sp, &vp->m_start, &vp->m_stop, lmode))
                return (1);

        /* If replacing entire lines, insert a replacement line. */
        if (lmode) {
                if (db_insert(sp, vp->m_start.lno, bp, vp->m_start.cno))
                        return (1);
                sp->lno = vp->m_start.lno;
                len = sp->cno = vp->m_start.cno;
        }

        /* Get the line we're editing. */
        if (db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
                if (!isempty)
                        return (1);
                len = 0;
        }

        /* Check to see if we're appending to the line. */
        if (vp->m_start.cno >= len)
                LF_SET(TXT_APPENDEOL);

        rval = v_txt(sp, vp, NULL, p, len,
            0, OOBLNO, F_ISSET(vp, VC_C1SET) ? vp->count : 1, flags);

        if (bp != NULL)
                FREE_SPACE(sp, bp, blen);
        return (rval);
}

/*
 * v_Replace -- [count]R
 *      Overwrite multiple characters.
 *
 * PUBLIC: int v_Replace(SCR *, VICMD *);
 */
int
v_Replace(SCR *sp, VICMD *vp)
{
        size_t len;
        u_int32_t flags;
        int isempty;
        char *p;

        flags = set_txt_std(sp, vp, 0);
        sp->showmode = SM_REPLACE;

        if (db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
                if (!isempty)
                        return (1);
                len = 0;
                LF_SET(TXT_APPENDEOL);
        } else {
                if (len == 0)
                        LF_SET(TXT_APPENDEOL);
                LF_SET(TXT_OVERWRITE | TXT_REPLACE);
        }
        vp->m_stop.lno = vp->m_start.lno;
        vp->m_stop.cno = len ? len - 1 : 0;

        return (v_txt(sp, vp, &vp->m_stop, p, len,
            0, OOBLNO, F_ISSET(vp, VC_C1SET) ? vp->count : 1, flags));
}

/*
 * v_subst -- [buffer][count]s
 *      Substitute characters.
 *
 * PUBLIC: int v_subst(SCR *, VICMD *);
 */
int
v_subst(SCR *sp, VICMD *vp)
{
        size_t len;
        u_int32_t flags;
        int isempty;
        char *p;

        flags = set_txt_std(sp, vp, 0);
        sp->showmode = SM_CHANGE;

        if (db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
                if (!isempty)
                        return (1);
                len = 0;
                LF_SET(TXT_APPENDEOL);
        } else {
                if (len == 0)
                        LF_SET(TXT_APPENDEOL);
                LF_SET(TXT_EMARK | TXT_OVERWRITE);
        }

        vp->m_stop.lno = vp->m_start.lno;
        vp->m_stop.cno =
            vp->m_start.cno + (F_ISSET(vp, VC_C1SET) ? vp->count - 1 : 0);
        if (vp->m_stop.cno > len - 1)
                vp->m_stop.cno = len - 1;

        if (p != NULL && cut(sp,
            F_ISSET(vp, VC_BUFFER) ? &vp->buffer : NULL,
            &vp->m_start, &vp->m_stop, 0))
                return (1);

        return (v_txt(sp, vp, &vp->m_stop, p, len, 0, OOBLNO, 1, flags));
}

/*
 * set_txt_std --
 *      Initialize text processing flags.
 */
static u_int32_t
set_txt_std(SCR *sp, VICMD *vp, u_int32_t flags)
{
        LF_SET(TXT_CNTRLT |
            TXT_ESCAPE | TXT_MAPINPUT | TXT_RECORD | TXT_RESOLVE);

        if (F_ISSET(vp, VC_ISDOT))
                LF_SET(TXT_REPLAY);

        if (O_ISSET(sp, O_ALTWERASE))
                LF_SET(TXT_ALTWERASE);
        if (O_ISSET(sp, O_AUTOINDENT))
                LF_SET(TXT_AUTOINDENT);
        if (O_ISSET(sp, O_BEAUTIFY))
                LF_SET(TXT_BEAUTIFY);
        if (O_ISSET(sp, O_SHOWMATCH))
                LF_SET(TXT_SHOWMATCH);
        if (F_ISSET(sp, SC_SCRIPT))
                LF_SET(TXT_CR);
        if (O_ISSET(sp, O_TTYWERASE))
                LF_SET(TXT_TTYWERASE);

        /*
         * !!!
         * Mapped keys were sometimes unaffected by the wrapmargin option
         * in the historic 4BSD vi.  Consider the following commands, where
         * each is executed on an empty line, in an 80 column screen, with
         * the wrapmargin value set to 60.
         *
         *      aABC DEF <ESC>....
         *      :map K aABC DEF ^V<ESC><CR>KKKKK
         *      :map K 5aABC DEF ^V<ESC><CR>K
         *
         * The first and second commands are affected by wrapmargin.  The
         * third is not.  (If the inserted text is itself longer than the
         * wrapmargin value, i.e. if the "ABC DEF " string is replaced by
         * something that's longer than 60 columns from the beginning of
         * the line, the first two commands behave as before, but the third
         * command gets fairly strange.)  The problem is that people wrote
         * macros that depended on the third command NOT being affected by
         * wrapmargin, as in this gem which centers lines:
         *
         *      map #c $mq81a ^V^[81^V^V|D`qld0:s/  / /g^V^M$p
         *
         * For compatibility reasons, we try and make it all work here.  I
         * offer no hope that this is right, but it's probably pretty close.
         *
         * XXX
         * Once I work my courage up, this is all gonna go away.  It's too
         * evil to survive.
         */
        if ((O_ISSET(sp, O_WRAPLEN) || O_ISSET(sp, O_WRAPMARGIN)) &&
            (!MAPPED_KEYS_WAITING(sp) || !F_ISSET(vp, VC_C1SET)))
                LF_SET(TXT_WRAPMARGIN);
        return (flags);
}