/*      $OpenBSD: v_mark.c,v 1.11 2022/12/26 19:16:04 jmc 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 <limits.h>
#include <stdlib.h>
#include <stdio.h>

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

/*
 * v_mark -- m[a-z]
 *      Set a mark.
 *
 * PUBLIC: int v_mark(SCR *, VICMD *);
 */
int
v_mark(SCR *sp, VICMD *vp)
{
        return (mark_set(sp, vp->character, &vp->m_start, 1));
}

enum which {BQMARK, FQMARK};
static int mark(SCR *, VICMD *, enum which);


/*
 * v_bmark -- `['`a-z]
 *      Move to a mark.
 *
 * Moves to a mark, setting both row and column.
 *
 * !!!
 * Although not commonly known, the "'`" and "'`" forms are historically
 * valid.  The behavior is determined by the first character, so "`'" is
 * the same as "``".  Remember this fact -- you'll be amazed at how many
 * people don't know it and will be delighted that you are able to tell
 * them.
 *
 * PUBLIC: int v_bmark(SCR *, VICMD *);
 */
int
v_bmark(SCR *sp, VICMD *vp)
{
        return (mark(sp, vp, BQMARK));
}

/*
 * v_fmark -- '['`a-z]
 *      Move to a mark.
 *
 * Move to the first nonblank character of the line containing the mark.
 *
 * PUBLIC: int v_fmark(SCR *, VICMD *);
 */
int
v_fmark(SCR *sp, VICMD *vp)
{
        return (mark(sp, vp, FQMARK));
}

/*
 * mark --
 *      Mark commands.
 */
static int
mark(SCR *sp, VICMD *vp, enum which cmd)
{
        MARK m;
        size_t len;

        if (mark_get(sp, vp->character, &vp->m_stop, M_BERR))
                return (1);

        /*
         * !!!
         * Historically, BQMARKS for character positions that no longer
         * existed acted as FQMARKS.
         *
         * FQMARKS move to the first non-blank.
         */
        switch (cmd) {
        case BQMARK:
                if (db_get(sp, vp->m_stop.lno, DBG_FATAL, NULL, &len))
                        return (1);
                if (vp->m_stop.cno < len ||
                    (vp->m_stop.cno == len && len == 0))
                        break;

                if (ISMOTION(vp))
                        F_SET(vp, VM_LMODE);
                cmd = FQMARK;
                /* FALLTHROUGH */
        case FQMARK:
                vp->m_stop.cno = 0;
                if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
                        return (1);
                break;
        default:
                abort();
        }

        /* Non-motion commands move to the end of the range. */
        if (!ISMOTION(vp)) {
                vp->m_final = vp->m_stop;
                return (0);
        }

        /*
         * !!!
         * If a motion component to a BQMARK, the cursor has to move.
         */
        if (cmd == BQMARK &&
            vp->m_stop.lno == vp->m_start.lno &&
            vp->m_stop.cno == vp->m_start.cno) {
                v_nomove(sp);
                return (1);
        }

        /*
         * If the motion is in the reverse direction, switch the start and
         * stop MARK's so that it's in a forward direction.  (There's no
         * reason for this other than to make the tests below easier.  The
         * code in vi.c:vi() would have done the switch.)  Both forward
         * and backward motions can happen for any kind of search command.
         */
        if (vp->m_start.lno > vp->m_stop.lno ||
            (vp->m_start.lno == vp->m_stop.lno &&
            vp->m_start.cno > vp->m_stop.cno)) {
                m = vp->m_start;
                vp->m_start = vp->m_stop;
                vp->m_stop = m;
        }

        /*
         * Yank cursor motion, when associated with marks as motion commands,
         * historically behaved as follows:
         *
         * ` motion                     ' motion
         *              Line change?            Line change?
         *              Y       N               Y       N
         *            --------------          ---------------
         * FORWARD:  |  NM      NM            | NM      NM
         *           |                        |
         * BACKWARD: |  M       M             | M       NM(1)
         *
         * where NM means the cursor didn't move, and M means the cursor
         * moved to the mark.
         *
         * As the cursor was usually moved for yank commands associated
         * with backward motions, this implementation regularizes it by
         * changing the NM at position (1) to be an M.  This makes mark
         * motions match search motions, which is probably A Good Thing.
         *
         * Delete cursor motion was always to the start of the text region,
         * regardless.  Ignore other motion commands.
         */
        vp->m_final = vp->m_start;

        /*
         * Forward marks are always line oriented, and it's set in the
         * vcmd.c table.
         */
        if (cmd == FQMARK)
                return (0);

        /*
         * BQMARK'S moving backward and starting at column 0, and ones moving
         * forward and ending at column 0 are corrected to the last column of
         * the previous line.  Otherwise, adjust the starting/ending point to
         * the character before the current one (this is safe because we know
         * the search had to move to succeed).
         *
         * Mark motions become line mode operations if they start at the first
         * nonblank and end at column 0 of another line.
         */
        if (vp->m_start.lno < vp->m_stop.lno && vp->m_stop.cno == 0) {
                if (db_get(sp, --vp->m_stop.lno, DBG_FATAL, NULL, &len))
                        return (1);
                vp->m_stop.cno = len ? len - 1 : 0;
                len = 0;
                if (nonblank(sp, vp->m_start.lno, &len))
                        return (1);
                if (vp->m_start.cno <= len)
                        F_SET(vp, VM_LMODE);
        } else
                --vp->m_stop.cno;

        return (0);
}