/*      $OpenBSD: v_match.c,v 1.9 2016/01/06 22:28:52 millert 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 <limits.h>
#include <stdio.h>
#include <string.h>

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

/*
 * v_match -- %
 *      Search to matching character.
 *
 * PUBLIC: int v_match(SCR *, VICMD *);
 */
int
v_match(SCR *sp, VICMD *vp)
{
        VCS cs;
        MARK *mp;
        size_t cno, len, off;
        int cnt, isempty, matchc, startc, (*gc)(SCR *, VCS *);
        char *p;

        /*
         * !!!
         * Historic practice; ignore the count.
         *
         * !!!
         * Historical practice was to search for the initial character in the
         * forward direction only.
         */
        if (db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
                if (isempty)
                        goto nomatch;
                return (1);
        }
        for (off = vp->m_start.cno;; ++off) {
                if (off >= len) {
nomatch:                msgq(sp, M_BERR, "No match character on this line");
                        return (1);
                }
                switch (startc = p[off]) {
                case '(':
                        matchc = ')';
                        gc = cs_next;
                        break;
                case ')':
                        matchc = '(';
                        gc = cs_prev;
                        break;
                case '[':
                        matchc = ']';
                        gc = cs_next;
                        break;
                case ']':
                        matchc = '[';
                        gc = cs_prev;
                        break;
                case '{':
                        matchc = '}';
                        gc = cs_next;
                        break;
                case '}':
                        matchc = '{';
                        gc = cs_prev;
                        break;
                case '<':
                        matchc = '>';
                        gc = cs_next;
                        break;
                case '>':
                        matchc = '<';
                        gc = cs_prev;
                        break;
                default:
                        continue;
                }
                break;
        }

        cs.cs_lno = vp->m_start.lno;
        cs.cs_cno = off;
        if (cs_init(sp, &cs))
                return (1);
        for (cnt = 1;;) {
                if (gc(sp, &cs))
                        return (1);
                if (cs.cs_flags != 0) {
                        if (cs.cs_flags == CS_EOF || cs.cs_flags == CS_SOF)
                                break;
                        continue;
                }
                if (cs.cs_ch == startc)
                        ++cnt;
                else if (cs.cs_ch == matchc && --cnt == 0)
                        break;
        }
        if (cnt) {
                msgq(sp, M_BERR, "Matching character not found");
                return (1);
        }

        vp->m_stop.lno = cs.cs_lno;
        vp->m_stop.cno = cs.cs_cno;

        /*
         * If moving right, non-motion commands move to the end of the range.
         * Delete and yank stay at the start.
         *
         * If moving left, all commands move to the end of the range.
         *
         * !!!
         * Don't correct for leftward movement -- historic vi deleted the
         * starting cursor position when deleting to a match.
         */
        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))
                vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
        else
                vp->m_final = vp->m_stop;

        /*
         * !!!
         * If the motion is across lines, and the earliest cursor position
         * is at or before any non-blank characters in the line, i.e. the
         * movement is cutting all of the line's text, and the later cursor
         * position has nothing other than whitespace characters between it
         * and the end of its line, the buffer is in line mode.
         */
        if (!ISMOTION(vp) || vp->m_start.lno == vp->m_stop.lno)
                return (0);
        mp = vp->m_start.lno < vp->m_stop.lno ? &vp->m_start : &vp->m_stop;
        if (mp->cno != 0) {
                cno = 0;
                if (nonblank(sp, mp->lno, &cno))
                        return (1);
                if (cno < mp->cno)
                        return (0);
        }
        mp = vp->m_start.lno < vp->m_stop.lno ? &vp->m_stop : &vp->m_start;
        if (db_get(sp, mp->lno, DBG_FATAL, &p, &len))
                return (1);
        for (p += mp->cno + 1, len -= mp->cno; --len; ++p)
                if (!isblank(*p))
                        return (0);
        F_SET(vp, VM_LMODE);
        return (0);
}