/*      $OpenBSD: ex_join.c,v 1.8 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 <bitstring.h>
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

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

/*
 * ex_join -- :[line [,line]] j[oin][!] [count] [flags]
 *      Join lines.
 *
 * PUBLIC: int ex_join(SCR *, EXCMD *);
 */
int
ex_join(SCR *sp, EXCMD *cmdp)
{
        recno_t from, to;
        size_t blen, clen, len, tlen;
        int echar, extra, first;
        char *bp, *p, *tbp;

        NEEDFILE(sp, cmdp);

        from = cmdp->addr1.lno;
        to = cmdp->addr2.lno;

        /* Check for no lines to join. */
        if (!db_exist(sp, from + 1)) {
                msgq(sp, M_ERR, "No following lines to join");
                return (1);
        }

        GET_SPACE_RET(sp, bp, blen, 256);

        /*
         * The count for the join command was off-by-one,
         * historically, to other counts for other commands.
         */
        if (FL_ISSET(cmdp->iflags, E_C_COUNT))
                ++cmdp->addr2.lno;

        /*
         * If only a single address specified, or, the same address
         * specified twice, the from/two addresses will be the same.
         */
        if (cmdp->addr1.lno == cmdp->addr2.lno)
                ++cmdp->addr2.lno;

        clen = tlen = 0;
        for (first = 1,
            from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
                /*
                 * Get next line.  Historic versions of vi allowed "10J" while
                 * less than 10 lines from the end-of-file, so we do too.
                 */
                if (db_get(sp, from, 0, &p, &len)) {
                        cmdp->addr2.lno = from - 1;
                        break;
                }

                /* Empty lines just go away. */
                if (len == 0)
                        continue;

                /*
                 * Get more space if necessary.  Note, tlen isn't the length
                 * of the new line, it's roughly the amount of space needed.
                 * tbp - bp is the length of the new line.
                 */
                tlen += len + 2;
                ADD_SPACE_RET(sp, bp, blen, tlen);
                tbp = bp + clen;

                /*
                 * Historic practice:
                 *
                 * If force specified, join without modification.
                 * If the current line ends with whitespace, strip leading
                 *    whitespace from the joined line.
                 * If the next line starts with a ), do nothing.
                 * If the current line ends with ., insert two spaces.
                 * Else, insert one space.
                 *
                 * One change -- add ? and ! to the list of characters for
                 * which we insert two spaces.  I expect that POSIX 1003.2
                 * will require this as well.
                 *
                 * Echar is the last character in the last line joined.
                 */
                extra = 0;
                if (!first && !FL_ISSET(cmdp->iflags, E_C_FORCE)) {
                        if (isblank(echar))
                                for (; len && isblank(*p); --len, ++p);
                        else if (p[0] != ')') {
                                if (strchr(".?!", echar)) {
                                        *tbp++ = ' ';
                                        ++clen;
                                        extra = 1;
                                }
                                *tbp++ = ' ';
                                ++clen;
                                for (; len && isblank(*p); --len, ++p);
                        }
                }

                if (len != 0) {
                        memcpy(tbp, p, len);
                        tbp += len;
                        clen += len;
                        echar = p[len - 1];
                } else
                        echar = ' ';

                /*
                 * Historic practice for vi was to put the cursor at the first
                 * inserted whitespace character, if there was one, or the
                 * first character of the joined line, if there wasn't, or the
                 * last character of the line if joined to an empty line.  If
                 * a count was specified, the cursor was moved as described
                 * for the first line joined, ignoring subsequent lines.  If
                 * the join was a ':' command, the cursor was placed at the
                 * first non-blank character of the line unless the cursor was
                 * "attracted" to the end of line when the command was executed
                 * in which case it moved to the new end of line.  There are
                 * probably several more special cases, but frankly, my dear,
                 * I don't give a damn.  This implementation puts the cursor
                 * on the first inserted whitespace character, the first
                 * character of the joined line, or the last character of the
                 * line regardless.  Note, if the cursor isn't on the joined
                 * line (possible with : commands), it is reset to the starting
                 * line.
                 */
                if (first) {
                        sp->cno = (tbp - bp) - (1 + extra);
                        first = 0;
                } else
                        sp->cno = (tbp - bp) - len - (1 + extra);
        }
        sp->lno = cmdp->addr1.lno;

        /* Delete the joined lines. */
        for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; to > from; --to)
                if (db_delete(sp, to))
                        goto err;

        /* If the original line changed, reset it. */
        if (!first && db_set(sp, from, bp, tbp - bp)) {
err:            FREE_SPACE(sp, bp, blen);
                return (1);
        }
        FREE_SPACE(sp, bp, blen);

        sp->rptlines[L_JOINED] += (cmdp->addr2.lno - cmdp->addr1.lno) + 1;
        return (0);
}