/*      $OpenBSD: ex_at.c,v 1.14 2016/05/27 09:18:12 martijn 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_at -- :@[@ | buffer]
 *          :*[* | buffer]
 *
 *      Execute the contents of the buffer.
 *
 * PUBLIC: int ex_at(SCR *, EXCMD *);
 */
int
ex_at(SCR *sp, EXCMD *cmdp)
{
        CB *cbp;
        CHAR_T name;
        EXCMD *ecp;
        RANGE *rp;
        TEXT *tp;
        size_t len;
        char *p;

        /*
         * !!!
         * Historically, [@*]<carriage-return> and [@*][@*] executed the most
         * recently executed buffer in ex mode.
         */
        name = FL_ISSET(cmdp->iflags, E_C_BUFFER) ? cmdp->buffer : '@';
        if (name == '@' || name == '*') {
                if (!F_ISSET(sp, SC_AT_SET)) {
                        ex_emsg(sp, NULL, EXM_NOPREVBUF);
                        return (1);
                }
                name = sp->at_lbuf;
        }
        sp->at_lbuf = name;
        F_SET(sp, SC_AT_SET);

        CBNAME(sp, cbp, name);
        if (cbp == NULL) {
                ex_emsg(sp, KEY_NAME(sp, name), EXM_EMPTYBUF);
                return (1);
        }

        /*
         * !!!
         * Historically the @ command took a range of lines, and the @ buffer
         * was executed once per line.  The historic vi could be trashed by
         * this because it didn't notice if the underlying file changed, or,
         * for that matter, if there were no more lines on which to operate.
         * For example, take a 10 line file, load "%delete" into a buffer,
         * and enter :8,10@<buffer>.
         *
         * The solution is a bit tricky.  If the user specifies a range, take
         * the same approach as for global commands, and discard the command
         * if exit or switch to a new file/screen.  If the user doesn't specify
         * the  range, continue to execute after a file/screen switch, which
         * means @ buffers are still useful in a multi-screen environment.
         */
        CALLOC_RET(sp, ecp, 1, sizeof(EXCMD));
        TAILQ_INIT(&ecp->rq);
        CALLOC_RET(sp, rp, 1, sizeof(RANGE));
        rp->start = cmdp->addr1.lno;
        if (F_ISSET(cmdp, E_ADDR_DEF)) {
                rp->stop = rp->start;
                FL_SET(ecp->agv_flags, AGV_AT_NORANGE);
        } else {
                rp->stop = cmdp->addr2.lno;
                FL_SET(ecp->agv_flags, AGV_AT);
        }
        TAILQ_INSERT_HEAD(&ecp->rq, rp, q);

        /*
         * Buffers executed in ex mode or from the colon command line in vi
         * were ex commands.  We can't push it on the terminal queue, since
         * it has to be executed immediately, and we may be in the middle of
         * an ex command already.  Push the command on the ex command stack.
         * Build two copies of the command.  We need two copies because the
         * ex parser may step on the command string when it's parsing it.
         */
        len = 0;
        TAILQ_FOREACH_REVERSE(tp, &cbp->textq, _texth, q) {
                len += tp->len + 1;
        }

        MALLOC_RET(sp, ecp->cp, len * 2);
        ecp->o_cp = ecp->cp;
        ecp->o_clen = len;
        ecp->cp[len] = '\0';

        /* Copy the buffer into the command space. */
        p = ecp->cp + len;
        TAILQ_FOREACH_REVERSE(tp, &cbp->textq, _texth, q) {
                memcpy(p, tp->lb, tp->len);
                p += tp->len;
                *p++ = '\n';
        }

        LIST_INSERT_HEAD(&sp->gp->ecq, ecp, q);
        return (0);
}