/*************************************************************************\
* Copyright (c) 2008 UChicago Argonne LLC, as Operator of Argonne
*     National Laboratory.
* Copyright (c) 2002 The Regents of the University of California, as
*     Operator of Los Alamos National Laboratory.
* SPDX-License-Identifier: EPICS
* EPICS BASE is distributed subject to a Software License Agreement found
* in file LICENSE that is included with this distribution.
\*************************************************************************/

/*
 *      Author: Janet Anderson
 *      Date: 04-21-91
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "alarm.h"
#include "dbDefs.h"
#include "dbAccess.h"
#include "recGbl.h"
#include "devSup.h"
#include "eventRecord.h"
#include "epicsExport.h"

/* Create the dset for devEventSoft */
static long init_record(dbCommon *pcommon);
static long read_event(eventRecord *prec);

eventdset devEventSoft = {
    {5, NULL, NULL, init_record, NULL},
    read_event
};
epicsExportAddress(dset, devEventSoft);

static long init_record(dbCommon *pcommon)
{
    eventRecord *prec = (eventRecord *)pcommon;

    if (recGblInitConstantLink(&prec->inp, DBF_STRING, prec->val))
        prec->udf = FALSE;

    return 0;
}

struct eventvt {
    char newEvent[MAX_STRING_SIZE];
    epicsTimeStamp *ptime;
};

static long readLocked(struct link *pinp, void *vvt)
{
    struct eventvt *pvt = (struct eventvt *) vvt;
    long status = dbGetLink(pinp, DBR_STRING, pvt->newEvent, 0, 0);

    if (!status && pvt->ptime)
        dbGetTimeStamp(pinp, pvt->ptime);

    return status;
}

static long read_event(eventRecord *prec)
{
    long status;
    struct eventvt vt;

    if (dbLinkIsConstant(&prec->inp))
        return 0;

    vt.ptime = (dbLinkIsConstant(&prec->tsel) &&
        prec->tse == epicsTimeEventDeviceTime) ? &prec->time : NULL;

    status = dbLinkDoLocked(&prec->inp, readLocked, &vt);
    if (status == S_db_noLSET)
        status = readLocked(&prec->inp, &vt);

    if (!status) {
        if (strcmp(vt.newEvent, prec->val) != 0) {
            strcpy(prec->val, vt.newEvent);
            prec->epvt = eventNameToHandle(prec->val);
        }
        prec->udf = FALSE;
    }

    return status;
}