/*************************************************************************\
* Copyright (c) 2002 The University of Chicago, 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: Roger A. Cole
 *      Date:   07-20-91
 */
/*+/mod***********************************************************************
* TITLE envSubr.c - routines to get and set EPICS environment parameters
*
* DESCRIPTION
*       These routines are oriented for use with EPICS environment
*       parameters under UNIX and VxWorks.  They may be used for other
*       purposes, as well.
*
*       Many EPICS environment parameters are predefined in envDefs.h.
*
* QUICK REFERENCE
* #include "envDefs.h"
* ENV_PARAM     param;
*  char *envGetConfigParamPtr(       pParam                           )
*  char *envGetConfigParam(          pParam,    bufDim,    pBuf       )
*  long  envGetLongConfigParam(      pParam,    pLong                 )
*  long  envGetDoubleConfigParam(    pParam,    pDouble               )
*  long  envGetInetAddrConfigParam(  pParam,    pAddr                 )
*  long  envPrtConfigParam(          pParam                           )
*
* SEE ALSO
*       $epics/share/bin/envSetupParams, envDefs.h
*
*-***************************************************************************/

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

#include "epicsStdlib.h"
#include "epicsStdio.h"
#include "epicsString.h"
#include "errMdef.h"
#include "errlog.h"
#include "envDefs.h"
#include "epicsAssert.h"
#include "osiSock.h"


/*+/subr**********************************************************************
* NAME  envGetConfigParamPtr - returns a pointer to the configuration
*               parameter value string
*
* DESCRIPTION
*       Returns a pointer to a configuration parameter value.
*       If the configuration parameter isn't found in the environment,
*       then a pointer to the default value for the parameter is copied.
*       If no parameter is found and there is no default, then
*       NULL is returned.
*
* RETURNS
*       pointer to the environment variable value string, or
*       NULL if no parameter value and no default value was found
*
* EXAMPLES
* 1.    Get the value for the EPICS-defined environment parameter
*       EPICS_TS_NTP_INET.
*
*       #include "envDefs.h"
*       const char *pStr;
*
*       pStr = envGetConfigParamPtr(&EPICS_TS_NTP_INET);
*       if (pStr) {
*               printf("NTP time server is: %s\n", pStr);
*       }
*
*-*/
const char * epicsStdCall envGetConfigParamPtr(
const ENV_PARAM *pParam /* I pointer to config param structure */
)
{
    const char *pEnv;           /* pointer to environment string */

    pEnv = getenv(pParam->name);

    if (pEnv == NULL) {
        pEnv = pParam->pdflt;
    }

    if (pEnv) {
        if (pEnv[0u] == '\0') {
            pEnv = NULL;
        }
    }

    return pEnv;
}


/*+/subr**********************************************************************
* NAME  envGetConfigParam - get value of a configuration parameter
*
* DESCRIPTION
*       Gets the value of a configuration parameter and copies it
*       into the caller's buffer.  If the configuration parameter
*       isn't found in the environment, then the default value for
*       the parameter is copied.  If no parameter is found and there
*       is no default, then '\0' is copied and NULL is returned.
*
* RETURNS
*       pointer to callers buffer, or
*       NULL if no parameter value or default value was found
*
* EXAMPLES
* 1.    Get the value for the EPICS-defined environment parameter
*       EPICS_TS_NTP_INET.
*
*       #include "envDefs.h"
*       char       temp[80];
*
*       printf("NTP time server is: %s\n",
*                       envGetConfigParam(&EPICS_TS_NTP_INET, sizeof(temp), temp));
*
* 2.    Get the value for the DISPLAY environment parameter under UNIX.
*
*       #include "envDefs.h"
*       char       temp[80];
*       ENV_PARAM  display={"DISPLAY",""}
*
*       if (envGetConfigParam(&display, sizeof(temp), temp) == NULL)
*           printf("DISPLAY isn't defined\n");
*       else
*           printf("DISPLAY is %s\n", temp);
*
*-*/
char * epicsStdCall envGetConfigParam(
const ENV_PARAM *pParam,/* I pointer to config param structure */
int     bufDim,         /* I dimension of parameter buffer */
char    *pBuf           /* I pointer to parameter buffer  */
)
{
    const char *pEnv;           /* pointer to environment string */

    pEnv = envGetConfigParamPtr(pParam);
    if (!pEnv) {
        return NULL;
    }

    strncpy(pBuf, pEnv, bufDim-1);
    pBuf[bufDim-1] = '\0';

    return pBuf;
}

/*+/subr**********************************************************************
* NAME  envGetDoubleConfigParam - get value of a double configuration parameter
*
* DESCRIPTION
*       Gets the value of a configuration parameter and copies it into the
*       caller's real (double) buffer.  If the configuration parameter isn't
*       found in the environment, then the default value for the parameter
*       is copied.
*
*       If no parameter is found and there is no default, then -1 is
*       returned and the caller's buffer is unmodified.
*
* RETURNS
*       0, or
*       -1 if an error is encountered
*
* EXAMPLE
* 1.    Get the value for the real environment parameter EPICS_THRESHOLD.
*
*       #include "envDefs.h"
*       double  threshold;
*       long    status;
*
*       status = envGetDoubleConfigParam(&EPICS_THRESHOLD, &threshold);
*       if (status == 0) {
*           printf("the threshold is: %lf\n", threshold);
*       }
*       else {
*           printf("%s could not be found or was not a real number\n",
*                       EPICS_THRESHOLD.name);
*       }
*
*-*/
long epicsStdCall envGetDoubleConfigParam(
const ENV_PARAM *pParam,/* I pointer to config param structure */
double  *pDouble        /* O pointer to place to store value */
)
{
    char        text[128];
    char        *ptext;
    int         count;

    ptext = envGetConfigParam(pParam, sizeof text, text);
    if (ptext != NULL) {
        count = epicsScanDouble(text, pDouble);
        if (count == 1) {
            return 0;
        }
        (void)fprintf(stderr,"Unable to find a real number in %s=%s\n",
                pParam->name, text);
    }

    return -1;
}

/*+/subr**********************************************************************
* NAME  envGetInetAddrConfigParam - get value of an inet addr config parameter
*
* DESCRIPTION
*       Gets the value of a configuration parameter and copies it into
*       the caller's (struct in_addr) buffer.  If the configuration parameter
*       isn't found in the environment, then the default value for
*       the parameter is copied.
*
*       If no parameter is found and there is no default, then -1 is
*       returned and the callers buffer is unmodified.
*
* RETURNS
*       0, or
*       -1 if an error is encountered
*
* EXAMPLE
* 1.    Get the value for the inet address environment parameter EPICS_INET.
*
*       #include "envDefs.h"
*       struct  in_addr addr;
*       long    status;
*
*       status = envGetInetAddrConfigParam(&EPICS_INET, &addr);
*       if (status == 0) {
*           printf("the s_addr is: %x\n", addr.s_addr);
*       }
*       else {
*           printf("%s could not be found or was not an inet address\n",
*                       EPICS_INET.name);
*       }
*
*-*/
long epicsStdCall envGetInetAddrConfigParam(
const ENV_PARAM *pParam,/* I pointer to config param structure */
struct in_addr *pAddr   /* O pointer to struct to receive inet addr */
)
{
    char        text[128];
    char        *ptext;
    long        status;
    struct sockaddr_in sin;

    ptext = envGetConfigParam(pParam, sizeof text, text);
    if (ptext) {
                status = aToIPAddr (text, 0u, &sin);
                if (status == 0) {
                        *pAddr = sin.sin_addr;
                        return 0;
                }
        (void)fprintf(stderr,"Unable to find an IP address or valid host name in %s=%s\n",
                                                pParam->name, text);
    }
    return -1;
}

/*+/subr**********************************************************************
* NAME  envGetLongConfigParam - get value of an integer config parameter
*
* DESCRIPTION
*       Gets the value of a configuration parameter and copies it
*       into the caller's integer (long) buffer.  If the configuration
*       parameter isn't found in the environment, then the default value for
*       the parameter is copied.
*
*       If no parameter is found and there is no default, then -1 is
*       returned and the callers buffer is unmodified.
*
* RETURNS
*       0, or
*       -1 if an error is encountered
*
* EXAMPLE
* 1.    Get the value as a long for the integer environment parameter
*       EPICS_NUMBER_OF_ITEMS.
*
*       #include "envDefs.h"
*       long    count;
*       long    status;
*
*       status = envGetLongConfigParam(&EPICS_NUMBER_OF_ITEMS, &count);
*       if (status == 0) {
*           printf("and the count is: %d\n", count);
*       }
*       else {
*           printf("%s could not be found or was not an integer\n",
*                       EPICS_NUMBER_OF_ITEMS.name);
*       }
*
*-*/
long epicsStdCall envGetLongConfigParam(
const ENV_PARAM *pParam,/* I pointer to config param structure */
long    *pLong          /* O pointer to place to store value */
)
{
    char        text[128];
    char        *ptext;
    int         count;

    ptext = envGetConfigParam(pParam, sizeof text, text);
    if (ptext) {
        count = sscanf(text, "%ld", pLong);
        if (count == 1)
                return 0;
        (void)fprintf(stderr,"Unable to find an integer in %s=%s\n",
                pParam->name, text);
    }
    return -1;
}


long epicsStdCall
envGetBoolConfigParam(const ENV_PARAM *pParam, int *pBool)
{
    char text[20];

    if(!envGetConfigParam(pParam, sizeof(text), text))
        return -1;
    *pBool = epicsStrCaseCmp(text, "yes")==0;
    return 0;
}

/*+/subr**********************************************************************
* NAME  envPrtConfigParam - print value of a configuration parameter
*
* DESCRIPTION
*       Prints the value of a configuration parameter.
*
* RETURNS
*       0
*
* EXAMPLE
* 1.    Print the value for the EPICS-defined environment parameter
*       EPICS_TS_NTP_INET.
*
*       #include "envDefs.h"
*
*       envPrtConfigParam(&EPICS_TS_NTP_INET);
*
*-*/
long epicsStdCall envPrtConfigParam(
const ENV_PARAM *pParam)        /* pointer to config param structure */
{
    const char *pVal;

    pVal = envGetConfigParamPtr(pParam);
    if (pVal == NULL)
        fprintf(stdout, "%s is undefined\n", pParam->name);
    else
        fprintf(stdout,"%s: %s\n", pParam->name, pVal);
    return 0;
}

/*+/subr**********************************************************************
* NAME  epicsPrtEnvParams - print value of all configuration parameters
*
* DESCRIPTION
*       Prints all configuration parameters and their current value.
*
* RETURNS
*       0
*
* EXAMPLE
* 1.    Print the value for all EPICS-defined environment parameters.
*
*       #include "envDefs.h"
*
*       epicsPrtEnvParams();
*
*-*/
long epicsStdCall
epicsPrtEnvParams(void)
{
    const ENV_PARAM **ppParam = env_param_list;

    while (*ppParam != NULL)
        envPrtConfigParam(*(ppParam++));

    return 0;
}

/*
 * envGetInetPortConfigParam ()
 */
LIBCOM_API unsigned short epicsStdCall envGetInetPortConfigParam 
                (const ENV_PARAM *pEnv, unsigned short defaultPort)
{
    long        longStatus;
    long        epicsParam;

    longStatus = envGetLongConfigParam (pEnv, &epicsParam);
    if (longStatus!=0) {
        epicsParam = (long) defaultPort;
        errlogPrintf ("EPICS Environment \"%s\" integer fetch failed\n", pEnv->name);
        errlogPrintf ("setting \"%s\" = %ld\n", pEnv->name, epicsParam);
    }

    if (epicsParam<=IPPORT_USERRESERVED || epicsParam>USHRT_MAX) {
        errlogPrintf ("EPICS Environment \"%s\" out of range\n", pEnv->name);
        /*
         * Quit if the port is wrong due coding error
         */
        assert (epicsParam != (long) defaultPort);
        epicsParam = (long) defaultPort;
        errlogPrintf ("Setting \"%s\" = %ld\n", pEnv->name, epicsParam);
    }

    /*
     * ok to clip to unsigned short here because we checked the range
     */
    return (unsigned short) epicsParam;
}