/* 
 * tclClock.c --
 *
 *	Contains the time and date related commands.  This code
 *	is derived from the time and date facilities of TclX,
 *	by Mark Diekhans and Karl Lehenbauer.
 *
 * Copyright 1991-1995 Karl Lehenbauer and Mark Diekhans.
 * Copyright (c) 1995 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * SCCS: @(#) tclClock.c 1.37 97/07/29 10:29:58
 * SCCS: @(#) tclClock.c 1.41 98/02/17 17:18:15
 */

#include "tcl.h"
#include "tclInt.h"
#include "tclPort.h"

/*
 * The date parsing stuff uses lexx and has tons o statics.
 */
static Tcl_Mutex clockMutex;

/*
 * Function prototypes for local procedures in this file:
 */

static int		FormatClock _ANSI_ARGS_((Tcl_Interp *interp,
			    unsigned long clockVal, int useGMT,
			    char *format));

	    if (useGMT) {
		zone = -50000; /* Force GMT */
	    } else {
		zone = TclpGetTimeZone((unsigned long) baseClock);
	    }

	    scanStr = Tcl_GetStringFromObj(objv[2], &dummy);
	    Tcl_MutexLock(&clockMutex);
	    if (TclGetDate(scanStr, (unsigned long) baseClock, zone,
		    (unsigned long *) &clockVal) < 0) {
		Tcl_MutexUnlock(&clockMutex);
		Tcl_AppendStringsToObj(resultPtr,
			"unable to convert date-time string \"",
			scanStr, "\"", (char *) NULL);
		return TCL_ERROR;
	    }
	    Tcl_MutexUnlock(&clockMutex);

	    Tcl_SetLongObj(resultPtr, (long) clockVal);
	    return TCL_OK;
	case 3:			/* seconds */
	    if (objc != 2) {
		Tcl_WrongNumArgs(interp, 2, objv, NULL);
		return TCL_ERROR;

    int useGMT;				/* Boolean */
    char *format;			/* Format string */
{
    struct tm *timeDataPtr;
    Tcl_DString buffer;
    int bufSize;
    char *p;
    Tcl_Obj *resultPtr;
    int result;
#ifdef TCL_USE_TIMEZONE_VAR
    int savedTimeZone;
    char *savedTZEnv;
#ifndef HAVE_TM_ZONE
    int savedTimeZone = 0;	/* lint. */
    char *savedTZEnv = NULL;	/* lint. */
#endif
    Tcl_Obj *resultPtr;

    resultPtr = Tcl_GetObjResult(interp);
#ifdef HAVE_TZSET
    /*
     * Some systems forgot to call tzset in localtime, make sure its done.
     */
    static int  calledTzset = 0;

    Tcl_MutexLock(&clockMutex);
    if (!calledTzset) {
        tzset();
        calledTzset = 1;
    }
    Tcl_MutexUnlock(&clockMutex);
#endif

#ifdef TCL_USE_TIMEZONE_VAR
#ifndef HAVE_TM_ZONE
    /*
     * This is a horrible kludge for systems not having the timezone in
     * struct tm.  No matter what was specified, they use the global time
     * zone.  (Thanks Solaris).
     * This is a kludge for systems not having the timezone string in
     * struct tm.  No matter what was specified, they use the local
     * timezone string.
     */

    if (useGMT) {
        char *varValue;

        varValue = Tcl_GetVar2(interp, "env", "TZ", TCL_GLOBAL_ONLY);
        if (varValue != NULL) {
	    savedTZEnv = strcpy(ckalloc(strlen(varValue) + 1), varValue);
        } else {

	} else {
	    bufSize++;
	}
    }
    Tcl_DStringInit(&buffer);
    Tcl_DStringSetLength(&buffer, bufSize);

    Tcl_MutexLock(&clockMutex);
    if ((TclStrftime(buffer.string, (unsigned int) bufSize, format,
	    timeDataPtr) == 0) && (*format != '\0')) {
    result = TclStrftime(buffer.string, (unsigned int) bufSize, format,
	    timeDataPtr);
	Tcl_AppendStringsToObj(resultPtr, "bad format string \"",
		format, "\"", (char *) NULL);
    Tcl_MutexUnlock(&clockMutex);
	return TCL_ERROR;
    }


#ifndef HAVE_TM_ZONE
#ifdef TCL_USE_TIMEZONE_VAR
    if (useGMT) {
        if (savedTZEnv != NULL) {
            Tcl_SetVar2(interp, "env", "TZ", savedTZEnv, TCL_GLOBAL_ONLY);
            ckfree(savedTZEnv);
        } else {
            Tcl_UnsetVar2(interp, "env", "TZ", TCL_GLOBAL_ONLY);
        }
        timezone = savedTimeZone;
        tzset();
    }
#endif
    if ((result == 0) && (*format != '\0')) {
	Tcl_AppendStringsToObj(resultPtr, "bad format string \"", format, 
		"\"", (char *) NULL);
	return TCL_ERROR;
    }

    Tcl_SetStringObj(resultPtr, buffer.string, -1);
    Tcl_DStringFree(&buffer);
    return TCL_OK;
}