/*F********************************************************************
Arduino Timezone Library Copyright (C) 2018 by Jack Christensen and
licensed under GNU GPL v3.0, https://www.gnu.org/licenses/gpl.html
Arduino Timezone Library example sketch.
Self-adjusting clock for one time zone.
TimeChangeRules can be hard-coded or read from EEPROM, see comments.
Jack Christensen Mar 2012
**********************************************************************/
#include <Timezone.h>   // https://github.com/JChristensen/Timezone

//************************* DEFINES ************************************
#define  BAUD  9600

//************************* PROTOTYPES ************************************
time_t compileTime();
void printDateTime( time_t t, const char *tz );

//************************* VARIABLES ************************************
// US CENTRAL TIME ZONE (Chicago, Dallas)
TimeChangeRule Dst = {"CDT", Second, Sun, Mar, 2, -300};// Dylht time = UTC - 5 hrs
TimeChangeRule Std = {"CST", First, Sun, Nov, 2, -360};// Std time: UTC - 6 hrs
Timezone Tz( Dst, Std );
// IF TimeChangeRules IN EEPROM, COMMENT OUT THREE
// LINES ABOVE AND UNCOMMENT LINE BELOW
//Timezone Tz( 100 );                                   // EEPROM ADDRESS 100
TimeChangeRule *Tcr;     // POINTER TO TIME CHANGE RULE, USE TO GET TZ ABBREV

/*F********************************************************************
*
**********************************************************************/
void 
setup()
{
	Serial.begin( BAUD );
	setTime( Tz.toUTC( compileTime() ) );
	//setTime( 01, 55, 00, 11, 3, 2012);
	// diff way set (hr,min,sec,day,mnth,yr)
}
/*F********************************************************************
*
**********************************************************************/
void 
loop()
{
	time_t  utc = now();

	time_t local = Tz.toLocal( utc, &Tcr);
	Serial.println();
	printDateTime( utc, "UTC");
	printDateTime( local, Tcr->abbrev );
	delay( 10000 );
}
/*F********************************************************************
* FORMAT AND PRINT A TIME_T VALUE, WITH A TIME ZONE APPENDED
**********************************************************************/
void 
printDateTime( time_t t, const char *tz)
{
    char buf[32];
    char m[4];    // TEMP STG FOR MON STRING (DateStrings.cpp SHARED BUFFER)
    strcpy( m, monthShortStr( month( t ) ) );
    sprintf( buf, "%.2d:%.2d:%.2d %s %.2d %s %d %s", hour( t ), minute(t)
		, second(t), dayShortStr(weekday(t)), day(t), m, year(t), tz);
    Serial.println( buf );
}
/*F********************************************************************
* return compile date and time as a time_t value
**********************************************************************/
time_t 
compileTime()
{
                  // FUDGE FACTOR TO ALLOW FOR COMPILE TIME (SECONDS, YMMV)
	const time_t FUDGE( 10 ); 
	const char *compDate = __DATE__, *compTime = __TIME__, *months 
		= "JanFebMarAprMayJunJulAugSepOctNovDec";
	char chMon[4], *m;
	tmElements_t tm;

	strncpy( chMon, compDate, 3);
	chMon[3] = '\0';
	m = strstr( months, chMon);
	tm.Month = ( (m - months) / 3 + 1);

	tm.Day = atoi( compDate + 4);
	tm.Year = atoi( compDate + 7) - 1970;
	tm.Hour = atoi( compTime);
	tm.Minute = atoi( compTime + 3);
	tm.Second = atoi( compTime + 6);
	time_t t = makeTime( tm );
	return t + FUDGE;          // ADD FUDGE FACTOR TO ALLOW FOR COMPILE TIME
}