#include <stdlib.h>
#include <time.h>
#include <sys/time.h>
#include "datetime.h"

RTC_DATA_ATTR struct time_struct now; // keep track of time
//String time_zone_base = "UTC";
const char *ntpServer = "pool.ntp.org";
const long gmtOffset_sec = 3600;
const int daylightOffset_sec = 3600;

void printLocalTime();
int8_t get_date_dtls(String time_zone);


// TODO refactore complete file

void setupDateTime()
{
	configTime(gmtOffset_sec, daylightOffset_sec, ntpServer);
	printLocalTime();
	get_date_dtls("");
}

void printLocalTime()
{
	struct tm timeinfo;
	if (!getLocalTime(&timeinfo))
	{
		Serial.println("Failed to obtain time");
		return;
	}
	Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");
}

// Time APIs
int8_t get_date_dtls(String time_zone)
{
	//String time_zone_string = time_zone_base + time_zone;
	//setenv("TZ", time_zone_string.c_str(), 1);
	//setenv("TZ", "CET-1CEST,M3.5.0/02,M10.5.0/03", 1);

	struct tm timeinfo;
	if (!getLocalTime(&timeinfo))
	{
		Serial.println("Failed to obtain time");
		return -1;
	}
	time_t epoch = mktime(&timeinfo);

	sscanf(ctime(&epoch), "%s %s %hhd %hhd:%hhd:%hhd %d", now.wday, now.month, &now.mday, &now.mil_hour, &now.min, &now.sec, &now.year);

	now.month_num = timeinfo.tm_mon + 1;
	// gives offset of first day of the month with respect to Monday
	//https://www.tondering.dk/claus/cal/chrweek.php#calcdow
	// 1=Monday to 7=Sunday
	uint8_t a = (14 - now.month_num) / 12;
	uint16_t y = now.year - a;
	uint16_t m = now.month_num + (12 * a) - 2;
	// change +7 at the end to whatever first day of week you want.
	// But change the header '"Mon   Tue   Wed   Thu   Fri   Sat   Sun"' as well above.
	// currently +7 => Monday
	// +1 => Sunday
	now.day_offset = (((1 + y + (y / 4) - (y / 100) + (y / 400) + ((31 * m) / 12)) % 7) + 7) % 7;

	// convert to 12 hour
	if (now.mil_hour > 12)
	{
		now.hour = now.mil_hour - 12;
	}
	else
	{
		now.hour = now.mil_hour;
	}

	Serial.printf("Time is %d %d:%d:%d on %s on the %d/%d/%d . It is the month of %s. day_offset: %d\n", now.mil_hour, now.hour, now.min, now.sec, now.wday, now.mday, now.month_num, now.year, now.month, now.day_offset);
	return 0;
}
/*
int8_t set_time()
{

	struct tm t;
	t.tm_year = 2020 - 1900;
	t.tm_mon = 1 - 1; // Month, 1 - jan to 12 - dec
	t.tm_mday = 27;   // Day of the month
	t.tm_hour = 9;
	t.tm_min = 57;
	t.tm_sec = 0;
	t.tm_isdst = -1; // Is DST on? 1 = yes, 0 = no, -1 = unknown

	time_t epoch;
	epoch = mktime(&t);

	struct timeval now;
	now.tv_sec = epoch;
	now.tv_usec = 0;

	struct timezone tz = {-330, 0};
	return settimeofday(&now, &tz);
}
*/