/* 
PROGRAMMINFO

Funktion: Datum und Uhzeit vom ntp Server auslesen. Über Variablen korrigierbar (Sommerzeit)

Version: 05.03.2021

C++ Arduino IDE V1.8.13

Board: ESP32vn IoT UNO V1.0.4

Einstellungen:
https://dl.espressif.com/dl/package_esp32_index.json
http://dan.drown.org/stm32duino/package_STM32duino_index.json
https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_dev_index.json


Librarys
- WiFi.h V0.16.1
 */

#include <WiFi.h>
#include "time.h"

const char* ssid       = "xxx";
const char* password   = "xxx";

const char* ntpServer = "de.pool.ntp.org";
const long  gmtOffset_sec = 3600;
const int   daylightOffset_sec = 3600;
int second;
int minute;
int hour;
int day;
int month;
int year;
int weekday;
long current;
struct tm timeinfo;


/*
struct tm
{
int    tm_sec;   //   Seconds [0,60].
int    tm_min;   //   Minutes [0,59].
int    tm_hour;  //   Hour [0,23].
int    tm_mday;  //   Day of month [1,31].
int    tm_mon;   //   Month of year [0,11].
int    tm_year;  //   Years since 1900.
int    tm_wday;  //   Day of week [0,6] (Sunday =0).
int    tm_yday;  //   Day of year [0,365].
int    tm_isdst; //   Daylight Savings flag.
}

*/  

void printLocalTime()
{

  if(!getLocalTime(&timeinfo)){
    Serial.println("Es konnte keine Zeit ermittelt werden");
    return;
  }
  Serial.print("Ausgelesenes Datum vom ntpServer:  ");
  Serial.println(&timeinfo, "%A, %d %B %Y %H:%M:%S");
}

void setup()
{
  Serial.begin(115200);
  
  //WiFi Verbindung
  Serial.printf("Verbunden mit %s ", ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
      delay(500);
      Serial.print(".");
  }
  Serial.println(" CONNECTED");
  
  //init Datum Zeit
  configTime(gmtOffset_sec, daylightOffset_sec, ntpServer);
  printLocalTime();

  //WiFi trennen, wenn es nicht mehr benötigt wird
  WiFi.disconnect(true);
  WiFi.mode(WIFI_OFF);
}

void loop()
{
  delay(3000);
  
  printLocalTime();
  second = timeinfo.tm_sec;
  minute = timeinfo.tm_min;
  hour = timeinfo.tm_hour; //Sommerzeit Korrktur: hour = timeinfo.tm_hour - 1; 
  day = timeinfo.tm_mday;
  month = timeinfo.tm_mon + 1;
  year = timeinfo.tm_year + 1900;
  weekday = timeinfo.tm_wday + 1;
  Serial.print("Datum von den korrigierten Variablen:  ");
  Serial.print(day);
  Serial.print(".");
  Serial.print(month);
  Serial.print(".");
  Serial.print(year);
  Serial.print(" - ");
  Serial.print(hour);
  Serial.print(":");
  Serial.print(minute);
  Serial.print(":");
  Serial.print(second);
  Serial.println(" Uhr"); 
  Serial.println(); 
}