// ESP32 NTP OLED
//   PP le 11 mars 2025
//https://randomnerdtutorials.com/esp32-date-time-ntp-client-server-arduino/
//
// Learn about the ESP32 WiFi simulation in
// https://docs.wokwi.com/guides/esp32-wifi
//  simuler le wifi par : wokwigw.exe


#include <WiFi.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

#define NTP_SERVER     "pool.ntp.org"    //serveur de temps
#define UTC_OFFSET     3600              //fuseau horaire UTC+1 en secondes
#define UTC_OFFSET_DST 0                 //heure d'été en secondes

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);



// ***   fonction printLocalTime ****
void printLocalTime(){
  struct tm timeinfo;
  if(!getLocalTime(&timeinfo)){     
    Serial.println("Failed to obtain time");    // attente serveur temps
    return;
  }
  Serial.println(&timeinfo, "%A %B %d %Y %H:%M:%S");
  Serial.print("Day of week: ");
  Serial.println(&timeinfo, "%A");
  Serial.print("Month: ");
  Serial.println(&timeinfo, "%B");
  Serial.print("Day of Month: ");
  Serial.println(&timeinfo, "%d");
  Serial.print("Year: ");
  Serial.println(&timeinfo, "%Y");
  Serial.print("Hour: ");
  Serial.println(&timeinfo, "%H");
  Serial.print("Hour (12 hour format): ");
  Serial.println(&timeinfo, "%I");
  Serial.print("Minute: ");
  Serial.println(&timeinfo, "%M");
  Serial.print("Second: ");
  Serial.println(&timeinfo, "%S");

  Serial.println("Time variables");
  char timeHour[3];
  strftime(timeHour,3, "%H", &timeinfo);
  Serial.println(timeHour);
  char timeWeekDay[10];
  strftime(timeWeekDay,10, "%A", &timeinfo);
  Serial.println(timeWeekDay);
  Serial.println();

        //affichage sur OLED
  display.setTextSize(2);                     // taille 2 pour date et heure 
  display.setCursor(5,0);                     // curseur  a l'origine
  display.print(&timeinfo, "%d/%m/%Y");       // jour/mois/annéee
  display.setCursor(5,24);                    // curseur en ligne (2x12)
  display.print(&timeinfo, " %H:%M:%S");     // heure:minute:seconde
  display.display();                          // met a jour l'affichage

}
// ***** fin fonction ****



void setup() {
  Serial.begin(115200);

   if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  delay(200);

  display.clearDisplay();                  // efface l'afficheur
  display.setTextColor(WHITE);             // texte en blanc sur fond noir
  display.setTextWrap(false);              // inhibe le retour a la ligne sur OLED
  display.display();                       // met a jour l'affichage

  //****************************
  //   SIMULATION DU WIFI
  //****************************
  WiFi.begin("Wokwi-GUEST", "", 6);       // simule le wifi
  while (WiFi.status() != WL_CONNECTED) { // attente connexion wifi
    delay(250);
    Serial.println("WiFi non connecté");
  }

  Serial.println("");                     // connexion réalisé
  Serial.println("WiFi connecté");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
  //****************************

  configTime(UTC_OFFSET, UTC_OFFSET_DST, NTP_SERVER);
}

void loop() {

  printLocalTime();              //appel fonction printLocalTime
  
  delay(500);
  display.clearDisplay();      // efface l'afficheur
}