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

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

// create an OLED display object connected to I2C
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);


// constants won't change
const int buttonPin = 18; // ESP32connected to button's pin
const int LEDPin    = 2; // ESP32 pin connected to LED's pin

// variables will change:
int ledState = LOW;     // the current state of LED
int lastButtonState;    // the previous state of button
int currentButtonState; // the current state of button
void setup() {
  Serial.begin(9600);                // initialize serial
  pinMode(buttonPin, INPUT_PULLUP); // set ESP32 pin to input pull-up mode
  pinMode(LEDPin, OUTPUT);          // set ESP32 pin to output mode
  currentButtonState = digitalRead(buttonPin);

  // initialize OLED display with I2C address 0x3C
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("failed to start SSD1306 OLED"));
    while (1);
  }

  delay(2000);         // wait two seconds for initializing
  oled.clearDisplay(); // clear display

  oled.setTextSize(2);         // set text size
  oled.setTextColor(WHITE);    // set text color
  oled.setCursor(0, 2);       // set position to display (x,y)
  oled.println("INTI"); // set text
  oled.setTextSize(1);         // set text size
  oled.println("");
  oled.println("International"); // set text
  oled.println("");
  oled.println("University"); // set text
  oled.display();              // display on OLED

}


void loop() {
  lastButtonState    = currentButtonState;      // save the last state
  currentButtonState = digitalRead(buttonPin); // read new state
   // Delay for stability
  delay(100);

  if(lastButtonState == HIGH && currentButtonState == LOW) {
    Serial.println("Button is pressed");
    //Display in the screen

      oled.clearDisplay(); // clear display
      oled.setTextSize(1);         // set text size
      oled.setTextColor(WHITE);    // set text color
      oled.setCursor(4, 2);       // set position to display (x,y)
      oled.println("Button is pressed"); // set text
      oled.display();              // display on OLED

    // toggle state of LED
    ledState = !ledState;
    // control LED arccoding to the toggled state
    digitalWrite(LEDPin, ledState);
    //delay for showing buttin is pressed
    delay(1000);
    oled.clearDisplay(); // clear display
    oled.setTextSize(2);         // set text size
    oled.setTextColor(WHITE);    // set text color
    oled.setCursor(0, 2);       // set position to display (x,y)
    oled.println("INTI"); // set text
    oled.setTextSize(1);         // set text size
    oled.println("");
    oled.println("International"); // set text
    oled.println("");
    oled.println("University"); // set text
    oled.display();
  }
  delay(100);

}