#include <Arduino.h>

const int led1 = 21;  // LED pin connected to GPIO25
const int led2 = 22;  // LED pin connected to GPIO26
const int led3 = 23;  // LED pin connected to GPIO27
const int button1 = 19;  // Push button 1 pin connected to GPIO14
const int button2 = 18;  // Push button 2 pin connected to GPIO12

int ledState = LOW;     // Current state of the LEDs (LOW - off, HIGH - on)
int blinkDelay = 500;  // Delay between LED blinks (in milliseconds)

void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(button1, INPUT_PULLUP);  // Enable internal pull-up resistor
  pinMode(button2, INPUT_PULLUP);  // Enable internal pull-up resistor
}

void loop() {
  // Initial LED behavior (all on for 3 seconds)
  if (millis() < 3000) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
  } else {
    // Turn off LEDs after initial lighting
    digitalWrite(led1, LOW);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);
  }

  // Check for button presses (both buttons pressed)
  if (!digitalRead(button1) && !digitalRead(button2)) {
    blinkLEDsSequentially();  // Blinking LEDs sequentially
  } else {
    // Check for single button press
    if (!digitalRead(button1) || !digitalRead(button2)) {
      blinkAllLEDsTogether();  // Blinking all LEDs together
    }
  }

  delay(10);  // Short delay to avoid excessive loop cycles
}

void blinkLEDsSequentially() {
  for (int i = 0; i < 3; i++) {
    digitalWrite(led1 + i, HIGH);
    delay(blinkDelay);
    digitalWrite(led1 + i, LOW);
    delay(blinkDelay);
  }
}

void blinkAllLEDsTogether() {
  while (true) {
    digitalWrite(led1, ledState);
    digitalWrite(led2, ledState);
    digitalWrite(led3, ledState);
    ledState = !ledState;  // Toggle LED state for blink effect
    delay(blinkDelay);
  }
}