#define BUTTON_PIN_1 27  // ESP32 pin GPIO27, connected to button 1
#define BUTTON_PIN_2 26  // ESP32 pin GPIO26, connected to button 2
#define BUTTON_PIN_3 25  // ESP32 pin GPIO25, connected to button 3
#define BUTTON_PIN_4 33  // ESP32 pin GPIO33, connected to button 4

#define LED_PIN_1 2   // ESP32 pin GPIO2, connected to LED 1
#define LED_PIN_2 4   // ESP32 pin GPIO4, connected to LED 2
#define LED_PIN_3 18  // ESP32 pin GPIO18, connected to LED 3
#define LED_PIN_4 19  // ESP32 pin GPIO19, connected to LED 4

// variables for each LED and button
int led_state_1 = LOW;    // current state of LED 1
int led_state_2 = LOW;    // current state of LED 2
int led_state_3 = LOW;    // current state of LED 3
int led_state_4 = LOW;    // current state of LED 4

int button_state_1;       // current state of button 1
int button_state_2;       // current state of button 2
int button_state_3;       // current state of button 3
int button_state_4;       // current state of button 4

int last_button_state_1;  // previous state of button 1
int last_button_state_2;  // previous state of button 2
int last_button_state_3;  // previous state of button 3
int last_button_state_4;  // previous state of button 4

void setup() {
    Serial.begin(115200);
    Serial.println("Hello, ESP32!");
    
    // Setup pin modes
    pinMode(LED_PIN_1, OUTPUT);
    pinMode(LED_PIN_2, OUTPUT);
    pinMode(LED_PIN_3, OUTPUT);
    pinMode(LED_PIN_4, OUTPUT);

    pinMode(BUTTON_PIN_1, INPUT_PULLUP);
    pinMode(BUTTON_PIN_2, INPUT_PULLUP);
    pinMode(BUTTON_PIN_3, INPUT_PULLUP);
    pinMode(BUTTON_PIN_4, INPUT_PULLUP);
    
    // Initialize button states
    button_state_1 = digitalRead(BUTTON_PIN_1);
    button_state_2 = digitalRead(BUTTON_PIN_2);
    button_state_3 = digitalRead(BUTTON_PIN_3);
    button_state_4 = digitalRead(BUTTON_PIN_4);
}

void loop() {
    // Read states of each button
    button_state_1 = digitalRead(BUTTON_PIN_1);
    button_state_2 = digitalRead(BUTTON_PIN_2);
    button_state_3 = digitalRead(BUTTON_PIN_3);
    button_state_4 = digitalRead(BUTTON_PIN_4);
    
    // Check if any button is pressed and toggle corresponding LED
    toggleLED(BUTTON_PIN_1, button_state_1, last_button_state_1, led_state_1, LED_PIN_1);
    toggleLED(BUTTON_PIN_2, button_state_2, last_button_state_2, led_state_2, LED_PIN_2);
    toggleLED(BUTTON_PIN_3, button_state_3, last_button_state_3, led_state_3, LED_PIN_3);
    toggleLED(BUTTON_PIN_4, button_state_4, last_button_state_4, led_state_4, LED_PIN_4);
    
    // Update last button states
    last_button_state_1 = button_state_1;
    last_button_state_2 = button_state_2;
    last_button_state_3 = button_state_3;
    last_button_state_4 = button_state_4;
}

void toggleLED(int button_pin, int button_state, int& last_button_state, int& led_state, int led_pin) {
    if (last_button_state == HIGH && button_state == LOW) {
        Serial.println("Button pressed");
        led_state = !led_state;
        digitalWrite(led_pin, led_state);
    }
}