#include <EEPROM.h>

const int redLedPin = 8;   
const int greenLedPin = 9;  
const char writePassword = 'X';  // Пароль для запису
const char readPassword = 'Y';   // Пароль для зчитування

void setup() {
    pinMode(redLedPin, OUTPUT);
    pinMode(greenLedPin, OUTPUT);
    
    digitalWrite(redLedPin, HIGH);  
    
    Serial.begin(9600);
    Serial.println("Hello");
}

void loop() {
    if (Serial.available() > 0) {
        String input = Serial.readStringUntil('?');  
        
        int dividerPos = input.indexOf('/');
        if (dividerPos == -1) {
            dividerPos = input.indexOf('\\');
        }

        if (dividerPos != -1 && input.length() > dividerPos + 1) {
            char password = input.charAt(0);
            String commandAndData = input.substring(1, dividerPos);
            int byteValue = input.substring(dividerPos + 1).toInt();

            if (password == writePassword) {
                handleWrite(byteValue);
            } else if (password == readPassword) {
                handleRead();
            } else {
                handleInvalidPassword();
            }
        }
    }
}

void handleWrite(int byteValue) {
    digitalWrite(redLedPin, LOW);  
    digitalWrite(greenLedPin, HIGH); 

    EEPROM.write(0, byteValue);  

    delay(1000);  

    digitalWrite(greenLedPin, LOW);  
}

void handleRead() {
    digitalWrite(redLedPin, LOW);  
    digitalWrite(greenLedPin, HIGH); 

    int byteValue = EEPROM.read(0); 

    delay(1000); 

    digitalWrite(greenLedPin, LOW);
    
    Serial.println(byteValue);
}

void handleInvalidPassword() {
    Serial.println("Invalid password.");
    
    for (int i = 0; i < 5; i++) {
        digitalWrite(redLedPin, LOW);
        delay(500);
        digitalWrite(redLedPin, HIGH);
        delay(500);
    }
}