#include <EEPROM.h>

// Define pins
const int ledPin = 0;      // PB0, PWM-capable pin
const int buttonOnOff = 1; // PB1
const int buttonUp = 2;    // PB2
const int buttonDown = 3;  // PB3

// Variables to store the state of the LED and brightness
bool ledState = false;
int brightness = 128; // Initial brightness (range 0-255)
const int brightnessStep = 15; // Adjust brightness by this value

void setup() {
  // Initialize the LED pin as an output
  pinMode(ledPin, OUTPUT);

  // Initialize the button pins as inputs with internal pull-up resistors
  pinMode(buttonOnOff, INPUT_PULLUP);
  pinMode(buttonUp, INPUT_PULLUP);
  pinMode(buttonDown, INPUT_PULLUP);

  // Read the last saved brightness from EEPROM
  brightness = EEPROM.read(0);

  // If the value read from EEPROM is not in the valid range, reset to default brightness
  if (brightness < 0 || brightness > 255) {
    brightness = 128;
  }

  // Set initial LED state
  analogWrite(ledPin, ledState ? brightness : 0);
}

void loop() {
  // Check the on/off button
  if (digitalRead(buttonOnOff) == LOW) {
    delay(50); // Debounce delay
    if (digitalRead(buttonOnOff) == LOW) {
      ledState = !ledState; // Toggle LED state
      analogWrite(ledPin, ledState ? brightness : 0);
      while (digitalRead(buttonOnOff) == LOW); // Wait for button release
    }
  }

  // Check the brightness up button
  if (digitalRead(buttonUp) == LOW) {
    delay(50); // Debounce delay
    if (digitalRead(buttonUp) == LOW) {
      brightness = min(255, brightness + brightnessStep); // Increase brightness
      if (ledState) {
        analogWrite(ledPin, brightness);
      }
      // Save the new brightness value to EEPROM
      EEPROM.write(0, brightness);
      while (digitalRead(buttonUp) == LOW); // Wait for button release
    }
  }

  // Check the brightness down button
  if (digitalRead(buttonDown) == LOW) {
    delay(50); // Debounce delay
    if (digitalRead(buttonDown) == LOW) {
      brightness = max(0, brightness - brightnessStep); // Decrease brightness
      if (ledState) {
        analogWrite(ledPin, brightness);
      }
      // Save the new brightness value to EEPROM
      EEPROM.write(0, brightness);
      while (digitalRead(buttonDown) == LOW); // Wait for button release
    }
  }
}