#include <Wire.h>

#define I2C_ADDRESS 8

#define BUTTON_PIN 4
#define SOLENOID_PIN 1

bool switchHasToggled = false;

unsigned long activationTimestamp = 0;

bool solenoidState = false;

void setup() {
  Wire.begin(I2C_ADDRESS);       // join i2c bus with address defined in I2C_ADDRESS
  Wire.onRequest(requestEvent); // register event

  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(SOLENOID_PIN, OUTPUT);

  digitalWrite(SOLENOID_PIN, LOW);
}

void loop() {

  unsigned long currentTime = millis();

  if (digitalRead(BUTTON_PIN) == LOW && currentTime - activationTimestamp > 800) {
    switchHasToggled = true;
    activationTimestamp = currentTime;
    digitalWrite(SOLENOID_PIN, HIGH);
    solenoidState = true;
  }

  if (currentTime - activationTimestamp > 500 && solenoidState == true) {
    digitalWrite(SOLENOID_PIN, LOW);
    solenoidState = false;
  }



}

// function that executes whenever data is requested by master
// this function is registered as an event, see setup()
void requestEvent() {
  if (switchHasToggled) {
    Wire.write('a');
    switchHasToggled = false;
  } else {
    Wire.write('b');
  }
  //Wire.write("hello "); // respond with message of 6 bytes
  // as expected by master
}