/*
  State change detection (edge detection)

  Often, you don't need to know the state of a digital input all the time, but
  you just need to know when the input changes from one state to another.
  For example, you want to know when a button goes from OFF to ON. This is called
  state change detection, or edge detection.

  This example shows how to detect when a button or button changes from off to on
  and on to off.

  The circuit:
  - pushbutton attached to pin 2 from +5V
  - 10 kilohm resistor attached to pin 2 from ground
  - LED attached from pin 13 to ground through 220 ohm resistor (or use the
    built-in LED on most Arduino boards)

  created  27 Sep 2005
  modified 30 Aug 2011
  by Tom Igoe

  This example code is in the public domain.

  https://www.arduino.cc/en/Tutorial/BuiltInExamples/StateChangeDetection
*/

// this constant won't change:
const int buttonPin = 2;  // the pin that the pushbutton is attached to
const int ledPin = 12;    // the pin that the LED is attached to

// Variables will change:
int buttonPushCounter = 0;  // counter for the number of button presses
int buttonState = 0;        // current state of the button
int lastButtonState = 0;    // previous state of the button
int PowerState = 0;         // 0 = awake, 1 = go to sleep

void setup() {
  // initialize the button pin as a input:
  pinMode(buttonPin, INPUT);
  // initialize the LED as an output:
  pinMode(ledPin, OUTPUT);
  // initialize serial communication:
  Serial.begin(9600);
  // LED off to start with
  digitalWrite(ledPin, LOW);
  //  confirm Switch State
  Serial.println(digitalRead(buttonPin));
  // Initialization Complete
  Serial.println("Initialization Complete!");
  
}


void loop() {
  // read the pushbutton input pin:
  buttonState = digitalRead(buttonPin);

  // compare the buttonState to its previous state
  if (buttonState != lastButtonState) {
    // if the state has changed, increment the counter
    if (buttonState == HIGH) {
      // if the current state is HIGH then the button went from off to on:
      if (PowerState == 0) {
        PowerState = 1;  // allow for sleeping
      } else {
        PowerState = 0; // wake status
      }
      Serial.print(PowerState);
      Serial.println(" PowerState");
      buttonPushCounter++;
      Serial.println("on");
      Serial.print("number of button pushes: ");
      Serial.println(buttonPushCounter);
    } else {
      // if the current state is LOW then the button went from on to off:
      Serial.println("off");
    }
    // Delay a little bit to avoid bouncing
    delay(50);
    // if Powerstate 1 then put to sleep
    //attach interrupt
    //after wakeup
    //detach interrupt
    //continue
  }
  // save the current state as the last state, for next time through the loop
  lastButtonState = buttonState;
  // Serial.println(lastButtonState);


  // turns on the LED every 2 button pushes by checking the modulo of the
  // button push counter. the modulo function gives you the remainder of the
  // division of two numbers:
  if (buttonPushCounter % 2 == 0) {
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }
}