const int buttonPin = 3;     // the number of the pushbutton pin
const int ledPin1 =  0;      // the number of the LED pin1
const int ledPin2 =  1;      // the number of the LED pin2
const int ledPin3 =  6;      // the number of the LED pin3


// variables will change:
int buttonState = 0;         // variable for reading the pushbutton status
int buttonCount =  0;

int delay_interval = 0;

void setup() {
  Serial.begin(115200);
  // initialize the LED pin1 as an output:
  pinMode(ledPin1, OUTPUT);
  // initialize the LED pin2 as an output:
  pinMode(ledPin2, OUTPUT);
  // initialize the LED pin3 as an output:
  pinMode(ledPin3, OUTPUT);
  // initialize the button pin as an input pullup:
  pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);
  Serial.print("buttonState: ");
  Serial.println(buttonState);
  Serial.print("buttonCount: ");
  Serial.println(buttonCount);
  
  if (buttonState == LOW) {
    buttonCount+=  1; 
    delay(500);
    if (buttonCount > 3) {
      buttonCount = 0;
    }
  }

  if (buttonCount == 0) {
    digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, LOW);
    digitalWrite(ledPin3, LOW);
  } else if (buttonCount == 1) {
// fade in from min to max in increments of 5 points:
  for (int fadeValue = 0 ; fadeValue <= 255; fadeValue += 5) {
    // sets the value (range from 0 to 255):
    analogWrite(ledPin1, fadeValue);
    // wait for 30 milliseconds to see the dimming effect
    delay(30);
  }

  // fade out from max to min in increments of 5 points:
  for (int fadeValue = 255 ; fadeValue >= 0; fadeValue -= 5) {
    // sets the value (range from 0 to 255):
    analogWrite(ledPin1, fadeValue);
    // wait for 30 milliseconds to see the dimming effect
    delay(30);
  }
  
  } else if (buttonCount == 2) {
// fade in from min to max in increments of 5 points:
  for (int fadeValue = 0 ; fadeValue <= 255; fadeValue += 5) {
    // sets the value (range from 0 to 255):
    analogWrite(ledPin2, fadeValue);
    // wait for 30 milliseconds to see the dimming effect
    delay(30);
  }

  // fade out from max to min in increments of 5 points:
  for (int fadeValue = 255 ; fadeValue >= 0; fadeValue -= 5) {
    // sets the value (range from 0 to 255):
    analogWrite(ledPin2, fadeValue);
    // wait for 30 milliseconds to see the dimming effect
    delay(30);
  }
  } else if (buttonCount == 3) {
// fade in from min to max in increments of 5 points:
  for (int fadeValue = 0 ; fadeValue <= 255; fadeValue += 5) {
    // sets the value (range from 0 to 255):
    analogWrite(ledPin3, fadeValue);
    // wait for 30 milliseconds to see the dimming effect
    delay(30);
  }

  // fade out from max to min in increments of 5 points:
  for (int fadeValue = 255 ; fadeValue >= 0; fadeValue -= 5) {
    // sets the value (range from 0 to 255):
    analogWrite(ledPin3, fadeValue);
    // wait for 30 milliseconds to see the dimming effect
    delay(30);
  }
}  
  }