#include <Adafruit_NeoPixel.h>
#define PIN 9
Adafruit_NeoPixel strip = Adafruit_NeoPixel(4, PIN, NEO_GRB + NEO_KHZ800);  // Parameter 1 = number of pixels in strip shown as 60. Parameter 2 = pin number defined above as 6

//button states
int buttonPin = 6;
boolean buttonState;
boolean previousButtonState = 1;

//calibrating time
unsigned long timer;
int pressTime = 2000; //how many milliseconds must the button be pressed to register a calibration press

//LED
const int LED = 9;
int brightness = 0;    // how bright the LED is
int fadeAmount = 5;    // how many points to fade the LED by


//sensor states
int sensorPin = 10;
int sensorValue = 0;
int maxValue;
int minValue;

boolean maxSet = false;
boolean minSet = false;


// to remember what part of the configuration you are in
int configState = 0; 



void setup(){
  //start serial connection
  Serial.begin(9600);


  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(sensorPin, INPUT);
  strip.begin();
  strip.show(); // Initialize all pixels to 'off'

  pinMode(LED, OUTPUT);
  strip.begin();
  strip.show(); // Initialize all pixels to 'off'

}

void loop(){
  buttonState = digitalRead(buttonPin);
  sensorValue = analogRead(sensorPin);//read the sensor pin and save its value
  Serial.println(sensorValue);

  //look for the instant that the buttonState goes from HIGH 'not pressed' to LOW 'pressed'
  if(buttonState == LOW && previousButtonState == HIGH){
    //start timer (take a sample of what time it is and remember it)
    timer = millis(); 
    //set previousButtonState to LOW or 'pressed';
    previousButtonState = LOW;
    Serial.println("button pressed");
    delay (3000);
  }

  //see if the button is still pressed
  // do this to calibrate types of glasses
  if(buttonState == LOW && previousButtonState == LOW){
    //calculate how long the button has been pressed
    //if(millis() - timer >= pressTime){//if the time that it has been held is greater than 3 seconds then read the sensor for calibration
      //analize that value
     // if(sensorValue > maxValue){//if the sensor value is greater than max value - glass is full - then set max value to sensor value
        maxValue = sensorValue;
        maxSet = true;
        //configState = 1;
        Serial.print("max set = ");
        Serial.println(sensorValue);
        strip.setPixelColor(0,255,255,0); //set leds to yellow to indicate you are half way thru the calibration 
        strip.show();                  
        delay(2000);
        strip.setPixelColor(0,0,0,0);  //set leds to yellow to indicate you are half way thru the calibration 
        strip.show();                  
        delay (3000);
      
     // if(sensorValue < maxValue){// if the sensor value is less than max value then set min value to the sensor value
        minValue = sensorValue; 
        minSet = true;
        //configState = 2;
        Serial.print("min set");
        Serial.println(sensorValue);
        strip.setPixelColor(0,255,255,0);  //set leds to yellow to indicate you are half way thru the calibration 
        strip.show();                  
        delay (2000);
        strip.setPixelColor(0,0,0,0);  //set leds to yellow to indicate you are half way thru the calibration 
        strip.show();                  
        delay (2000);
  
    previousButtonState = HIGH; //button has been released and we set the previous buttonstate to HIGH 

      //}
    }
  

  if(buttonState == HIGH){
    previousButtonState = HIGH; //button has been released and we set the previous buttonstate to HIGH 
  }

  //turn LED lights RED when glass is 3/4 full
  if(maxSet == true && minSet == true){
    if(sensorValue <= maxValue * 0.75 && sensorValue >= maxValue * 0.74){
      Serial.println("at 3/4 range");
      Serial.println(sensorValue);
      lightFade();
      strip.setPixelColor(0,brightness,0,0);  //set leds to yellow to indicate you are half way thru the calibration 
      strip.show();                  
      delay (3000);
    }
    else if(sensorValue <= maxValue * 0.25 && sensorValue >= maxValue * 0.24){
      Serial.println("at 1/4 range");
      Serial.println(sensorValue);
      strip.setPixelColor(0,strip.Color(0,0,0));
      strip.show();  
    }
  }
}


void lightFade(){
  
    brightness = brightness + fadeAmount; 
    if (brightness <= 0 || brightness >= 255) {
      fadeAmount = -fadeAmount ;
      strip.setPixelColor(0,brightness,0,0); //flash LED Red when sensor value is less than or equal to the minimum value
      strip.show();          //Sends the comand to the pixels to Light up in the specified code above.
      delay (30);
  
    }
  
}