const int ledPinRed = 11;
const int ledPinGreen = 10;
const int ledPinBlue = 9;
const int flexPin = A0;

int pastValue = 0;
int openMillis = 0;
int closedMillis = 0;

// how long will the gesture have to run in millis to register as a gesture?
const int lengthThreshold = 100;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(ledPinRed, OUTPUT);
  pinMode(ledPinGreen, OUTPUT);
  pinMode(ledPinBlue, OUTPUT);
}
void loop() {
  int mapped = readDegrees();

  // if the hand is in a fist
  bool isClosed = mapped > 120;

  // save the current value
  bool currentValue = mapped;

  if (isClosed == true) {
    // the closed fist mode overrides any other mode
    tunesMode();
  } else if (currentValue > pastValue) {
    // increment counter for hand closing
    closedMillis++;
    // if the hand was opening, reset that counter to reset detection
    if (openMillis > 0) {
      openMillis = 0;
    }
    // turn on warming mode if hand has been closing for time threshold
    if (closedMillis > lengthThreshold) {
      warmingMode();
    }
  } else {
    // increment counter for hand opening
    openMillis++;
    // if the hand was closing, reset that counter to reset detection
    if (closedMillis > 0) {
      closedMillis = 0;
    }
    // turn on messaging mode if hand has been closing for time threshold
    if (openMillis > lengthThreshold) {
      messagingMode();
    }
  }

  // set the past value to compare with the current state on next loop
  pastValue = mapped;

  // delay to ensure accurate sensor readings
  delay(1);
}
int readDegrees() {
  int flexValue = analogRead(flexPin);
  // convert the value to one that is relative to 0 and positive
  int normalized = abs(flexValue - 76);
  // convert the range to degrees (must be recalibrated according to resistor strength)
  return map(normalized, 0, 35, 0, 90);
}
void tunesMode() {
  // tunes mode is yellow
    //Serial.println("Tunes");
    analogWrite(ledPinRed, 255);
    analogWrite(ledPinBlue, 0);
    analogWrite(ledPinGreen, 0);
}
void messagingMode() {
  // message mode is purple
      //Serial.println("Messaging");
      analogWrite(ledPinRed, 0);
      analogWrite(ledPinBlue, 0);
      analogWrite(ledPinGreen, 255);
}
void warmingMode() {
  // warming mode is blue
      //Serial.println("Warming");
      analogWrite(ledPinRed, 0);
      analogWrite(ledPinBlue, 255);
      analogWrite(ledPinGreen, 0);
}