// DEFINE ALL PINS TO COMPONENTS
// LED PINS + BRIGHTNESSES
const int LED_YELLOW_PIN = 5; int YELLOW_BRIGHTNESS = 0;
const int LED_BLUE_PIN = 6; int BLUE_BRIGHTNESS = 0;
const int LED_GREEN_PIN = 9; int GREEN_BRIGHTNESS = 0;
const int LED_RED_PIN = 10; int RED_BRIGHTNESS = 0;
// POT_PIN
#define potValue analogRead(POT_PIN)
const int POT_PIN = A0;  
// LED brightness
int POT_INPUT_VALUE = 0;
int POT_INPUT_PREV_VALUE = 0;
int LED_BRIGHTNESS = 0;     
int time = 0;
 
void setup() {
  // ESTABLISH PIN MODES 
  pinMode(LED_YELLOW_PIN, OUTPUT);
  pinMode(LED_BLUE_PIN, OUTPUT);   
  pinMode(LED_GREEN_PIN, OUTPUT);  
  pinMode(LED_RED_PIN, OUTPUT);  
  // CREATE TIME-STAMP
  time = millis();
  // READ POTENTIOMETER. MAP IT TO PMW VALUE AND SAVE TO VARIABLE 
  POT_INPUT_VALUE = potValue;
  POT_INPUT_PREV_VALUE = potValue;
  // ENABLE SERIAL MONITOR FOR DEBUGGING
  Serial.begin(9600);         
}

// ------ PRINT VALUES TO SCREEN --------
void displayValues() {
  Serial.print("Sensor: ");
  Serial.println(POT_INPUT_VALUE);
  Serial.print("PWM Output: ");
  Serial.println(LED_BRIGHTNESS);
}

// -------- OUTPUT TO LED'S --------
void outputLED() {
  analogWrite(LED_YELLOW_PIN, YELLOW_BRIGHTNESS);
  analogWrite(LED_RED_PIN, RED_BRIGHTNESS);
  analogWrite(LED_GREEN_PIN, GREEN_BRIGHTNESS);
  analogWrite(LED_BLUE_PIN, BLUE_BRIGHTNESS);
  
}

// -------- UPDATE EACH INDIVIDUAL LED'S BRIGHTNESS BASED ON THE POT WHILE MAKING WAVE PATTERN --------
void updateValues() {
  LED_BRIGHTNESS = map(POT_INPUT_VALUE, 0, 1023, 0, 255);

  YELLOW_BRIGHTNESS = LED_BRIGHTNESS;
  RED_BRIGHTNESS = LED_BRIGHTNESS;
  GREEN_BRIGHTNESS = LED_BRIGHTNESS;
  BLUE_BRIGHTNESS = LED_BRIGHTNESS;
}

//  ------------------- POT VALUE HAS CHANGED. UPDATE LED'S GRADUALLY IN WAVY PATTERN ----------------
  void changingValues() {
    // LED'S GRADUATE UP
    if (potValue > POT_INPUT_PREV_VALUE){
      Serial.println("ADJUST +");                                                               // DEBUGGING
      // STARTING WITH THE RED LED, GRADUALLY ADJUST EACH LED BRIGTHNESS IN A WAVE-LIKE PATTERN (LEFT TO RIGHT)
      for(int i = LED_BRIGHTNESS; i <= map(potValue, 0, 1023, 0, 255); i+= 6){
        Serial.print("PWM: ");                                                              // DEBUGGING
        Serial.println(i);                                                                  // DEBUGGING
        delay(50);
        analogWrite(LED_RED_PIN, i);
        delay(50);
        analogWrite(LED_GREEN_PIN, i);
        delay(50);
        analogWrite(LED_BLUE_PIN, i);
        delay(50);
        analogWrite(LED_YELLOW_PIN, i);
        delay(50);
      }
    }

    else if (potValue < POT_INPUT_PREV_VALUE){
      Serial.println("ADJUST -");                                                                     // DEBUGGING
      // STARTING WITH THE YELLOW LED, GRADUALLY ADJUST EACH LED BRIGTHNESS IN A WAVE-LIKE PATTERN (RIGHT TO LEFT)
      for(int i = LED_BRIGHTNESS; i >= map(potValue, 0, 1023, 0, 255); i-= 6){
        Serial.print("PWM: ");                                                                    // DEBUGGING
        Serial.println(i);                                                                        // DEBUGGING
        delay(50);
        analogWrite(LED_YELLOW_PIN, i);
        delay(50);
        analogWrite(LED_BLUE_PIN, i);
        delay(50);
        analogWrite(LED_GREEN_PIN, i);
        delay(50);
        analogWrite(LED_RED_PIN, i);
        delay(50);
      }
    }

    Serial.println("--function end--");                                            // DEBUGGING
    LED_BRIGHTNESS = map(potValue, 0, 1023, 0, 255);
    outputLED();

  }
 
// ===================================================================================================
// =======================================  MAIN LOOP  ===============================================

void loop() {
  time = millis();                                                // TIME STAMP FOR ALLOWING USER ADJUSTMENT TIME
  delay(10);

  // CHECK FOR POT CHANGES WITHIN TIME LIMIT TO ALLOW USER TIME TO ADJUST FURTHER
  while(abs(potValue - POT_INPUT_VALUE) > 5 && millis() - time < 100){
    Serial.print("---- Start Loop Time: ");                                           // DEBUGGING
    Serial.println(millis());
    Serial.print("Current Value: ");
    Serial.println(potValue);
    Serial.print("Prev Value ");
    Serial.println(POT_INPUT_VALUE);
  }
  Serial.println("--OUT--- ");                                        // DEBUGGING
  Serial.print("Time: ");                                             // DEBUGGING
  Serial.println(millis());                                           // DEBUGGING


  // IF VALUE DIFFERENCE IS LARGE ENOUGH GO TO changingValues()
  if(abs(potValue - POT_INPUT_VALUE) > 12){
    // POT_INPUT_VALUE = potValue;                                   // UPDATE POT INPUT VARIABLE
    changingValues();                                                // CALL FUNCTION THAT GRADUATES LED CHANGING IN WAVY PATTERN
  }

  // UPDATE POT VALUE
  POT_INPUT_VALUE = potValue;                                        // UPDATE POT INPUT VARIABLE

  //displayValues();                                                  // DEBUGGING
  updateValues();
  outputLED();
}