#include <Arduino.h>

// Pin Definitions
const uint8_t RedPIN = 15;
const uint8_t GreenPIN = 13;
const uint8_t YellowPIN = 12;
const uint8_t BluePIN = 14;

// Brightness Values
int RedValue = 0;
int GreenValue = 0;
int YellowValue = 0;
int BlueValue = 0;

// Calibration Factors (based on efficiency, range: 0.0 to 1.0)
const float RedCalibration = 0.8;   // Reduce brightness for Red
const float GreenCalibration = 1.0; // Green is at ideal efficiency
const float YellowCalibration = 0.9; // Slightly reduce brightness for Yellow
const float BlueCalibration = 0.7;  // Reduce brightness for Blue

// Timing Variables
unsigned long previousMillis = 0;
const int interval = 30; // Time between brightness updates (ms)

// Mode and States
volatile int currentMode = 0;  // The current mode (0, 1, etc.)
bool RedIncreasing = true;     // True if fading in, false if fading out
bool GreenIncreasing = true;
bool YellowIncreasing = true;
bool BlueIncreasing = true;

void setup() {
  // Pin Modes
  pinMode(RedPIN, OUTPUT);
  pinMode(GreenPIN, OUTPUT);
  pinMode(YellowPIN, OUTPUT);
  pinMode(BluePIN, OUTPUT);

  // Interrupt for Mode Switching
  attachInterrupt(digitalPinToInterrupt(2), changeMode, FALLING);
}

void loop() {
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    switch (currentMode) {
      case 0:
        // Mode 0: Fade Red in and out
        updateBrightness(RedPIN, RedValue, RedIncreasing, RedCalibration);
        break;

      case 1:
        // Mode 1: Fade Blue and Green alternately
        updateBrightness(BluePIN, BlueValue, BlueIncreasing, BlueCalibration);
        updateBrightness(GreenPIN, GreenValue, GreenIncreasing, GreenCalibration);
        break;

      case 2:
        // Mode 2: Fade all LEDs together
        updateBrightness(RedPIN, RedValue, RedIncreasing, RedCalibration);
        updateBrightness(GreenPIN, GreenValue, GreenIncreasing, GreenCalibration);
        updateBrightness(YellowPIN, YellowValue, YellowIncreasing, YellowCalibration);
        updateBrightness(BluePIN, BlueValue, BlueIncreasing, BlueCalibration);
        break;

      default:
        // Default: Turn all LEDs off
        analogWrite(RedPIN, 0);
        analogWrite(GreenPIN, 0);
        analogWrite(YellowPIN, 0);
        analogWrite(BluePIN, 0);
        break;
    }
  }
}

void updateBrightness(uint8_t pin, int &value, bool &increasing, float calibration) {
  if (increasing) {
    value++;
    if (value >= 255) increasing = false; // Reverse direction
  } else {
    value--;
    if (value <= 0) increasing = true; // Reverse direction
  }

  // Apply calibration factor
  int calibratedValue = value * calibration;
  analogWrite(pin, calibratedValue);
}

void changeMode() {
  currentMode = (currentMode + 1) % 3; // Cycle through modes (0, 1, 2)
}