const int buttonPin = 2;    // GPIO for Button
const int redPin = 9;       // GPIO for Red LED
const int greenPin = 8;     // GPIO for Green LED
const int bluePin = 7;      // GPIO for Blue LED

int buttonState = 0;        // Current state of the button
int lastButtonState = 0;    // Previous state of the button
int mode = 0;               // Mode to track which LED color or fade sequence is active
bool ledOn = false;         // Track if RGB LED is ON or OFF
bool fadeMode = false;      // Track if we are in fade sequence mode
unsigned long buttonPressTime = 0;   // Time when the button is pressed
const unsigned long holdTime = 2000; // 2 seconds hold time for fade mode
const int fadeDelay = 5;    // Delay for smooth fade transitions

void setup() 
{
  pinMode(buttonPin, INPUT);
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
  turnOffAllLEDs();  // Initially, turn off all LEDs
}

void loop() 
{
  buttonState = digitalRead(buttonPin);
  
  if (buttonState == HIGH && lastButtonState == LOW) 
  {
    buttonPressTime = millis();  // Record button press time
  }
  
  if (buttonState == LOW && lastButtonState == HIGH) 
  {
    unsigned long pressDuration = millis() - buttonPressTime;
    if (pressDuration < holdTime) 
    {
      handleShortPress();  // Short press handling
    } 
    else if (pressDuration >= holdTime) 
    {
      handleLongPress();  // Long press handling (switch to fade mode)
    }
    delay(50);  // Debounce delay
  }

  // If fade mode is active, continuously run fade sequences
  if (fadeMode) 
  {
    cycleFadeSequences();  
  }
  
  lastButtonState = buttonState;
}

// Function to handle short button press (less than hold time)
void handleShortPress() 
{
  if (!fadeMode) 
  {
    // Solid color mode
    if (ledOn) 
    {
      cycleLEDs();  // Cycle through solid colors
    } 
    else 
    {
      ledOn = true;
      mode = 1;  // Start with Red
      turnOnLED(mode);
    }
  } 
  else 
  {
    // Fade sequence mode
    cycleFadeSequences();  // Cycle through fade sequences
  }
}

// Function to handle long button press (hold for holdTime)
void handleLongPress() 
{
  if (!fadeMode) 
  {
    fadeMode = true;  // Enter fade sequence mode
    mode = 1;         // Start with first fade sequence
  } 
  else 
  {
    fadeMode = false; // Exit fade mode to solid color mode
    turnOffAllLEDs();
    ledOn = false;
    mode = 0;         // Reset mode
  }
}

// Function to cycle through solid colors (Red, Green, Blue, etc.)
void cycleLEDs() 
{
  mode++;
  if (mode > 10) 
  {
    mode = 1;  // Wrap around to the first color after the last
  }
  turnOnLED(mode);
}

// Function to turn on the corresponding LED based on mode
void turnOnLED(int mode) 
{
  turnOffAllLEDs();  // Turn off all LEDs before turning on the next one
  switch (mode) 
  {
    case 1: analogWrite(redPin, 255); Serial.println("RED"); break;
    case 2: analogWrite(greenPin, 255); Serial.println("GREEN"); break;
    case 3: analogWrite(bluePin, 255); Serial.println("BLUE"); break;
    case 4: analogWrite(redPin, 255); analogWrite(greenPin, 255); Serial.println("YELLOW"); break;
    case 5: analogWrite(greenPin, 255); analogWrite(bluePin, 255); Serial.println("CYAN"); break;
    case 6: analogWrite(redPin, 255); analogWrite(bluePin, 255); Serial.println("MAGENTA"); break;
    case 7: analogWrite(redPin, 255); analogWrite(greenPin, 255); analogWrite(bluePin, 255); Serial.println("WHITE"); break;
    case 8: analogWrite(redPin, 255); analogWrite(greenPin, 128); Serial.println("ORANGE"); break;
    case 9: analogWrite(redPin, 128); analogWrite(bluePin, 128); Serial.println("PURPLE"); break;
    case 10: analogWrite(greenPin, 191); analogWrite(bluePin, 255); Serial.println("LIGHT BLUE"); break;
  }
}

// Function to cycle through 10 fade sequences
void cycleFadeSequences() 
{
  if (!fadeMode) return; // Exit if fade mode is off
  
  mode++;
  if (mode > 10) 
  {
    mode = 1;  // Wrap around to the first fade sequence after the last
  }
  runFadeSequence(mode);

  // Small delay between each fade sequence (optional)
  delay(500);
}

// Function to execute fade sequences based on the mode
void runFadeSequence(int mode) 
{
  switch (mode) 
  {
    case 1: fadeBetweenColors(255, 0, 0, 0, 255, 0); Serial.println("Fade1");break;       // Fade Red to Green
    case 2: fadeBetweenColors(0, 255, 0, 0, 0, 255); Serial.println("Fade2"); break;       // Fade Green to Blue
    case 3: fadeBetweenColors(0, 0, 255, 255, 0, 0); Serial.println("Fade3"); break;       // Fade Blue to Red
    case 4: fadeBetweenColors(255, 0, 255, 255, 255, 0); Serial.println("Fade4"); break;   // Fade Magenta to Yellow
    case 5: fadeBetweenColors(0, 255, 255, 255, 0, 255); Serial.println("Fade5"); break;   // Fade Cyan to Magenta
    case 6: fadeBetweenColors(255, 255, 0, 0, 255, 255); Serial.println("Fade6"); break;   // Fade Yellow to Cyan
    case 7: fadeBetweenColors(255, 255, 255, 128, 0, 128); Serial.println("Fade7"); break; // Fade White to Purple
    case 8: fadeBetweenColors(255, 128, 0, 0, 255, 128); Serial.println("Fade8"); break;   // Fade Orange to Light Blue
    case 9: 
    fadeBetweenColors(128, 0, 128, 0, 191, 255); 
    Serial.println("Fade9"); 
    break;   // Fade Purple to Light Blue
    case 10: 
    fadeBetweenColors(0, 191, 255, 255, 0, 0); 
    Serial.println("Fade10"); 
    break;    // Fade Light Blue to Red
  }
}

// Function to fade smoothly between two colors
void fadeBetweenColors(int redStart, int greenStart, int blueStart, int redEnd, int greenEnd, int blueEnd) 
{
  for (int i = 0; i <= 255; i++) 
  {
    int redValue = map(i, 0, 255, redStart, redEnd);
    int greenValue = map(i, 0, 255, greenStart, greenEnd);
    int blueValue = map(i, 0, 255, blueStart, blueEnd);

    analogWrite(redPin, redValue);
    analogWrite(greenPin, greenValue);
    analogWrite(bluePin, blueValue);

    delay(fadeDelay);  // Control fade speed
  }
}

// Function to turn off all LEDs
void turnOffAllLEDs() 
{
  analogWrite(redPin, LOW);
  analogWrite(greenPin, LOW);
  analogWrite(bluePin, LOW);
}