#include <Adafruit_NeoPixel.h>

#define LED_PIN 2
#define POT_PIN 4
#define BUTTON_PIN 0 // Boot button
#define NUM_LEDS 1

Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

// Brightness variable (0-255)
int brightness = 5; // Default brightness
bool potentiometerActive = true; // Control logic flag
int currentColorIndex = 0; // Index for button-controlled color
unsigned long buttonPressStart = 0; // For detecting long presses
bool buttonHeld = false; // Tracks if the button is being held

// 15 Colors evenly divided
uint32_t colors[15] = {
  strip.Color(255, 0, 0),     // Red
  strip.Color(255, 64, 0),    // Red-Orange
  strip.Color(255, 128, 0),   // Orange
  strip.Color(255, 255, 0),   // Yellow
  strip.Color(128, 255, 0),   // Yellow-Green
  strip.Color(0, 255, 0),     // Green
  strip.Color(0, 255, 128),   // Green-Cyan
  strip.Color(0, 255, 255),   // Cyan
  strip.Color(0, 128, 255),   // Cyan-Blue
  strip.Color(0, 0, 255),     // Blue
  strip.Color(128, 0, 255),   // Blue-Purple
  strip.Color(255, 0, 255),   // Magenta
  strip.Color(255, 0, 128),   // Pink
  strip.Color(255, 20, 147),  // Deep Pink
  strip.Color(255, 255, 255)  // White
};

void setup() {
  strip.begin();
  strip.setBrightness(brightness); // Set initial brightness
  strip.show();
  pinMode(POT_PIN, INPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP); // Boot button with pull-up
  Serial.begin(115200);
  Serial.println("Enter brightness (0-255):");
}

void loop() {
  // Check for serial input to adjust brightness
  if (Serial.available()) {
    String input = Serial.readStringUntil('\n'); // Read input as a string
    int newBrightness = input.toInt(); // Convert input to an integer

    // Validate and update brightness
    if (newBrightness >= 0 && newBrightness <= 255) {
      brightness = newBrightness;
      strip.setBrightness(brightness);
      strip.show();
      Serial.print("Brightness updated to: ");
      Serial.println(brightness);
    } else {
      Serial.println("Invalid input. Enter a number between 0 and 255.");
    }
  }

  // Check the state of the button
  if (digitalRead(BUTTON_PIN) == LOW) { // Button pressed
    if (!buttonHeld) {
      buttonPressStart = millis(); // Record the time the button was pressed
      buttonHeld = true;
    } else if (millis() - buttonPressStart >= 3000) { // Hold button for 3 seconds
      // Button held for 3 seconds
      potentiometerActive = true; // Reactivate potentiometer control
      Serial.println("Potentiometer control reinstated.");
    }
  } else {
    if (buttonHeld) {
      if (millis() - buttonPressStart < 3000) { // Button was released before 3 seconds
        potentiometerActive = false; // Deactivate potentiometer control
        currentColorIndex = (currentColorIndex + 1) % 15; // Move to the next color
        strip.setPixelColor(0, colors[currentColorIndex]);
        strip.show();
        Serial.print("Button pressed, showing color index: ");
        Serial.println(currentColorIndex);
      }
      buttonHeld = false; // Reset button held state
    }
  }

  // Potentiometer control logic
  if (potentiometerActive) {
    // Read the potentiometer value (0 to 4095)
    int potValue = analogRead(POT_PIN);

    // Map the potentiometer value to a range of 0 to 14 (15 colors)
    int colorIndex = map(potValue, 0, 4095, 0, 14);

    // Set the LED to the corresponding color
    strip.setPixelColor(0, colors[colorIndex]);
    strip.show();

    delay(50); // Short delay for stability
  } else {
    delay(50); // Prevent rapid looping when potentiometer control is off
  }
}