#include <Adafruit_NeoPixel.h>

#define BUTTON_PIN   2  // Button pin
#define LED_PIN      5  // NeoPixel LED strip pin
#define LED_COUNT    16
#define BUZZER_PIN   6  // Buzzer pin
#define RESET_PIN    3  // Reset button pin

Adafruit_NeoPixel strip(LED_COUNT, LED_PIN, NEO_GRB + NEO_KHZ800);

enum State { IDLE, FIRST_CYCLE, FIRST_CYCLE_FINISHED, SECOND_CYCLE, SECOND_CYCLE_FINISHED, PAUSED, FINISHED, PULSING };
State state = IDLE;

unsigned long previousMillis = 0;
const long interval = 1000; // Interval at which to update the LEDs (1 second)
int ledIndex = LED_COUNT; // Start with all LEDs on for initialization
int pulseCount = 0; // Count pulses for the last LED

void setup() {
 pinMode(BUTTON_PIN, INPUT_PULLUP); // Use internal pull-up resistor
 pinMode(BUZZER_PIN, OUTPUT);       // Set the buzzer pin as output
 pinMode(RESET_PIN, INPUT_PULLUP);  // Use internal pull-up resistor for reset button
 strip.begin();
 setAllLedsColor(strip.Color(255, 0, 255)); // Initialize all pixels to magenta
 strip.show();
}

void loop() {
 static bool lastButtonState = HIGH;
 static bool lastResetButtonState = HIGH;
 bool currentButtonState = digitalRead(BUTTON_PIN);
 bool currentResetButtonState = digitalRead(RESET_PIN);

 // Detect button press
 if (currentButtonState == LOW && lastButtonState == HIGH) {
   delay(50); // Debounce
   if (digitalRead(BUTTON_PIN) == LOW) {
     if (state == IDLE) {
       state = FIRST_CYCLE;
       ledIndex = LED_COUNT;
       pulseCount = 0; // Reset pulse count for new cycle
       previousMillis = millis();
       setAllLedsColor(strip.Color(0, 255, 0)); // Start with all LEDs green for first cycle
     } else if (state == FIRST_CYCLE_FINISHED) {
       state = SECOND_CYCLE;
       ledIndex = LED_COUNT;
       pulseCount = 0; // Reset pulse count for new cycle
       previousMillis = millis();
       setAllLedsColor(strip.Color(255, 255, 0)); // Start with all LEDs yellow for second cycle
     } else if (state == SECOND_CYCLE_FINISHED) {
       state = IDLE;
       setAllLedsColor(strip.Color(255, 255, 0)); // All LEDs yellow for the next cycle
     } else if (state == FIRST_CYCLE || state == SECOND_CYCLE) {
       state = PAUSED;
     } else if (state == PAUSED) {
       state = (state == FIRST_CYCLE) ? FIRST_CYCLE : SECOND_CYCLE;
       previousMillis = millis() - (interval * (LED_COUNT - ledIndex)); // Adjust timing to resume correctly
     }
   }
 }
 lastButtonState = currentButtonState;

 // Detect reset button press
 if (currentResetButtonState == LOW && lastResetButtonState == HIGH) {
   delay(50); // Debounce
   if (digitalRead(RESET_PIN) == LOW) {
     // "Boot" effect
     strip.setPixelColor(0, strip.Color(255, 255, 0)); // First LED yellow
     strip.show();
     delay(200);
     setAllLedsColor(strip.Color(255, 255, 0)); // Reset all LEDs to yellow
     strip.show();
     state = IDLE; // Reset state to IDLE
   }
 }
 lastResetButtonState = currentResetButtonState;

 if (state == FIRST_CYCLE || state == SECOND_CYCLE) {
   updateCycle();
 }

 if (state == PULSING) {
   pulseLastLed();
 }
}

void setAllLedsColor(uint32_t color) {
 for (int i = 0; i < LED_COUNT; i++) {
   strip.setPixelColor(i, color);
 }
 strip.show();
}

void updateCycle() {
 unsigned long currentMillis = millis();
 if (currentMillis - previousMillis >= interval && ledIndex > 0) {
   previousMillis = currentMillis;
   ledIndex--;

   for (int i = 0; i < ledIndex; i++) {
     // Update colors based on the current segment
     if (state == FIRST_CYCLE) {
       if (ledIndex > 9) {
         strip.setPixelColor(i, strip.Color(0, 255, 0)); // Green
       } else if (ledIndex > 4) {
         strip.setPixelColor(i, strip.Color(255, 165, 0)); // Orange
       } else {
         strip.setPixelColor(i, strip.Color(255, 0, 0)); // Red
       }
     } else if (state == SECOND_CYCLE) {
       strip.setPixelColor(i, strip.Color(255, 165, 0)); // Orange
     }
   }
   strip.setPixelColor(ledIndex, strip.Color(0, 0, 0)); // Turn off the next LED
   strip.show();

   if (ledIndex == 0) {
     state = PULSING; // Transition to pulsing the last LED
   }
 }
}

void pulseLastLed() {
 static bool isOn = false;
 static unsigned long lastPulseTime = millis();
 if (millis() - lastPulseTime > 100 && pulseCount < 20) { // Faster pulse rate for the last LED, limit to 20 pulses
   isOn = !isOn;
   strip.setPixelColor(0, isOn ? strip.Color(255, 0, 0) : strip.Color(0, 0, 0)); // Toggle the last LED
   strip.show();
   lastPulseTime = millis();
   pulseCount++;
   if (pulseCount == 20) {
     strip.setPixelColor(0, strip.Color(0, 0, 0)); // Ensure the last LED is off after pulsing
     strip.show();
     beep(); // Beep to signal the end of the cycle
     state = (state == FIRST_CYCLE) ? FIRST_CYCLE_FINISHED : SECOND_CYCLE_FINISHED; // Mark the cycle as finished
   }
 }
}

void beep() {
 digitalWrite(BUZZER_PIN, HIGH);
 delay(100); // Beep for 100 milliseconds
 digitalWrite(BUZZER_PIN, LOW);
}