#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Set the LCD address to 0x27 for a 16 char and 2 line display
LiquidCrystal_I2C lcd(0x27, 16, 2);

const int RELAY_PIN = 8; // Relay connected to pin 8
const int GREEN_LED_PIN = 9; // Green LED connected to pin 9
const int RED_LED_PIN = 10; // Red LED connected to pin 10
const int BUZZER_PIN = 11; // Buzzer connected to pin 11
const unsigned long RELAY_ON_DURATION = 10000; // 10 seconds
const unsigned long RELAY_OFF_DURATION = 20000; // 20 seconds

unsigned long relayOnStartTime = 0;
unsigned long relayOffStartTime = 0;
unsigned long lastUpdate = 0;
unsigned long blinkTimer = 0;

bool isRelayOn = false;
int blinkCount = 0;

void setup() {
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  digitalWrite(RELAY_PIN, LOW); // Turn off the relay initially
  digitalWrite(GREEN_LED_PIN, LOW);
  digitalWrite(RED_LED_PIN, HIGH);
  noTone(BUZZER_PIN);

  lcd.begin(16, 2); // Initialize the LCD with 16 columns and 2 rows
  lcd.backlight();
  lcd.clear();
}

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

  if (!isRelayOn && currentMillis - relayOffStartTime >= RELAY_OFF_DURATION) {
    // Turn on the relay, green LED, and buzzer
    digitalWrite(RELAY_PIN, HIGH);
    tone(BUZZER_PIN, 2000, 500);

    // Display "Valve Open" and the timer
    lcd.clear();
    lcd.print("Valve Open");

    // Update the relay on start time and state
    relayOnStartTime = currentMillis;
    isRelayOn = true;
    blinkCount = 0; // Reset blink count
    blinkTimer = currentMillis;
  }

  if (isRelayOn && currentMillis - relayOnStartTime >= RELAY_ON_DURATION) {
    // Turn off the relay, green LED, and buzzer
    digitalWrite(RELAY_PIN, LOW);
    noTone(BUZZER_PIN);

    // Display "Valve Close" and the timer
    lcd.clear();
    lcd.print("Valve Close");

    // Update the relay off start time and state
    relayOffStartTime = currentMillis;
    isRelayOn = false;
    blinkCount = 0; // Reset blink count
    blinkTimer = currentMillis;
  }

  // Blink LEDs in a 3-blink pattern with slower intervals
  if (isRelayOn) {
    if (currentMillis - blinkTimer >= 500) { // Every 500ms
      digitalWrite(GREEN_LED_PIN, HIGH);
      delay(200); // On duration for each blink
      digitalWrite(GREEN_LED_PIN, LOW);
      blinkTimer = currentMillis;
      blinkCount++;
    }
  } else {
    if (currentMillis - blinkTimer >= 500) { // Every 500ms
      digitalWrite(RED_LED_PIN, HIGH);
      delay(200); // On duration for each blink
      digitalWrite(RED_LED_PIN, LOW);
      blinkTimer = currentMillis;
      blinkCount++;
    }
  }

  // Reset blinkCount after 3 blinks
  if (blinkCount >= 3) {
    blinkTimer = currentMillis + 1000; // Add delay for pause
    blinkCount = 0;
  }

  // Update the timer display every second
  if (currentMillis - lastUpdate >= 1000) {
    lastUpdate = currentMillis;
    if (isRelayOn) {
      updateTimer(relayOnStartTime, RELAY_ON_DURATION);
    } else {
      updateTimer(relayOffStartTime, RELAY_OFF_DURATION);
    }
  }
}

void updateTimer(unsigned long startTime, unsigned long duration) {
  unsigned long currentMillis = millis();
  unsigned long elapsedTime = currentMillis - startTime;
  unsigned long secondsRemaining = (duration - elapsedTime) / 1000;
  unsigned long minutes = secondsRemaining / 60;
  unsigned long seconds = secondsRemaining % 60;

  lcd.setCursor(0, 1);
  lcd.print("Timer: ");
  lcd.print(minutes);
  lcd.print(":");
  if (seconds < 10) {
    lcd.print("0");
  }
  lcd.print(seconds);
}