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

#define BUTTON_PIN 2
#define START_BUTTON_PIN 3
#define ALARM_PIN 4

LiquidCrystal_I2C lcd(0x27, 16, 2);

int timerDurations[] = {1, 15, 30, 45, 60};
int currentTimerIndex = 4; // Default to 60 minutes
int remainingTime;
bool timerRunning = false;
unsigned long previousMillis = 0;
const long interval = 1000; // 1 second in milliseconds

int resetButtonPressCount = 0; // Counter for reset button presses
unsigned long lastResetPressTime = 0; // Track the last time the reset button was pressed
const unsigned long resetTimeout = 3000; // Time window for counting resets (3 seconds)

void setup() {
    pinMode(BUTTON_PIN, INPUT_PULLUP);
    pinMode(START_BUTTON_PIN, INPUT_PULLUP);
    pinMode(ALARM_PIN, OUTPUT);
    lcd.init();
    lcd.backlight();
    resetTimer();
}

void loop() {
    if (buttonPressed(BUTTON_PIN)) {
        changeTimer();
    }

    if (buttonPressed(START_BUTTON_PIN)) {
        if (!timerRunning && remainingTime == 0) {
            resetTimer(); // Reset timer if it's finished
        } else {
            timerRunning = true;
        }
    }

    if (timerRunning) {
        unsigned long currentMillis = millis();
        if (currentMillis - previousMillis >= interval) {
            previousMillis = currentMillis;
            if (remainingTime > 0) {
                remainingTime--;
                updateDisplay();
            } else {
                triggerAlarm();
            }
        }
    }

    // Check if the reset button is pressed more than 3 times within 3 seconds
    if (resetButtonPressCount > 3 && (millis() - lastResetPressTime) <= resetTimeout) {
        resetRunningTime(); // Reset the running time
        resetButtonPressCount = 0; // Reset the counter
    }
}

bool buttonPressed(int pin) {
    if (digitalRead(pin) == LOW) {
        delay(50); // Debounce delay
        if (digitalRead(pin) == LOW) {
            while (digitalRead(pin) == LOW); // Wait for release

            // If the button is the reset button (BUTTON_PIN), increment the counter
            if (pin == BUTTON_PIN) {
                resetButtonPressCount++;
                lastResetPressTime = millis(); // Update the last press time
            }

            return true;
        }
    }
    return false;
}

void changeTimer() {
    if (!timerRunning) {
        currentTimerIndex = (currentTimerIndex + 1) % 5; // Cycle through all options
        resetTimer();
    }
}

void resetTimer() {
    remainingTime = timerDurations[currentTimerIndex] * 60; // Convert minutes to seconds
    updateDisplay();
    digitalWrite(ALARM_PIN, LOW); // Ensure alarm is off on reset
    timerRunning = false;
}

void resetRunningTime() {
    remainingTime = timerDurations[currentTimerIndex] * 60; // Reset to the selected duration
    updateDisplay();
    digitalWrite(ALARM_PIN, LOW); // Ensure alarm is off
    timerRunning = false; // Stop the timer
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Time Reset!");
    delay(1000); // Display the message for 1 second
    updateDisplay(); // Update the display with the new time
}

void updateDisplay() {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Time left: ");
    lcd.setCursor(0, 1);
    lcd.print(remainingTime / 60);
    lcd.print(" min ");
    lcd.print(remainingTime % 60);
    lcd.print(" sec");
}

void triggerAlarm() {
    digitalWrite(ALARM_PIN, HIGH);
    timerRunning = false;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Time's up!");
}