#include <TimerOne.h>

// Pin Definitions
const int a = 22, b = 23, c = 24, d = 25, e = 26, f = 27, g = 28;  // Segment pins for the first display
const int a1 = 30, b1 = 31, c1 = 32, d1 = 33, e1 = 34, f1 = 36, g1 = 35; // Segment pins for the second display
const int red = 43;        // 7-Segment Display Pin
const int buzzer = 3;      // Buzzer pin 
const int pushbutton = 10; // Button pin
const int motionSensor = 2; // Motion sensor pin

// Global Variables
int counter = 60;          // Timer countdown (start at 60 seconds)
bool isCounting = false;   // Timer countdown active state
bool motionDetected = false; // Motion detected flag
bool buzzerActive = false; // Flag for buzzer status

// Timer Interrupt Function
void myTimerIsr_1() {
  if (isCounting && motionDetected) {
    if (counter > 0) {
      counter--; // Countdown logic
    } else {
      Timer1.detachInterrupt(); // Stop timer when it reaches 0
      buzzerActive = true;      // Activate buzzer tone
    }
  }
}

void setup() {
  // Initialize Segment Pins
  pinMode(a, OUTPUT); pinMode(b, OUTPUT); pinMode(c, OUTPUT); pinMode(d, OUTPUT); pinMode(e, OUTPUT); pinMode(f, OUTPUT); pinMode(g, OUTPUT);
  pinMode(a1, OUTPUT); pinMode(b1, OUTPUT); pinMode(c1, OUTPUT); pinMode(d1, OUTPUT); pinMode(e1, OUTPUT); pinMode(f1, OUTPUT); pinMode(g1, OUTPUT);

  pinMode(red, OUTPUT);         // Set up LED
  pinMode(buzzer, OUTPUT);      // Set up Buzzer
  pinMode(pushbutton, INPUT);   // Set up Button
  pinMode(motionSensor, INPUT); // Set up Motion Sensor

  Timer1.initialize(1000000);   // Timer interrupt every 1 second
}

void loop() {
  // Check Button Press to Start Countdown
  if (digitalRead(pushbutton) == HIGH && !isCounting) {
    isCounting = true;        // Enable countdown
    motionDetected = false;   // Reset motion detection
    counter = 60;             // Reset counter to 60 seconds
    digitalWrite(red, HIGH);  // Turn on LED
    buzzerActive = false;     // Deactivate buzzer
    noTone(buzzer);           // Ensure buzzer is off
    Timer1.attachInterrupt(myTimerIsr_1); // Start the timer interrupt
  }

  // Check Motion Sensor
  if (digitalRead(motionSensor) == HIGH) {
    motionDetected = true; // Set motion detected flag
  }

  // Handle Buzzer Behavior
  if (buzzerActive) {
    tone(buzzer, 5000);   // BOOOMM
  }

  // Update Display
  show(counter);

  // Turn off LED when countdown ends
  if (counter == 0) {
    digitalWrite(red, LOW);  // Turn off LED
  }
}

// Function to Display Number on 7-Segment Displays
void show(uint16_t time) {
  if (time == 0) {
    seg2(0); seg1(0); // Show "00" on display
  } else {
    seg2(time / 10);  // Display tens place
    seg1(time % 10);  // Display units place
  }
}

// Function to Display Numbers on First 7-Segment Display
void seg1(int disp) {
  switch (disp) {
    case 0: digitalWrite(a, LOW); digitalWrite(b, LOW); digitalWrite(c, LOW); digitalWrite(d, LOW); digitalWrite(e, LOW); digitalWrite(f, LOW); digitalWrite(g, HIGH); break;
    case 1: digitalWrite(a, HIGH); digitalWrite(b, LOW); digitalWrite(c, LOW); digitalWrite(d, HIGH); digitalWrite(e, HIGH); digitalWrite(f, HIGH); digitalWrite(g, HIGH); break;
    case 2: digitalWrite(a, LOW); digitalWrite(b, LOW); digitalWrite(c, HIGH); digitalWrite(d, LOW); digitalWrite(e, LOW); digitalWrite(f, HIGH); digitalWrite(g, LOW); break;
    case 3: digitalWrite(a, LOW); digitalWrite(b, LOW); digitalWrite(c, LOW); digitalWrite(d, LOW); digitalWrite(e, HIGH); digitalWrite(f, HIGH); digitalWrite(g, LOW); break;
    case 4: digitalWrite(a, HIGH); digitalWrite(b, LOW); digitalWrite(c, LOW); digitalWrite(d, HIGH); digitalWrite(e, HIGH); digitalWrite(f, LOW); digitalWrite(g, LOW); break;
    case 5: digitalWrite(a, LOW); digitalWrite(b, HIGH); digitalWrite(c, LOW); digitalWrite(d, LOW); digitalWrite(e, HIGH); digitalWrite(f, LOW); digitalWrite(g, LOW); break;
    case 6: digitalWrite(a, LOW); digitalWrite(b, HIGH); digitalWrite(c, LOW); digitalWrite(d, LOW); digitalWrite(e, LOW); digitalWrite(f, LOW); digitalWrite(g, LOW); break;
    case 7: digitalWrite(a, LOW); digitalWrite(b, LOW); digitalWrite(c, LOW); digitalWrite(d, HIGH); digitalWrite(e, HIGH); digitalWrite(f, HIGH); digitalWrite(g, HIGH); break;
    case 8: digitalWrite(a, LOW); digitalWrite(b, LOW); digitalWrite(c, LOW); digitalWrite(d, LOW); digitalWrite(e, LOW); digitalWrite(f, LOW); digitalWrite(g, LOW); break;
    case 9: digitalWrite(a, LOW); digitalWrite(b, LOW); digitalWrite(c, LOW); digitalWrite(d, LOW); digitalWrite(e, HIGH); digitalWrite(f, LOW); digitalWrite(g, LOW); break;
    default: digitalWrite(a, HIGH); digitalWrite(b, HIGH); digitalWrite(c, HIGH); digitalWrite(d, HIGH); digitalWrite(e, HIGH); digitalWrite(f, HIGH); digitalWrite(g, HIGH); break;
  }
}

// Function to Display Numbers on Second 7-Segment Display
void seg2(int disp) {
  switch (disp) {
    case 0: digitalWrite(a1, LOW); digitalWrite(b1, LOW); digitalWrite(c1, LOW); digitalWrite(d1, LOW); digitalWrite(e1, LOW); digitalWrite(f1, LOW); digitalWrite(g1, HIGH); break;
    case 1: digitalWrite(a1, HIGH); digitalWrite(b1, LOW); digitalWrite(c1, LOW); digitalWrite(d1, HIGH); digitalWrite(e1, HIGH); digitalWrite(f1, HIGH); digitalWrite(g1, HIGH); break;
    case 2: digitalWrite(a1, LOW); digitalWrite(b1, LOW); digitalWrite(c1, HIGH); digitalWrite(d1, LOW); digitalWrite(e1, LOW); digitalWrite(f1, HIGH); digitalWrite(g1, LOW); break;
    case 3: digitalWrite(a1, LOW); digitalWrite(b1, LOW); digitalWrite(c1, LOW); digitalWrite(d1, LOW); digitalWrite(e1, HIGH); digitalWrite(f1, HIGH); digitalWrite(g1, LOW); break;
    case 4: digitalWrite(a1, HIGH); digitalWrite(b1, LOW); digitalWrite(c1, LOW); digitalWrite(d1, HIGH); digitalWrite(e1, HIGH); digitalWrite(f1, LOW); digitalWrite(g1, LOW); break;
    case 5: digitalWrite(a1, LOW); digitalWrite(b1, HIGH); digitalWrite(c1, LOW); digitalWrite(d1, LOW); digitalWrite(e1, HIGH); digitalWrite(f1, LOW); digitalWrite(g1, LOW); break;
    case 6: digitalWrite(a1, LOW); digitalWrite(b1, HIGH); digitalWrite(c1, LOW); digitalWrite(d1, LOW); digitalWrite(e1, LOW); digitalWrite(f1, LOW); digitalWrite(g1, LOW); break;
    case 7: digitalWrite(a1, LOW); digitalWrite(b1, LOW); digitalWrite(c1, LOW); digitalWrite(d1, HIGH); digitalWrite(e1, HIGH); digitalWrite(f1, HIGH); digitalWrite(g1, HIGH); break;
    case 8: digitalWrite(a1, LOW); digitalWrite(b1, LOW); digitalWrite(c1, LOW); digitalWrite(d1, LOW); digitalWrite(e1, LOW); digitalWrite(f1, LOW); digitalWrite(g1, LOW); break;
    case 9: digitalWrite(a1, LOW); digitalWrite(b1, LOW); digitalWrite(c1, LOW); digitalWrite(d1, LOW); digitalWrite(e1, HIGH); digitalWrite(f1, LOW); digitalWrite(g1, LOW); break;
    default: digitalWrite(a1, HIGH); digitalWrite(b1, HIGH); digitalWrite(c1, HIGH); digitalWrite(d1, HIGH); digitalWrite(e1, HIGH); digitalWrite(f1, HIGH); digitalWrite(g1, HIGH); break;
  }
}