//Import libraries
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <ESP32Servo.h>
#include <Keypad.h>

// LCD setup
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Servo setup
Servo lockerServo;
const int servoPin = 13;

// PIR sensor setup
const int pirSensorPin = 34;

// LED setup
const int redLedPin = 12;
const int greenLedPin = 25;

// Keypad setup
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {19, 18, 5, 4};  //Row #1,2,3,4
byte colPins[COLS] = {15, 14, 27, 26};  //Col #1,2,3,4
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// Locker state
bool isLockerOccupied = false;
const char* correctPin = "1234"; // Change to desired PIN
char enteredPin[5] = {0};
unsigned long lastMotionTime = 0;
const unsigned long motionTimeout = 5000; // 5 seconds to assume parcel placed

void setup() {
  // Initialize components
  Serial.begin(115200);
  lcd.init();
  lcd.backlight();
  lockerServo.attach(servoPin);
  pinMode(pirSensorPin, INPUT);
  pinMode(redLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);

  // Lock the servo initially
  lockerServo.write(0); // Locked position
  updateStatus();

  //lcd init
  lcd.print("Init lcd");
}

void loop() {
  // Check PIR sensor
  int pirState = digitalRead(pirSensorPin);
  if (pirState == HIGH) {
    lastMotionTime = millis(); // Record motion time
    if (!isLockerOccupied) {
      isLockerOccupied = true; // Assume parcel placed
      updateStatus();
    }
  } else if (isLockerOccupied && (millis() - lastMotionTime > motionTimeout)) {
    isLockerOccupied = false; // Assume parcel removed after timeout
    updateStatus();
  }

  // Handle keypad input using '#' to submit PIN
  char key = keypad.getKey();
  if (key) {
    static int pinIndex = 0;
    if (key == '#') { 
      enteredPin[pinIndex] = '\0';
      if (strcmp(enteredPin, correctPin) == 0) {
        Serial.println("Open locker");
        unlockLocker();
      } else {
        lcd.clear();
        lcd.print("Wrong PIN!");
        Serial.println("Wrong PIN!");
        delay(2000);
      }
      pinIndex = 0;
      memset(enteredPin, 0, sizeof(enteredPin));
    } else if (pinIndex < 4) {
      enteredPin[pinIndex++] = key;
      lcd.clear();
      lcd.print("Enter PIN: ");
      for (int i = 0; i < pinIndex; i++) lcd.print("*");
    }
  }
}

void updateStatus() {
  digitalWrite(redLedPin, isLockerOccupied ? HIGH : LOW);
  digitalWrite(greenLedPin, isLockerOccupied ? LOW : HIGH);
  lcd.clear();
  lcd.print(isLockerOccupied ? "Locker: Occupied" : "Locker: Empty");
  Serial.println(isLockerOccupied ? "Locker: Occupied" : "Locker: Empty");
}

void unlockLocker() {
  lcd.clear();
  lcd.print("Unlocking...");
  lockerServo.write(90); // Unlocked position
  delay(5000); // Keep unlocked for 5 seconds
  lockerServo.write(0); // Lock again
  lcd.clear();
  lcd.print("Locked");
}