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

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

// --- Keypad ---
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] = {2,3,4,5};
byte colPins[COLS] = {6,7,8,9};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// --- Servo & Outputs ---
Servo myServo;
const int servoPin  = 10;
const int relayPin  = 11;
const int buzzerPin = 12;
const int ledGreen  = 13;
const int ledRed    = A0;
const int pushPin   = A1;   // Emergency push-button

// --- System ---
String inputCode = "";
const String PASSWORD = "1234";
unsigned long unlockDuration = 5000;

// --- Smooth servo movement ---
void servoSmoothMove(int startPos, int endPos, int stepDelay){
  if (endPos > startPos){
    for (int pos = startPos; pos <= endPos; pos++){
      myServo.write(pos);
      delay(stepDelay);
    }
  } else {
    for (int pos = startPos; pos >= endPos; pos--){
      myServo.write(pos);
      delay(stepDelay);
    }
  }
}

void setup(){
  pinMode(relayPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledGreen, OUTPUT);
  pinMode(ledRed, OUTPUT);

  pinMode(pushPin, INPUT_PULLUP);   
  // Push button module: HIGH = idle, LOW = pressed

  digitalWrite(relayPin, HIGH);   // Solenoid OFF default

  myServo.attach(servoPin);
  myServo.write(180);             // posisi awal kunci tertutup

  Serial.begin(9600);

  // LCD init
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Enter Password:");
}

// --- LOOP UTAMA ---
void loop(){

  // ================================
  // 1. EMERGENCY BUTTON (A1)
  // ================================
  if (digitalRead(pushPin) == LOW) {   // LOW = ditekan
    delay(40); // debounce
    if (digitalRead(pushPin) == LOW) {
      buzzShort();
      accessGranted();
      return;
    }
  }

  // ================================
  // 2. KEYPAD INPUT
  // ================================
  char key = keypad.getKey();

  if(key){
    if(key == '#'){      
      checkCode();
    } 
    else if(key == '*'){   
      inputCode = "";
      buzzShort();

      lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("Enter Password:");
      lcd.setCursor(0,1);
      lcd.print("Cleared");
    } 
    else {
      inputCode += key;
      buzzShort();

      lcd.setCursor(0,1);
      lcd.print(inputCode);
    }
    Serial.println(inputCode);
  }
}

// --- CHECK PASSWORD ---
void checkCode(){
  if(inputCode == PASSWORD){
    accessGranted();
  } else {
    accessDenied();
  }
  inputCode = "";
}

// --- AKSES BENAR ---
void accessGranted(){
  digitalWrite(ledGreen, HIGH);
  digitalWrite(ledRed, LOW);

  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Access Granted");
  lcd.setCursor(0,1);
  lcd.print("Door Opening...");

  buzzShort();

  // Solenoid ON → pintu buka
  digitalWrite(relayPin, LOW);

  // Buka pintu: 180° → 0°
  servoSmoothMove(180, 0, 12);

  delay(unlockDuration);

  // Tutup pintu: 0° → 180°
  servoSmoothMove(0, 180, 12);

  digitalWrite(relayPin, HIGH);
  digitalWrite(ledGreen, LOW);

  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Door Locked");
  delay(1500);

  lcd.clear();
  lcd.print("Enter Password:");
}

// --- AKSES SALAH ---
void accessDenied(){
  digitalWrite(ledRed, HIGH);
  digitalWrite(ledGreen, LOW);

  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Access Denied!");
  lcd.setCursor(0,1);
  lcd.print("Wrong Code");

  for(int i=0;i<3;i++){
    digitalWrite(buzzerPin, HIGH);
    delay(300);
    digitalWrite(buzzerPin, LOW);
    delay(150);
  }

  digitalWrite(ledRed, LOW);

  lcd.clear();
  lcd.print("Enter Password:");
}

// --- Buzzer pendek ---
void buzzShort(){
  digitalWrite(buzzerPin, HIGH);
  delay(50);
  digitalWrite(buzzerPin, LOW);
}