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

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

// ================= PIR =================
const int pirPin = 2;

// ================= Buzzer =================
const int buzzerPin = 3;

// ================= LED-uri =================
const int greenLed = 4;
const int blueLed = 5;
const int redLed = 6;

// ================= Buton RESET =================
const int resetButton = 7;

// ================= 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] = {22, 23, 24, 25};
byte colPins[COLS] = {26, 27, 28, 29};

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

// ================= Parola =================
String correctPassword = "1234";
String enteredPassword = "";

// ================= Stari =================
bool armed = false;
bool alarmTriggered = false;

void setup() {

  Serial.begin(9600);

  // LCD
  lcd.init();
  lcd.backlight();

  // PIR
  pinMode(pirPin, INPUT);

  // Buzzer
  pinMode(buzzerPin, OUTPUT);

  // LED-uri
  pinMode(greenLed, OUTPUT);
  pinMode(blueLed, OUTPUT);
  pinMode(redLed, OUTPUT);

  // Buton reset
  pinMode(resetButton, INPUT_PULLUP);

  // Stare initiala
  digitalWrite(greenLed, HIGH);
  digitalWrite(blueLed, LOW);
  digitalWrite(redLed, LOW);

  lcd.setCursor(0, 0);
  lcd.print("Sistem alarma");

  lcd.setCursor(0, 1);
  lcd.print("Dezactivat");

  delay(3000);

  lcd.clear();
}

void loop() {

  readKeypad();

  checkResetButton();

  if (armed && !alarmTriggered) {
    detectMotion();
  }
}

// ================= Citire Keypad =================
void readKeypad() {

  char key = keypad.getKey();

  if (key) {

    // Adaugare cifre
    if (key != '#') {

      enteredPassword += key;

      lcd.clear();

      lcd.setCursor(0, 0);
      lcd.print("PIN: ");

      lcd.print(enteredPassword);
    }

    // Verificare parola
    if (key == '#') {

      if (enteredPassword == correctPassword) {

        armed = !armed;

        if (armed) {
          armSystem();
        }
        else {
          disarmSystem();
        }

      } else {

        lcd.clear();

        lcd.setCursor(0, 0);
        lcd.print("PIN GRESIT");

        tone(buzzerPin, 1000);

        delay(500);

        noTone(buzzerPin);

        delay(1000);
      }

      enteredPassword = "";

      lcd.clear();
    }
  }
}

// ================= Activare =================
void armSystem() {

  alarmTriggered = false;

  digitalWrite(greenLed, LOW);
  digitalWrite(blueLed, HIGH);
  digitalWrite(redLed, LOW);

  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("Sistem ACTIV");

  lcd.setCursor(0, 1);
  lcd.print("Monitorizare");

  Serial.println("Sistem activat");

  delay(1500);

  lcd.clear();
}

// ================= Dezactivare =================
void disarmSystem() {

  alarmTriggered = false;

  noTone(buzzerPin);

  digitalWrite(greenLed, HIGH);
  digitalWrite(blueLed, LOW);
  digitalWrite(redLed, LOW);

  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("Sistem OFF");

  lcd.setCursor(0, 1);
  lcd.print("Dezactivat");

  Serial.println("Sistem dezactivat");

  delay(1500);

  lcd.clear();
}

// ================= Detectare miscare =================
void detectMotion() {

  int motion = digitalRead(pirPin);

  if (motion == HIGH) {

    triggerAlarm();
  }
}

// ================= Buton RESET =================
void checkResetButton() {

  if (digitalRead(resetButton) == LOW) {

    delay(50);

    if (digitalRead(resetButton) == LOW) {

      alarmTriggered = false;
      armed = false;

      enteredPassword = "";

      noTone(buzzerPin);

      digitalWrite(redLed, LOW);
      digitalWrite(blueLed, LOW);
      digitalWrite(greenLed, HIGH);

      lcd.clear();

      lcd.setCursor(0, 0);
      lcd.print("RESET ALARMA");

      lcd.setCursor(0, 1);
      lcd.print("Sistem OFF");

      Serial.println("ALARMA RESETATA");

      // asteapta eliberarea butonului
      while (digitalRead(resetButton) == LOW);

      delay(500);

      lcd.clear();
    }
  }
}

// ================= Alarma =================
void triggerAlarm() {

  alarmTriggered = true;

  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("INTRUS DETECTAT");

  lcd.setCursor(0, 1);
  lcd.print("ALERTA !!!");

  Serial.println("==============================");
  Serial.println("MISCARE DETECTATA!");
  Serial.println("APEL CATRE PROPRIETAR...");
  Serial.println("==============================");

  while (alarmTriggered) {

    // verificare reset
    checkResetButton();

    if (!alarmTriggered) {
      break;
    }

    // alarma ON
    digitalWrite(redLed, HIGH);

    tone(buzzerPin, 1000);

    delay(200);

    // verificare reset
    checkResetButton();

    if (!alarmTriggered) {
      break;
    }

    // alarma OFF
    digitalWrite(redLed, LOW);

    noTone(buzzerPin);

    delay(200);

    // verificare keypad
    char key = keypad.getKey();

    if (key) {

      if (key != '#') {

        enteredPassword += key;

        lcd.clear();

        lcd.setCursor(0, 0);
        lcd.print("PIN: ");

        lcd.print(enteredPassword);
      }

      if (key == '#') {

        if (enteredPassword == correctPassword) {

          disarmSystem();

          enteredPassword = "";

          break;

        } else {

          enteredPassword = "";

          lcd.clear();

          lcd.setCursor(0, 0);
          lcd.print("COD GRESIT");

          delay(1000);

          lcd.clear();

          lcd.setCursor(0, 0);
          lcd.print("INTRUS DETECTAT");

          lcd.setCursor(0, 1);
          lcd.print("ALERTA !!!");
        }
      }
    }
  }
}