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

// ================== Multi-Zone Monitoring ==================

// PIR sensors
const int pirA = 2;
const int pirB = 3;
const int pirC = 4;

// DS18B20 sensors (each on a separate pin)
const int tempA_pin = 7;   // Zone A
const int tempB_pin = 8;   // Zone B
const int tempC_pin = 10;  // Zone C

OneWire oneWireA(tempA_pin);
OneWire oneWireB(tempB_pin);
OneWire oneWireC(tempC_pin);

DallasTemperature sensorA(&oneWireA);
DallasTemperature sensorB(&oneWireB);
DallasTemperature sensorC(&oneWireC);

// Alert devices
const int buzzerZone = 9;
const int ledZone = 13;

// Counters
int countA = 0, countB = 0, countC = 0;

// Thresholds
int movementThreshold = 5;
float tempThresholdZone = 40.0;


// ================== LCD + Ultrasonic + PIR + LM35 ==================

constexpr uint8_t PIR = 11;      
constexpr uint8_t LED = 33;      
constexpr uint8_t BUZ = 37;      
constexpr uint8_t TRIG = 27;     
constexpr uint8_t ECHO = 41;     
constexpr uint8_t TEMP_PIN = A0;   // LM35 should be analog pin
constexpr uint8_t TEMP_LED = 39;     
constexpr float TEMP_THRESHOLD = 37.0; 

LiquidCrystal_I2C lcd(0x27, 16, 2); 

// Timings
constexpr unsigned long DOT_T = 500;
constexpr unsigned long ALARM_T = 5000;
constexpr unsigned long LED_SOLID = 2000;
constexpr unsigned long LED_BLINK = 200;
constexpr unsigned long BUZ_SW = 100;

enum State { WAIT, ALARM };
State state = WAIT;

unsigned long dotT = 0, alarmT = 0;
uint8_t dotF = 0;
bool pirPrev = LOW;

// Ultrasonic vars
long duration;
int distance;


// ================== Setup ==================
void setup() {
  Serial.begin(9600);

  // --- Multi-zone pins ---
  pinMode(pirA, INPUT);
  pinMode(pirB, INPUT);
  pinMode(pirC, INPUT);
  pinMode(ledZone, OUTPUT);
  pinMode(buzzerZone, OUTPUT);

  sensorA.begin();
  sensorB.begin();
  sensorC.begin();

  Serial.println("=== Combined Monitoring System Started ===");

  // --- LCD + Ultrasonic pins ---
  pinMode(PIR, INPUT);
  pinMode(LED, OUTPUT);
  pinMode(BUZ, OUTPUT);
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(TEMP_LED, OUTPUT);

  lcd.init();
  lcd.backlight();

  lcd.setCursor(0,0); lcd.print("Waiting for");
  lcd.setCursor(0,1); lcd.print("Movements...");
}


// ================== Ultrasonic Distance Function ==================
int readUltrasonicDistance() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  duration = pulseIn(ECHO, HIGH, 30000); 
  distance = duration * 0.034 / 2;       
  return distance;
}


// ================== Loop ==================
void loop() {
  unsigned long now = millis();

  // -------- Multi-zone PIR + Temp --------
  if (digitalRead(pirA) == HIGH) countA++;
  if (digitalRead(pirB) == HIGH) countB++;
  if (digitalRead(pirC) == HIGH) countC++;

  sensorA.requestTemperatures();
  sensorB.requestTemperatures();
  sensorC.requestTemperatures();

  float tempValA = sensorA.getTempCByIndex(0);
  float tempValB = sensorB.getTempCByIndex(0);
  float tempValC = sensorC.getTempCByIndex(0);

  if (tempValA == DEVICE_DISCONNECTED_C) tempValA = -127;
  if (tempValB == DEVICE_DISCONNECTED_C) tempValB = -127;
  if (tempValC == DEVICE_DISCONNECTED_C) tempValC = -127;

  Serial.println("------ ZONE STATUS ------");
  Serial.print("Zone A -> Movements: "); Serial.print(countA);
  Serial.print(" | Temp: "); Serial.print(tempValA); Serial.println(" °C");

  Serial.print("Zone B -> Movements: "); Serial.print(countB);
  Serial.print(" | Temp: "); Serial.print(tempValB); Serial.println(" °C");

  Serial.print("Zone C -> Movements: "); Serial.print(countC);
  Serial.print(" | Temp: "); Serial.print(tempValC); Serial.println(" °C");
  Serial.println("-------------------------");

  bool motionDetected = (countA > movementThreshold || countB > movementThreshold || countC > movementThreshold);
  bool tempHigh = (tempValA > tempThresholdZone || tempValB > tempThresholdZone || tempValC > tempThresholdZone);

  if (motionDetected && tempHigh) {
    tone(buzzerZone, 2000);
    digitalWrite(ledZone, HIGH);
    delay(200);
    digitalWrite(ledZone, LOW);
    delay(200);
  } else {
    noTone(buzzerZone);
    digitalWrite(ledZone, LOW);
  }

  // -------- LCD + Ultrasonic + PIR --------
  int dist = readUltrasonicDistance();
  Serial.print("Distance: "); Serial.println(dist);

  if (state == WAIT) {
    if (now - dotT >= DOT_T) {
      dotT = now; dotF = (dotF + 1) % 4;
      lcd.setCursor(9,1);
      lcd.print(dotF==0?"   ":dotF==1?".  ":dotF==2?".. ":"...");
    }

    bool pir = digitalRead(PIR);

    if ((pir && !pirPrev) || (dist > 0 && dist < 20)) {
      alarmT = now; state = ALARM;
      lcd.clear();
      lcd.setCursor(0,0); lcd.print("Intruder Alert!");
      lcd.setCursor(0,1);

      if (dist > 0 && dist < 20) {
        lcd.print("Dist: "); lcd.print(dist); lcd.print("cm");
      } else {
        lcd.print("By PIR sensor");
      }
      digitalWrite(LED, HIGH);
    }
    pirPrev = pir;
  }
  else {
    unsigned long el = now - alarmT;

    if (el >= ALARM_T) {
      noTone(BUZ);
      digitalWrite(LED, LOW);
      lcd.clear();
      lcd.setCursor(0,0); lcd.print("Waiting for");
      lcd.setCursor(0,1); lcd.print("Movements...");
      dotF = 0; dotT = now; state = WAIT; 
    } else {
      if (el < LED_SOLID) digitalWrite(LED, HIGH);
      else digitalWrite(LED, ((el-LED_SOLID)%LED_BLINK) < (LED_BLINK/2));

      if (el < 2000) {
        tone(BUZ, (el % (2*BUZ_SW) < BUZ_SW) ? 1200 : 1800);
      } else {
        noTone(BUZ);
      }
    }
  }

  // -------- LM35 Temperature Sensor --------
  int tempRaw = analogRead(TEMP_PIN);    // FIXED: analogRead instead of digitalRead
  float voltage = tempRaw * (5.0 / 1023.0);  
  float temperatureC = voltage * 100.0;      

  Serial.println("=== LM35 ===");
  Serial.print("TempC: "); Serial.print(temperatureC); Serial.println(" °C");
  Serial.println("------------------");

  if (temperatureC > TEMP_THRESHOLD) {
    if ((millis() / 200) % 2 == 0) {
      digitalWrite(TEMP_LED, HIGH);
    } else {
      digitalWrite(TEMP_LED, LOW);
    }
  } else {
    digitalWrite(TEMP_LED, LOW);
  }

  delay(500);
}