#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>
#include <ESP32Servo.h>

// ── Pin Definitions ──────────────────────────────────────
#define DHTPIN        4
#define DHTTYPE       DHT22
#define PIR_PIN       13
#define SERVO_PIN     14

#define LED_LIVING    26
#define LED_BEDROOM   27
#define LED_KITCHEN   32
#define LED_BATHROOM  33

#define BTN_LIVING    34
#define BTN_BEDROOM   35
#define BTN_KITCHEN   18
#define BTN_BATHROOM  19

// ── Objects ──────────────────────────────────────────────
DHT dht(DHTPIN, DHTTYPE);
Servo doorServo;
LiquidCrystal_I2C lcd(0x27, 16, 2);

// ── State Variables ───────────────────────────────────────
bool ledState[4]   = {false, false, false, false};
bool lastBtn[4]    = {HIGH, HIGH, HIGH, HIGH};
bool doorLocked    = true;
bool motionDetected = false;

const int ledPins[4] = {LED_LIVING, LED_BEDROOM, LED_KITCHEN, LED_BATHROOM};
const int btnPins[4] = {BTN_LIVING, BTN_BEDROOM, BTN_KITCHEN, BTN_BATHROOM};
const char* roomNames[4] = {"Living Room", "Bedroom", "Kitchen", "Bathroom"};

unsigned long lastSensorRead = 0;
unsigned long lastSerialPrint = 0;
unsigned long lastLCDUpdate   = 0;
unsigned long lastMotionCheck = 0;
int lcdPage = 0;

float temperature = 0, humidity = 0;

// ── Setup ─────────────────────────────────────────────────
void setup() {
  Serial.begin(115200);
  Serial.println("=================================");
  Serial.println("  IoT Home Automation System");
  Serial.println("  ESP32 | Wokwi Simulator");
  Serial.println("=================================");
  Serial.println("Commands via Serial Monitor:");
  Serial.println("  1-4 : Toggle room lights");
  Serial.println("  d   : Toggle door lock");
  Serial.println("  a   : All lights ON");
  Serial.println("  o   : All lights OFF");
  Serial.println("  s   : Show status");
  Serial.println("=================================\n");

  // LED & Button pins
  for (int i = 0; i < 4; i++) {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW);
    pinMode(btnPins[i], INPUT_PULLUP);
  }

  pinMode(PIR_PIN, INPUT);

  // Servo
  doorServo.attach(SERVO_PIN);
  doorServo.write(0); // locked position

  // DHT
  dht.begin();

  // LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Home Automation");
  lcd.setCursor(0, 1);
  lcd.print("  System Ready  ");
  delay(2000);
  lcd.clear();
}

// ── Toggle LED Helper ─────────────────────────────────────
void toggleLED(int index) {
  ledState[index] = !ledState[index];
  digitalWrite(ledPins[index], ledState[index] ? HIGH : LOW);
  Serial.print("[LIGHT] ");
  Serial.print(roomNames[index]);
  Serial.println(ledState[index] ? " → ON" : " → OFF");
}

// ── Door Control ──────────────────────────────────────────
void toggleDoor() {
  doorLocked = !doorLocked;
  doorServo.write(doorLocked ? 0 : 90);
  Serial.print("[DOOR]  ");
  Serial.println(doorLocked ? "Locked 🔒" : "Unlocked 🔓");
}

// ── All Lights ────────────────────────────────────────────
void setAllLights(bool state) {
  for (int i = 0; i < 4; i++) {
    ledState[i] = state;
    digitalWrite(ledPins[i], state ? HIGH : LOW);
  }
  Serial.print("[LIGHT] All lights → ");
  Serial.println(state ? "ON" : "OFF");
}

// ── Print Status ──────────────────────────────────────────
void printStatus() {
  Serial.println("\n──── System Status ────");
  Serial.printf("Temperature : %.1f °C\n", temperature);
  Serial.printf("Humidity    : %.1f %%\n", humidity);
  Serial.printf("Motion      : %s\n", motionDetected ? "Detected" : "None");
  Serial.printf("Door        : %s\n", doorLocked ? "Locked" : "Unlocked");
  for (int i = 0; i < 4; i++) {
    Serial.printf("%-12s: %s\n", roomNames[i], ledState[i] ? "ON" : "OFF");
  }
  Serial.println("───────────────────────\n");
}

// ── Handle Serial Commands ────────────────────────────────
void handleSerial() {
  if (!Serial.available()) return;
  char cmd = Serial.read();
  switch (cmd) {
    case '1': toggleLED(0); break;
    case '2': toggleLED(1); break;
    case '3': toggleLED(2); break;
    case '4': toggleLED(3); break;
    case 'd': case 'D': toggleDoor(); break;
    case 'a': case 'A': setAllLights(true);  break;
    case 'o': case 'O': setAllLights(false); break;
    case 's': case 'S': printStatus();       break;
    default: break;
  }
}

// ── Handle Physical Buttons ───────────────────────────────
void handleButtons() {
  for (int i = 0; i < 4; i++) {
    bool current = digitalRead(btnPins[i]);
    if (current == LOW && lastBtn[i] == HIGH) {
      delay(50); // debounce
      toggleLED(i);
    }
    lastBtn[i] = current;
  }
}

// ── Read DHT Sensor ───────────────────────────────────────
void readSensors() {
  if (millis() - lastSensorRead < 2000) return;
  lastSensorRead = millis();

  float t = dht.readTemperature();
  float h = dht.readHumidity();
  if (!isnan(t) && !isnan(h)) {
    temperature = t;
    humidity    = h;
  }

  motionDetected = digitalRead(PIR_PIN);

  // Auto-unlock door on motion (optional smart behaviour)
  if (motionDetected && doorLocked) {
    Serial.println("[PIR]   Motion detected! Auto-unlocking door...");
    doorLocked = false;
    doorServo.write(90);
  }
}

// ── Update LCD (alternating pages) ───────────────────────
void updateLCD() {
  if (millis() - lastLCDUpdate < 3000) return;
  lastLCDUpdate = millis();
  lcd.clear();

  if (lcdPage == 0) {
    lcd.setCursor(0, 0);
    lcd.print("Temp:");
    lcd.print(temperature, 1);
    lcd.print((char)223);
    lcd.print("C");
    lcd.setCursor(0, 1);
    lcd.print("Humid:");
    lcd.print(humidity, 1);
    lcd.print("%");
  } else if (lcdPage == 1) {
    lcd.setCursor(0, 0);
    lcd.print("Motion:");
    lcd.print(motionDetected ? "YES" : "NO ");
    lcd.setCursor(0, 1);
    lcd.print("Door:");
    lcd.print(doorLocked ? "LOCKED  " : "UNLOCKED");
  } else {
    // Show light states compactly: L B K Ba
    lcd.setCursor(0, 0);
    lcd.print("L  B  K  Ba");
    lcd.setCursor(0, 1);
    for (int i = 0; i < 4; i++) {
      lcd.print(ledState[i] ? "ON " : "-- ");
    }
  }
  lcdPage = (lcdPage + 1) % 3;
}

// ── Periodic Serial Dashboard ─────────────────────────────
void serialDashboard() {
  if (millis() - lastSerialPrint < 5000) return;
  lastSerialPrint = millis();
  printStatus();
}

// ── Loop ──────────────────────────────────────────────────
void loop() {
  handleSerial();
  handleButtons();
  readSensors();
  updateLCD();
  serialDashboard();
  delay(10);
}