#include <WiFi.h>
#include <PubSubClient.h>
#include <DHTesp.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <ESP32Servo.h>

// --- Pin Definitions ---
const int DHT_PIN       = 15;
const int TRIG_PIN      = 5;
const int ECHO_PIN      = 18;
const int SERVO_PIN     = 13;
const int BUZZER_PIN    = 12;

// --- Objects ---
DHTesp dht;
LiquidCrystal_I2C lcd(0x27, 16, 2);
Servo doorServo;

// --- Wi-Fi & ThingsBoard Credentials ---
const char* ssid        = "Wokwi-GUEST";
const char* password    = "";
const char* mqtt_server = "mqtt.thingsboard.cloud";
const char* mqtt_clid   = "workshopsyahrul";
const char* mqtt_user   = "TiIOT";
const char* mqtt_pass   = "12345678";
const char* mqtt_topic  = "v1/devices/me/telemetry";

WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;

float readDistance() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH);
  return (duration * 0.034 / 2);
}

void setup_wifi() {
  delay(10);
  Serial.println("\n========================================");
  Serial.print("Connecting to Wi-Fi: ");
  Serial.println(ssid);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password, 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\n[OK] Wi-Fi Connected!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());
  Serial.println("========================================\n");
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("[MQTT] Connecting to ThingsBoard Cloud...");
    if (client.connect(mqtt_clid, mqtt_user, mqtt_pass)) {
      Serial.println(" [CONNECTED OK!]");
    } else {
      Serial.print(" [FAILED] rc=");
      Serial.print(client.state());
      Serial.println(" Retrying in 5 seconds...");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  // Setup Servo Pintu
  doorServo.attach(SERVO_PIN);
  doorServo.write(0); // Pintu Tertutup (0 derajat)

  // Setup LCD I2C
  Wire.begin(21, 22);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Smart Class IoT");
  lcd.setCursor(0, 1);
  lcd.print("Initializing...");
  delay(2000);
  lcd.clear();

  // Setup Sensor DHT22
  dht.setup(DHT_PIN, DHTesp::DHT22);

  setup_wifi();
  client.setServer(mqtt_server, 1883);
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  unsigned long now = millis();
  if (now - lastMsg > 3000) { // Pengiriman data tiap 3 detik
    lastMsg = now;

    TempAndHumidity data = dht.getTempAndHumidity();
    float temp = data.temperature;
    float hum = data.humidity;
    float dist = readDistance();

    String statusRuang = "NORMAL";
    String statusPintu = "CLOSED";

    // Logika Otomatisasi: Ada orang mendekat (< 50 cm) ATAU Suhu Panas (> 30 C)
    if (dist < 50.0 || temp > 30.0) {
      doorServo.write(90); // Pintu Terbuka (90 derajat)
      statusPintu = "OPEN";
      
      if (temp > 30.0) {
        statusRuang = "WARNING_HOT";
        tone(BUZZER_PIN, 1000, 200); // Buzzer Peringatan
      } else {
        statusRuang = "PERSON_NEAR";
        tone(BUZZER_PIN, 2000, 100);
      }
    } else {
      doorServo.write(0); // Pintu Tertutup
      statusPintu = "CLOSED";
      noTone(BUZZER_PIN);
    }

    // Tampilan Layar LCD Lokal
    lcd.setCursor(0, 0);
    lcd.print("T:");
    lcd.print(temp, 1);
    lcd.print("C H:");
    lcd.print(hum, 0);
    lcd.print("%   ");

    lcd.setCursor(0, 1);
    lcd.print("D:");
    lcd.print((int)dist);
    lcd.print("cm P:");
    lcd.print(statusPintu);
    lcd.print("   ");

    // Payload JSON Kaya Telemetry ThingsBoard
    String payload = "{";
    payload += "\"suhu\":" + String(temp, 2) + ",";
    payload += "\"kelembaban\":" + String(hum, 1) + ",";
    payload += "\"jarak_cm\":" + String(dist, 1) + ",";
    payload += "\"status\":\"" + statusRuang + "\",";
    payload += "\"pintu\":\"" + statusPintu + "\"";
    payload += "}";

    // Publish MQTT
    client.publish(mqtt_topic, payload.c_str());

    // Log Serial Monitor
    Serial.println("========================================");
    Serial.print("Suhu        : "); Serial.print(temp, 2); Serial.println(" C");
    Serial.print("Kelembaban  : "); Serial.print(hum, 1); Serial.println(" %");
    Serial.print("Jarak Pintu : "); Serial.print(dist, 1); Serial.println(" cm");
    Serial.print("Status Pintu: "); Serial.println(statusPintu);
    Serial.print("Status Ruang: "); Serial.println(statusRuang);
    Serial.print("Payload JSON: "); Serial.println(payload);
    Serial.println("Status Transmisi: PUBLISHED OK");
    Serial.println("========================================\n");
  }
}