#include <WiFi.h>
#include <PubSubClient.h>
#include "DHT.h"

// ===== กำหนดค่า DHT =====
#define DHTPIN 25       // ขา Data ต่อกับ GPIO25
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// ===== กำหนด LED =====
#define LED_PIN 23

// ===== ตั้งค่า WiFi =====
const char* ssid     = "Wokwi-GUEST";  
const char* password = "";

// ===== ตั้งค่า NETPIE MQTT =====
const char* mqtt_server   = "mqtt.netpie.io";
const int   mqtt_port     = 1883;

// ---- ค่า client ที่ต้องสร้างจาก NETPIE ----
// (เปลี่ยนให้ตรงกับ Project ของครูเอง)
const char* mqtt_ClientID = "254012dc-378b-4f32-8eac-edec66bdde8a";
const char* mqtt_username = "GxKKaszzni1he3r6fruDcxeR55vfjwwg";
const char* mqtt_password = "WxpS79w49te5eGr7d84xzCLhFdPSm9V4";

WiFiClient espClient;
PubSubClient client(espClient);

unsigned long lastMsg = 0;
int interval = 2000;  // ส่งทุก ๆ 2 วินาที

// ===== ฟังก์ชันรับข้อความจาก NETPIE =====
void callback(char* topic, byte* message, unsigned int length) {
  String msg;
  for (unsigned int i = 0; i < length; i++) {
    msg += (char)message[i];
  }

  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  Serial.println(msg);

  // ถ้าได้รับข้อความ "ON" → เปิด LED
  if (msg == "ON") {
    digitalWrite(LED_PIN, HIGH);
    Serial.println("LED ON");
  } 
  // ถ้าได้รับข้อความ "OFF" → ปิด LED
  else if (msg == "OFF") {
    digitalWrite(LED_PIN, LOW);
    Serial.println("LED OFF");
  }
}

void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect(mqtt_ClientID, mqtt_username, mqtt_password)) {
      Serial.println("connected");

      // subscribe เพื่อรอรับคำสั่งควบคุม LED
      client.subscribe("@msg/led");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);
  dht.begin();

  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW); // ปิด LED เริ่มต้น
}

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

  unsigned long now = millis();
  if (now - lastMsg > interval) {
    lastMsg = now;

    float h = dht.readHumidity();
    float t = dht.readTemperature();

    if (isnan(h) || isnan(t)) {
      Serial.println("Failed to read from DHT sensor!");
      return;
    }

    // แพ็คเป็น JSON ก่อนส่ง
    String payload = String("{\"data\":{\"temperature\":") + t + 
                     String(",\"humidity\":") + h + String("}}");

    Serial.print("Publish message: ");
    Serial.println(payload);

    client.publish("@shadow/data/update", payload.c_str());
  }
}