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

// WIFI config
const char* ssid = "Wokwi-GUEST";
const char* password = "";
WiFiClient wifiClient;
// MQTT client config
const char* mqttServer = "broker.hivemq.com";
const int mqttPort = 1883;
const char* mqttUser = "";
const char* mqttPassword = "";
const char* topic_pub = "ITKPS/Lab/counter";
const char* SUBTOPIC_LED = "esp32-dht22/LED";
const char* SUBTOPIC_TEMP = "esp32-dht22/Temp";
const char* SUBTOPIC_HUMIDITY = "esp32-dht22/Humidity";
PubSubClient mqttClient(wifiClient);
// some variables buffer
String publishMessage;
int i = 0;

//LED
const int LED_PIN = 13;

//DHT
const int DHT_PIN = 15;
DHTesp dhtSensor;

void setup_wifi() {
// Start by connecting to a WiFi network
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.print("WiFi connected on ");
Serial.print("IP address: ");
Serial.print(WiFi.localIP());
Serial.print(" MAC address: ");
Serial.println(WiFi.macAddress());
}

void reconnectMQTT() {
// Loop until we're reconnected
char mqttinfo[80];
char clientId[100] = "\0";
snprintf (mqttinfo, 75, "Attempting MQTT connection at %s:%d (%s/%s)...", mqttServer, mqttPort, mqttUser, mqttPassword);
while (!mqttClient.connected()) {
Serial.println(mqttinfo);
sprintf(clientId, "ESP32Client-%04X", random(0xffff));
if (mqttClient.connect(clientId)) {
Serial.println("...MQTT Broker connected...");
// subscribe here after connected


} else {
Serial.print("failed, rc=");
Serial.print(mqttClient.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}

void callback(char *topic, byte *payload, unsigned int length) {
  Serial.print("Receive Topic: ");
  Serial.println(topic);
  Serial.print("Payload: ");
  Serial.print((char *)payload); // แสดง Payload 
  
  if (!strcmp(topic, SUBTOPIC_LED)) {
    if (!strncmp((char *)payload, "on", length)) {
      digitalWrite(LED_PIN, HIGH);
      Serial.println("LED ON");
    } else if (!strncmp((char *)payload, "off", length)) {
      digitalWrite(LED_PIN, LOW);
      Serial.println("LED OFF");
    } else {
      Serial.println("Unknown Command");
    }
  }
}


void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);

  setup_wifi();
  mqttClient.setServer(mqttServer, mqttPort);
}

//float old_temperature = 0;
//float old_humidity = 0;

void loop() {
  if (!mqttClient.connected()) {
    reconnectMQTT();
  }
  mqttClient.loop();

  // อ่านค่าจากเซนเซอร์
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  float temperature = data.temperature;
  float humidity = data.humidity;

  if (isnan(temperature) || isnan(humidity)) {
    Serial.println("Failed to read from DHT sensor!");
  } else {
    // แสดงผลใน Serial Monitor
    Serial.println("Temp: " + String(temperature, 2) + "C");
    Serial.println("Humidity: " + String(humidity, 1) + "%");

    // Publish ข้อมูลไปยัง MQTT Broker
    if (mqttClient.publish(SUBTOPIC_TEMP, String(temperature, 2).c_str())) {
      Serial.println("Temperature published successfully");
    } else {
      Serial.println("Failed to publish temperature");
    }

    if (mqttClient.publish(SUBTOPIC_HUMIDITY, String(humidity, 1).c_str())) {
      Serial.println("Humidity published successfully");
    } else {
      Serial.println("Failed to publish humidity");
    }
  }

  delay(4000); // เวลาหน่วงเพื่ออ่านค่าใหม่
}