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

#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASSWORD ""
#define MQTT_SERVER "broker.hivemq.com"
#define MQTT_PORT 1883
#define MQTT_TOPIC "smartgarden/sensors"
#define MQTT_TOPIC_CONTROL "smartgarden/control"

#define DHTPIN 21
#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);
WiFiClient wifiClient;
PubSubClient client(wifiClient);

void setup() {
  Serial.begin(9600);
  connectWiFi();
  client.setServer(MQTT_SERVER, MQTT_PORT);
  dht.begin();
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
  float temperature = dht.readTemperature();
  if (!isnan(temperature)) {
    publishSensorData(temperature);
  }
  delay(2000);
}

void connectWiFi() {
  Serial.println("Connecting to WiFi...");
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESP32Client")) {
      Serial.println("connected");
      client.subscribe(MQTT_TOPIC_CONTROL);
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void publishSensorData(float temperature) {
  StaticJsonDocument<200> doc;
  doc["temperature"] = temperature;
  char buffer[256];
  serializeJson(doc, buffer);
  client.publish(MQTT_TOPIC, buffer);
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived in topic: ");
  Serial.println(topic);
  String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.println("Message received: " + message);
  // Process control message here (e.g., turn on/off relay)
}