#include <DHTesp.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>  // Make sure to include the ArduinoJson library

#define WIFI_AP_NAME        "Wokwi-GUEST"  // Define WiFi SSID
#define WIFI_PASSWORD       ""             // Define WiFi password, empty if open

#define TOKEN               "zyo4pzjnobkeaxz7bniu"   // ThingsBoard Device Token
#define THINGSBOARD_SERVER  "thingsboard.cloud"     // ThingsBoard Server URL

#define SERIAL_DEBUG_BAUD   115200   // Serial connection speed for debug
#define DHT_PIN             16       // Pin connected to the DHT sensor
#define LED_PIN             12       // Define the LED pin (change as needed)

WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);

DHTesp dht;

void setup() {
  pinMode(LED_PIN, OUTPUT);  // Set the LED pin as an output
  digitalWrite(LED_PIN, LOW);  // Start with the LED off

  Serial.begin(SERIAL_DEBUG_BAUD);  // Start the serial communication
  WiFi.begin(WIFI_AP_NAME, WIFI_PASSWORD);  // Connect to WiFi network
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected to WiFi");

  mqttClient.setServer(THINGSBOARD_SERVER, 1883);  // Set the MQTT server
  mqttClient.setCallback(mqttCallback);  // Set the MQTT callback function
  connectToMQTT();  // Connect to MQTT Broker
  dht.setup(DHT_PIN, DHTesp::DHT22);  // Initialize the DHT sensor
}

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

  mqttClient.loop();

  // Handle Serial command input to control the LED
  if (Serial.available() > 0) {
    String command = Serial.readStringUntil('\n');
    handleSerialCommand(command);
  }

  static unsigned long lastSendTime = 0;
  if (millis() - lastSendTime > 100) {  // Send data every 2 seconds
    sendDHTData();
    lastSendTime = millis();
  }
}

void connectToMQTT() {
  while (!mqttClient.connected()) {
    Serial.println("Connecting to MQTT...");
    if (mqttClient.connect("ESP32Client", TOKEN, NULL)) {
      Serial.println("Connected to MQTT");
      mqttClient.subscribe("v1/devices/me/rpc/request/+");  // Subscribe to RPC requests
    } else {
      Serial.print("Failed, rc=");
      Serial.print(mqttClient.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void sendDHTData() {
  TempAndHumidity lastValues = dht.getTempAndHumidity();
  if (!isnan(lastValues.humidity) && !isnan(lastValues.temperature)) {
    String payload = String("{\"temperature\":") + lastValues.temperature + 
                     ", \"humidity\":" + lastValues.humidity + "}";
    mqttClient.publish("v1/devices/me/telemetry", payload.c_str());
    Serial.println("Data sent: " + payload);
  } else {
    Serial.println("Failed to read from DHT sensor!");
  }
}

void mqttCallback(char* topic, byte* payload, unsigned int length) {
    String message;
    for (unsigned int i = 0; i < length; i++) {
        message += (char)payload[i];
    }
    message.trim();

    StaticJsonDocument<200> doc;
    DeserializationError error = deserializeJson(doc, message);

    if (!error) {
        String method = doc["method"];
        bool params = doc["params"];

        if (method == "setState") {
            digitalWrite(LED_PIN, params ? HIGH : LOW);  // Set LED state based on params
            Serial.println(params ? "LED turned ON via ThingsBoard" : "LED turned OFF via ThingsBoard");
            // Report the change back to ThingsBoard
            String telemetry = String("{\"LED State\":") + (params ? "\"ON\"" : "\"OFF\"") + "}";
            mqttClient.publish("v1/devices/me/telemetry", telemetry.c_str());
        } else if (method == "getState") {
            // Report current state
            bool currentState = digitalRead(LED_PIN) == HIGH;
            String telemetry = String("{\"LED State\":") + (currentState ? "\"ON\"" : "\"OFF\"") + "}";
            mqttClient.publish("v1/devices/me/telemetry", telemetry.c_str());
        }
    }
}

void handleSerialCommand(String command) {
  command.trim();
  if (command.equalsIgnoreCase("ON")) {
    digitalWrite(LED_PIN, HIGH);
    Serial.println("LED turned ON via Serial");
    mqttClient.publish("v1/devices/me/telemetry", "{\"LED\":\"ON\"}");
  } else if (command.equalsIgnoreCase("OFF")) {
    digitalWrite(LED_PIN, LOW);
    Serial.println("LED turned OFF via Serial");
    mqttClient.publish("v1/devices/me/telemetry", "{\"LED\":\"OFF\"}");
  }
}