// Sources:
//   https://www.survivingwithandroid.com/esp32-mqtt-client-publish-and-subscribe/
//   http://www.hivemq.com/demos/websocket-client/
//   https://github.com/adafruit/Adafruit_MPU6050/blob/master/examples/basic_readings/basic_readings.ino
//   https://stevesnoderedguide.com/configuring-the-mqtt-publish-node (and configuring the MQTT subscribe node)
//   https://nodered.org/docs/getting-started/local
//   https://lastminuteengineers.com/ds1307-rtc-arduino-tutorial/

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

const char *WIFI_SSID = "Wokwi-GUEST";
const char *WIFI_PWD = "";

const char *MQTT_SERVER = "broker.hivemq.com";
const uint16_t MQTT_PORT = 1883;

const byte DHT_PIN = 15;

WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);
DHTesp dhtSensor;

void CallbackMqtt(char* topic, byte* payload, unsigned int length)
{
  Serial.print("Callback - ");
  Serial.print("Message:");
  for (int i = 0; i < length; i++)
  {
    Serial.print((char)payload[i]);
  }
  Serial.println();
}

void SetupMqtt()
{
  mqttClient.setServer(MQTT_SERVER, MQTT_PORT);
  // set the callback function
  mqttClient.setCallback(CallbackMqtt);
}

void ConnectToMqtt()
{
  Serial.println("Connecting to MQTT Broker...");
  while (!mqttClient.connected())
  {
    char clientId[100] = "\0";
    sprintf(clientId, "ESP32Client-%04X", random(0xffff));
    Serial.println(clientId);

    if (mqttClient.connect(clientId))
    {
      Serial.println("Connected to MQTT broker.");
      // subscribe to topic
      mqttClient.subscribe("/sensors/commands");
    }
  }
}

void ConnectToWiFi()
{
  Serial.print("Connecting to WiFi ");
  Serial.println(WIFI_SSID);

  WiFi.begin(WIFI_SSID, WIFI_PWD, 6);
  while (WiFi.status() != WL_CONNECTED)
  {
    Serial.print(".");
    delay(500);
  }
  Serial.print("\nConnected to ");
  Serial.println(WIFI_SSID);
}



void setup()
{
  Serial.begin(115200);
  Serial.println("Setup begin");

  ConnectToWiFi();
  SetupMqtt();

  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);

  Serial.println("Setup end");
}

const size_t BUFFER_SIZE = 100;
const char *BUFFER_FORMAT = "%1.3f";
char buffer[BUFFER_SIZE + 1];  // Extra one for NULL terminator.

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

  static uint64_t last_time;
  uint64_t now = millis();
  if (now - last_time > 1 * 1000)
  {
    // Get new sensor events with the readings.
    TempAndHumidity dht22Data = dhtSensor.getTempAndHumidity();

    // Publish and print the values.
    snprintf(buffer, BUFFER_SIZE, BUFFER_FORMAT, dht22Data.temperature);
    mqttClient.publish("/sensors24/dht22_temp", buffer);
    snprintf(buffer, BUFFER_SIZE, BUFFER_FORMAT, dht22Data.humidity);
    mqttClient.publish("/sensors24/dht22_hum", buffer);
    Serial.println("Temp: " + String(dht22Data.temperature, 2) + "°C");
    Serial.println("Humidity: " + String(dht22Data.humidity, 1) + "%");


    last_time = now;
  }
}