/**
   ESP32 + DHT22 + NTP and MQTT Example for Wokwi
   
   https://wokwi.com/projects/341509185573225043
*/

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

#define NTP_SERVER     "pool.ntp.org"
#define UTC_OFFSET     0
#define UTC_OFFSET_DST 0

#define ONBOARD_LED 2
#define LED 13
#define DHT_PIN 15

/**const int DHT_PIN = 15;*/
String timestamp ="";
String temp = "";
String humid = "";
String pstring = "";

DHTesp dhtSensor;
WiFiClient espClient;
PubSubClient client(espClient);

// MQTT Broker
const char *mqtt_broker = "broker.mqttdashboard.com";
const char *topic_in = "tonitestin";
const char *topic_out = "tonitestout";
const char *mqtt_username = "";
const char *mqtt_password = "";
const int mqtt_port = 1883;

//Local Time printing function
void printLocalTime() {
  struct tm timeinfo;
  if (!getLocalTime(&timeinfo)) {
   Serial.println("Connection Err");
    return;
  }
  //Serial.println(&timeinfo, "%H:%M:%S");
  // Serial.println(&timeinfo, "%Y%m%dT%H%M%S");
  char timeStringBuff[50]; //50 chars should be enough
  strftime(timeStringBuff, sizeof(timeStringBuff), "%Y%m%dT%H%M%S", &timeinfo);
  //print like "const char*"
  Serial.println(timeStringBuff);

  //Optional: Construct String object 
  //String asString(timeStringBuff);
  timestamp = timeStringBuff;
}

void setup() {
  pinMode(LED, OUTPUT);
  pinMode(ONBOARD_LED,OUTPUT);

  Serial.begin(9600);
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);
  
  //WiFi connection
  Serial.print("Connecting to WiFi");
  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(250);
    digitalWrite(ONBOARD_LED,HIGH);
    delay(100);
    digitalWrite(ONBOARD_LED,LOW);
    Serial.print(".");
  }
  Serial.println(" Connected!");
  digitalWrite(ONBOARD_LED,HIGH);

  //MQTT Broker connection
  client.setServer(mqtt_broker, mqtt_port);
  client.setCallback(callback);
  while (!client.connected()) {
    String client_id = "esp32-client-";
    client_id += String(WiFi.macAddress());
    Serial.printf("The client %s connects to the public mqtt broker\n", client_id.c_str());
    if (client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {
        Serial.println("Public " + String(mqtt_broker) + " connected");
    } else {
        Serial.print("failed with state ");
        Serial.print(client.state());
        delay(2000);
    }
}
 // publish and subscribe
 client.publish(topic_out, "Hello World, I'm ESP32");
 client.subscribe(topic_in);

  configTime(UTC_OFFSET, UTC_OFFSET_DST, NTP_SERVER);
}

void callback(char *topic_in, byte *payload, unsigned int length) {
 Serial.print("Message arrived in topic: ");
 Serial.println(topic_in);
 Serial.print("Message:");
 for (int i = 0; i < length; i++) {
     Serial.print((char) payload[i]);
 }
 Serial.println();
 Serial.println("-----------------------");
 // Switch on the LED if an 1 was received as first character
  if ((char)payload[0] == '1') {
    digitalWrite(LED, HIGH);   
  } else {
    digitalWrite(LED, LOW); 
  }
}

void loop() {
    TempAndHumidity  data = dhtSensor.getTempAndHumidity();
  temp = "Temp: " + String(data.temperature, 2) + "°C";
  humid = "Humidity: " + String(data.humidity, 1) + "%";
  
  /**Serial.println(T);
  Serial.println(H);
  Serial.println("---");
  */
  delay(1000);
  
  printLocalTime();
  pstring = timestamp +", " + temp + ", " + humid;
  Serial.println("Message Out: " + pstring);
  Serial.println("---");
  //payload preparation and sending
  int len = pstring.length();
  char p [len];
  pstring.toCharArray(p, len);
  client.publish(topic_out, p);
  client.loop();
}