/*	Lab Trial Test
* Name:	Xu Dong
* Class: DEEC1
* Date:16-Jan-2025
*/ 

#include <WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h>
#define  ADC_IN 33
#define  ADC_REF 3.3

int GLED=18;
long previousMillis = 0; // will store last time LED 
int interval = 2000;// interval at which to blink (milliseconds)
int state = LOW;

long previousMillisADC = 0; // will store last time LED 
int intervalADC = 1000;// interval at which to blink (milliseconds)

const char* ssid = "Wokwi-GUEST";
const char* password = "";

const char* hostname = "broker.hivemq.com";
//const char* hostname = "broker.emqx.io";
//const char* hostname = "test.mosquitto.org";

WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "S10251651"; // yourStudentID must be unique
int PORTNUM = 1883;

void setup_wifi()
{
  WiFi.begin(ssid, password);
  while(WiFi.status() != WL_CONNECTED )
  {
    delay(1000);
    Serial.print(".");
  }
  Serial.println();
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("Given IP by the router to ESP32 is ");
  Serial.println(WiFi.localIP());
}

void connectMQTT()
{
  while(!client.connected() )
  {
    Serial.println("Connecting to MQTT ...");
    if (client.connect(espClientName) ) //, mqttUser, mqttPassword) )
    {
      Serial.println("Connected");
      MQTTSubscribe();
    }
    else
    {
      Serial.print("Failed with state ");
      Serial.print(client.state() );
      delay(2000);
    }
  }
}

void callback(String topic, byte* Payload, unsigned int length)
{
  String payload;
  Serial.print("Message received in topic: ");
  Serial.print(topic);
  Serial.print(" length is: ");
  Serial.println(length);

  Serial.print("Data received from broker: ");
  for (int i = 0; i<length; i++)
  {
    Serial.print( (char)Payload[i] );
    payload += (char)Payload[i];
  }

/// Handle your topics and payload here
// Example

  if (topic == "Trial2/S10251651")
  {
    if (payload == " ")
    {
      
      
    }
    else if (payload == "  ")
    {
      
    }
  }


}

void MQTTSubscribe() 
{
  client.subscribe(" ");  


}

void setup_MQTT() 
{
  client.setServer(hostname, PORTNUM);
  client.setCallback(callback); 

}

void setup() 
{
  Serial.begin(9600);
  delay(5000);

  pinMode( GLED , OUTPUT);
  setup_wifi();
  setup_MQTT();
}

void loop() 
{
  if ( !client.connected() )
  {
    connectMQTT();
  }
  client.loop();

  

  long currentMillis = millis(); 
  if ( currentMillis - previousMillis >= interval) 
  { 
      previousMillis = currentMillis; 
      if ( state == LOW)
      {
        state = HIGH;
        digitalWrite( GLED , LOW);
      }
      else
      {
        state = LOW;
        digitalWrite( GLED , HIGH);
      }

  } 
  long currentMillisADC = millis(); 
  if ( currentMillisADC - previousMillisADC >= intervalADC) 
  { 
      previousMillisADC = currentMillisADC; 
      int adcRes = analogRead(ADC_IN);
      delay(10);
      Serial.println(adcRes);
      float voltage= (float)adcRes*ADC_REF/4095;
      Serial.println(voltage);

      char snum[5];
      itoa(adcRes, snum, 10);
      client.publish("Trial2/S10251651",snum);
  }
}