/*Lab Test Jul 2024
 *Name: Heng Chen Gui
 *Class:DEEC1
 *Date:19 JuLY 2024
 */

char led_green = 18;

char led_green_state = LOW;
long led_green_previous_millis = 0;
int led_green_interval = 750;

int adc_interval = 1500;
long adc_previous_millis = 0;

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

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

const char* hostname = "broker.hivemq.com";

WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "esp32Client_2709909U"; // 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(1000);
    }
  }
}
void MQTTSubscribe()
{
}

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


void setup() {
  // put your setup code here, to run once:
{
pinMode(led_green, OUTPUT);
Serial.begin(115200);

setup_wifi();
setup_MQTT();
}

}

void loop() {
  // put your main code here, to run repeatedly:
  if ( !client.connected() )
  {
    connectMQTT();
  }
  client.loop();

  long current_millis = millis();

  if ( current_millis - led_green_previous_millis >= led_green_interval)

  {
  led_green_previous_millis = current_millis;

    //now reverse the led's state

    if (led_green_state == LOW)
        led_green_state = HIGH;
        else
        led_green_state = LOW;
      digitalWrite (led_green, led_green_state); 
  }
  //adc

  if ( current_millis - adc_previous_millis >= adc_interval)

  {
    adc_previous_millis = current_millis;

    //read ADC value

    int adc_value;
    adc_value = analogRead(A5);
    Serial.print("ADC"); Serial.println(adc_value);
    delay(5000);

    char str[4];
    sprintf(str, "%d", adc_value);

    //have your own topic and publish str into topic
    client.publish ("IOT/ROOM3/2709909U", str);

    if (adc_value < 2500)
    client.publish ("IOT/ROOM3/2709909U", "Alert");

    else if (adc_value >=2500)
    client.publish ("IOT/ROOM3/2709909U", "OK");

  }

}