/*  Project: Flood Level Monitor in PUB drain
    Project Member  : MO XiaoLong
                    : Pan Wei Kun
                    : Liu Yang
                    : Balamurali

*/



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

long previousMillisA = 0; 
int intervalA = 500;

int RLED = 23;
int YLED = 19;
int GLED = 18;

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

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

WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "Flood Level Monitor"; 
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) )
    {
      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 WaterLevel;

  for (int i = 0; i<length; i++)
  {
   
    WaterLevel += (char)payload[i];
  }


  if (topic == "DrainWaterLevel/Drain1")
  {
    Serial.print("Drain 1 Water Level: ");
    Serial.println( WaterLevel );
  }
}

void MQTTSubscribe() 
{
  
  client.subscribe("DrainWaterLevel/Drain1");  

}

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

}

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

  pinMode(GLED, OUTPUT);
  pinMode(YLED, OUTPUT);
  pinMode(RLED, OUTPUT);
  digitalWrite(GLED, LOW);
  digitalWrite(YLED, LOW);
  digitalWrite(RLED, LOW);

  setup_wifi();
  setup_MQTT();
}

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



  long currentMillisA = millis();  
  if (currentMillisA - previousMillisA >= intervalA) 
  {
    previousMillisA = currentMillisA;
    
    int adcRes = analogRead(A5);

    
    char str[4];
    sprintf(str, "%d", adcRes);
    
    client.publish("DrainWaterLevel/Drain1", str);
  

  if (adcRes >= 0 && adcRes <= 1500) 
    {
      digitalWrite(GLED, LOW);  // Turn on Green LED
      digitalWrite(YLED, HIGH);
      digitalWrite(RLED, HIGH);
    } else if (adcRes >= 1501 && adcRes <= 3000) 
    {
      digitalWrite(GLED, HIGH);
      digitalWrite(YLED, LOW);  // Turn on Yellow LED
      digitalWrite(RLED, HIGH);
    } else if (adcRes >= 3001 && adcRes <= 4095) 
    
    {
      digitalWrite(GLED, HIGH);
      digitalWrite(YLED, HIGH);
      digitalWrite(RLED, LOW);  // Turn on Red LED
    }
}
}