/*
  Lab Test Jan 2024
  Name: Min Khant Maw Soe
  Class: DEE1
  Date: 19/1/24
*/

#include <WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h>
#include "HX711.h"

// HX711 circuit wiring
const int LOADCELL_DOUT_PIN = 2;
const int LOADCELL_SCK_PIN = 4;

HX711 scale;
float calibration_factor = 420; // this calibration factor is adjusted according to my load cell


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

const char* hostname = "broker.hivemq.com";
WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "esp32Client_2706308g"; // yourStudentID must be unique
int PORTNUM = 1883;

long previousMillisA = 0;
int intervalA = 1000;

int GLED = 18;
int RLED = 23;
int YLED = 19;
long previousMillisY = 0;
int intervalY = 2000;
int LEDStateY = 1;

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 MQTTSubscribe() 
{
  // Subsccribe to your topics here
  client.subscribe("ADC/LT51G/2706308g_weight");
}

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 messageTemp;
  //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] );
    messageTemp += (char)payload[i];
  }

  // Handle your topics and payload here
  // Example
  if (topic == "ADC/LT51G/2706308g_weight")
  {
    // Temperature
    if (messageTemp == "Red")
    {
      digitalWrite(RLED, LOW);
    }
    else
    {
      digitalWrite(RLED, HIGH);
    }

    if (messageTemp == "Yellow")
    {
      digitalWrite(YLED, LOW);
    }
    else
    {
      digitalWrite(YLED, HIGH);
    }    

    if (messageTemp == "Green")
    {
      digitalWrite(GLED, LOW);
    }
    else
    {
      digitalWrite(GLED, HIGH);
    }
  }
}

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

void setup()
{
  Serial.begin(9600);
  delay(5000);
  pinMode(YLED, OUTPUT);
  pinMode(GLED, OUTPUT);
  pinMode(RLED, OUTPUT);

  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  scale.set_scale(calibration_factor); //Adjust to this calibration factor
  scale.tare(); 

  setup_wifi();
  setup_MQTT(); 
}

void loop()
{
  long currentMillisA = millis();
  float weight;
  
  if (currentMillisA - previousMillisA >= intervalA)
  {
    previousMillisA = currentMillisA;

    weight = scale.get_units();

    Serial.print("Weight in kg: ");
    Serial.println(String(weight,1)); 
    Serial.println("---");

    // weight
    if (weight >= 2.0 && weight <= 4.0){
      // Publish the analog value to the specified MQTT topic
      String mqttTopic = "ADC/LT51G/2706308g_weight";
      String payload = String("Yellow");
      client.publish(mqttTopic.c_str(), payload.c_str());    
    }
    else if (weight < 2.0)
    {
      // Publish the analog value to the specified MQTT topic
      String mqttTopic = "ADC/LT51G/2706308g_weight";
      String payload = String("Green");
      client.publish(mqttTopic.c_str(), payload.c_str());   
    }
    else if (weight > 4.0)
    {
      // Publish the analog value to the specified MQTT topic
      String mqttTopic = "ADC/LT51G/2706308g_weight";
      String payload = String("Red");
      client.publish(mqttTopic.c_str(), payload.c_str());   
    }

  }


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

}