#include <WiFi.h>
#include <PubSubClient.h>
#include <Wire.h>
#include <ArduinoJson.h>
#include <LiquidCrystal_I2C.h>
#include <Servo.h>

const int pressurePin = 34;
const int leakagePin1 = 35;
const int leakagePin2 = 32;
const int buzzerPin = 4;
const int ledPin1 = 5;
const int ledPin2 = 23;
const int servoPin = 18; 
const float pressureThreshold = 1000;
const float leakageThreshold = 1000;

#define ORG "h6ary6"
#define DEVICE_TYPE "abcd"
#define DEVICE_ID "1234"
#define TOKEN "12345678"
#define LCD_ADDRESS 0x27

char server[] = ORG ".messaging.internetofthings.ibmcloud.com";
char publishTopic[] = "iot-2/evt/Data/fmt/json";
char subscribetopic[] = "iot-2/cmd/command/fmt/String";
char authMethod[] = "use-token-auth";
char token[] = TOKEN;
char clientId[] = "d:" ORG ":" DEVICE_TYPE ":" DEVICE_ID;

WiFiClient wifiClient;
PubSubClient client(server, 1883, wifiClient);
LiquidCrystal_I2C lcd(LCD_ADDRESS, 20, 4);
Servo servoMotor;

void setup() 
{
  Wire.begin();
  lcd.begin(20, 4);
  lcd.clear();
  lcd.print("Initializing...");

  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  servoMotor.attach(servoPin);
  servoMotor.write(0);
  noTone(buzzerPin);
  Serial.begin(115200);
  wificonnect();
  mqttconnect();

  client.setCallback(callback);
}

void loop() 
{
  if (!client.loop()) 
  {
    mqttconnect();
  }

  float pressureValue = analogRead(pressurePin);
  float leakageValue1 = analogRead(leakagePin1);
  float leakageValue2 = analogRead(leakagePin2);

  if (pressureValue < pressureThreshold)  
  {
    tone(buzzerPin, 1000,50);
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, LOW);
    lcd.setCursor(0, 3);
    lcd.print("Low Pressure!");
    servoMotor.write(90); 
  } 
  else if(leakageValue1 > leakageThreshold)
  {
    tone(buzzerPin, 1000,50);
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, LOW);
    lcd.setCursor(0, 3);
    lcd.print("Gas Detected Zone A ");
    servoMotor.write(90);
  }
  else if (leakageValue2 > leakageThreshold)
  {
     tone(buzzerPin, 1000,50);
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, LOW);
    lcd.setCursor(0, 3);
    lcd.print("Gas Detected Zone B ");
    servoMotor.write(90); 
  } 
  else 
  {
    noTone(buzzerPin);
    digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, HIGH);
    lcd.setCursor(0, 3);
    lcd.print("No Gas Detected");
    servoMotor.write(100);
  }

  PublishData(pressureValue, leakageValue1, leakageValue2);

  lcd.setCursor(0, 0);
  lcd.print("Pressure: ");
  lcd.print(pressureValue, 2);
  lcd.print("    ");

  lcd.setCursor(0, 1);
  lcd.print("Leakage1: ");
  lcd.print(leakageValue1, 2);
  lcd.print("    ");

  lcd.setCursor(0, 2);
  lcd.print("Leakage2: ");
  lcd.print(leakageValue2, 2);
  lcd.print("    ");

  delay(1000);
}

void PublishData(float pressure, float leakage1, float leakage2) 
{
  if (!client.connected()) 
  {
    mqttconnect();
  }

  DynamicJsonDocument doc(200);
  doc["pressure"] = pressure;
  doc["leakage1"] = leakage1;
  doc["leakage2"] = leakage2;

  String payload;
  serializeJson(doc, payload);

  Serial.print("Sending payload: ");
  Serial.println(payload);

  if (client.publish(publishTopic, (char *)payload.c_str())) 
  {
    Serial.println("Publish ok");
  } 
  else 
  {
    Serial.println("Publish failed");
  }
}

void mqttconnect() 
{
  if (!client.connected()) 
  {
    Serial.print("Reconnecting client to ");
    Serial.println(server);
    while (!client.connect(clientId, authMethod, token)) 
    {
      Serial.print(".");
      delay(500);
    }

    initManagedDevice();
    Serial.println();
  }
}

void wificonnect() 
{
  Serial.println("Connecting to WiFi...");
  WiFi.begin("Wokwi-GUEST", "");

  while (WiFi.status() != WL_CONNECTED) 
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

void initManagedDevice() 
{
  if (client.subscribe(subscribetopic)) 
  {
    Serial.println(subscribetopic);
    Serial.println("Subscribe to cmd OK");
  } 
  else 
  {
    Serial.println("Subscribe to cmd FAILED");
  }
}

void callback(char *subscribetopic, byte *payload, unsigned int payloadLength) 
{
  Serial.print("Callback invoked for topic: ");
  Serial.println(subscribetopic);
  for (int i = 0; i < payloadLength; i++) 
  {
    Serial.print((char)payload[i]);
  }
  Serial.println();
}