//a child safety lock to ensure no child gets outdoor without a elder accompaning them

//The height of the person opening the door is calculated based on the distance between the person and the sensor.

//The slide switch is used as the lock opener and the servo represents the state of the lock.

//A sms will be sent when child is trying to open the door. 

#include <ESP32Servo.h>   //including the libraries
#include <Ultrasonic.h>
#include <WiFi.h>
#include "Adafruit_MQTT.h"
#include "Adafruit_MQTT_Client.h"
#include <SoftwareSerial.h>


// Ultrasonic Pins
int trigPin = 15;
int echoPin = 4;
Ultrasonic ultrasonic(trigPin, echoPin);

//adafruit credentials
#define AIO_SERVER      "io.adafruit.com"
#define AIO_SERVERPORT  1883
#define AIO_USERNAME    "Subi_7"
#define AIO_KEY         "aio_dcLZ42uPJScT29nIqWYqEZ72xQ3m" 
WiFiClient client;

// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.
Adafruit_MQTT_Client mqtt(&client, AIO_SERVER, AIO_SERVERPORT, AIO_USERNAME, AIO_KEY);
//setting up MQTT publish to send data to required feed in adafruit
Adafruit_MQTT_Publish send = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/feeds/notification_trigger");

// Servo Pin
int servoPin = 18;
Servo myServo;

void setup() {
  Serial.begin(115200);//initiating the servo
  myServo.attach(servoPin);
  pinMode(21, INPUT_PULLUP);
  Serial.print("Connecting to WiFi");//code to coonect to wifi
  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
}
}

void connect() {// to connect to adafruit
  Serial.print(F("Connecting to Adafruit IO... "));
  int8_t ret;
  
  while ((ret = mqtt.connect()) != 0) {
    switch (ret) {
      case 1: Serial.println(F("Wrong protocol")); break;
      case 2: Serial.println(F("ID rejected")); break;
      case 3: Serial.println(F("Server unavail")); break;
      case 4: Serial.println(F("Bad user/pass")); break;
      case 5: Serial.println(F("Not authed")); break;
      case 6: Serial.println(F("Failed to subscribe")); break;
      default: Serial.println(F("Connection failed")); break;
    }

    if(ret >= 0)
      mqtt.disconnect();

    Serial.println(F("Retrying connection..."));
    delay(10000);
  }
  Serial.println(F("Adafruit IO Connected!"));
}

void loop() {
  if(! mqtt.ping(3)) {
    // reconnect to adafruit io
    if(! mqtt.connected())
      connect();
  }

  long distance = ultrasonic.read();
  long Height = 400 - distance;   //Measuring the height of the person
  
  if(digitalRead(21)){
    
    Serial.print("Height: ");
    Serial.println(Height);
    Serial.print(" cm");
    
    if (!send.publish(static_cast<int32_t>(Height))) {  //function to send data to adafruit                   //Publish to Adafruit
      Serial.println(F("Failed"));
    }else {
      Serial.println(F("Sent!"));
    }
    
    if (Height >= 122) { // Check if height is more than 4 feet (122 cm)
    myServo.write(90); // Unlock the door
    Serial.println("Door Unlocked: The Person is taller than 4 feet.");
    }else {
    myServo.write(0); // Lock the door
    Serial.println("Door Locked: Person not tall enough.");
    }

  }
  delay(5000); // Delay before the next measurement
}