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

#define PHOTORESISTOR 34
#define LED_PIN 5
#define TRIG 4
#define ECHO 2

#define PORT 1883

const char* WIFI_SSID = "Wokwi-GUEST";
const char* WIFI_PASSWORD = "";

const char* MQTT_CLIENT_ID = "ESPLab5";
const char* MQTT_BROKER = "broker.mqtt-dashboard.com";
const char* MQTT_USER = "";
const char* MQTT_PASSWORD = "";
const char* MQTT_TOPIC = "Lab5_temp_topic";

WiFiClient espClient;
PubSubClient client(espClient);

double distance = 0;
boolean alart=true;
String message;
boolean turned=false;
boolean flag=false;

void callback(char* topic, byte* payload, unsigned int length){
  String message; 
  for(int i=0;i<length;i++){
    message += (char)payload[i];
  }

  // Десеріалізація JSON повідомлення
  DynamicJsonDocument doc(1024);
  deserializeJson(doc, payload, length);
  String command = doc["command"].as<String>();

  // Керування дозволом на роботу мікроконтролера
  if (command == "on") {
    turned = true;
    Serial.println("Device enabled");
  } else if (command == "off") {
    turned = false;
    digitalWrite(LED_PIN, LOW); // Вимкнути світлодіод, якщо пристрій вимкнено
    Serial.println("Device disabled");
  }
}


void setup() {
  pinMode(LED_PIN, OUTPUT);
  pinMode(TRIG, OUTPUT);
	pinMode(ECHO, INPUT);
  Serial.begin(9600);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  while(WiFi.status() != WL_CONNECTED){
    delay(100);
  }
  client.setServer(MQTT_BROKER, PORT);
  client.setCallback(callback);
  client.connect(MQTT_CLIENT_ID, MQTT_USER, MQTT_PASSWORD);
  client.subscribe(MQTT_TOPIC);
  String message = "Alright!";
  client.publish(MQTT_TOPIC, message.c_str());
  client.loop();
}

void loop() {
  // put your main code here, to run repeatedly:
  if(!client.connected()){
    Serial.println("Client is not connected");
    while (!client.connected()) {
      if (client.connect(MQTT_CLIENT_ID, MQTT_USER, MQTT_PASSWORD)) {
        Serial.println("Connected to MQTT Broker!");
        client.subscribe(MQTT_TOPIC);
      } else {
        Serial.println("Failed try again in 5 seconds");
        delay(5000);
      }
    }
    Serial.println("Client is connected");
  }
  client.loop();
  int value_phr = analogRead(PHOTORESISTOR);
  //Serial.print("Value = ");
  //Serial.println(value_phr);
  if(value_phr > 2000 && turned){
		digitalWrite(TRIG, 0);
		digitalWrite(TRIG, 1);
		delayMicroseconds(12);
		digitalWrite(TRIG, 0);

		distance = pulseIn(ECHO,1) /(2*29);
    //Serial.println(distance);
    if(distance > 200){
      digitalWrite(LED_PIN,0);
      if(alart && !flag){
        alart = false;
        flag = true;
        message = "{\"Alert\":\"All Good!\"}";
        client.publish(MQTT_TOPIC, message.c_str());
      } 
    } else {
      digitalWrite(LED_PIN,1);
      alart = true;
      flag = false;
      message = "{\"Alert\":\"Someone close!\"}";
      client.publish(MQTT_TOPIC, message.c_str());
    }
  }	else if(!turned) {
    message = "{\"Alert\":\"You can enable system\"}";
    client.publish(MQTT_TOPIC, message.c_str());
    digitalWrite(LED_PIN,0);
  }
}