#include <WiFi.h>
#include <WiFiMulti.h>
#include <stdio.h>
#include <stdbool.h>
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
#include <esp_err.h>
#include "PubSubClient.h"


#include "Ultrasonic.h"
const int DISTANCE_THRESHOLD = 12; // meters
Ultrasonic ultrasonic(5, 4);

// variables will change:
float distance_m;

const char* ssid = "Wokwi-GUEST";
const char* pass = "";
const char* mqttServer = "test.mosquitto.org";
int port = 1883;
String stMac;
char mac[50];
char clientId[50];

WiFiClient espClient;
PubSubClient client(espClient);

const int ledPin = 18;

void setup() {
  Serial.begin (9600);       // initialize serial port
  pinMode(ledPin, OUTPUT);

  Serial.begin(115200);
  randomSeed(analogRead(0));

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {

    delay(100);
    Serial.println("connecting. . .");
    Serial.println(ssid);

    wifiConnect();

    Serial.println("WiFi Connected");
    Serial.println("IP address: ");
    Serial.println(WiFi.localIP());
    Serial.println(WiFi.macAddress());
    stMac = WiFi.macAddress();
    stMac.replace(":", "_");
    Serial.println(stMac);

    client.setServer(mqttServer, port);
    client.setCallback(callback);
    pinMode(ledPin, OUTPUT);
  }
}

void wifiConnect() {
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println(".");
  }
}

void mqttReconnect() {
  while (!client.connected()) {
    Serial.println("Attempting MQTT connection. . .");
    long r = random(1000);
    sprintf(clientId, "clientId-%Id", r);
    if (client.connect(clientId)) {
      Serial.print(clientId);
      Serial.println("connected");
      client.subscribe("/IoT");
    } else {
      Serial.print("faied, rc=");
      Serial.print(client.state());
      Serial.println("Try again in 5 seconds");
      delay(5000);
    }
  }
}

void callback(char* topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String stMessage;

  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    stMessage += (char)message[i];
  }
  Serial.println();

  if (String(topic) == "IoT") {
    Serial.print("Changing output to ");
    if (stMessage == "on") {
      Serial.println("on");
      digitalWrite(ledPin, HIGH);
    }
    else if (stMessage == "off") {
      Serial.println("off");
      digitalWrite(ledPin, LOW);
    }
  }
}



void loop() {

  // measure duration of pulse from ECHO pin

  // calculate the distance
  distance_m = ultrasonic.read(CM);

  if (distance_m < DISTANCE_THRESHOLD)
    digitalWrite(ledPin, HIGH); // turn LED on
  else
    digitalWrite(ledPin, LOW);  // turn LED off

  // print the value to Serial Monitor
  Serial.print("distance: ");
  Serial.print(distance_m);
  Serial.println(" m");

  delay(500);
}