const int NTC_PIN = 34;
const int TRIG_PIN = 4;
const int ECHO_PIN = 35;
const int PH_PIN = 32;
const float BETA = 3950; // should match the Beta Coefficient of the thermistor
#include <WiFi.h>
#include <PubSubClient.h>
#include <iostream>
#include <iomanip>
#include <sstream>
const char* ssid = "Wokwi-GUEST";
const char* password = "";

//***Set server***
const char* mqttServer = "0.tcp.ap.ngrok.io";
int port = 16537 ;

WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);

void wifiConnect() {
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" Connected!");
}

void mqttConnect() {
  while (!mqttClient.connected()) {
    Serial.println("Attemping MQTT connection...");
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    if (mqttClient.connect(clientId.c_str())) {
      Serial.println("connected");

      //***Subscribe all topic you need***

    }
    else {
      Serial.println("try again in 5 seconds");
      delay(5000);
    }
  }
}
//MQTT Receiver
void callback(char* topic, byte* message, unsigned int length) {
  Serial.println(topic);
  String strMsg;
  for (int i = 0; i < length; i++) {
    strMsg += (char)message[i];
  }
  Serial.println(strMsg);

  //***Code here to process the received package***

}
float getDistance() {
  unsigned long duration;



  digitalWrite(TRIG_PIN, 0);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, 1);
  delayMicroseconds(5);
  digitalWrite(TRIG_PIN, 0);


  duration = pulseIn(ECHO_PIN, HIGH);

  return float(duration / 2 / 29.412);
}
void setup() {
  Serial.begin (115200);
  pinMode(NTC_PIN, INPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  pinMode(PH_PIN, INPUT);
  wifiConnect();
  delay(1000);
  analogReadResolution(10);
  mqttClient.setServer(mqttServer, port);
  mqttClient.setCallback(callback);
  mqttClient.setKeepAlive( 90 );
}


void loop() {
  if(!mqttClient.connected()) {
   mqttConnect();
  }
  mqttClient.loop();
  // put your main code here, to run repeatedly:
  int analogValue = analogRead(NTC_PIN);
  float celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
  int pH = analogRead(PH_PIN);
  float distance=getDistance();
  pH = map(pH, 0, 1023, 0, 14);
  Serial.print("Temperature: ");
  Serial.print(celsius);
  Serial.println(" ℃");
  Serial.print("pH: ");
  Serial.println(pH);
  Serial.print("Water level: ");
  Serial.println(distance);
  char msgTemp[50];
  char msgPh[50];
  char msgLevel[50];
  snprintf(msgTemp,50,"%.2f",celsius);
  snprintf(msgPh,50,"%d",pH);
  snprintf(msgLevel,50,"%.2f",distance);
  mqttClient.publish("temperature",msgTemp);
  mqttClient.publish("pH",msgPh);
  mqttClient.publish("waterLevel",msgLevel);
  delay(1000);
}