#include <PubSubClient.h>
#include <WiFi.h>
#include "DHTesp.h"
#include <NTPClient.h>
#include <WiFiUdp.h>

#define BUZZER 13

// pin and instance of the DHT sensor
const int DHT_PIN = 12;
DHTesp dhtSensor;

WiFiClient espClient;
// mqttClient the variable 
PubSubClient mqttClient(espClient);

WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP);

bool isScheduledON = false;
unsigned long scheduledOnTime;

char tempAr[6];

// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
void setup() {
  Serial.begin(115200);
  setupWifi();

  setupMqtt(); 

  //initiate the temperature sensor
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);
  
  timeClient.begin();
  timeClient.setTimeOffset(5.5*3600);

  pinMode(BUZZER, OUTPUT);
  digitalWrite(BUZZER, LOW);
}

// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
void loop() {
  if (!mqttClient.connected()){
    connectToBroker();
  }

  mqttClient.loop();

  updateTemperature();
  Serial.println(tempAr);
  // publish the temperature
  mqttClient.publish("ENTC-ADMIN-TEMP", tempAr);

  checkSchedule();

  delay(1000);
}

// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
void buzzerOn(bool on){
  if (on){
    tone(BUZZER,256);
  }else{
    noTone(BUZZER);
  }
}

// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
void setupMqtt(){
  // setting the server
  mqttClient.setServer("test.mosquitto.org", 1883);
  mqttClient.setCallback(receiveCallback);
}

// receving msg part >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
void receiveCallback(char* topic,byte* payload,unsigned int length){
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");

  // to take the value another variable
  char payloadCharAr[length];
  for (int i= 0; i<length; i++){
    Serial.print((char) payload[i]); // convert bite into char to print 
    payloadCharAr[i] = (char)payload[i]; // each i will be casted
  }
  Serial.println(); // new line to print values after the msg

  // depending on the on off topic, on off the LED
  if(strcmp(topic, "ENTC-ADMIN-MAIN-ON-OFF") == 0){  // strcmp: string compare meethod
    // if(payloadCharAr[0]='1'){
    //   buzzreOn(true);
    // }else{
    //   buzzerOn(false);
    // }
    // insterd of above if else function we can use
    buzzerOn(payloadCharAr[0]='1');

    // then we have to subscribe
  }else if(strcmp(topic, "ENTC-ADMIN-SCH-ON") == 0){
    if(payloadCharAr[0]='N'){ // NOT N the 1st character we send
      isScheduledON = false; 
    }else{
      isScheduledON = true;
      scheduledOnTime = atol(payloadCharAr);  // array to long
    }
  }
}

// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
void connectToBroker(){
  while (!mqttClient.connected()){
    Serial.println("Attempting MQTT connection...");
    if (mqttClient.connect("ESP32-56465466")){
      Serial.println("Connected");
      // after connected we can subscribe 
      mqttClient.subscribe("ENTC-ADMIN-MAIN-ON-OFF");
      mqttClient.subscribe("ENTC-ADMIN-SCH-ON");

    }else{
      Serial.print("failed");
      Serial.print(mqttClient.state()); // give the state that connected or not
      delay(5000);
    }
  }
}
 
// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
void updateTemperature(){
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  String(data.temperature,2).toCharArray(tempAr,6);
  // fectch the temp value and convert into 2 decimal string
  // only get char array with 6 values
}

// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
void setupWifi(){
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println("Wokwi-GUEST");
  // connet to the wifi
  WiFi.begin("Wokwi-GUEST", "");

  while (WiFi.status() != WL_CONNECTED){
    delay(500);
    Serial.print(".");
  }

  Serial.println("WiFi Connected");
  Serial.println("IP Address: ");
  // get the IP address
  Serial.println(WiFi.localIP());


}

// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
unsigned long getTime(){
  timeClient.update();
  return timeClient.getEpochTime();
}

// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
void checkSchedule(){
  if(isScheduledON){
    unsigned long currentTime = getTime();
      
    if (currentTime > scheduledOnTime){
      buzzerOn(true);
      isScheduledON = false;
      mqttClient.publish("ENCT-ADMIN-MAIN-ON-OFF-ESP", "1"); // then sink 
      mqttClient.publish("ENCT-ADMIN-SCH-ESP-ON", "0");
      Serial.println("Scheduled ON");      
    }
  }
}

// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>