#include <WiFi.h>
#include <LiquidCrystal_I2C.h>
#include "MQ135.h"
#include "DHTesp.h"
#include <PubSubClient.h>

const char* ssid = "Wokwi-GUEST";
const char* password = "";

//***Set server***
const char* mqttServer = "broker.hivemq.com"; 
int server_port = 1883;

WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);
//***Http Request***
const char* host = "maker.ifttt.com";
const int port = 80;
const char* request = "/trigger/helloworld/with/key/d3M-nEH9ge-nBh3Uec7fnS?value1=45";

// const char* MQTT_PUB_HOTEN = "21127659/hoten";
// const char* MQTT_REC_MSSV = "21127659/mssv";

LiquidCrystal_I2C lcd(0x27, 16, 2);
// MQ135 gasSensor = MQ135(A2);

int dht_pin = 15;
DHTesp dhtSensor;

int redled_pin = 2;
int greenled_pin = 4;

void sendRequest() {
  WiFiClient client;
  while(!client.connect(host, port)) {
    Serial.println("connection fail");
    delay(1000);
  }
  client.print(String("GET ") + request + " HTTP/1.1\r\n"
              + "Host: " + host + "\r\n"
              + "Connection: close\r\n\r\n");
  delay(500);

  while(client.available()) {
    String line = client.readStringUntil('\r');
    Serial.print(line);
  }
}

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 = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    if(mqttClient.connect(clientId.c_str())) {
      Serial.println("connected");

      //***Subscribe all topic you need***
      // mqttClient.subscribe(MQTT_REC_MSSV);
    }
    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***

}

void setup() {
  Serial.begin(9600);
  Serial.print("Connecting to WiFi");

  wifiConnect();
  sendRequest();

  mqttClient.setServer(mqttServer, port);
  mqttClient.setCallback(callback);
  mqttClient.setKeepAlive( 90 );

  // dht
  dhtSensor.setup(dht_pin, DHTesp::DHT22);

  // mq135
  // float rzero = gasSensor.getRZero();
  // delay(3000);
  // Serial.print("MQ135 RZERO Calibration Value : ");
  // Serial.println(rzero);

  // lcd
  lcd.init(); 
  lcd.begin(16,2);//Defining 16 columns and 2 rows of lcd display
  lcd.backlight();

  // led
  pinMode(redled_pin, OUTPUT);
  pinMode(greenled_pin, OUTPUT);
  digitalWrite(redled_pin, LOW);
  digitalWrite(greenled_pin, LOW);

}

void loop() {
  // dht
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  Serial.println("Temp: " + String(data.temperature, 2) + "C");
  Serial.println("Humidity: " + String(data.humidity, 1) + "%");
  Serial.println("---");

  lcd.setCursor(0,0);
  lcd.print("Temp : ");
  lcd.print(String(data.temperature, 2) + "C");
  lcd.setCursor(0,1);
  lcd.print("Humidity : ");  
  lcd.print(String(data.humidity, 1) + "%");
  delay(3000);
  lcd.clear();
  
  // mq135
  // float ppm = gasSensor.getPPM();
  // Serial.print("CO2 ppm value : ");
  // Serial.println(ppm);

  // lcd.setCursor(0,0);
  // lcd.print("   Tech Maker   ");
  // lcd.setCursor(0,1);
  // lcd.print("CO2 : ");
  // lcd.print(ppm);
  // lcd.print("PPM");
  // delay(3000);
  // lcd.clear();

  // led
  // if (ppm <= 150)
  // {
  //   digitalWrite(greenled_pin, HIGH);
  // }
  // else
  //   digitalWrite(redled_pin, HIGH);

  if(!mqttClient.connected()) {
    mqttConnect();
  }
  mqttClient.loop();

  //***Publish data to MQTT Server***
  // mqttClient.publish(MQTT_PUB_HOTEN, hoten);
  // Serial.printf("Publishing on topic %s message: %s \n", MQTT_PUB_HOTEN, hoten);
  // Serial.printf("Subscribe on topic %s message: %s \n", MQTT_REC_MSSV, mssv);

  delay(5000);
}