// JSON
#include <ArduinoJson.h>
//WiFi
#include <WiFi.h>
//const char* ssid = "VA";
//const char* password = "qwerty123";
WiFiClient espClient;

//OLED
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);


//MQTT
#include <PubSubClient.h>

#define wifi_ssid "YourSSID"             //wifi ssid
#define wifi_password "YourPASS"     //wifi password

#define mqtt_server ""       // server name or IP
#define mqtt_user ""           // username
#define mqtt_password ""   // password
#define mqtt_clientId ""


PubSubClient client(espClient);

// MQTT Topics
#define humidity_topic "homeassistant/humidity"
#define temperature_topic "homeassistant/temperature"
#define co2_topic "homeassistant/co2"

//DHT
#include <DHT.h>
#include <DHT_U.h>
#define DHTTYPE DHT22 // Тип датчика
#define DHTPIN 4 //К какому пину подключен датчик DHT
DHT dht (DHTPIN, DHTTYPE);

//MQ135
#include <MQ135.h>
MQ135 gasSensor = MQ135 (A0); //Датчик газа подключен к аналоговому пину

//Timer
//#include <TimeLib.h>
//#include <SimpleTimer.h>
//SimpleTimer timer;

unsigned long lastSampleTime = 0;
const long sampleDelay = 30000;

void setup() {
  Serial.begin(115200);
  dht.begin();
  //Wire.begin( I2C_SDA_PIN, I2C_SCL_PIN );
  setupWifi();
  client.setServer(mqtt_server, 1883);
  //timer.setInterval(5000L,sendTemps);
  //lightMeter.begin(BH1750_CONTINUOUS_HIGH_RES_MODE);

//OLED
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  delay(2000);
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0, 10);
  // Display static text
  display.println("loading");


}



void sendTemps (){

float h = dht.readHumidity(); 
float t = dht.readTemperature(); 

 if (isnan(h) || isnan(t)){
     return;
     }

float rzero = gasSensor.getRZero();
float ppm = gasSensor.getPPM();
float rzeroc = gasSensor.getCorrectedRZero(t, h);
float ppmc = gasSensor.getCorrectedPPM(t, h);


Serial.print("Humidity: ");
  Serial.println(h);
  Serial.print("Temperature: ");
  Serial.println(t);
  Serial.print("A0: ");
  Serial.println(analogRead (A0));
  Serial.print("Rzero: ");
  Serial.println(rzero);
  Serial.print("Rzeroc: ");
  Serial.println(rzeroc);
  Serial.print("PPM: ");
  Serial.println(ppm);
  Serial.print("PPMC: ");
  Serial.println(ppmc);

}
void setupWifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(wifi_ssid);

  WiFi.mode(WIFI_STA);
  WiFi.begin(wifi_ssid, wifi_password);

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

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect(mqtt_clientId, mqtt_user, mqtt_password)) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  unsigned long currentMillis = millis();
  float h = dht.readHumidity(); 
  float t = dht.readTemperature(); 

 if (isnan(h) || isnan(t)){
     return;
     }

  float rzero = gasSensor.getRZero();
  float ppm = gasSensor.getPPM();
  float rzeroc = gasSensor.getCorrectedRZero(t, h);
  float ppmc = gasSensor.getCorrectedPPM(t, h);

  DynamicJsonDocument doc(1024);
  doc["id"] = "sensors";
  doc["humid"] = h;
  doc["temp"] = t;
  doc["co2"] = ppm;

  // Serialize JSON document
  String payload;
  serializeJson(doc, payload);
  client.publish("homeassistant/sensors", payload.c_str());  
  delay(30000);


  //void topic2_subscriber(String topic, String message_h) {
  //Serial.println(s+"Message arrived in function 2 ["+topic+"] "+message_h);
  //client.publish("ext_sensor/Humidity_Ext", String(message_h).c_str(),true);            
  //Serial.println(s+"Message sended in topic ext_sensor/Humidity_Ext: "+message_h); 
  
  if (currentMillis - lastSampleTime >= sampleDelay) {
    lastSampleTime = currentMillis;

    if (isnan(t)) {
      Serial.println("Error reading temperature!");
    }
    else {
      
      client.publish(temperature_topic, String(t).c_str(), true);

      Serial.print("Temperature: ");
      Serial.print(t);
      Serial.println(" *C");
    }
    // Get humidity event and print its value.
    if (isnan(h)) {
      Serial.println("Error reading humidity!");
    }
    else {
      
      client.publish(humidity_topic, String(h).c_str(), true);

      Serial.print("Humidity: ");
      Serial.print(h);
      Serial.println("%");
    }
    client.publish(co2_topic, String(ppm).c_str(), true);

      Serial.print("CO2: ");
      Serial.print(ppm);
      Serial.println("ppm");
  }
//SimpleTimer.run();

// OLED
// clear display
  display.clearDisplay();
  
  // display temperature
  display.setTextSize(1);
  display.setCursor(0,0);
  display.print("Temperature: ");
  display.setTextSize(2);
  display.setCursor(0,10);
  display.print(t);
  display.print(" ");
  display.setTextSize(1);
  display.cp437(true);
  display.write(167);
  display.setTextSize(2);
  display.print("C");
  
  // display humidity
  display.setTextSize(1);
  display.setCursor(0, 35);
  display.print("Humidity: ");
  display.setTextSize(2);
  display.setCursor(0, 45);
  display.print(h);
  display.print(" %"); 
  
  display.display(); 
}