// Need to create a payload function for publish a json string

#include <ESP8266WiFi.h>
#include <Ethernet.h>
#include "PubSubClient.h"
#include "time.h"
#include "Adafruit_Sensor.h"
#include "DHT.h"
#include "U8glib.h" //https://github.com/olikraus/u8glib/wiki

// Erzwinge Deep Sleep
//#define FORCE_DEEPSLEEP
// DHT Sensor auswahl
#define DHTTYPE DHT22

// define Batterie Staus
// unsigned int batt;
// double battV;

// WiFi credentials.
const char* WIFI_SSID = "xxxxx";
const char* WIFI_PASS = "xxx";
// MQTT credentials.
const char* MQTT_USER = "xxx";
const char* MQTT_PASS = "xxx";
const char* MQTT_CLIENT = "ESP8266-IOT-DH22";
const char* MQTT_BROKER = "x";
const char* MQTT_Topic = "ESP01/DHT22";

char buf [4];

int timezone = 0; //4 = Sommerzeit
int dst = 0;

String clientName;
// On a ESP32-01
int DHTPIN = 2;    // DHT22 PIN

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NO_ACK);
WiFiClient net;
PubSubClient client(net);
DHT dht(DHTPIN, DHTTYPE);

void callback(char* topic, byte* payload, unsigned int length)
{
  // handle message arrived
}
//PubSubClient client(MQTT_BROKER, 1883, callback, net);
void reconnect();
void connectwifi();
void draw(float temperatur, float feuchtigkeit);



// setup () only run once
void setup()
{
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.setTimeout(2000);

  // Wait for serial to initialize.
  while (!Serial) { }
    Serial.println("Device Started");
    Serial.println("-------------------------------------");
    Serial.println("DHT22 sketch!");
    Serial.println("-------------------------------------");
//connect wifif fuction to connect to a wifi network
    connectwifi();
    delay(1500);
// INitiat MQQT Server
    client.setServer(MQTT_BROKER, 1883);
// client is now configured for use
    delay(1500);
//Get current time for MQTT transmission for ntp server
    configTime(3600, 0, "pool.ntp.org", "time.nist.gov");
    Serial.println("\nWaiting for time");
    while (!time(nullptr)) {
      Serial.print(".");
      delay(1000);
    }
  time_t now = time(nullptr);
  Serial.println(ctime(&now));
  Serial.println("-------------------------------------");
// Init DHT22
  dht.begin();

}

void loop()
{

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

// Whether or not the PubSubClient client is connected. Note that a client is considered connected if the connection has been closed but there is still unread data.
  if (!client.connected()) {
// reconnect
    reconnect();
  }
//loop() to allow the client to process incoming messages and maintain its connection to the server.
    if (!client.loop()) {
    Serial.print("Client disconnected...");
// Connect with MQTT credentials
    if (client.connect(MQTT_CLIENT, MQTT_USER, MQTT_PASS)) {
      Serial.println("MQTT reconnected.");
    } else {
      Serial.println("MQTT connection failed.");
    }

  }
  if (client.loop())
  {
    Serial.println("Read Sensor data");

// Check if any reads failed and exit early (to try again).

//read sonsor data from SensorPin
    Serial.print("Temperatur:");
    Serial.println(String(t));
    Serial.print("Feuchtigkeit:");
    Serial.println(String(h));
    Serial.println("-------------------------------------");
    Serial.println("Publish MQTT");
    Serial.print("MQTT Client:  ");
    Serial.println(MQTT_CLIENT);
    Serial.print("MQTT Broker:  ");
    Serial.println(MQTT_BROKER);
    Serial.print("Topic:  ");
    Serial.println(MQTT_Topic);
    Serial.println("-------------------------------------");
    Serial.print("Date:  ");
    time_t now = time(nullptr);
    Serial.println(ctime(&now));
    Serial.println("-------------------------------------");
// Create the JSON String called payload to be send via MQQT
    String payload = "{\"Date\":";
    payload += "\"";
    payload += now;
    payload += "\"";
    payload += ",\"Node\":";
    payload += "\"";
    payload += MQTT_CLIENT;
    payload += "\"";
    payload += ",\"IP\":";
    payload += "\"";
    payload += WiFi.localIP().toString();
    payload += "\"";
    payload += ",\"Temperatur\":";
    payload += "\"";
    payload += String(t);
    payload += "\"";
    payload += ",\"Humidity\":";
    payload += "\"";
    payload += String(h);
    payload += "\"";
    payload += "}";
    Serial.println("Payload: ");
    Serial.println(payload)
/   Serial.println("-------------------------------------");
// Publish data on screen
   u8g.firstPage();
   do {
      draw(t,h);
      } while ( u8g.nextPage() );
      delay(1);

// clinet.publish will publish the JSON string
     if (client.publish(MQTT_Topic, (char*) payload.c_str())) {
      Serial.println("Publish ok");
      delay(10*60*1000);
    }
    else {
      Serial.println("Publish failed");
      abort();
    }
 }
}

//publish a payload (json) string
boolean publishmqtt(String payload)
{
  if (!client.connected())
  {
    if (client.connect((char*) MQTT_CLIENT))
    {
      Serial.println("Connected to MQTT broker again");
      Serial.print("Topic is: ");
      Serial.println(MQTT_Topic);
    }
    else
    {
      Serial.println("MQTT connect failed");
      Serial.println("Will reset and try again...");
      abort();
    }
  }

  if (client.connected())
  {
    Serial.print("Sending payload: ");
    Serial.println(payload);
    if (client.publish(MQTT_Topic, (char*) payload.c_str()))
    {
      Serial.println("Publish ok");
    }
   }
    else
    {
      Serial.println("Publish failed");
    }
}
// need a funtion for int to Char* and other
String macToStr(const uint8_t* mac)
{
  String result;
  for (int i = 0; i < 6; ++i)
  {
    result += String(mac[i], 16);
    if (i < 5)
      result += ':';
  }
  return result;
}

void reconnect() {
  // Solange wiederholen bis Verbindung wiederhergestellt ist
  while (!net.connected()) {
    Serial.print("Versuch des MQTT Verbindungsaufbaus...");

    //Verbindungsversuch:
    if (client.connect(MQTT_CLIENT, MQTT_USER, MQTT_PASS)) {
      Serial.println("Erfolgreich verbunden!");
      // Nun versendet der Arduino eine Nachricht in outTopic ...
      // client.publish("outTopic","Arduino nach Hause telefonieren");

      // und meldet sich bei inTopic für eingehende Nachrichten an:
      // client.subscribe("inTopic");
    } else { // Im Fehlerfall => Fehlermeldung und neuer Versuch
      Serial.print("Fehler, rc=");
      Serial.println(client.state());
      Serial.println("-------------------------------------");
      Serial.println("Nächster Versuch in 5 Sekunden");
      // 5 Sekunden Pause vor dem nächsten Versuch
      delay(5000);
    }
  }
}

void connectwifi()
{
  // Connect to Wifi.
  Serial.println();
  Serial.println();
  Serial.println("Connecting to");
  Serial.println(WIFI_SSID);
  Serial.println("-------------------------------------");
  // WiFi.begin(WIFI_SSID, WIFI_PASS);

  // WiFi fix: https://github.com/esp8266/Arduino/issues/2186
  WiFi.persistent(false);
  WiFi.mode(WIFI_OFF);
  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_SSID, WIFI_PASS);

  unsigned long wifiConnectStart = millis();

  while (WiFi.status() != WL_CONNECTED)
  {
    // Check to see if
    if (WiFi.status() == WL_CONNECT_FAILED) {
      Serial.println("Failed to connect to WiFi. Please verify credentials: ");
      Serial.println("-------------------------------------");
      delay(10000);
    }

    delay(500);
    Serial.print(".");
    // Only try for 5 seconds.
    if (millis() - wifiConnectStart > 30000)
    {
      Serial.println("Failed to connect to WiFi");
      Serial.println("-------------------------------------");
      return;
    }
   }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("-------------------------------------");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println("-------------------------------------");

  clientName += "esp8266-";
  uint8_t mac[6];
  WiFi.macAddress(mac);
  clientName += macToStr(mac);
  clientName += "-";
  clientName += String(micros() & 0xff, 16);

  Serial.print("Connecting as ");
  Serial.println(clientName);
  Serial.println("-------------------------------------");
  }

double mapDouble(double x, double in_min, double in_max, double out_min, double out_max)
{
  double temp = (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
  temp = (int) (4*temp + .5);
  return (double) temp/4;
}

//draw t & h on the OLED display
void draw(float temperatur, float feuchtigkeit) {

  u8g.setFont(u8g_font_fub25); //https://github.com/olikraus/u8glib/wiki/fontsize
  u8g.setPrintPos(10, 32);
  u8g.print(temperatur, 1);
  u8g.setFont(u8g_font_fub25);
  u8g.setPrintPos(10, 64);
  u8g.print(feuchtigkeit, 1);
  u8g.setFont(u8g_font_fub25);
  u8g.drawStr(95, 32, "C");
  u8g.setFont(u8g_font_ncenB12);
  u8g.drawStr(85, 10, "o");
  u8g.setFont(u8g_font_fub25);
  u8g.drawStr(85, 64, "%");

}