// LCD
byte customCharSun[] = {B00100, B10001, B01110, B11111, B11111, B01110, B10001, B00100};
byte customCharMoon[] = {B11000, B01110, B00110, B00111, B00111, B00110, B01110, B11000};
byte customCharArrowRight[] = {B01000, B01100, B01110, B01111, B01110, B01100, B01000, B00000};
byte customCharDegC[] = {B01000, B10100, B01000, B00011, B00100, B00100, B00011, B00000};
byte customCharConn[] = {B00000, B00000, B11100, B00010, B11001, B00101, B10101, B00000};
byte customCharDisconn[] = {B10001, B01010, B00100, B01010, B10001, B00000, B10000, B00000};
byte customCharReduction2[] = {B00000, B11111, B01110, B00100, B00000, B11111, B01110, B00100}; //(2 arrows down)
byte customCharFlame[] = {B00100, B00100, B01010, B01010, B10101, B10101, B10101, B01110};
//boolean displayActive = false;
unsigned long displayLastOnMillis = 0;

void enableDisplay() {
  lcd.backlight();
  displayActive = true;
  displayLastOnMillis = millis();
}

void disableDisplay() {
  lcd.noBacklight();
  displayActive = false;
}

void extendDisplayTimeout() {
  displayLastOnMillis = millis();
}

void handleDisplayTimeout() {
  if (displayActive && (millis() - displayLastOnMillis) > (displayTimeout * 1000)) {
    disableDisplay();
  }
}

void initDisplay() {
  lcd.init();
  lcd.createChar(0, customCharMoon);
  lcd.createChar(1, customCharSun);
  lcd.createChar(2, customCharArrowRight);
  lcd.createChar(3, customCharDegC);
  lcd.createChar(4, customCharConn);
  lcd.createChar(5, customCharDisconn);
  lcd.createChar(6, customCharReduction2);
  lcd.createChar(7, customCharFlame);

  lcd.setCursor(0, 0);

  lcd.print("WiFiThermostat  ");
  lcd.setCursor(0, 1);
  lcd.print("(c) by FloKra.at");

  //  for ( int i = 0; i < 3; i++) {
  //    lcd.backlight();
  //    delay(200);
  //    lcd.noBacklight();
  //    delay(200);
  //  }
  lcd.backlight();
  //delay(1000);
  ///lcd.clear();
  displayActive = true;
  displayLastOnMillis = millis();
}

void displayShowWifiConnected() {
  lcd.setCursor(0, 0);

  lcd.print("WiFi connected  ");
  lcd.setCursor(0, 1);
  lcd.print("IP:             ");
  lcd.setCursor(4, 1);
  lcd.print(WiFi.localIP());

  lcd.backlight();
  displayActive = true;
  displayLastOnMillis = millis();
  delay(2000);
}

void displayShowWifiConnectionError() {
  lcd.setCursor(0, 0);
  lcd.print("WiFi connecting ");
  lcd.setCursor(0, 1);
  lcd.print("FAILED          ");
  lcd.backlight();
  displayActive = true;
  displayLastOnMillis = millis();
  delay(2000);

  lcd.setCursor(0, 0);
  lcd.print("AP mode active  ");
  lcd.setCursor(0, 1);
  lcd.print("                ");
  lcd.setCursor(0, 1);
  lcd.print(persWM.getApSsid());
  lcd.backlight();
  displayActive = true;
  displayLastOnMillis = millis();
  delay(2000);
  
  lcd.setCursor(0, 0);
  lcd.print("Password:       ");
  lcd.setCursor(0, 1);
  lcd.print("                ");
  lcd.setCursor(0, 1);
  lcd.print(wifiAPModePassword);
  lcd.backlight();
  displayActive = true;
  displayLastOnMillis = millis();
  delay(2000);
}

void displayShowMQTTConnected() {
  lcd.setCursor(0, 0);

  lcd.print("MQTT connected  ");
  lcd.setCursor(0, 1);
  lcd.print("                ");
  lcd.setCursor(0, 1);
  lcd.print(mqtt_server);

  lcd.backlight();
  displayActive = true;
  displayLastOnMillis = millis();

  displayShowFullscreenMsg = true;
  countDisplayInterval = 0;
  //displayInterval_saved = displayInterval; //already done in loadconf2
  displayInterval = displayOverlayMsgTimeout;
  //delay(2000);
}

void displayShowMQTTConnectionError() {
  lcd.setCursor(0, 0);
  lcd.print("MQTT connection ");
  lcd.setCursor(0, 1);
  lcd.print("FAILED          ");

  lcd.backlight();
  displayActive = true;
  displayLastOnMillis = millis();
  displayShowFullscreenMsg = true;
  countDisplayInterval = 0;
  //displayInterval_saved = displayInterval; //already done in loadconf2
  displayInterval = displayOverlayMsgTimeout;
  //delay(2000);
}

void displayShowLine2OverlayMessage(char* msg) {
  lcd.setCursor(0, 1);
  lcd.print("                ");
  lcd.setCursor(0, 1);
  lcd.write((uint8_t)2); // arrow right symbol
  lcd.print(" ");
  lcd.print(msg);

  for (int i = strlen(msg); i < 14; i++) {
    lcd.print(" ");
  }

  displayShowLine2OverlayMsg = true;
  countDisplayInterval = 0;
  //displayInterval_saved = displayInterval; //already done in loadconf2
  displayInterval = displayOverlayMsgTimeout;
}

void displayAddConnectionIcon() {
  lcd.setCursor(14, 1);
  lcd.print(" ");
  if (mqttConnected) lcd.write((uint8_t)4); // connected symbol
  else lcd.write((uint8_t)5); // disconnected symbol
}

void updateDisplay() {
  if (displayShowFullscreenMsg) {
    displayShowFullscreenMsg = false;
    displayInterval = displayInterval_saved;
    updateDisplayImmediately = true;
  }
  else {
    boolean showTemp = false;
    char ch_temp[6];
    char ch_hum[4];
    char tempLabel[2];
    long now = millis();

    if (togglingTempHumAIDisplay) {

      if ( ((now - outTempHumLastUpdate) < maxMeasurementAge) && outTempHumLastUpdate != 0 && whichTempToDisplay == 1 && ((now - lastDisplayToggle) > (displayInterval * 1000)) ) {
        // outside temp has been updated < 5 min ago, last displayed temp was INSIDE and display interval is overdue
        whichTempToDisplay = 2; // 1= I, 2= A
        lastDisplayToggle = now;
      }
      else if ( whichTempToDisplay != 1 && ((now - lastDisplayToggle) > (displayInterval * 1000)) ) {
        whichTempToDisplay = 1; // 1= I, 2= A
        lastDisplayToggle = now;
      }

      lastDisplayUpdate = now;

      if (whichTempToDisplay == 2) { //2 = outside temp/hum received via MQTT
        if ( outTempHumLastUpdate != 0 && (now - outTempHumLastUpdate) < maxMeasurementAge ) {
          showTemp = true;
          dtostrf(outTemp, 5, 1, ch_temp);
          sprintf(ch_hum, "%2i", outHum);
          strcpy(tempLabel, otemplab);
        }
      }
      else {
        if ( lastTempUpdate != 0 && (now - lastTempUpdate) < maxMeasurementAge ) {
          showTemp = true;
          dtostrf(currTemp, 5, 1, ch_temp);
          sprintf(ch_hum, "%2i", currHum);
          strcpy(tempLabel, itemplab);
        }
      }

      // 12345667890123456
      // =20.0° 35% >22.5°
      // A -10.2° 95%    N
      // A 22.2° 95%     N
      // A 5.2° 95%      N



      // LCD line 1
      // print temperature incl = and ° symbol + humidity to lcd, line 1, first 11 chars
      lcd.setCursor(0, 0);

      if (showTemp) {
        //lcd.write(0x3D); // = Zeichen
        lcd.print(tempLabel);
        lcd.print(" ");
        lcd.print(ch_temp);
        //lcd.write(0xDF); // degree symbol
        lcd.write((uint8_t)3); // °C symbol
        lcd.print(" ");

        if (currHum == 0) lcd.print("--");
        else if (currHum < 10) {
          lcd.print(" ");
          lcd.print(ch_hum);
        }
        else {
          lcd.print(ch_hum);
        }
        lcd.print("%");
        lcd.print("        ");
      }
      else {
        lcd.print("               ");
      }
    }

    else { // non toggling temperature I + A display without humidity in line 1
      lcd.setCursor(0, 0);
      lcd.print(itemplab);

      if ( lastTempUpdate != 0 && (now - lastTempUpdate) < maxMeasurementAge ) {
        dtostrf(currTemp, 5, 1, ch_temp);
        lcd.print(ch_temp);
      }
      else {
        lcd.print(" --.-");
      }
      lcd.write((uint8_t)3); // °C symbol
      lcd.print(" ");

      if ( outTempHumLastUpdate != 0 && (now - outTempHumLastUpdate) < maxMeasurementAge ) {

        lcd.print(" ");
        lcd.print(otemplab);
        
        dtostrf(outTemp, 5, 1, ch_temp);
        lcd.print(ch_temp);
        lcd.write((uint8_t)3); // °C symbol
      }
      else {
        lcd.print("        ");
      }
    }

    updateCurrSetTemp();

    char ch_currSetTemp[6];
    dtostrf(currSetTemp, 5, 1, ch_currSetTemp);

    // LCD line 2
    // display target temperature to line 2, 8 chars length incl space at the end
    lcd.setCursor(0, 1);

    if ( doRestart ) {
      lcd.print("Restarting... ");
    }
    else if ( pendingRestart ) {
      lcd.print("Restart?      ");
    }
    else if ( heatingMode == 0 ) { // when the heating mode is OFF, do not display target temp - instead show "Heating off" info in line 2
      //         1234567890123456
      lcd.print("               ");
      lcd.setCursor(0, 1);
      lcd.print(offMessage);
      //for(int i=strlen(offMessage); i < 14; i++) {
      //lcd.print(" ");
      //}
      displayAddConnectionIcon();
    }
    else if ( displayShowLine2OverlayMsg ) {
      displayShowLine2OverlayMsg = false;
      displayInterval = displayInterval_saved;
      if (pendingPresetToggle) {
        preset = pendingPreset;
        updateCurrentPresetName();
        pendingPresetToggle = false;
      }
      updateDisplayImmediately = true;
    }
    else {
      lcd.write((uint8_t)2); // arrow right symbol
      //lcd.print(" ");
      lcd.print(ch_currSetTemp);
      //lcd.write(0xDF); // degree symbol
      lcd.write((uint8_t)3); // °C symbol
      
      lcd.print(" ");

      lcd.setCursor(8, 1);
      lcd.print("        ");

      // display status info to line 2 from char 9 -> 8 chars length
      lcd.setCursor(9, 1);
      if ( preset == 0 ) { // day/normal mode
        lcd.write((uint8_t)1); // sun symbol if mode is day/normal
      }
      else if ( preset == 1 ) { // night/reduction mode
        lcd.write((uint8_t)0); // moon symbol if mode is night/reduction
      }
      else if ( preset == 2 ) { // night/reduction mode
        lcd.write((uint8_t)6); // reduction 2 (2 arrows down) symbol if mode is reduction 2
      }

      lcd.setCursor(12, 1);
      if (turnHeatingOn) {
        lcd.write((uint8_t)7); // flame symbol if heating is active
      }
      else {
        lcd.print(" ");
      }
      displayAddConnectionIcon();
    }
  }
}