/**********************************************************************
  Arduino Ethernet Webserver
  nach: https://werner.rothschopf.net/202001_arduino_webserver_post.htm
  This version:
  - don't uses Arduino String class
  - read parameters POST
  - care about non defined pages
  - keeps the loop tidy
  - handle favicon.ico
  - don't use F-Makro in client.print
 **********************************************************************/

#define CS 53    // Pin 53 für CS Ethernet-Shield OKY3487

#include <SPI.h>
#include <Ethernet.h>
#include <StreamLib.h>  // https://github.com/jandrassy/StreamLibdownload 

byte mac[] { 0x52, 0x64, 0x75, 0x69, 0x6E, 0x6E };           // you can change the MAC and IP addresses to suit your network
IPAddress ip( 192, 168, 1, 97 );
EthernetServer server(80);                                   // Port 80 is HTTP port

void printHardwareInfo()
{
  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
    Serial.println(F("Ethernet shield was not found"));
  }
  else if (Ethernet.hardwareStatus() == EthernetW5100) {
    Serial.println(F("W5100 detected"));
  }
  else
  {
    if (Ethernet.hardwareStatus() == EthernetW5200) {
      Serial.println(F("W5200 detected"));
    }
    else if (Ethernet.hardwareStatus() == EthernetW5500) {
      Serial.println(F("W5500 detected"));
    }
    if (Ethernet.linkStatus() == Unknown) {        // cable connection
      Serial.println(F("Link status detection is only available with W5200 and W5500"));
    }
    else if (Ethernet.linkStatus() == LinkON) {
      Serial.println(F("Link status: On"));             
    }
    else if (Ethernet.linkStatus() == LinkOFF) {
      Serial.println(F("Link status: Off"));
    }
  }
}

void setup()
{
  Serial.begin(9600);
  Serial.println(F("\nsimple webserver"));

  delay(750);
  #ifdef CS
    Ethernet.init(CS);
  #endif
  Ethernet.begin(mac, ip);                           // Start the Ethernet shield:
  printHardwareInfo();
  server.begin();                                    // Start the webserver:
  Serial.print(F("server available at http://"));
  Serial.println(Ethernet.localIP());
}

void checkForClient()
{
  EthernetClient client = server.available();

  if (client) {
    Serial.println(F("\n[server] client connected"));
    uint8_t i = 0;                                // index / current read position
    const uint16_t buffersize = 100;              // size of read buffer (reads a complete line) (if larger than 255, modify i also!
    const uint16_t smallbuffersize = 30;          // a smaller buffer for results
    char lineBuffer[buffersize] {'\0'};           // buffer for incomming data
    char method[8];                               // largest one 7+1. HTTP request methods in RFC7231 + RFC5789: GET HEAD POST PUT DELETE CONNECT OPTONS TRACE PATCH
    char uri[smallbuffersize];                    // the requestet page, shorter than smallbuffersize - method
    char requestParameter[smallbuffersize];       // parameter appended to the URI after a ?
    char postParameter[smallbuffersize];          // parameter transmitted in the body / by POST
    enum class Status {REQUEST, CONTENT_LENGTH, EMPTY_LINE, BODY};
    Status status = Status::REQUEST;

    while (client.connected()) {
      while (client.available()) {
        char c = client.read();
        Serial.print(c);  // Debug print received characters to Serial monitor
        if ( c == '\n' )
        {
          if (status == Status::REQUEST)               // read the first line
          {
            //Serial.print(F("lineBuffer="));Serial.println(lineBuffer);
            // now split the input
            char *ptr;
            ptr = strtok(lineBuffer, " ");  // strtok will destroy the newRequest
            strlcpy(method, ptr, smallbuffersize);
            Serial.print(F("method=")); Serial.println(method);
            ptr = strtok(NULL, " ");
            strlcpy(uri, ptr, smallbuffersize);   // enthält noch evtl. parameter
            if (strchr(uri, '?') != NULL)
            {
              ptr = strtok(uri, "?");  // split URI from parameters
              strcpy(uri, ptr);
              ptr = strtok(NULL, " ");
              strcpy(requestParameter, ptr);
              Serial.print(F("requestParameter=")); Serial.println(requestParameter);
            }
            Serial.print(F("uri=")); Serial.println(uri);
            status = Status::EMPTY_LINE;                          // jump to next status
          }
          else if (status == Status::CONTENT_LENGTH)              // MISSING check for Content-Length
          {
            status = Status::EMPTY_LINE;
          }
          else if (status > Status::REQUEST && i < 2)            // check if we have an empty line
          {
            status = Status::BODY;
          }
          else if (status == Status::BODY)
          {
            strlcpy(postParameter, lineBuffer, smallbuffersize);
            break; // we have received one line payload and break out
          }
          i = 0;
          strcpy(lineBuffer, "");
        }
        else
        {
          if (i < buffersize)
          {
            lineBuffer[i] = c;
            i++;
            lineBuffer[i] = '\0';
          }
          // MISSING wenn status 3 und content-length --> abbrechen.
        }
      }
      if (status == Status::BODY) // status 3 could end without linefeed, therefore we takeover here also
      {
        strlcpy(postParameter, lineBuffer, smallbuffersize);
      }
      Serial.print(F("\r\npostParameter=")); Serial.println(postParameter);
      // Simple evaluation of postParameter from body
      // Post data looks like pinD2=On
      // strncmp() vergleicht zwei Strings bis maximal zum angegebenen Zeichen
      // oder in einem der beiden Strings ein Nullbyte gefunden wurde.
      // Rückgabewert: 0 => Die verglichenen Strings sind bis zum angegebenen Zeichen identisch

      if (strncmp(postParameter, "dL", 2) == 0 ) {
        sendStatistics(client);
      }

      if (strncmp(postParameter, "rS", 2) == 0) {
        //resetFunc(); // Resetten
      }

      if (!strcmp(uri, "/") || !strcmp(uri, "/index.htm")   ) // the homepage
        sendPage(client);
      else if (!strcmp(uri, "/favicon.ico"))                  // a favicon
        sendFavicon(client);
        //send204(client);                                    // i you don't have a favicon, send a defined empty response
      else                                                    // if we don't know the page, send error 404
        send404(client);
    }
  }
}


void sendPage(EthernetClient &client)
{
  // Serial.println("[server] 200 response send");
  const size_t MESSAGE_BUFFER_SIZE = 64;
  char buffer[MESSAGE_BUFFER_SIZE];  // a buffer needed for the StreamLib
  BufferedPrint message(client, buffer, sizeof(buffer));

  message.println(F("HTTP/1.0 200 OK\r\n"                // \r\n Header Fields are terminated by a carriage return (CR) and line feed (LF) character sequence.
                   "Content-Type: text/html\r\n"         // The Media type of the body of the request (used with POST and PUT requests).
                   "\r\n"                                // a blank line to split HTTP header and HTTP body
                   "<!doctype html>\n"                   // the HTTP Page itself
                   //"<html lang='en'>\n"
                   "<head>\n"
                   "<meta charset='utf-8'>\n"
                   "<meta name='viewport' content='width=device-width'>\n"
                   "<title>Webserver Heizzentrale</title>\n"
                   "</head>\n"
                   "<body style='font-family:Helvetica, sans-serif'>\n"));  //für ohne Seriffen
  message.print(F("<h1>Webserver MONI-TOR</h1>"
                  "<table cellpadding='0' cellspacing='0'>"
                  "<tbody>"
                  //"<!-- Zeile 1 -->"
                  "<tr><td bgcolor='#ffccff' height='20' width='100'><br>"
                  "</td><td>xxxx</td><td>xxxx</td><td>xxxx</td><td>xxxx</td>"
                  "<td>xxxx</td><td>xxxx</td><td width='100'><br></td>"
                  "<td bgcolor='#ccccff'>xxx</td>"
                  "<td bgcolor='#ccccff'>xxx</td>"
                  "<td bgcolor='#ccccff'>xxx</td>"
                  "<td>xxx</td><td>xxx</td><td>xxx</td></tr>"
                  //"<!-- Zeile 22 -->"
                  "<tr><td><br></td>"
                  "<td colspan='7' align='center'>"
                  /////// Form für Download Statistics ///////
                  "<form method='post' action='/' name='dL'>"
                  //"<form method='post' action='/' name='dL' style='float: left;'>"
                  // dass beide Elemente in einer ROW sind  ^^^^^^^^^^^^^^^^^^^^
                  "<input name='dL' value='Download Statistics' type='submit'></form>\n"
                  /////// Ende Form für Download Statistics ///////
                  /////// Form für Reset System ///////
                  "<form method='post' action='/' name='rS'>"
                  "<input name='rS' value='Reset System' type='submit'></form>\n"
                  /////// Ende Form für Reset System ///////
                  "</td><td bgcolor='#ffccff'><br></td>"
                  "<td bgcolor='#ffccff'><br></td>"
                  "<td><br></td><td bgcolor='#ffccff'><br></td>"
                  "<td bgcolor='#ffccff'><br></td></tr>"
                  //"<!-- Ende Zeilen -->"
                  "</tbody></table><br><br></body></html>"));
  message.flush();
  client.stop();
}


void send404(EthernetClient &client)
{
  // Serial.println("[server] response 404 file not found");
  const size_t MESSAGE_BUFFER_SIZE = 64;
  char buffer[MESSAGE_BUFFER_SIZE];  // a buffer needed for the StreamLib
  BufferedPrint message(client, buffer, sizeof(buffer));
  message.println(F("HTTP/1.0 404 Not Found\r\n"
                   "Content-Type: text/plain\r\n"              // we will send a simple plain text without html tags
                   "\r\n"
                   "404 File Fot Found\n"));
  message.flush();
  client.stop();
}


void send204(EthernetClient &client)
{
  // Serial.println("[server] response 204 no content");
  const size_t MESSAGE_BUFFER_SIZE = 64;
  char buffer[MESSAGE_BUFFER_SIZE];  // a buffer needed for the StreamLib
  BufferedPrint message(client, buffer, sizeof(buffer));
  message.println(F("HTTP/1.0 204 no content\r\n"));  // no content
  message.flush();
  client.stop();
}


void sendFavicon(EthernetClient &client)
{
  const static byte tblFavicon[] PROGMEM = {
    0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x10, 0x10, 0x00, 0x00, 0x01, 0x00, 0x08, 0x00, 0x68, 0x05,
    0x00, 0x00, 0x16, 0x00, 0x00, 0x00, 0x28, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x20, 0x00,
    0x00, 0x00, 0x01, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01,
    0x01, 0x00, 0x83, 0x77, 0x09, 0x00, 0x49, 0x3F, 0x0D, 0x00, 0xD3, 0xBD, 0x09, 0x00, 0x25, 0x21,
    0x09, 0x00, 0xF3, 0xDD, 0x0B, 0x00, 0x11, 0x11, 0x05, 0x00, 0xA1, 0x93, 0x0B, 0x00, 0x69, 0x5D,
    0x09, 0x00, 0xFB, 0xE5, 0x07, 0x00, 0x09, 0x09, 0x03, 0x00, 0x07, 0x05, 0x01, 0x00, 0xB3, 0xA1,
    0x0F, 0x00, 0x79, 0x6D, 0x0F, 0x00, 0x91, 0x85, 0x0F, 0x00, 0x35, 0x31, 0x09, 0x00, 0xFD, 0xE9,
    0x03, 0x00, 0x05, 0x03, 0x03, 0x00, 0xD9, 0xC7, 0x0D, 0x00, 0xF5, 0xE1, 0x09, 0x00, 0x01, 0x03,
    0x01, 0x00, 0x57, 0x51, 0x0D, 0x00, 0xA9, 0x9B, 0x0D, 0x00, 0xFF, 0xE7, 0x01, 0x00, 0x1F, 0x1B,
    0x07, 0x00, 0x7F, 0x73, 0x0B, 0x00, 0x97, 0x8B, 0x0B, 0x00, 0x3D, 0x39, 0x09, 0x00, 0xD7, 0xC5,
    0x09, 0x00, 0xA5, 0x97, 0x09, 0x00, 0xFB, 0xE7, 0x07, 0x00, 0xF9, 0xE1, 0x0B, 0x00, 0x5D, 0x55,
    0x0D, 0x00, 0x03, 0x01, 0x01, 0x00, 0xF5, 0xDF, 0x09, 0x00, 0x17, 0x11, 0x07, 0x00, 0x73, 0x69,
    0x0B, 0x00, 0x0F, 0x0D, 0x03, 0x00, 0xB9, 0xAB, 0x0D, 0x00, 0x7B, 0x71, 0x0D, 0x00, 0xE5, 0xCF,
    0x09, 0x00, 0x03, 0x03, 0x01, 0x00, 0x99, 0x8D, 0x0B, 0x00, 0x41, 0x3B, 0x0B, 0x00, 0xFD, 0xE7,
    0x03, 0x00, 0x8B, 0x7D, 0x0D, 0x00, 0x51, 0x4B, 0x0B, 0x00, 0xD3, 0xC1, 0x09, 0x00, 0x29, 0x25,
    0x09, 0x00, 0xA5, 0x95, 0x09, 0x00, 0x6B, 0x61, 0x0D, 0x00, 0x09, 0x07, 0x03, 0x00, 0x7D, 0x6F,
    0x0B, 0x00, 0x95, 0x89, 0x0D, 0x00, 0x39, 0x35, 0x09, 0x00, 0xDD, 0xC9, 0x09, 0x00, 0xF7, 0xE3,
    0x09, 0x00, 0xAB, 0x9B, 0x0D, 0x00, 0xFF, 0xE7, 0x05, 0x00, 0x21, 0x1D, 0x07, 0x00, 0x81, 0x75,
    0x0B, 0x00, 0x99, 0x8B, 0x0B, 0x00, 0x3F, 0x3B, 0x09, 0x00, 0x61, 0x57, 0x0D, 0x00, 0x1B, 0x17,
    0x07, 0x00, 0x03, 0x03, 0x05, 0x00, 0xFD, 0xE7, 0x07, 0x00, 0x01, 0x01, 0x03, 0x00, 0x4B, 0x45,
    0x0B, 0x00, 0xD3, 0xBF, 0x09, 0x00, 0x29, 0x23, 0x07, 0x00, 0xF5, 0xDD, 0x0B, 0x00, 0xA3, 0x95,
    0x0B, 0x00, 0x0B, 0x09, 0x03, 0x00, 0x07, 0x05, 0x03, 0x00, 0xB7, 0xA7, 0x09, 0x00, 0x79, 0x6F,
    0x0D, 0x00, 0x37, 0x33, 0x09, 0x00, 0xFF, 0xE9, 0x03, 0x00, 0xDB, 0xC7, 0x0F, 0x00, 0xF7, 0xE1,
    0x09, 0x00, 0x5B, 0x51, 0x09, 0x00, 0xA9, 0x9B, 0x0F, 0x00, 0xFF, 0xE7, 0x03, 0x00, 0x21, 0x1B,
    0x07, 0x00, 0x7F, 0x73, 0x0D, 0x00, 0x97, 0x8B, 0x0D, 0x00, 0xD7, 0xC5, 0x0B, 0x00, 0xA7, 0x97,
    0x09, 0x00, 0xF9, 0xE3, 0x07, 0x00, 0x5F, 0x55, 0x0D, 0x00, 0x03, 0x01, 0x03, 0x00, 0xF5, 0xDF,
    0x0B, 0x00, 0x19, 0x13, 0x05, 0x00, 0x0F, 0x0D, 0x05, 0x00, 0xBD, 0xAD, 0x0D, 0x00, 0x03, 0x03,
    0x03, 0x00, 0xFD, 0xE7, 0x05, 0x00, 0x8D, 0x81, 0x0B, 0x00, 0x6D, 0x63, 0x09, 0x00, 0x97, 0x89,
    0x0B, 0x00, 0x3F, 0x3B, 0x0B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3A, 0x0F,
    0x60, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5B, 0x41, 0x28, 0x0B,
    0x30, 0x4C, 0x5D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x27, 0x18, 0x43, 0x00, 0x45, 0x41,
    0x0C, 0x10, 0x62, 0x14, 0x00, 0x00, 0x00, 0x00, 0x14, 0x39, 0x2C, 0x64, 0x43, 0x00, 0x03, 0x14,
    0x08, 0x12, 0x44, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F, 0x12, 0x2E, 0x21, 0x00, 0x45, 0x00,
    0x00, 0x4A, 0x5B, 0x43, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x11, 0x5B, 0x00, 0x00, 0x2F, 0x00,
    0x00, 0x00, 0x43, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x37, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x50, 0x06,
    0x21, 0x00, 0x00, 0x00, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5B, 0x53, 0x3E,
    0x0D, 0x31, 0x31, 0x31, 0x48, 0x20, 0x24, 0x1D, 0x1D, 0x58, 0x48, 0x5A, 0x21, 0x5D, 0x17, 0x34,
    0x19, 0x2C, 0x53, 0x17, 0x17, 0x07, 0x3D, 0x2C, 0x17, 0x17, 0x17, 0x3C, 0x60, 0x51, 0x17, 0x5F,
    0x1B, 0x1E, 0x2C, 0x17, 0x09, 0x4B, 0x3C, 0x2C, 0x17, 0x2C, 0x2C, 0x63, 0x43, 0x3D, 0x17, 0x22,
    0x54, 0x0E, 0x64, 0x64, 0x3D, 0x0D, 0x2B, 0x35, 0x64, 0x3D, 0x64, 0x4D, 0x4A, 0x57, 0x17, 0x2C,
    0x08, 0x00, 0x21, 0x21, 0x00, 0x15, 0x16, 0x23, 0x00, 0x21, 0x00, 0x43, 0x46, 0x09, 0x17, 0x17,
    0x1C, 0x5E, 0x00, 0x00, 0x00, 0x16, 0x09, 0x36, 0x00, 0x00, 0x00, 0x14, 0x2D, 0x10, 0x17, 0x17,
    0x2C, 0x26, 0x3E, 0x25, 0x0B, 0x18, 0x02, 0x33, 0x0B, 0x33, 0x54, 0x55, 0x50, 0x4E, 0x17, 0x17,
    0x17, 0x2C, 0x09, 0x50, 0x05, 0x05, 0x05, 0x22, 0x22, 0x50, 0x09, 0x2C, 0x17, 0x17, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
    };

  const size_t MESSAGE_BUFFER_SIZE = 64;
  char buffer[MESSAGE_BUFFER_SIZE];  // a buffer needed for the StreamLib
  BufferedPrint message(client, buffer, sizeof(buffer));
  message.print(F("HTTP/1.0 200 OK\r\n"
                 "Content-Type: image/x-icon\r\n"
                 "\r\n"));

  for (uint16_t i = 0; i < sizeof(tblFavicon); i++)
  {
    byte p = pgm_read_byte_near(tblFavicon + i);
    message.write(p);
  }
  message.flush();
  client.stop();
}


void sendStatistics(EthernetClient &client) {
  const size_t MESSAGE_BUFFER_SIZE = 64;
  char buffer[MESSAGE_BUFFER_SIZE];  // a buffer needed for the StreamLib
  BufferedPrint message(client, buffer, sizeof(buffer));
  message.print(F("HTTP/1.0 200 OK\r\n"
                 "Content-Type: application/octet-stream\r\n"
                 "Content-Disposition: attachment; filename=statistics.bin\r\n"
                 "Content-Length: 262144\r\n"
                 "\r\n"));

  // Schicke 256kB Dummy-Daten
  for (int i = 0; i < 1024; i++) {
    for (byte j = 0; j < 256; j++) {
    message.write(j);
    }
  }
  message.flush();
  client.stop();
}

void loop()
{
  checkForClient();  // listen for incoming clients
  // put your other main code here, to run repeatedly. avoid any delay()
}