text: // The MIT License (MIT)
  //
  // Copyright (c) 2015 Adafruit Industries
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in all
  // copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  // SOFTWARE.
  #ifndef _ADAFRUIT_MQTT_FONA_H_
  #define _ADAFRUIT_MQTT_FONA_H_
  
  #include <Adafruit_FONA.h>
  #include "Adafruit_MQTT.h"
  
  #define MQTT_FONA_INTERAVAILDELAY 100
  #define MQTT_FONA_QUERYDELAY 500
  
  
  // FONA-specific version of the Adafruit_MQTT class.
  // Note that this is defined as a header-only class to prevent issues with using
  // the library on non-FONA platforms (since Arduino will include all .cpp files
  // in the compilation of the library).
  class Adafruit_MQTT_FONA : public Adafruit_MQTT {
   public:
    Adafruit_MQTT_FONA(Adafruit_FONA *f, const char *server, uint16_t port,
                         const char *cid, const char *user, const char *pass):
      Adafruit_MQTT(server, port, cid, user, pass),
      fona(f)
    {}
  
    Adafruit_MQTT_FONA(Adafruit_FONA *f, const char *server, uint16_t port,
                       const char *user="", const char *pass=""):
      Adafruit_MQTT(server, port, user, pass),
      fona(f)
    {}
  
    bool connectServer() {
      char server[40];
      strncpy(server, servername, 40);
  #ifdef ADAFRUIT_SLEEPYDOG_H
      Watchdog.reset();
  #endif
  
      // connect to server
      DEBUG_PRINTLN(F("Connecting to TCP"));
      return fona->TCPconnect(server, portnum);
    }
  
    bool disconnectServer() {
      return fona->TCPclose();
    }
  
    bool connected() {
      // Return true if connected, false if not connected.
      return fona->TCPconnected();
    }
  
    uint16_t readPacket(uint8_t *buffer, uint16_t maxlen, int16_t timeout) {
      uint8_t *buffp = buffer;
      DEBUG_PRINTLN(F("Reading data.."));
  
      if (!fona->TCPconnected()) return 0;
  
  
      /* Read data until either the connection is closed, or the idle timeout is reached. */
      uint16_t len = 0;
      int16_t t = timeout;
      uint16_t avail;
  
      while (fona->TCPconnected() && (timeout >= 0)) {
        //DEBUG_PRINT('.');
        while (avail = fona->TCPavailable()) {
          //DEBUG_PRINT('!');
  
          if (len + avail > maxlen) {
  	  avail = maxlen - len;
  	  if (avail == 0) return len;
          }
  
          // try to read the data into the end of the pointer
          if (! fona->TCPread(buffp, avail)) return len;
  
          // read it! advance pointer
          buffp += avail;
          len += avail;
          timeout = t;  // reset the timeout
  
          //DEBUG_PRINTLN((uint8_t)c, HEX);
  
          if (len == maxlen) {  // we read all we want, bail
            DEBUG_PRINT(F("Read:\t"));
            DEBUG_PRINTBUFFER(buffer, len);
  	  return len;
          }
        }
  #ifdef ADAFRUIT_SLEEPYDOG_H
        Watchdog.reset();
  #endif
        timeout -= MQTT_FONA_INTERAVAILDELAY;
        timeout -= MQTT_FONA_QUERYDELAY; // this is how long it takes to query the FONA for avail()
        delay(MQTT_FONA_INTERAVAILDELAY);
      }
      
      return len;
    }
  
    bool sendPacket(uint8_t *buffer, uint16_t len) {
      DEBUG_PRINTLN(F("Writing packet"));
      if (fona->TCPconnected()) {
        bool ret = fona->TCPsend((char *)buffer, len);
        //DEBUG_PRINT(F("sendPacket returned: ")); DEBUG_PRINTLN(ret);
        if (!ret) {
          DEBUG_PRINTLN("Failed to send packet.");
          return false;
        }
      } else {
        DEBUG_PRINTLN(F("Connection failed!"));
        return false;
      }
      return true;
    }
  
   private:
    uint32_t serverip;
    Adafruit_FONA *fona;
  };
  
  
  #endif
  