#include "heltec.h"
#include <SPI.h>
#include <TinyGPS++.h>
#include <HardwareSerial.h>
#include <arduino.h>

#define RXPin 35
#define TXPin 34
#define GPSBaud 9600
#define BAND    868E6  //you can set band here directly,e.g. 868E6,915E6

TinyGPSPlus gps;
HardwareSerial ss(1);

unsigned int appDataSize;
uint8_t appData[9];
uint32_t LatitudeBinary, LongitudeBinary;
uint16_t altitudeGps;
uint8_t hdopGps;
unsigned int counter;
String rssi = "RSSI --";
String packSize = "--";
String packet ;
String LatHex;
String LongHex;
uint8_t txBuffer[6];

void setup()
{
  counter = 0;
  Heltec.begin(true /*DisplayEnable Enable*/, true /*Heltec.Heltec.Heltec.LoRa Disable*/, true /*Serial Enable*/, true /*PABOOST Enable*/, BAND /*long BAND*/);
  ss.begin(GPSBaud, SERIAL_8N1, RXPin, TXPin);
  Heltec.display->init();
  Heltec.display->flipScreenVertically();
  Heltec.display->setFont(ArialMT_Plain_10);
  Heltec.display->clear();
  Heltec.display->drawString(0, 0, "Heltec.LoRa Initial success!");
  Heltec.display->display();
  delay(1000);
  Serial.begin(115200);

//######################################################
  LoRa.setTxPower(20,RF_PACONFIG_PASELECT_PABOOST);
  LoRa.setSpreadingFactor(12);
//  LoRa.setSignalBandwidth(500E3);
  LoRa.setCodingRate4(8); // 4/8
  //LoRa.setPreambleLengh(long length);
//######################################################
}

void loop()
{
  LatitudeBinary = ((gps_latitude() + 90) / 180) * 16777215;
  LatHex =  String(LatitudeBinary, HEX);
  LongitudeBinary = ((gps_longitude() + 180) / 360) * 16777215;
  LongHex =  String(LatitudeBinary, HEX);
  altitudeGps = gps_meters();
  hdopGps = gps_HDOP() * 10;

  while (ss.available() > 0) gps.encode(ss.read());
  Heltec.display->clear();
  Heltec.display->setTextAlignment(TEXT_ALIGN_LEFT);
  Heltec.display->setFont(ArialMT_Plain_10);
  Heltec.display->drawString(0, 0, "Sending packet: ");
  Heltec.display->drawString(90, 0, String(counter));
  Heltec.display->drawString(0, 10, String(LatitudeBinary) + "  " + LatHex);
  Heltec.display->drawString(0, 20, String(LongitudeBinary) + "  " + LongHex);
  Heltec.display->drawString(0, 30, String(gps_latitude(), 10));
  Heltec.display->drawString(0, 40, String(gps_longitude(), 10));
  Heltec.display->display();

  // send packet
  LoRa.beginPacket();
  txBuffer[0] = ( LatitudeBinary >> 16 ) & 0xFF;
  txBuffer[1] = ( LatitudeBinary >> 8 ) & 0xFF;
  txBuffer[2] = LatitudeBinary & 0xFF;
  txBuffer[3] = ( LongitudeBinary >> 16 ) & 0xFF;
  txBuffer[4] = ( LongitudeBinary >> 8 ) & 0xFF;
  txBuffer[5] = LongitudeBinary & 0xFF;
//  txBuffer[6] = ( altitudeGps >> 8 ) & 0xFF;
//  txBuffer[7] = altitudeGps & 0xFF;
//  txBuffer[8] = hdopGps & 0xFF;
  LoRa.write(txBuffer, sizeof(txBuffer));
  LoRa.endPacket();

  counter++;
  digitalWrite(LED, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED, LOW);    // turn the LED off by making the voltage LOW
  delay(4000);                       // wait for a jiffy
}

float gps_latitude()
  {
  if (gps.location.isValid()){
   return gps.location.lat();
  }
  else
  {
   return 88;
  }
}
float gps_longitude(){
  if (gps.location.isValid()){
    return gps.location.lng();
  }
  else{
    return 88;
  }
}
float gps_meters() {
  return gps.altitude.meters();
}
float gps_HDOP(){
  return gps.hdop.hdop();
}