#include <TinyGPSPlus.h>
#include <WiFi.h>
#include <HTTPClient.h>
/*
   This sample code demonstrates the normal use of a TinyGPSPlus (TinyGPSPlus) object.
   It requires the use of SoftwareSerial, and assumes that you have a
   4800-baud serial GPS device hooked up on pins 4(rx) and 3(tx).
*/
int validFlag = 0;
const char* ssid     = "network";
const char* password = "123456789";
static const uint32_t GPSBaud = 9600;

const char* SERVER_NAME = "http://team3ie20.atwebpages.com/gpsdata.php";

//ESP32_API_KEY is the exact duplicate of, ESP32_API_KEY in config.php file
//Both values must be same
String ESP32_API_KEY = "Ad5F10jkBM0";
// The TinyGPSPlus object
TinyGPSPlus gps;
unsigned long previousMillis = 0;
long interval = 30000;
// The serial connection to the GPS device


void setup()
{
  Serial.begin(115200);
  Serial2.begin(GPSBaud);

  Serial.println(F("FullExample.ino"));
  Serial.println(F("An extensive example of many interesting TinyGPSPlus features"));
  Serial.print(F("Testing TinyGPSPlus library v. ")); Serial.println(TinyGPSPlus::libraryVersion());
  Serial.println(F("by Mikal Hart"));
  Serial.println();
  Serial.println(F("Sats HDOP  Latitude   Longitude   Fix  Date       Time     Date Alt    Course Speed Card  Distance Course Card  Chars Sentences Checksum"));
  Serial.println(F("           (deg)      (deg)       Age                      Age  (m)    --- from GPS ----  ---- to London  ----  RX    RX        Fail"));
  Serial.println(F("----------------------------------------------------------------------------------------------------------------------------------------"));
  WiFi.begin(ssid, password);
  Serial.println("Connecting");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("Connected to WiFi network with IP Address: ");
  Serial.println(WiFi.localIP());
}

void loop()
{
  if (WiFi.status() == WL_CONNECTED) {
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis > interval) {
      previousMillis = currentMillis;
      //Send an HTTP POST request every 30 seconds
      sendGpsToServer();
    }
  }
  //NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
  else {
    Serial.println("WiFi Disconnected");
  }

  static const double LONDON_LAT = 51.508131, LONDON_LON = -0.128002;

  printInt(gps.satellites.value(), gps.satellites.isValid(), 5);
  printFloat(gps.hdop.hdop(), gps.hdop.isValid(), 6, 1);
  printFloat(gps.location.lat(), gps.location.isValid(), 11, 6);
  printFloat(gps.location.lng(), gps.location.isValid(), 12, 6);
  printInt(gps.location.age(), gps.location.isValid(), 5);
  printDateTime(gps.date, gps.time);
  printFloat(gps.altitude.meters(), gps.altitude.isValid(), 7, 2);
  printFloat(gps.course.deg(), gps.course.isValid(), 7, 2);
  printFloat(gps.speed.kmph(), gps.speed.isValid(), 6, 2);
  printStr(gps.course.isValid() ? TinyGPSPlus::cardinal(gps.course.deg()) : "*** ", 6);

  unsigned long distanceKmToLondon =
    (unsigned long)TinyGPSPlus::distanceBetween(
      gps.location.lat(),
      gps.location.lng(),
      LONDON_LAT,
      LONDON_LON) / 1000;
  printInt(distanceKmToLondon, gps.location.isValid(), 9);

  double courseToLondon =
    TinyGPSPlus::courseTo(
      gps.location.lat(),
      gps.location.lng(),
      LONDON_LAT,
      LONDON_LON);

  printFloat(courseToLondon, gps.location.isValid(), 7, 2);

  const char *cardinalToLondon = TinyGPSPlus::cardinal(courseToLondon);

  printStr(gps.location.isValid() ? cardinalToLondon : "*** ", 6);

  printInt(gps.charsProcessed(), true, 6);
  printInt(gps.sentencesWithFix(), true, 10);
  printInt(gps.failedChecksum(), true, 9);
  Serial.println();

  smartDelay(1000);

  if (millis() > 5000 && gps.charsProcessed() < 10)
    Serial.println(F("No GPS data received: check wiring"));
}

// This custom version of delay() ensures that the gps object
// is being "fed".
static void smartDelay(unsigned long ms)
{
  unsigned long start = millis();
  do
  {
    while (Serial2.available())
      gps.encode(Serial2.read());
  } while (millis() - start < ms);
}

static void printFloat(float val, bool valid, int len, int prec)
{
  if (!valid)
  {
    while (len-- > 1)
      Serial.print('*');
    Serial.print(' ');
  }
  else
  {
    Serial.print(val, prec);
    int vi = abs((int)val);
    int flen = prec + (val < 0.0 ? 2 : 1); // . and -
    flen += vi >= 1000 ? 4 : vi >= 100 ? 3 : vi >= 10 ? 2 : 1;
    for (int i = flen; i < len; ++i)
      Serial.print(' ');
  }
  smartDelay(0);
}

static void printInt(unsigned long val, bool valid, int len)
{
  char sz[32] = "*****************";
  if (valid)
    sprintf(sz, "%ld", val);
  sz[len] = 0;
  for (int i = strlen(sz); i < len; ++i)
    sz[i] = ' ';
  if (len > 0)
    sz[len - 1] = ' ';
  Serial.print(sz);
  smartDelay(0);
}

static void printDateTime(TinyGPSDate &d, TinyGPSTime &t)
{
  if (!d.isValid())
  {
    Serial.print(F("********** "));
  }
  else
  {
    char sz[32];
    sprintf(sz, "%02d/%02d/%02d ", d.month(), d.day(), d.year());
    Serial.print(sz);
  }

  if (!t.isValid())
  {
    Serial.print(F("******** "));
  }
  else
  {
    char sz[32];
    sprintf(sz, "%02d:%02d:%02d ", t.hour(), t.minute(), t.second());
    Serial.print(sz);
  }

  printInt(d.age(), d.isValid(), 5);
  smartDelay(0);
}

static void printStr(const char *str, int len)
{
  int slen = strlen(str);
  for (int i = 0; i < len; ++i)
    Serial.print(i < slen ? str[i] : ' ');
  smartDelay(0);
}

int sendGpsToServer()
{
  //NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
  //Can take up to 60 seconds
  boolean newData = false;
  for (unsigned long start = millis(); millis() - start < 2000;) {
    while (Serial2.available()) {
      if (gps.encode(Serial2.read())) {
        if (gps.location.isValid() == 1) {
          validFlag = 1;
          newData = true;
          break;
        }
        else {
          validFlag = 0;
          newData = true;
          break;
        }
      }
    }
  }
  //NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

  //MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
  //If newData is true
  if (true) {
    newData = false;

    //NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
    String latitude, longitude;
    //float altitude;
    //unsigned long date, time, speed, satellites;
    if (validFlag == 1) {
      latitude  = String(gps.location.lat(), 6); // Latitude in degrees (double)
      longitude = String(gps.location.lng(), 6); // Longitude in degrees (double)
    }
    else{
      latitude  ="3.3";
      longitude ="3.3";
    }
    //altitude = gps.altitude.meters(); // Altitude in meters (double)
    //date = gps.date.value(); // Raw date in DDMMYY format (u32)
    //time = gps.time.value(); // Raw time in HHMMSSCC format (u32)
    //speed = gps.speed.kmph();

    Serial.print("Latitude= ");
    Serial.print(latitude);
    Serial.print(" Longitude= ");
    Serial.println(longitude);
    //NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

    //NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
    HTTPClient http;

    //domain name with path
    http.begin(SERVER_NAME);

    //Specify content-type header
    http.addHeader("Content-Type", "application/x-www-form-urlencoded");

    //----------------------------------------------
    //HTTP POST request data
    String gps_data;
    gps_data = "api_key=" + ESP32_API_KEY;
    gps_data += "&lat=" + latitude;
    gps_data += "&lng=" + longitude;

    Serial.print("gps_data: ");
    Serial.println(gps_data);
    //----------------------------------------------

    //----------------------------------------------
    //Send HTTP POST Request and get response
    int httpResponseCode = http.POST(gps_data);
    String httpResponseString = http.getString();
    //----------------------------------------------

    //--------------------------------------------------------------------------------
    // If you need an HTTP request with a content type: text/plain
    //http.addHeader("Content-Type", "text/plain");
    //int httpResponseCode = http.POST("Hello, World!");

    // If you need an HTTP request with a content type: application/json, use the following:
    //http.addHeader("Content-Type", "application/json");
    //int httpResponseCode = http.POST("{\"value1\":\"19\",\"value2\":\"67\",\"value3\":\"78\"}");
    //--------------------------------------------------------------------------------

    //----------------------------------------------
    if (httpResponseCode > 0) {
      Serial.print("HTTP Response code: ");
      Serial.println(httpResponseCode);
      Serial.println(httpResponseString);
    }
    //----------------------------------------------
    else {
      Serial.print("Error on HTTP request - Error code: ");
      Serial.println(httpResponseCode);
      Serial.println(httpResponseString);
    }
    //----------------------------------------------
    // Free resources
    http.end();
    //NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

  }
}