// Display Jupiters 4 moons
// It uses the current date time and corrects to get UTC time
// Make sure you set the correct Time Zone below

#define APP_TIME_ZONE   -4  // I am East Coast in Daylight Savings

void jSats() {

  // Get the current info
  RTC_Date tnow = ttgo->rtc->getDateTime();

  hh = tnow.hour;
  mm = tnow.minute;
  ss = tnow.second;
  dday = tnow.day;
  mmonth = tnow.month;
  yyear = tnow.year;

  float tDay = dday; // Calculate the day plus fractional day
  tDay += (hh - APP_TIME_ZONE) / 24.0;
  tDay += mm / 1440.0;
  int16_t tYear = yyear;
  int8_t tMonth = mmonth;

  int16_t cYear, cMonth;
  if (tMonth < 3) {
    cYear = tYear - 1;
    cMonth = tMonth + 12;
  } else {
    cYear = tYear;
    cMonth = tMonth;
  }
  // Calculate the Julian Date offset from Epoch
  int a = cYear / 100;
  int b = 2 - a + (int)(a / 4);
  long c = 365.25 * cYear;
  long d = 30.6001 * (cMonth + 1);
  float N = b + c + d + tDay - 694025.5;

  // Calc moon positions
  float P = PI / 180;
  float MT = (358.476 + 0.9856003 * N) * P;
  float MJ = (225.328 + 0.0830853 * N) * P;
  float JJ = 221.647 + 0.9025179 * N;
  float VT = 1.92 * sin(MT) + 0.02 * sin(2 * MT);
  float VJ = 5.55 * sin(MJ) + 0.17 * sin(2 * MJ);
  float K = (JJ + VT - VJ) * P;
  float DT = sqrt(28.07 - 10.406 * cos(K));
  float Z1 = sin(K) / DT;
  float I = atan(Z1 / sqrt(1 - Z1 * Z1));
  I = I / P;
  float F = (N - DT / 173);
  float F1 = I - VJ;
  float U1 = 84.5506 + 203.405863 * F + F1;
  float U2 = 41.5015 + 101.2916323 * F + F1;
  float U3 = 109.9770 + 50.2345169 * F + F1;
  float U4 = 176.3586 + 21.4879802 * F + F1;
  float X1 = 5.906 * sin(U1 * P);
  float X2 = 9.397 * sin(U2 * P);
  float X3 = 14.989 * sin(U3 * P);
  float X4 = 26.364 * sin(U4 * P);
  // Print out results

  ttgo->tft->fillScreen(TFT_BLACK);
  ttgo->tft->setTextSize(2);
  ttgo->tft->setCursor( 0, 10);
  ttgo->tft->setTextColor(TFT_ORANGE);
  ttgo->tft->print(" IO: ");
  ttgo->tft->print(X1, 1);
  ttgo->tft->setCursor( 0, 30);
  ttgo->tft->setTextColor(TFT_BLUE);
  ttgo->tft->print(" EU: ");
  ttgo->tft->println(X2, 1);
  ttgo->tft->setCursor( 0, 50);
  ttgo->tft->setTextColor(TFT_GREEN);
  ttgo->tft->print(" GA: ");
  ttgo->tft->println(X3, 1);
  ttgo->tft->setCursor( 0, 70);
  ttgo->tft->setTextColor(TFT_YELLOW);
  ttgo->tft->print(" CA: ");
  ttgo->tft->println(X4, 1);

  //Now display them as they would appear

  ttgo->tft->fillCircle(119, 155, 6, TFT_RED); // Jupiter

  ttgo->tft->setTextColor(TFT_ORANGE);
  ttgo->tft->fillCircle(int(X1 * 4 + 119), 155, 2, TFT_ORANGE);
  ttgo->tft->drawString("I", int(X1 * 4 + 119)-3, 175 , 1);
  ttgo->tft->setTextColor(TFT_BLUE);
  ttgo->tft->fillCircle(int(X2 * 4 + 119), 155, 2, TFT_BLUE);
  ttgo->tft->drawString("E", int(X2 * 4 + 119)-3, 175, 1);
  ttgo->tft->setTextColor(TFT_GREEN);
  ttgo->tft->fillCircle(int(X3 * 4 + 119), 155, 2, TFT_GREEN);
  ttgo->tft->drawString("G", int(X3 * 4 + 119)-3, 175, 1);
  ttgo->tft->setTextColor(TFT_YELLOW);
  ttgo->tft->fillCircle(int(X4 * 4 + 119), 155, 2, TFT_YELLOW);
  ttgo->tft->drawString("C", int(X4 * 4 + 119)-3, 175, 1);


  // Wait for touch to return
  int16_t x, y;
  while (!ttgo->getTouch(x, y)) {} // Wait for touch
  while (ttgo->getTouch(x, y)) {}  // Wait for release
  ttgo->tft->fillScreen(TFT_BLACK);
}