/*
  Airplane Data Logging for Dynon EFIS-D10A, Dynon EMS-D10, Garmin GNS430W
  (c) 2022 Ken Staton

  issue: hot insert drive not always starting. don't worry about remove and re-insert.
  issue: clock sync.
      how long does backup battery last??
      use GPS time for RTC sync when drifts more than 20 seconds

  measured data rates
  G: GPS Rx1 115 bytes/sec message end: '\x003'
  F: EFIS Rx2 3300 bytes/sec message end: '\n'
  E: EMS Rx3 480 bytes/sec message end: '\n'
 */

#define DEBUG false // USB serial debug printing
// setup will BLOCK until USB serial starts

#define UTCm7 (7*60*60) // your timezone relative to UTC in seconds

#include "GPS_position.h"

#include <USBHost_t36.h>
#include <TimeLib.h>


// Setup USBHost_t36 and as many HUB ports as needed.
USBHost myusb;

// Instances for the number of hubs
USBHub hub1(myusb);

// Instances for the number of USB drives you are using.
USBDrive myDrive1(myusb);

// Instances for accessing the files on each drive
USBFilesystem myFiles1(myusb);

// Timer events
IntervalTimer myTimer;


// vvv GLOBALS vvv

File myFile;
volatile bool tick = false;
bool LED_ON = false;


// https://www.pjrc.com/teensy/td_uart.html
#define Serial1RxBufferSIZE 1024  // 10 seconds
char Serial1RxBuffer[Serial1RxBufferSIZE]; // global scope or static char. power of 2. 

#define Serial2RxBufferSIZE 8192  // 2 seconds
char Serial2RxBuffer[Serial2RxBufferSIZE]; // global scope or static char. power of 2. 

#define Serial3RxBufferSIZE 1024  // 2 seconds
char Serial3RxBuffer[Serial3RxBufferSIZE]; // global scope or static char. power of 2. 


// ^^^ end GLOBAL ^^^


void TimerISR() { // callback for myTimer
  tick = true;    // only sets global 
}





void setup()
{
  int i;
  char fname[16];

  myTimer.begin(TimerISR, 100000); // period in microseconds = 0.1 sec

  setSyncProvider(getTeensy3Time);
  setSyncInterval(300); // default is 5 min. this call should force a sync
 

  if (DEBUG) {
    Serial.begin(115200);
    while (!Serial) {
      ; // wait for Arduino Serial Monitor to connect.
    }  
  }

  if (DEBUG) RTCDisplay();

  Serial1.begin(9600); // MUST match Garmin
  Serial1.addMemoryForRead(Serial1RxBuffer, Serial1RxBufferSIZE);

  Serial2.begin(115200); // MUST match Dynon EMS
  Serial2.addMemoryForRead(Serial2RxBuffer, Serial2RxBufferSIZE);

  Serial3.begin(115200); // MUST match Dynon EMS
  Serial3.addMemoryForRead(Serial3RxBuffer, Serial3RxBufferSIZE);
    

  SdFile::dateTimeCallback(dateTime);
  
  myusb.begin();
  
  // .begin(USBDrive) is a temporary feature, future USBFilesystem will begin automatically
  if (DEBUG) Serial.println("\nInitializing USB drive 1...");
  if (!myFiles1.begin(&myDrive1)) {
    if (DEBUG) Serial.print("initialization failed with code: ");
    if (DEBUG) myFiles1.printError(Serial);
    return; // setup() is done!
  }

  if (DEBUG) Serial.printf(F("       connected: %d\n"), myDrive1.msDriveInfo.connected);
  if (DEBUG) Serial.printf(F("     initialized: %d\n"), myDrive1.msDriveInfo.initialized);
  if (DEBUG) Serial.printf(F("      fs started: %d\n"), myDrive1.filesystemsStarted());
  
  if (DEBUG) Serial.printf("Find next file number...\n");
  i=next_file_number();
  sprintf(fname,"Log%04d.txt",i);
  if (DEBUG) Serial.printf("Testing for file %s\n",fname);
  
  myFile = myFiles1.open(fname, FILE_WRITE);
  // see https://github.com/wwatson4506/UsbMscFat/blob/UsbMscFat-FS_DATES/examples/ReadWriteUSB/ReadWriteUSB.ino

  if (myFile) {
    if (DEBUG) Serial.printf("Writing to %s...\n",fname);
    myFile.println("Log Started "); // first line
  } else {
    // if the file didn't open, print an error:
    if (DEBUG) Serial.printf("error opening %s \n",fname);
  }


  if (DEBUG) RTCDisplay();
  if (DEBUG) Serial.printf("t.s = %f\n", getdatetime());
  if (DEBUG) Serial.println("init done...");  

} // end of setup()



int next_file_number() {
  // returns the first unused file number
  char fname[16];
  bool fileexists = true; // assume true
  int i=0; // always start at 0

  do {
      sprintf(fname,"Log%04d.txt",i);
      //Serial.printf("%s",fname);
      if (myFiles1.exists(fname) == 0) {
          fileexists=false;
      } else {
          i++;
      }
  } while (fileexists == true);   
  return(i);
}


void RTCDisplay() {
  // display the time
  Serial.print(year()); 
  Serial.print(" ");
  Serial.print(month());
  Serial.print(" ");
  Serial.print(day());
  Serial.print(" ");
  
  Serial.print(hour());
  printDigits(minute());
  printDigits(second());
  Serial.println(); 
}

void printDigits(int digits){
  // utility function for digital clock display: prints preceding colon and leading 0
  Serial.print(":");
  if(digits < 10)
    Serial.print('0');
  Serial.print(digits);
}


void toggleLED() {
  if (LED_ON) {
    digitalWrite(LED_BUILTIN, LOW);
    LED_ON = false; 
  } else { /* LED_OFF */
    digitalWrite(LED_BUILTIN, HIGH);
    LED_ON = true;
  }  
}


void halt(int hz) {
  int t_ms;
  float period;
  period = 1.0/hz;
  t_ms = period * 1000/2;

  //if (DEBUG) Serial.printf("blink period %d\n",t_ms);
  // LED_BUILTIN interferes with I2C !!
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, LOW);
  while (true) {
    toggleLED();
    delay(t_ms);
  }
}

// read about time https://www.pjrc.com/teensy/td_libs_Time.html
// /Applications/Teensyduino.app/Contents/Java/hardware/teensy/avr/libraries/Time/TimeLib.h

time_t getTeensy3Time()
{
  return Teensy3Clock.get();
}

/*
 * User provided date time callback function.
 * See SdFile::dateTimeCallback() for usage.
 */
void dateTime(uint16_t* date, uint16_t* time) {
  // User gets date and time from GPS or real-time
  // clock in real callback function
  time_t now();
  // return date using FAT_DATE macro to format fields via parameter pointer
  *date = FAT_DATE(year(), month(), day());

  // return time using FAT_TIME macro to format fields via parameter pointer
  *time = FAT_TIME(hour(), minute(), second());
}



time_t getdatetime(){
  // gets time from GPS
  // returns time_t with nanoseconds as a float
  time_t t;
  TimeElements tm;

  t = 0

  return(t);
}


void loop(void) { 
  int i;
  char fname[16];
  
  # process eom uart1
  # process eom uart2
  # process eom uart3
  if (tick) {
    tick = false;

    if (myFile) {
      if (msg1>0) {
        myFile.print("G:");
        # write(Rx1,msg1)
        msg1=0;
      }
      if (msg2>0) {
        myFile.print("F:");
        # write(Rx2,msg2)
        msg2=0;
      }
      if (msg3>0) {
        myFile.print("E:");
        # write(Rx3,msg3)
        msg3=0;
      }
    } else { /* open a new file */
      myDrive1.begin();
      myDrive1.startFilesystems();
      if (DEBUG) Serial.print("try opening new file...\n");
      if (DEBUG) Serial.println("\nInitializing USB drive 1...");
      if (DEBUG) Serial.printf(F("       connected: %d\n"), myDrive1.msDriveInfo.connected);
      if (DEBUG) Serial.printf(F("     initialized: %d\n"), myDrive1.msDriveInfo.initialized);
      if (DEBUG) Serial.printf(F("        fs start: %d\n"), myDrive1.filesystemsStarted());
      if (!myFiles1.begin(&myDrive1)) {
        if (DEBUG) Serial.print("initialization failed with code: ");
        if (DEBUG) myFiles1.printError(Serial);
      }
      i=next_file_number();
      sprintf(fname,"Log%04d.txt",i);
      myFile = myFiles1.open(fname, FILE_WRITE);
      myFile.println("Log Started "); // first line
    } /* open new file */
  } /* tick */
}