// STRUCTURES
// This data structure encapsulates all the properties associated with an individual file
struct file {
  char fileName[16]; // The name for this file as will appear on the display
  unsigned int fileSize; // From 0-65,535
  unsigned long fileDate; // Timestamp
};
// This data structure contains info relating to each "disk" (RFID card) that is scanned
struct card {
  byte rfidUID[4]; // Unique identifier of the RFID tag  
  file contents[4]; // The array of files this card contains
  byte correctFileID; // The file that needs uploading from this disc
};

// CONSTANTS
// The number of different cards players can insert
const int numTags = 3;
// The number of files contained on each card
const byte numFiles = 4;
// Define the data held on each "disk"
//A37708DA, 43702BDA,  5C 7B E4 AF,8E 92 AF 9F
// nav is card A, guid is card Y, traj is card F
const card cardList[numTags] = {
  { {0x43,0x70, 0x2B, 0xDA}, { {"ORION.nav", 100, 1}, {"HERCULES.nav", 200, 1}, {"LEO.nav", 100, 1}, {"BOOTES.nav", 100, 1}, }, 3 }, 
  { {0x5C,0x7B, 0xE4, 0xAF}, { {"Alpha_6.guid", 300, 1}, {"Alpha_9.guid", 200, 1}, {"Alpha_3.guid", 100, 1}, {"Alpha_8.guid", 300, 1}, }, 1}, 
  { {0x8E,0x92, 0xAF, 0x9F}, { {"07685.traj", 400, 1}, {"52301.traj", 200, 1}, {"91254.traj", 100, 1}, {"82316.traj", 200, 1}, }, 2}, 
};
// GPIO pins attached to each component
// Rotary encoder/button
const byte encDataPin = 6; //sw
const byte encClockPin = 7; //dio
const byte buttonPin = 8; //clk
// Green LED that indicates floppy drive is active
const byte floppyLedPin = A0;
// Chip select line to the RFID reader
const byte rfidSS = 10; ///sck
// Blue LEDs that indicate which data has been loaded
const byte ledPins[] = {2, 3, 4};

// GLOBALS
// Initialise the LCD display (the HD44780 library auto-detects I2C address)
hd44780_I2Cexp lcd;
// Create an instance of the MFRC522 class, using the specified chip select pin
// We won't use a RST line, so set that to UINT8_MAX
MFRC522 rfid(rfidSS, UINT8_MAX);
// Is a disc currently inserted?
bool isDiscPresent = false;
// The index of the currently inserted disc
int8_t currentCard = -1;
// The file selected on the currently inserted disc
uint8_t selectedFile = 0;
// Timestamp at which we last checked whether disc was changed
unsigned long timeSinceLastScan;
// The cards whose data has been successfully loaded
bool dataLoaded[] = {false, false, false};