//======================================================================
// cat.ino
//======================================================================

#include "cat.h"

#define ACK 0
#define CAT_PREFIX 0xC0
#define IOP_PREFIX 0xD0
#define EEPROM_READ_PREFIX 0xE0
#define EEPROM_WRITE_PREFIX 0xF0

//======================================================================
// CAT from PC-to-IOP
//
// The general concept for IOP use of CAT is for the IOP to pass thru
// all incoming CAT data (from the PC) to the Raduino.
//
// This might change in the future, if we want to grab CAT data straight
// from the PC.  That might apply to things like specific audio filter
// settings or something, but since the Raduino modes are an important
// part of the mix, I think the commands really need to come from the 
// Raduino... and besides, what if a PC is not connected?
//
//
// For data coming from the Raduino, the IOP does have to do a minimal
// processing to extra any Raduino-to-IOP commands.
//======================================================================

void initCAT(long baud, int portConfig)
{
  // CAT with PC via USB
  USBSERIAL.begin(baud);
  USBSERIAL.flush();

  // CAT with Raduino via UART
  HWSERIAL.begin(baud, portConfig);
  USBSERIAL.flush();
}

//======================================================================

void processIOPCommand(const byte* buf, int len)
{
}

//======================================================================

enum serial_mode_t {
  NORMAL = 0,
  CAT_MODE,
  IOP_MODE,
  EEPROM_READ,
  EEPROM_WRITE,
} serialMode = NORMAL;

int readLength = 0;

int cmdLength = 0;
byte cmdBuffer[16];

uint16_t eepromStartIndex;
uint16_t eepromReadLength;
int magicFlag = 0;

//----------------------------------------------------------------------

void serviceCAT()
{
  int incomingByte;

  // read from the USB serial, pass through to UART serial
  for (int i = 0; i < USBSERIAL.available(); i++) {
    incomingByte = USBSERIAL.read();
    HWSERIAL.write(incomingByte);
  }

  // read from the UART serial, see what we need to do with it
  for (int i = 0; i < HWSERIAL.available(); i++) {
    incomingByte = HWSERIAL.read();

    switch(serialMode) {
      case NORMAL:
      if (incomingByte == ACK) {
        USBSERIAL.write(incomingByte);
      } else {
        readLength = incomingByte & 0x0F;
        if (readLength > 0) {
          switch(incomingByte & 0xF0) {
            case CAT_PREFIX:
            case EEPROM_WRITE_PREFIX:
            serialMode = CAT_MODE;
            break;
  
            case IOP_PREFIX:
            serialMode = IOP_MODE;
            cmdLength = 0;
            break;
  
            case EEPROM_READ_PREFIX:
            serialMode = EEPROM_READ;
            readLength = 5;
            magicFlag = 0;
            break;

            default:
            // should never happen
            break;
          }
        }
      }
      break;

      case CAT_MODE:
      // In CAT mode, we just pass thru the remaining bytes to the PC.
      USBSERIAL.write(incomingByte);
      readLength--;
      if (readLength == 0) {
        serialMode = NORMAL;
      }
      break;

      case IOP_MODE:
      cmdBuffer[cmdLength] = incomingByte;
      cmdLength++;
      readLength--;
      if (readLength == 0) {
        processIOPCommand(cmdBuffer, cmdLength);
        serialMode = NORMAL;
      }
      break;

      case EEPROM_READ:
      readLength--;
      switch(readLength) {
        case 4:
        eepromStartIndex = incomingByte;
        if (incomingByte == 0x16) {
          magicFlag++;
        }
        break;
        
        case 3:
        eepromStartIndex += (256 * incomingByte);
        if (incomingByte == 0xe8) {
          magicFlag++;
        }
        break;
        
        case 2:
        eepromReadLength = incomingByte;
        break;
        
        case 1:
        eepromReadLength += (256 * incomingByte);
        break;
        
        case 0:
        USBSERIAL.write(incomingByte);
        if (magicFlag == 2) {
          readLength = 126 + 2;
        } else {
          readLength = eepromReadLength + 2;
        }
        serialMode = CAT_MODE;
        break;

        default:
        // should never happen
        break;
      }
      break;

      case EEPROM_WRITE:
      // TODO
      break;

      default:
      // should never happen...
      break;
    }
  }
}

//======================================================================
// EOF
//======================================================================