#include "Arduino.h"
#include "SPI.h"

#include "SegmentDisplay.h"
#include "SegmentDisplayChars.h"


void SegmentDisplay::begin()
{
  #if !defined(SDSupportSPI)
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);

  digitalWrite(clockPin, LOW);
  digitalWrite(dataPin, LOW);
  #endif

  digitalWrite(latchPin, HIGH);
  digitalWrite(latchPin, LOW);
  digitalWrite(latchPin, HIGH);

  #if defined(SDSupportSPI)
  SPI.begin();
  //SPI.setClockDivider(SPI_CLOCK_DIV128);
  #endif
}


void SegmentDisplay::end()
{
  #if defined(SDSupportSPI)
  SPI.end();
  #endif
}


void SegmentDisplay::writeNumber(int value)
{
  unsigned char digitMask = 1;

  for (unsigned char digit = digits; digit > 0; digit--)
  {
    writeDigit((unsigned char)(value % 10), digitMask);

    value /= 10;
    digitMask <<= 1;
  }
}


#define ASCIIZero 48
#define ASCIINine 57
#define ASCIIUppercaseA 65
#define ASCIIUppercaseZ 90
#define ASCIILowercaseA 97
#define ASCIILowercaseZ 122


void SegmentDisplay::writeText(char* value)
{
  unsigned char digitMask = 1;
  unsigned char digit = digits;
  unsigned char charValue;

  while (digit > 0 && value != '\0')
  {
    charValue = *value;

    // Lowercase
    if (charValue >= ASCIILowercaseA && charValue <= ASCIILowercaseZ)
      writeDisplay(SDCharacterSegments[charValue - ASCIILowercaseA], digitMask);

    // Uppercase
    else if  (charValue >= ASCIIUppercaseA && charValue <= ASCIIUppercaseZ)
      writeDisplay(SDCharacterSegments[charValue - ASCIIUppercaseA], digitMask);

    // Numbers
    else if (charValue >= ASCIIZero && charValue <= ASCIINine)
      writeDisplay(SDNumberSegments[charValue - ASCIIZero], digitMask);

    // Space / unknown
    else
      writeDisplay(0, digitMask);

    digit--;
    digitMask <<= 1;
    value++;
  }

  while (digit > 0)
  {
    writeDisplay(0, digitMask);

    digit--;
    digitMask <<= 1;
  }
}


inline void SegmentDisplay::writeDigit(unsigned char value, unsigned char digitMask)
{
  writeDisplay(SDNumberSegments[value], digitMask);
}


#if defined(SDSupportSPI)

inline void SegmentDisplay::writeDisplay(unsigned char characterMask, unsigned char digitMask)
{
  SPI.beginTransaction(SPISettings(clockSpeed, MSBFIRST, SPI_MODE0));
  SPI.transfer(characterMask);
  SPI.transfer(digitMask);
  SPI.endTransaction();
}

#else

inline void SegmentDisplay::writeDisplay(unsigned char characterMask, unsigned char digitMask)
{
  digitalWrite(latchPin, LOW);

  shiftOut(dataPin, clockPin, MSBFIRST, characterMask);
  shiftOut(dataPin, clockPin, MSBFIRST, digitMask);

  digitalWrite(latchPin, HIGH);
}

#endif