// Use the MD_MAX72XX library to Print some text on the display
//
// Demonstrates the use of the library to print text.
//
// User can enter text on the serial monitor and this will display as a
// message on the display.

#include <MD_MAX72xx.h>
#include <SPI.h>

#define PRINT(s, v) { Serial.print(F(s)); Serial.print(v); }

// Define the number of devices we have in the chain and the hardware interface
// NOTE: These pin numbers will probably not work with your hardware and may
// need to be adapted
#define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
#define MAX_DEVICES 4
#define INTENSITY 5

#define CLK_PIN   18  // or SCK
#define DATA_PIN  23  // or MOSI
#define CS_PIN    5  // or SS

// SPI hardware interface
//MD_MAX72XX mx = MD_MAX72XX(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);
// Arbitrary pins
MD_MAX72XX mx = MD_MAX72XX(HARDWARE_TYPE, DATA_PIN, CLK_PIN, CS_PIN, MAX_DEVICES);

// Text parameters
#define CHAR_SPACING  1 // pixels between characters

// Global message buffers shared by Serial and Scrolling functions
#define BUF_SIZE  75
char message[BUF_SIZE] = "150002";
bool newMessageAvailable = true;

void readSerial(void)
{
  static uint8_t  putIndex = 0;

  while (Serial.available())
  {
    message[putIndex] = (char)Serial.read();
    if ((message[putIndex] == '\n') || (putIndex >= BUF_SIZE - 3)) // end of message character or full buffer
    {
      // put in a message separator and end the string
      message[putIndex] = '\0';
      // restart the index for next filling spree and flag we have a message waiting
      putIndex = 0;
      newMessageAvailable = true;
    }
    else
      // Just save the next char in next location
      message[putIndex++];
  }
}

void clearMatrix(uint8_t modStart, uint8_t modEnd)
{
  int16_t   col = ((modEnd + 1) * COL_SIZE) - 1;
  mx.control(modStart, modEnd, MD_MAX72XX::UPDATE, MD_MAX72XX::OFF);
  //mx.setIntensity(5);

  do{
    mx.setColumn(col--, 0);
  } while (col > 0);

  //mx.control(modStart, modEnd, MD_MAX72XX::UPDATE, MD_MAX72XX::ON);
}

void printText(uint8_t modStart, uint8_t modEnd, char *pMsg)
// Print the text string to the LED matrix modules specified.
// Message area is padded with blank columns after printing.
{
  uint8_t   state = 0;
  uint8_t   curLen;
  uint16_t  showLen;
  uint16_t  showLen2;
  uint8_t   cBuf[8];
  int16_t   col = ((modEnd + 1) * COL_SIZE) - 1;
  int16_t   startCol;

  // Calculate the total width of the text to be displayed (including spaces between characters)
  int textWidth = 0;
  char* tempMsg = pMsg;
  while (*tempMsg != '\0') {
    showLen = mx.getChar(*tempMsg++, sizeof(cBuf) / sizeof(cBuf[0]), cBuf);
    textWidth += showLen + CHAR_SPACING;
  }

  // Calculate the start column to center the text
  startCol = ((modEnd + 1) * COL_SIZE - textWidth) / 2;

  //mx.control(modStart, modEnd, MD_MAX72XX::UPDATE, MD_MAX72XX::OFF);

  Serial.println("");
  Serial.println("MAX_INTENSITY: " + String(MAX_INTENSITY));
  Serial.println("modStart: " + String(modStart));
  Serial.println("modEnd: " + String(modEnd));
  Serial.println("colSize: " + String(COL_SIZE));
  Serial.println("col: " + String(col));
  Serial.println("textWidth: " + String(textWidth));
  Serial.println("startCol: " + String(startCol));
  Serial.println("");

  clearMatrix(0, MAX_DEVICES -1);

  do     // finite state machine to print the characters in the space available
  {
    switch(state)
    {
      case 0: // Load the next character from the font table
        // if we reached end of message, reset the message pointer
        if (*pMsg == '\0')
        {
          //showLen = col - (modEnd * COL_SIZE);  // padding characters
          showLen = 0;
          state = 2;
          break;
        }

        // retrieve the next character form the font file
        showLen = mx.getChar(*pMsg++, sizeof(cBuf)/sizeof(cBuf[0]), cBuf);
        curLen = 0;
        state++;
        // !! deliberately fall through to next state to start displaying

      case 1: // display the next part of the character
        mx.setColumn(col-startCol, cBuf[curLen++]);
        col--;

        // done with font character, now display the space between chars
        if (curLen == showLen)
        {
          showLen = CHAR_SPACING;
          state = 2;
        }
        break;

      case 2: // initialize state for displaying empty columns
        curLen = 0;
        state++;
        // fall through

      case 3:	// display inter-character spacing or end of message padding (blank columns)
        //mx.setColumn(col-startCol, 0);
        col--; curLen++;
        if (curLen == showLen)
          state = 0;
        break;

      default:
        col = -1;   // this definitely ends the do loop
    }
  } while (col > -1);

  mx.control(modStart, modEnd, MD_MAX72XX::UPDATE, MD_MAX72XX::ON);
}

void setup()
{
  mx.begin();

  Serial.begin(57600);
  Serial.print("\n[MD_MAX72XX Message Display]\nType a message for the display\nEnd message line with a newline");
}

void loop()
{
  readSerial();
  if (newMessageAvailable)
  {
    PRINT("\nProcessing new message: ", message);
    //itoa(5000, message, 10);
    printText(0, MAX_DEVICES - 1, message);
    newMessageAvailable = false;
  }
}