#include <EEPROM.h>
#include <Wire.h>

/*
typedef unsigned char u8;
struct routing
{
  u8 dst;
  u8 src;
  u8 null;
};

struct sysex
{
  u8 start;
  u8 vendor;
  u8 null;
  u8 null2;
  u8 matrixsize;
  u8 null3;
  routing r[12];
  u8 null4;
  u8 end;
};
*/

// sysex message is HDR 2 + preamble 5, 12*3 + end 1 byte = 2 + 5 + 36 + 1 = 44
uint8_t Code[44] = {0xF0, 0x3F, 0x0, 
0x0, 0x10, 0x0,
0x0, 0x1, 0x0,
0x1, 0x1, 0x0,
0x2, 0x1, 0x0,
0x3, 0x1, 0x0,
0x4, 0x1, 0x0,
0x5, 0x1, 0x0,
0x6, 0x1, 0x0,
0x7, 0x1, 0x0, 
0x8, 0x1, 0x0, 
0x9, 0x1, 0x0, 
0xA, 0x1, 0x0, 
0xB, 0x1, 0x0, 
0x0, 0xF7};

int x, y;

void(* resetFunc) (void) = 0;

void senddmx(int port, int eingang, int ausgang);

void setup ()
{
  Serial.begin (115200); // input from Nextion
  senddmx(4,0,0);
}

int e;
void
loop ()
{
  senddmx(0, e, 0);
  senddmx(1, e, 0);
  senddmx(2, e, 0);
  senddmx(5, 0, 0);
  delay (1000);
  e = (e + 1) % 13;
}

#define OFFSET_EINGANG (6)


void
serialEvent ()
{
  int mode;
  int port;
  int ausgang;
  int eingang;

  // if more than 4 bytes available, read the values
  // otherwise early return
  if (Serial.available() >= 4)
  {
    mode= Serial.read();
    port = Serial.read ();
    ausgang = Serial.read ();
    eingang = Serial.read ();
    if (mode==1 && port==3)
    {
      resetFunc();
    }
  }
  else
    return;

  // sanity checks
  // port needs to be between 0 and 5
  if (port < 0 || port > 5)
    return;
  // if port is 4 we want ausgang and eingang to be 0...
  if (port == 4 && (ausgang != 0 || eingang != 0))
    return;
  // for all other port values, we check ausgang and eingang are in bounds of 0-11 + 12 (mute)
  if (port < 4 && (eingang < 0 || eingang > 12 || ausgang < 0 || ausgang > 11))
    return;

   senddmx(port, eingang, ausgang);
}

void senddmx(int port, int eingang, int ausgang)
{
  if (port == 4)
  {
    for (int i = 0; i < 36; i++)
    {
      EEPROM.write (i, Code[OFFSET_EINGANG + i]);
      EEPROM.write (i + 36, Code[OFFSET_EINGANG + i]);
      EEPROM.write (i + 36 * 2, Code[OFFSET_EINGANG + i]);
    }
    return;
  }

  if (port < 4)
  {
    // read init values from eprom for port
    // and write into array to send
    // 36 is size of 12 outputs x 3 matrix units
    for (int i = 0; i < 36; i++)
      Code[OFFSET_EINGANG + i] = EEPROM.read (port * 36 + i);

    // select eingang for ausgang
    Code[OFFSET_EINGANG + (ausgang * 3) + 1] = eingang;
    
    // save this in the EPROM
    EEPROM.write (port * 36 + (ausgang * 3) + 1, eingang);
  }
  
  if (port == 5)
  {
    Serial1.begin (31250, SERIAL_8N1);
    Serial2.begin (31250, SERIAL_8N1);
    Serial3.begin (31250, SERIAL_8N1);
    for(port = 0; port < 3; port++)
    {
      // read init values from eprom for port
      // and write into array to send
      // 36 is size of 12 outputs x 3 matrix units
      for (int i = 0; i < 36; i++)
        Code[OFFSET_EINGANG + i] = EEPROM.read (port * 36 + i);

      // write the whole array to serial port for matrix port
      switch (port)
      {
        case 0:
          Serial1.write (Code, sizeof(Code));
          Serial1.flush();
          break;
        case 1:
          Serial2.write (Code, sizeof(Code));
          Serial2.flush();
          break;
        case 2:
          Serial3.write (Code, sizeof(Code));
          Serial3.flush();
          break;
      }
    }
    Serial1.end();
    Serial2.end();
    Serial3.end();
  }
 }