// https://wokwi.com/projects/355570007735623681
// https://forum.arduino.cc/t/midi-notes-dont-stop-on-cv-to-midi-box/1084044
// MONOPHONIC CV to MIDI adaptor for Monophonic synthisizers.

void xprintf(const char *format, ...);    // programmer misses printf, so sue me.

int gateLevel = 0;
int gateOld = 0;
int noteNum = 0;

int midCh = 1;

class fakeMIDI {
  public:
    void begin(unsigned char);
    void sendNoteOn(unsigned char, unsigned char, unsigned char);
    void sendNoteOff(unsigned char, unsigned char, unsigned char);

  private:

};

void fakeMIDI::begin(unsigned char x)
{
  xprintf("begin MIDI object %d\n", x);
}

void fakeMIDI::sendNoteOn(unsigned char theNote, unsigned char theIDK, unsigned char theChannel)
{
  xprintf("note %2d ON  w/ IDK %3d.\n", theNote, theIDK);
}

void fakeMIDI::sendNoteOff(unsigned char theNote, unsigned char theIDK, unsigned char theChannel)
{
  xprintf("note %2d OFF w/ IDK %3d.\n", theNote, theIDK);
}

fakeMIDI MIDI;

//

void setup()
{
  mySetup(115200);
  xprintf("\nhello world.\n"); 

  MIDI.begin(222);

  pinMode(A1, INPUT_PULLUP);
}

void loop() {

  int pitchPin = analogRead(A0);  // read analog pins
  int gatePin = !digitalRead(A1); // IRL gate is a variable voltage threshold

  float voltage = pitchPin * (5.0 / 1023.0); // get voltage for pitch cv input
  int noteNum = (voltage / 0.08) + 24;

// remove this, it is just to make fewer notes on the slide fader
  noteNum = map(pitchPin, 0, 1024, 48, 62);   // remove. just making the steps big

  gateLevel = gatePin;        // digital input here
  if (gateLevel == 1)         // if the gate is open
      myMidiNoteOn(noteNum, 127, midCh);    //  turn on, if necessary, the note

  if (gateLevel != gateOld) { // when the gate goes down
  	if (!gateLevel)
    	myMidiNoteOff();        // turn off any playing note
  }

  gateOld = gateLevel;

  delay(50);    // why?
}

bool noteIsOn;
unsigned char noteIs;

void myMidiNoteOn(unsigned char newNote, unsigned char IDK, unsigned char theChannel)
{
  if (noteIsOn && noteIs != newNote) {
    MIDI.sendNoteOff(noteIs, 0, midCh);
    delay(29);    // why?
  }

  if (noteIsOn && noteIs == newNote)
    return;

  noteIsOn = true;    // remember note is on
  noteIs = newNote;   // and which, so we can turn it off
  MIDI.sendNoteOn(noteIs, 127, midCh);
}

// we want an independent means to turn off a note
void myMidiNoteOff()
{
  if (!noteIsOn)
    return;
  
  MIDI.sendNoteOff(noteIs, 0, midCh);
  delay(29);    // why?
  noteIsOn = false;    
}

// 

// programmer misses printf...

void xprintf(const char *format, ...)
{
  char buffer[256];
  va_list args;
  va_start(args, format);
  vsprintf(buffer, format, args);
  va_end(args);
  Serial.print(buffer);
}

// programmer forgets day of week, version

void mySetup(unsigned long bandRate)
{
  Serial.begin(bandRate);
  
  char s[] = __FILE__;
  byte b = sizeof(s);
  while ( (b > 0) && (s[b] != 47)) b--;
  char *u = s + b + 1;
 
  xprintf("\nHEllo WOrld!\n");
  xprintf("%s  %s\n\n", __DATE__, u);

  xprintf("!\n");
}