//needs debouncing and investigation of pin 0

#include <MIDIUSB.h>

static const int matrixInPins[] = {1, 0, 2, 3, 4, 5, 6, 7}; //x
static const int matrixOutPins[] = {8, 9, 10, 16, 14, 15, 18}; //y
int channel = 1;
int midiNotes[7][8] = {
//  1   0   2   3   4   5   6   7  
  { 0,  0, 76, 69, 80, 70, 83, 45}, //8
  { 0,  0, 77,  0, 82,  0, 73,  0}, //9
  { 0,  0,  0, 49,  0,  0,  0,  0}, //10
  { 0,  0, 51,  0, 46,  0, 48, 47}, //16
  { 0,  0,  0,  0,  0,  0,  0, 52}, //14
  {24, 22, 79,  0, 81,  0, 75, 50}, //15
  {25, 23, 78, 71,  0, 72, 74, 84}  //18
};
int noteToSend = 0;
int noteSent = 0;
int noteToStop = 0;
int noteStopped = 0;
int scanIn;
int scanOut;
  
void setup() {
  Serial1.end();
  for (int i = 0; i < sizeof(matrixInPins); ++i)
    pinMode(matrixInPins[i], INPUT_PULLUP);
  for (int i = 0; i < sizeof(matrixOutPins); ++i) {
    pinMode(matrixOutPins[i], OUTPUT);
    digitalWrite(matrixOutPins[i], HIGH);
  }
}

void scan() {
  for (scanOut = 0; scanOut < 7; ++scanOut) {
    digitalWrite(matrixOutPins[scanOut], LOW);
    for (scanIn = 0; scanIn < 8; ++scanIn) {
      if (digitalRead(matrixInPins[scanIn]) == LOW) {
        //Serial.print(matrixInPins[scanIn]);
        //Serial.print(":");
        //Serial.println(matrixOutPins[scanOut]);
        noteToSend = midiNotes[scanOut][scanIn];
        //Serial.println(noteToSend);
        sendNote();
      }
      if (digitalRead(matrixInPins[scanIn]) == HIGH && midiNotes[scanOut][scanIn] == noteSent) {
        noteToStop = noteSent;
        stopNote();
      }
    }
    digitalWrite(matrixOutPins[scanOut], HIGH);
  }
}
void sendNote() {
    if (noteToSend != noteSent) {
      noteOn(channel, noteToSend, 64);
      MidiUSB.flush();
      noteSent = noteToSend;
    }
}
void stopNote() {
  if (noteToStop != noteStopped) {
    noteOff(channel, noteToStop, 64);
    //allNotesOff(channel, noteToStop, 64);
    //controlChange(123, 0, channel);
    MidiUSB.flush();
    noteStopped = noteToStop;
    noteToStop = 0;
    noteToSend = 0;
    noteSent = 0;
  }
}

void noteOn(byte channel, byte pitch, byte velocity) {
  midiEventPacket_t noteOn = {0x09, 0x90 | channel, pitch, velocity};
  MidiUSB.sendMIDI(noteOn);
}

void noteOff(byte channel, byte pitch, byte velocity) {
  midiEventPacket_t noteOff = {0x08, 0x80 | channel, pitch, velocity};
  MidiUSB.sendMIDI(noteOff);
}

void controlChange(byte channel, byte control, byte value) {
  midiEventPacket_t event = {0x0B, 0xB0 | channel, control, value};
  MidiUSB.sendMIDI(event);
}

void loop() {
  scan();
}