//
// MIDI Keyboard  20200613
//
#include <MIDI.h>
MIDI_CREATE_DEFAULT_INSTANCE();

#include <PWMDAC_Synth.h>
PWMDAC_CREATE_WAVETABLE(sawtoothWavetable, PWMDAC_SAWTOOTH_WAVE);
PROGMEM const Instrument instrument = {sawtoothWavetable, {8, 128, 11, 4}};
PWMDAC_CREATE_INSTANCE(&instrument);

#define MIDI_ENABLE_PIN     2

#define OCTAVE_ANALOG_PIN   0
#define VELOCITY_ANALOG_PIN 1
#define JS_V_ANALOG_PIN     2 // Joystick Vertical
#define JS_H_ANALOG_PIN     3 // Joystick Horizontal

// MIDI channel to send from MIDI OUT
byte current_midi_channel = 1; // 1==CH1, ...
                               
// MIDI IN receive callbacks to control PWM sound
void HandleNoteOn(byte channel, byte pitch, byte velocity) {
  if( velocity == 0 ) PWMDACSynth::noteOff(channel, pitch, velocity);
  PWMDACSynth::noteOn(channel, pitch, velocity);
}

// A list of pressing buttons with notes
typedef struct _Button {
  byte cathode8;
  byte sw_anode5;
} Button;
typedef struct _ButtonNote {
  struct _Button button;
  byte note;
} ButtonNote;
ButtonNote button_notes[10];
void freeButtonNote(struct _ButtonNote *bnp) {
  bnp->button.cathode8 =
  bnp->button.sw_anode5 = bnp->note = 0xFF;
}
void initButtonNotes() {
  ButtonNote *bnp = button_notes;
  char i=NumberOf(button_notes);
  for( ; i>0; i--, bnp++ ) { freeButtonNote(bnp); }
}
struct _ButtonNote *searchButtonNote(struct _Button *button_p) {
  ButtonNote *bnp = button_notes;
  char i=NumberOf(button_notes);
  for( ; i>0; i--, bnp++ )
    if(
      bnp->button.cathode8 == button_p->cathode8 &&
      bnp->button.sw_anode5 == button_p->sw_anode5
    )
      return bnp;
  return NULL;
}
struct _ButtonNote *getActiveNote() {
  ButtonNote *bnp = button_notes;
  char i=NumberOf(button_notes);
  for( ; i>0; i--, bnp++ ) if( bnp->note != 0xFF ) return bnp;
  return NULL;
}

void ButtonReleased(struct _Button *button_p) {
  ButtonNote *bnp = searchButtonNote(button_p);
  if( bnp == NULL ) return;
  char velocity = analogRead(VELOCITY_ANALOG_PIN) >> 3;
  PWMDACSynth::noteOff(current_midi_channel, bnp->note, velocity);
  MIDI.sendNoteOff(bnp->note, velocity, current_midi_channel);
  freeButtonNote(bnp);
}

void ButtonPressed(struct _Button *button_p) {
  int note = button_p->cathode8 + 8 * button_p->sw_anode5;
  // Search empty entry to regist button 
  Button null_button;
  null_button.cathode8 = 0xFF;
  null_button.sw_anode5 = 0xFF;
  ButtonNote *bnp = searchButtonNote(&null_button);
  if( bnp == NULL ) return; // Button note table full - reject it
  ButtonNote bn;
  note += 12 * map(
    analogRead(OCTAVE_ANALOG_PIN), 0,1023, 0,8
  );
  if( note > 0x7F ) note -= 12;
  bn.note = note;
  bn.button = *button_p;
  *bnp = bn;
  char velocity = analogRead(VELOCITY_ANALOG_PIN) >> 3;
  HandleNoteOn(current_midi_channel, bnp->note, velocity);
  MIDI.sendNoteOn(bnp->note, velocity, current_midi_channel);
}

void setup() {
  PWMDACSynth::setup();
  initButtonNotes();
  DDRB  &= 0b11000000; // port 8..13 for INPUT
  PORTB |= 0b00111111; // analog HIGH -> INPUT_PULLUP
  DDRD  |= 0b11110000; // port 4..7 for OUTPUT (for 74HC138 + LED pin)
  PORTD |= 0b10000000; // port 7 to HIGH OUTPUT
  MIDI.begin(MIDI_CHANNEL_OMNI); // receives all MIDI channels
  MIDI.turnThruOff(); // Disable MIDI IN -> MIDI OUT mirroring
  MIDI.setHandleNoteOff(PWMDACSynth::noteOff);
  MIDI.setHandleNoteOn(HandleNoteOn);
  MIDI.setHandlePitchBend(PWMDACSynth::pitchBend);
  MIDI.setHandleControlChange(PWMDACSynth::controlChange);
  pinMode( MIDI_ENABLE_PIN, OUTPUT );
  digitalWrite( MIDI_ENABLE_PIN, HIGH ); // enable MIDI port
}

byte in_values[8]= {
  0xFF,0xFF,0xFF,0xFF,
  0xFF,0xFF,0xFF,0xFF,
};
boolean was_js_button_on = false;
boolean js_enabled = true;
void loop() {
  Button button;
  byte portd_value = 0;
  for( button.cathode8 = 0 ; button.cathode8 < 8; button.cathode8++ ) {
    PORTD &= 0b10001111;  // Port 4..6 bit off
    PORTD |= portd_value; // Put 3-bit value to port 4..6 (button cathode)
    byte *in_value_p = in_values + button.cathode8;
    delayMicroseconds(3); // To avoid getting electrically unstable PINB value
    byte in_value = PINB | 0b11100000; // Get value from port 8..12 (button anode)
    byte in_value_change = in_value ^ *in_value_p;
    if( in_value_change ) {
      *in_value_p = in_value;
      byte sw_anode5_mask = 1;
      for( button.sw_anode5 = 0; button.sw_anode5 < 5; button.sw_anode5++ ) {
        if( in_value_change & sw_anode5_mask ) {
          if( in_value & sw_anode5_mask )
            ButtonReleased(&button);
          else
            ButtonPressed(&button);
        }
        sw_anode5_mask <<= 1;
      }
    }
    portd_value += 0b00010000;
    if( button.cathode8 % 4 == 0 ) PWMDACSynth::update();
  }
  MIDI.read();
  if( was_js_button_on != (digitalRead(13)==LOW) ) {
    was_js_button_on = !was_js_button_on;
    if( was_js_button_on ) {
      js_enabled = !js_enabled;
      digitalWrite( 7, (js_enabled?HIGH:LOW) );
      MIDI.sendPitchBend( 0, current_midi_channel );
      MIDI.sendControlChange( 1, 0, current_midi_channel );
    }
  }
  if( js_enabled ) {
    MidiChannel *mcp = PWMDACSynth::getChannel(current_midi_channel);
    int new_pitch_bend = (511 - analogRead(JS_H_ANALOG_PIN)) * 16;
    if( (mcp->getPitchBend() & 0xFFF0) != (new_pitch_bend & 0xFFF0) ) {
      PWMDACSynth::pitchBend( current_midi_channel, new_pitch_bend );
      MIDI.sendPitchBend( new_pitch_bend, current_midi_channel );
    }
    int new_modulation = abs(511 - analogRead(JS_V_ANALOG_PIN)) >> 2;
    if( new_modulation > 127 ) new_modulation = 127;
    if( mcp->modulation != new_modulation ) {
      PWMDACSynth::controlChange( current_midi_channel, 1, new_modulation );
      MIDI.sendControlChange( 1, new_modulation, current_midi_channel ); // Modulation MSB only
    }
  }
}