#include <Bounce2.h>

//The number of push buttons
const int NUM_OF_BUTTONS = 8;

// the MIDI channel number to send messages
const int MIDI_CHAN = 1;

// Create Bounce objects for each button and switch. The Bounce object
// automatically deals with contact chatter or "bounce", and
// it makes detecting changes very simple.
// 5 = 5 ms debounce time which is appropriate for good quality mechanical push buttons.
// If a button is too "sensitive" to rapid touch, you can increase this time.

//button debounce time
const int DEBOUNCE_TIME = 5;

Bounce buttons[NUM_OF_BUTTONS + 1] =
{
  Bounce (0, DEBOUNCE_TIME),
  Bounce (1, DEBOUNCE_TIME),
  Bounce (2, DEBOUNCE_TIME),
  Bounce (3, DEBOUNCE_TIME),
  Bounce (4, DEBOUNCE_TIME),
  Bounce (5, DEBOUNCE_TIME),
  Bounce (6, DEBOUNCE_TIME),
  Bounce (7, DEBOUNCE_TIME),
  Bounce (8, DEBOUNCE_TIME)
};

const int MIDI_MODE_NOTES = 0;
const int MIDI_MODE_CCS = 1;

//Variable that stores the current MIDI mode of the device (what type of messages the push buttons send).
int midiMode = MIDI_MODE_NOTES;

//Arrays the store the exact note and CC messages each push button will send.
const int MIDI_NOTE_NUMS[NUM_OF_BUTTONS] = {40, 41, 42, 43, 36, 37, 38, 39};
const int MIDI_NOTE_VELS[NUM_OF_BUTTONS] = {110, 110, 110, 110, 110, 110, 110, 110};
const int MIDI_CC_NUMS[NUM_OF_BUTTONS] = {24, 25, 26, 27, 20, 21, 22, 23};
const int MIDI_CC_VALS[NUM_OF_BUTTONS] = {127, 127, 127, 127, 127, 127, 127, 127};

//==============================================================================
//==============================================================================
//==============================================================================
//The setup function. Called once when the Teensy is turned on or restarted

void setup()
{
  // Configure the pins for input mode with pullup resistors.
  // The buttons/switch connect from each pin to ground.  When
  // the button is pressed/on, the pin reads LOW because the button
  // shorts it to ground.  When released/off, the pin reads HIGH
  // because the pullup resistor connects to +5 volts inside
  // the chip.  LOW for "on", and HIGH for "off" may seem
  // backwards, but using the on-chip pullup resistors is very
  // convenient.  The scheme is called "active low", and it's
  // very commonly used in electronics... so much that the chip
  // has built-in pullup resistors!

  for (int i = 0; i < NUM_OF_BUTTONS + 1; i++)
  {
    pinMode (i, INPUT_PULLUP);
  }

}

//==============================================================================
//==============================================================================
//==============================================================================
//The loop function. Called over-and-over once the setup function has been called.

void loop()
{
  //==============================================================================
  // Update all the buttons/switch. There should not be any long
  // delays in loop(), so this runs repetitively at a rate
  // faster than the buttons could be pressed and released.
  for (int i = 0; i < NUM_OF_BUTTONS + 1; i++)
  {
    buttons[i].update();
  }

  //==============================================================================
  // Check the status of each push button

  for (int i = 0; i < NUM_OF_BUTTONS; i++)
  {

    //========================================
    // Check each button for "falling" edge.
    // Falling = high (not pressed - voltage from pullup resistor) to low (pressed - button connects pin to ground)

    if (buttons[i + 1].fallingEdge())
    {
      //If in note mode send a MIDI note-on message.
      //Else send a CC message.
      if (midiMode == MIDI_MODE_NOTES)
        usbMIDI.sendNoteOn (MIDI_NOTE_NUMS[i], MIDI_NOTE_VELS[i], MIDI_CHAN);
      else
        usbMIDI.sendControlChange (MIDI_CC_NUMS[i], MIDI_CC_VALS[i], MIDI_CHAN);
    }

    //========================================
    // Check each button for "rising" edge
    // Rising = low (pressed - button connects pin to ground) to high (not pressed - voltage from pullup resistor)

    else if (buttons[i + 1].risingEdge())
    {
      //If in note mode send a MIDI note-off message.
      //Else send a CC message with a value of 0.
      if (midiMode == MIDI_MODE_NOTES)
        usbMIDI.sendNoteOff (MIDI_NOTE_NUMS[i], 0, MIDI_CHAN);
      else
        usbMIDI.sendControlChange (MIDI_CC_NUMS[i], 0, MIDI_CHAN);
    }

  } //for (int i = 0; i < NUM_OF_BUTTONS; i++)

  //==============================================================================
  // Check the status of the toggle switch, and set the MIDI mode based on this.
  if (buttons[0].fallingEdge())
  {
    midiMode = MIDI_MODE_NOTES;
  }
  else if (buttons[0].risingEdge())
  {
    midiMode = MIDI_MODE_CCS;
  }

  //==============================================================================
  // MIDI Controllers should discard incoming MIDI messages.
  // http://forum.pjrc.com/threads/24179-Teensy-3-Ableton-Analog-CC-causes-midi-crash
  while (usbMIDI.read())
  {
    // ignoring incoming messages, so don't do anything here.
  }
  
}