//
// pianoleds.h
//
// Maps incoming MIDI note events onto a WS2812B strip mounted above an
// 88-key keybed.
//
#ifndef _pianoleds_h
#define _pianoleds_h

#include <circle/usb/usbmidi.h>
#include <circle/types.h>
#include <WS28XX/ws28xxstripe.h>
#include "config.h"

class CPianoLEDs
{
public:
	CPianoLEDs (void);
	~CPianoLEDs (void);

	boolean Initialize (void);

	// Attach to a USB MIDI device. Safe to call again after the gadget has
	// been re-enumerated, which destroys and recreates the device object.
	void AttachMIDIDevice (CUSBMIDIDevice *pMIDIDevice);

	// Push pending state to the strip. Call from the main loop only; this
	// blocks for ~5.3ms of SPI traffic and must never run in IRQ context.
	// Does nothing when no state has changed since the last call.
	void Update (void);

	// Extinguish every pixel and forget all held notes.
	void AllOff (void);

private:
	// Called in IRQ context by the USB MIDI driver.
	static void MIDIPacketHandler (unsigned nCable, u8 *pPacket, unsigned nLength,
				       unsigned nDevice, void *pParam);

	void OnMIDIPacket (const u8 *pPacket, unsigned nLength);

	void SetKey (u8 ucNote, u8 ucVelocity, boolean bHint);

	// Scale a colour channel by velocity and the global brightness ceiling.
	static u8 Scale (u8 ucChannel, u8 ucVelocity);

	static boolean ChannelMatches (u8 ucChannel, u8 ucWanted);

private:
	CWS28XXStripe m_Stripe;

	// Written in IRQ context, read by Update(). Index is
	// note - MIDI_NOTE_MIN. Zero means the key is not lit.
	volatile u8 m_KeyVelocity[KEY_COUNT];
	volatile u8 m_HintVelocity[KEY_COUNT];

	volatile boolean m_bDirty;
};

#endif