/*
    Copyright (C) 2006-2008 Paul Davis

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "ardour/midi_ring_buffer.h"
#include "ardour/midi_buffer.h"
#include "ardour/event_type_map.h"

using namespace std;

namespace ARDOUR {

/** Read a block of MIDI events from buffer into a MidiBuffer.
 *
 * Timestamps of events returned are relative to start (i.e. event with stamp 0
 * occurred at start), with offset added.
 */
template<typename T>
size_t
MidiRingBuffer<T>::read(MidiBuffer& dst, nframes_t start, nframes_t end, nframes_t offset)
{
	if (this->read_space() == 0) {
		return 0;
	}

	T                 ev_time;
	Evoral::EventType ev_type;
	uint32_t          ev_size;

	size_t count = 0;

	//cerr << "MRB read " << start << " .. " << end << " + " << offset << endl;

	while (this->read_space() >= sizeof(T) + sizeof(Evoral::EventType) + sizeof(uint32_t)) {

		this->full_peek(sizeof(T), (uint8_t*)&ev_time);

		if (ev_time > end) {
			//cerr << "MRB event @ " << ev_time << " past end @ " << end << endl;
			break;
		} else if (ev_time < start) {
			//cerr << "MRB event @ " << ev_time << " before start @ " << start << endl;
			break;
		}

		bool success = read_prefix(&ev_time, &ev_type, &ev_size);
		if (!success) {
			cerr << "WARNING: error reading event prefix from MIDI ring" << endl;
			continue;
		}

		// This event marks a loop end (i.e. the next event's timestamp will be non-monotonic)
		if (ev_type == LoopEventType) {
			/*ev_time -= start;
			  ev_time += offset;*/
			cerr << "MRB loop boundary @ " << ev_time << endl;

			// Return without reading data or writing to buffer (loop events have no data)
			// FIXME: This is not correct, loses events after the loop this cycle
			return count + 1;
		}

		uint8_t status;
		success = this->full_peek(sizeof(uint8_t), &status);
		assert(success); // If this failed, buffer is corrupt, all hope is lost

		// Ignore event if it doesn't match channel filter
		if (is_channel_event(status) && get_channel_mode() == FilterChannels) {
			const uint8_t channel = status & 0x0F;
			if (!(get_channel_mask() & (1L << channel))) {
				//cerr << "MRB skipping event due to channel mask" << endl;
				this->skip(ev_size); // Advance read pointer to next event
				continue;
			}
		}

		/*cerr << "MRB " << this << " - Reading event, time = "
			<< ev_time << " - " << start << " => " << ev_time - start
			<< ", size = " << ev_size << endl;*/

		assert(ev_time >= start);
		ev_time -= start;
		ev_time += offset;

		// write the timestamp to address (write_loc - 1)
		uint8_t* write_loc = dst.reserve(ev_time, ev_size);
		if (write_loc == NULL) {
			cerr << "MRB: Unable to reserve space in buffer, event skipped";
			continue;
		}
		
		// write MIDI buffer contents
		success = Evoral::EventRingBuffer<T>::full_read(ev_size, write_loc);
		
#if 0
		cerr << "wrote MidiEvent to Buffer: " << hex;
		for (size_t i=0; i < ev_size; ++i) {
			cerr << (int) write_loc[i] << ' ';
		}
		cerr << dec << endl;
#endif

		if (success) {
			if (is_channel_event(status) && get_channel_mode() == ForceChannel) {
				write_loc[0] = (write_loc[0] & 0xF0) | (get_channel_mask() & 0x0F);
			}
			++count;
		} else {
			cerr << "WARNING: error reading event contents from MIDI ring" << endl;
		}
	}
	
	return count;
}

template class MidiRingBuffer<nframes_t>;

} // namespace ARDOUR