/*
 * Copyright (C) 2010-2011 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2010-2018 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2011-2015 David Robillard <d@drobilla.net>
 * Copyright (C) 2013-2018 Robin Gareus <robin@gareus.org>
 * Copyright (C) 2015-2017 Nick Mainsbridge <mainsbridge@gmail.com>
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "ardour/midi_track.h"
#include "ardour/midi_region.h"
#include "ardour/tempo.h"
#include "ardour/types.h"

#include "gui_thread.h"
#include "midi_region_view.h"
#include "public_editor.h"
#include "step_editor.h"
#include "step_entry.h"

using namespace ARDOUR;
using namespace Gtk;
using namespace std;
using namespace Temporal;

StepEditor::StepEditor (PublicEditor& e, std::shared_ptr<MidiTrack> t, MidiTimeAxisView& mtv)
	: _editor (e)
	, _track (t)
	, _mtv (mtv)
{
	step_edit_insert_position = timepos_t (Temporal::BeatTime);
	_step_edit_triplet_countdown = 0;
	_step_edit_within_chord = 0;
	_step_edit_chord_duration = Temporal::Beats();
	step_edit_region_view = 0;

	_track->PlaylistChanged.connect (*this, invalidator (*this),
	                                 std::bind (&StepEditor::playlist_changed, this),
	                                 gui_context());
	playlist_changed ();
}

StepEditor::~StepEditor()
{
	StepEntry::instance().set_step_editor (0);
}

void
StepEditor::start_step_editing ()
{
	_step_edit_triplet_countdown = 0;
	_step_edit_within_chord = 0;
	_step_edit_chord_duration = Temporal::Beats();
	step_edit_region.reset ();
	step_edit_region_view = 0;
	last_added_pitch = -1;
	last_added_end = Temporal::Beats();

	resync_step_edit_position ();
	prepare_step_edit_region ();
	reset_step_edit_beat_pos ();

	assert (step_edit_region);
	assert (step_edit_region_view);

	StepEntry::instance().set_step_editor (this);
	delete_connection = StepEntry::instance().signal_delete_event().connect (sigc::mem_fun (*this, &StepEditor::step_entry_hidden));
	hide_connection = StepEntry::instance(). signal_hide().connect (sigc::mem_fun (*this, &StepEditor::step_entry_done));

	step_edit_region_view->show_step_edit_cursor (step_edit_beat_pos);
	step_edit_region_view->set_step_edit_cursor_width (StepEntry::instance().note_length());

	StepEntry::instance().present ();
}

void
StepEditor::resync_step_edit_position ()
{
	step_edit_insert_position = _editor.get_preferred_edit_position (Editing::EDIT_IGNORE_NONE, false, true).beats();
}

void
StepEditor::resync_step_edit_to_edit_point ()
{
	resync_step_edit_position ();
	if (step_edit_region) {
		reset_step_edit_beat_pos ();
	}
}

void
StepEditor::prepare_step_edit_region ()
{
	std::shared_ptr<Region> r = _track->playlist()->top_region_at (step_edit_insert_position);

	if (r) {
		step_edit_region = std::dynamic_pointer_cast<MidiRegion>(r);
	}

	if (step_edit_region) {
		RegionView* rv = _mtv.midi_view()->find_view (step_edit_region);
		step_edit_region_view = dynamic_cast<MidiRegionView*> (rv);

	} else {

		const Meter& m = Temporal::TempoMap::use()->meter_at (step_edit_insert_position);
		/* 1 bar long region */
		step_edit_region = _mtv.add_region (step_edit_insert_position, timecnt_t (Beats::beats (m.divisions_per_bar()), step_edit_insert_position), true);

		RegionView* rv = _mtv.midi_view()->find_view (step_edit_region);
		step_edit_region_view = dynamic_cast<MidiRegionView*>(rv);
	}
}


void
StepEditor::reset_step_edit_beat_pos ()
{
	assert (step_edit_region);
	assert (step_edit_region_view);

	const timepos_t ep = _editor.get_preferred_edit_position();
	timecnt_t distance_from_start (step_edit_region->position().distance (ep));

	if (distance_from_start.is_negative()) {
		/* this can happen with snap enabled, and the edit point == Playhead. we snap the
		   position of the new region, and it can end up after the edit point.
		*/
		distance_from_start = timecnt_t (ep.time_domain());
	}

	step_edit_beat_pos = distance_from_start.beats();
	step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
}

bool
StepEditor::step_entry_hidden (GdkEventAny*)
{
	step_entry_done ();
	return true;
}

void
StepEditor::step_entry_done ()
{
	hide_connection.disconnect ();
	delete_connection.disconnect ();

	/* everything else will follow the change in the model */
	_track->set_step_editing (false);
}

void
StepEditor::stop_step_editing ()
{
	StepEntry::instance().hide ();

	if (step_edit_region_view) {
		step_edit_region_view->hide_step_edit_cursor();
	}

	step_edit_region.reset ();
}

void
StepEditor::check_step_edit ()
{
	MidiRingBuffer<samplepos_t>& incoming (_track->step_edit_ring_buffer());
	uint8_t* buf;
	uint32_t bufsize = 32;

	buf = new uint8_t[bufsize];

	while (incoming.read_space()) {
		samplepos_t time;
		Evoral::EventType type;
		uint32_t size;

		if (!incoming.read_prefix (&time, &type, &size)) {
			break;
		}

		if (size > bufsize) {
			delete [] buf;
			bufsize = size;
			buf = new uint8_t[bufsize];
		}

		if (!incoming.read_contents (size, buf)) {
			break;
		}

		if ((buf[0] & 0xf0) == MIDI_CMD_NOTE_ON && size == 3) {
			step_add_note (buf[0] & 0xf, buf[1], buf[2], Temporal::Beats());
		}
	}
	delete [] buf;
}

int
StepEditor::step_add_bank_change (uint8_t /*channel*/, uint8_t /*bank*/)
{
	return 0;
}

int
StepEditor::step_add_program_change (uint8_t /*channel*/, uint8_t /*program*/)
{
	return 0;
}

void
StepEditor::step_edit_sustain (Temporal::Beats beats)
{
	if (step_edit_region_view) {
		step_edit_region_view->step_sustain (beats);
	}
}

void
StepEditor::move_step_edit_beat_pos (Temporal::Beats beats)
{
	if (!step_edit_region_view) {
		return;
	}

	const Temporal::Beats zero;

	if (beats > zero) {
		step_edit_beat_pos = min (step_edit_beat_pos + beats, step_edit_region->length().beats());
	} else if (beats < zero) {
		if (-beats < step_edit_beat_pos) {
			step_edit_beat_pos += beats; // its negative, remember
		} else {
			step_edit_beat_pos = Temporal::Beats();
		}
	}

	step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
}

int
StepEditor::step_add_note (uint8_t channel, uint8_t pitch, uint8_t velocity, Temporal::Beats beat_duration)
{
	/* do these things in case undo removed the step edit region
	 */
	if (!step_edit_region) {
		resync_step_edit_position ();
		prepare_step_edit_region ();
		reset_step_edit_beat_pos ();
		step_edit_region_view->show_step_edit_cursor (step_edit_beat_pos);
		step_edit_region_view->set_step_edit_cursor_width (StepEntry::instance().note_length());
	}

	assert (step_edit_region);
	assert (step_edit_region_view);

	if (beat_duration == 0.0) {
		beat_duration = StepEntry::instance().note_length();
	} else if (beat_duration == 0.0) {
		bool success;
		beat_duration = _editor.get_draw_length_as_beats (success, step_edit_insert_position);

		if (!success) {
			return -1;
		}
	}

	MidiStreamView* msv = _mtv.midi_view();

	/* make sure its visible on the vertical axis */

	if (pitch < msv->lowest_note() || pitch > msv->highest_note()) {
		msv->maybe_extend_note_range (pitch);
		msv->set_note_visibility_range_style (MidiStreamView::ContentsRange);
	}

	/* make sure its visible on the horizontal axis */

	timepos_t fpos = step_edit_region_view->region()->region_beats_to_absolute_time (step_edit_beat_pos + beat_duration);

	if (fpos >= (_editor.leftmost_sample() + _editor.current_page_samples())) {
		_editor.reset_x_origin (fpos.samples() - (_editor.current_page_samples()/4));
	}

	Temporal::Beats at = step_edit_beat_pos;
	Temporal::Beats len = beat_duration;

	if ((last_added_pitch >= 0) && (pitch == last_added_pitch) && (last_added_end == step_edit_beat_pos)) {

		/* avoid any apparent note overlap - move the start of this note
		   up by 1 tick from where the last note ended
		*/

		at  += Temporal::Beats::ticks(1);
		len -= Temporal::Beats::ticks(1);
	}

	step_edit_region_view->step_add_note (channel, pitch, velocity, at, len);

	last_added_pitch = pitch;
	last_added_end = at+len;

	if (_step_edit_triplet_countdown > 0) {
		_step_edit_triplet_countdown--;

		if (_step_edit_triplet_countdown == 0) {
			_step_edit_triplet_countdown = 3;
		}
	}

	if (!_step_edit_within_chord) {
		step_edit_beat_pos += beat_duration;
		step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
	} else {
		step_edit_beat_pos += Temporal::Beats::ticks(1); // tiny, but no longer overlapping
		_step_edit_chord_duration = max (_step_edit_chord_duration, beat_duration);
	}

	step_edit_region_view->set_step_edit_cursor_width (StepEntry::instance().note_length());

	return 0;
}

void
StepEditor::set_step_edit_cursor_width (Temporal::Beats beats)
{
	if (step_edit_region_view) {
		step_edit_region_view->set_step_edit_cursor_width (beats);
	}
}

bool
StepEditor::step_edit_within_triplet() const
{
	return _step_edit_triplet_countdown > 0;
}

bool
StepEditor::step_edit_within_chord() const
{
	return _step_edit_within_chord;
}

void
StepEditor::step_edit_toggle_triplet ()
{
	if (_step_edit_triplet_countdown == 0) {
		_step_edit_within_chord = false;
		_step_edit_triplet_countdown = 3;
	} else {
		_step_edit_triplet_countdown = 0;
	}
}

void
StepEditor::step_edit_toggle_chord ()
{
	if (_step_edit_within_chord) {
		_step_edit_within_chord = false;
		if (step_edit_region_view) {
			step_edit_beat_pos += _step_edit_chord_duration;
			step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
		}
	} else {
		_step_edit_triplet_countdown = 0;
		_step_edit_within_chord = true;
	}
}

void
StepEditor::step_edit_rest (Temporal::Beats beats)
{
	bool success;

	if (beats == 0.0) {
		beats = _editor.get_draw_length_as_beats (success, step_edit_insert_position);
	} else {
		success = true;
	}

	if (success && step_edit_region_view) {
		step_edit_beat_pos += beats;
		step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
	}
}

void
StepEditor::step_edit_beat_sync ()
{
	step_edit_beat_pos = step_edit_beat_pos.round_up_to_beat();
	if (step_edit_region_view) {
		step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
	}
}

void
StepEditor::step_edit_bar_sync ()
{
	Session* _session = _mtv.session ();

	if (!_session || !step_edit_region_view || !step_edit_region) {
		return;
	}

	timepos_t pos = step_edit_region_view->region()->region_beats_to_absolute_time (step_edit_beat_pos);

	/* have to go to BBT to round up to bar, unfortunately */
	TempoMap::SharedPtr tmap (TempoMap::use());
	BBT_Argument bbt (tmap->bbt_at (pos).round_up_to_bar ());

	/* now back to beats */
	pos = timepos_t (tmap->quarters_at (bbt));
	step_edit_beat_pos = step_edit_region->position().distance (pos).beats().round_up_to_beat();
	step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
}

void
StepEditor::playlist_changed ()
{
	step_edit_region_connection.disconnect ();
	_track->playlist()->RegionRemoved.connect (step_edit_region_connection, invalidator (*this),
	                                           std::bind (&StepEditor::region_removed, this, _1),
	                                           gui_context());
}

void
StepEditor::region_removed (std::weak_ptr<Region> wr)
{
	std::shared_ptr<Region> r (wr.lock());

	if (!r) {
		return;
	}

	if (step_edit_region == r) {
		step_edit_region.reset();
		step_edit_region_view = 0;
		// force a recompute of the insert position
		step_edit_beat_pos = Temporal::Beats::from_double (-1);
	}
}

string
StepEditor::name() const
{
	return _track->name();
}