/*
 * Oak Video Editor - Non-Linear Video Editor
 * Copyright (C) 2025 Olive CE Team
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "tracklist.h"

#include "node/factory.h"
#include "node/math/math/math.h"
#include "node/math/merge/merge.h"
#include "node/output/viewer/viewer.h"
#include "node/project/sequence/sequence.h"

namespace olive
{

TrackList::TrackList(Sequence *parent, const Track::Type &type,
					 const QString &track_input)
	: QObject(parent)
	, track_input_(track_input)
	, total_length_(0)
	, type_(type)
{
}

Track *TrackList::GetTrackAt(int index) const
{
	if (index >= 0 && index < track_cache_.size()) {
		return track_cache_.at(index);
	} else {
		return nullptr;
	}
}

void TrackList::TrackConnected(Node *node, int element)
{
	if (element == -1) {
		parent()->InvalidateAll(track_input(), element);
		return;
	}

	Track *track = dynamic_cast<Track *>(node);

	if (!track) {
		return;
	}

	// Determine where in the cache this block will be
	int cache_index = -1;
	for (int i = element + 1; i < ArraySize(); i++) {
		// Find next track because this will be the index we insert at
		cache_index = GetCacheIndexFromArrayIndex(i);

		if (cache_index >= 0) {
			break;
		}
	}

	// If there was no next, this will be inserted at the end
	if (cache_index == -1) {
		cache_index = track_cache_.size();
	}

	track_cache_.insert(cache_index, track);
	track_array_indexes_.insert(cache_index, element);

	// Update track indexes in the list (including this track)
	UpdateTrackIndexesFrom(cache_index);

	connect(track, &Track::TrackLengthChanged, this,
			&TrackList::UpdateTotalLength);
	connect(track, &Track::TrackHeightChanged, this, [this]() {
		Track *t = static_cast<Track *>(sender());
		emit TrackHeightChanged(t, t->GetTrackHeightInPixels());
	});

	track->set_type(type_);
	track->set_sequence(parent());

	emit TrackListChanged();

	// This function must be called after the track is added to track_cache_, since it uses track_cache_ to determine
	// the track's index
	emit TrackAdded(track);

	UpdateTotalLength();
}

void TrackList::TrackDisconnected(Node *node, int element)
{
	if (element == -1) {
		// User has replaced the entire array, we will invalidate everything
		parent()->InvalidateAll(track_input(), element);
		return;
	}

	Track *track = dynamic_cast<Track *>(node);

	if (!track) {
		return;
	}

	// Traverse through Tracks uncaching and disconnecting them
	emit TrackRemoved(track);

	int cache_index = GetCacheIndexFromArrayIndex(element);

	// Remove track here
	track_cache_.removeAt(cache_index);
	track_array_indexes_.removeAt(cache_index);

	// Update indices for all subsequent tracks
	UpdateTrackIndexesFrom(cache_index);

	track->SetIndex(-1);
	track->set_type(Track::kNone);
	track->set_sequence(nullptr);

	disconnect(track, &Track::TrackLengthChanged, this,
			   &TrackList::UpdateTotalLength);

	emit TrackListChanged();

	UpdateTotalLength();
}

void TrackList::UpdateTrackIndexesFrom(int index)
{
	for (int i = index; i < track_cache_.size(); i++) {
		track_cache_.at(i)->SetIndex(i);
	}
}

Project *TrackList::GetParentGraph() const
{
	return parent()->parent();
}

const QString &TrackList::track_input() const
{
	return track_input_;
}

NodeInput TrackList::track_input(int element) const
{
	return NodeInput(parent(), track_input(), element);
}

Sequence *TrackList::parent() const
{
	return static_cast<Sequence *>(QObject::parent());
}

int TrackList::ArraySize() const
{
	return parent()->InputArraySize(track_input());
}

void TrackList::ArrayAppend()
{
	parent()->InputArrayAppend(track_input());
}

void TrackList::ArrayRemoveLast()
{
	parent()->InputArrayRemoveLast(track_input());
}

void TrackList::UpdateTotalLength()
{
	total_length_ = 0;

	foreach (Track *track, track_cache_) {
		if (track) {
			total_length_ = qMax(total_length_, track->track_length());
		}
	}

	emit LengthChanged(total_length_);
}

}
