/***

  Olive - Non-Linear Video Editor
  Copyright (C) 2019 Olive 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/output/viewer/viewer.h"

TrackList::TrackList(ViewerOutput *parent, const Timeline::TrackType &type, NodeInputArray *track_input) :
  QObject(parent),
  track_input_(track_input),
  type_(type)
{
  connect(track_input, &NodeInputArray::EdgeAdded, this, &TrackList::TrackConnected);
  connect(track_input, &NodeInputArray::EdgeRemoved, this, &TrackList::TrackDisconnected);
  connect(track_input, &NodeInputArray::SizeChanged, this, &TrackList::TrackListSizeChanged);
}

const Timeline::TrackType &TrackList::type() const
{
  return type_;
}

void TrackList::TrackAddedBlock(Block *block)
{
  emit BlockAdded(block, static_cast<TrackOutput*>(sender())->Index());
}

void TrackList::TrackRemovedBlock(Block *block)
{
  emit BlockRemoved(block);
}

void TrackList::TrackListSizeChanged(int size)
{
  int old_size = track_cache_.size();

  track_cache_.resize(size);

  // Fill new slots with nullptr
  for (int i=old_size;i<size;i++) {
    track_cache_.replace(i, nullptr);
  }
}

const QVector<TrackOutput *> &TrackList::Tracks() const
{
  return track_cache_;
}

TrackOutput *TrackList::TrackAt(int index) const
{
  if (index < 0 || index >= track_cache_.size()) {
    return nullptr;
  }

  return track_cache_.at(index);
}

const rational &TrackList::TrackLength() const
{
  return total_length_;
}

int TrackList::TrackCount() const
{
  return track_cache_.size();
}

TrackOutput* TrackList::AddTrack()
{
  TrackOutput* track = new TrackOutput();
  GetParentGraph()->AddNode(track);

  track_input_->Append();

  // Connect this track directly to this output
  NodeParam::ConnectEdge(track->output(),
                         track_input_->At(track_input_->GetSize() - 1));

  // FIXME: Test code only
  if (track_input_->GetSize() > 1) {
    TrackOutput* last_track = nullptr;

    for (int i=track_cache_.size()-1;i>=0;i--) {
      TrackOutput* test_track = track_cache_.at(i);

      if (test_track && test_track != track) {
        last_track = test_track;
        break;
      }
    }

    if (last_track && last_track->output()->IsConnected()) {
      foreach (NodeEdgePtr edge, last_track->output()->edges()) {
        if (!track_input_->ContainsSubParameter(edge->input())) {
          Node* blend = NodeFactory::CreateFromID("org.olivevideoeditor.Olive.alphaoverblend");
          GetParentGraph()->AddNode(blend);

          NodeParam::ConnectEdge(track->output(), static_cast<NodeInput*>(blend->GetParameterWithID("blend_in")));
          NodeParam::ConnectEdge(last_track->output(), static_cast<NodeInput*>(blend->GetParameterWithID("base_in")));
          NodeParam::ConnectEdge(blend->output(), edge->input());
        }
      }
    }
  }
  // End test code

  return track;
}

void TrackList::RemoveTrack()
{
  if (track_cache_.isEmpty()) {
    return;
  }

  TrackOutput* track = track_cache_.last();

  GetParentGraph()->TakeNode(track);

  delete track;

  track_input_->RemoveLast();
}

void TrackList::TrackConnected(NodeEdgePtr edge)
{
  int track_index = track_input_->IndexOfSubParameter(edge->input());

  Q_ASSERT(track_index >= 0);

  Node* connected_node = edge->output()->parentNode();

  if (connected_node->IsTrack()) {
    TrackOutput* connected_track = static_cast<TrackOutput*>(connected_node);

    track_cache_.replace(track_index, connected_track);

    connect(connected_track, &TrackOutput::BlockAdded, this, &TrackList::TrackAddedBlock);
    connect(connected_track, &TrackOutput::BlockRemoved, this, &TrackList::TrackRemovedBlock);
    connect(connected_track, &TrackOutput::TrackLengthChanged, this, &TrackList::UpdateTotalLength);
    connect(connected_track, &TrackOutput::TrackHeightChanged, this, &TrackList::TrackHeightChangedSlot);

    connected_track->SetIndex(track_index);
    connected_track->set_track_type(type_);

    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(connected_track);

    UpdateTotalLength();

  }
}

void TrackList::TrackDisconnected(NodeEdgePtr edge)
{
  int track_index = track_input_->IndexOfSubParameter(edge->input());

  Q_ASSERT(track_index >= 0);

  Node* connected_node = edge->output()->parentNode();
  TrackOutput* track = connected_node->IsTrack() ? static_cast<TrackOutput*>(connected_node) : nullptr;

  if (track) {
    track_cache_.replace(track_index, nullptr);

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

    track->SetIndex(-1);
    track->set_track_type(Timeline::kTrackTypeNone);

    disconnect(track, &TrackOutput::BlockAdded, this, &TrackList::TrackAddedBlock);
    disconnect(track, &TrackOutput::BlockRemoved, this, &TrackList::TrackRemovedBlock);
    disconnect(track, &TrackOutput::TrackLengthChanged, this, &TrackList::UpdateTotalLength);
    disconnect(track, &TrackOutput::TrackHeightChanged, this, &TrackList::TrackHeightChangedSlot);

    emit TrackListChanged();

    UpdateTotalLength();
  }
}

NodeGraph *TrackList::GetParentGraph() const
{
  return static_cast<NodeGraph*>(parent()->parent());
}

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

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

  emit LengthChanged(total_length_);
}

void TrackList::TrackHeightChangedSlot(int height)
{
  emit TrackHeightChanged(static_cast<TrackOutput*>(sender())->Index(), height);
}