/***

  Olive - Non-Linear Video Editor
  Copyright (C) 2021 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 "timelineundo.h"

namespace olive {

BlockTrimCommand::BlockTrimCommand(Track *track, Block* block, rational new_length, Timeline::MovementMode mode) :
  prepped_(false),
  track_(track),
  block_(block),
  new_length_(new_length),
  mode_(mode),
  deleted_adjacent_command_(nullptr),
  trim_is_a_roll_edit_(false)
{
}

void BlockTrimCommand::redo()
{
  if (!prepped_) {
    prep();
    prepped_ = true;
  }

  if (doing_nothing_) {
    return;
  }

  // Begin an operation since we'll be doing a lot
  track_->BeginOperation();

  // Determine how much time to invalidate
  TimeRange invalidate_range;

  if (mode_ == Timeline::kTrimIn) {
    invalidate_range = TimeRange(block_->in(), block_->in() + trim_diff_);
    block_->set_length_and_media_in(new_length_);
  } else {
    invalidate_range = TimeRange(block_->out(), block_->out() - trim_diff_);
    block_->set_length_and_media_out(new_length_);
  }

  if (needs_adjacent_) {
    if (we_created_adjacent_) {
      // Add adjacent and insert it
      adjacent_->setParent(track_->parent());

      if (mode_ == Timeline::kTrimIn) {
        track_->InsertBlockBefore(adjacent_, block_);
      } else {
        track_->InsertBlockAfter(adjacent_, block_);
      }
    } else if (we_removed_adjacent_) {
      track_->RippleRemoveBlock(adjacent_);

      // It no longer inputs/outputs anything, remove it
      if (remove_block_from_graph_ && NodeCanBeRemoved(adjacent_)) {
        if (!deleted_adjacent_command_) {
          deleted_adjacent_command_ = CreateAndRunRemoveCommand(adjacent_);
        } else {
          deleted_adjacent_command_->redo();
        }
      }
    } else {
      rational adjacent_length = adjacent_->length() + trim_diff_;

      if (mode_ == Timeline::kTrimIn) {
        adjacent_->set_length_and_media_out(adjacent_length);
      } else {
        adjacent_->set_length_and_media_in(adjacent_length);
      }
    }
  }

  track_->EndOperation();

  if (dynamic_cast<TransitionBlock*>(block_)) {
    // Whole transition needs to be invalidated
    invalidate_range = block_->range();
  }

  track_->Node::InvalidateCache(invalidate_range, Track::kBlockInput);
}

void BlockTrimCommand::undo()
{
  if (doing_nothing_) {
    return;
  }

  track_->BeginOperation();

  // Will be POSITIVE if trimming shorter and NEGATIVE if trimming longer
  if (needs_adjacent_) {
    if (we_created_adjacent_) {
      // Adjacent is ours, just delete it
      track_->RippleRemoveBlock(adjacent_);
      adjacent_->setParent(&memory_manager_);
    } else {
      if (we_removed_adjacent_) {
        if (deleted_adjacent_command_) {
          // We deleted adjacent, restore it now
          deleted_adjacent_command_->undo();
        }

        if (mode_ == Timeline::kTrimIn) {
          track_->InsertBlockBefore(adjacent_, block_);
        } else {
          track_->InsertBlockAfter(adjacent_, block_);
        }
      } else {
        rational adjacent_length = adjacent_->length() - trim_diff_;

        if (mode_ == Timeline::kTrimIn) {
          adjacent_->set_length_and_media_out(adjacent_length);
        } else {
          adjacent_->set_length_and_media_in(adjacent_length);
        }
      }
    }
  }

  TimeRange invalidate_range;

  if (mode_ == Timeline::kTrimIn) {
    block_->set_length_and_media_in(old_length_);

    invalidate_range = TimeRange(block_->in(), block_->in() + trim_diff_);
  } else {
    block_->set_length_and_media_out(old_length_);

    invalidate_range = TimeRange(block_->out(), block_->out() - trim_diff_);
  }

  if (dynamic_cast<TransitionBlock*>(block_)) {
    // Whole transition needs to be invalidated
    invalidate_range = block_->range();
  }

  track_->EndOperation();

  track_->Node::InvalidateCache(invalidate_range, Track::kBlockInput);
}

void BlockTrimCommand::prep()
{
  // Store old length
  old_length_ = block_->length();

  // Determine if the length isn't changing, in which case we set a flag to do nothing
  if ((doing_nothing_ = (old_length_ == new_length_))) {
    return;
  }

  // Will be POSITIVE if trimming shorter and NEGATIVE if trimming longer
  trim_diff_ = old_length_ - new_length_;

  // Retrieve our adjacent block (or nullptr if none)
  if (mode_ == Timeline::kTrimIn) {
    adjacent_ = block_->previous();
  } else {
    adjacent_ = block_->next();
  }

  // Ignore when trimming the out with no adjacent, because the user must have trimmed the end
  // of the last block in the track, so we don't need to do anything elses
  needs_adjacent_ = (mode_ == Timeline::kTrimIn || adjacent_);

  if (needs_adjacent_) {
    // If we're trimming shorter, we need an adjacent, so check if we have a viable one.
    we_created_adjacent_ = (trim_diff_ > 0 && (!adjacent_ || (!dynamic_cast<GapBlock*>(adjacent_) && !trim_is_a_roll_edit_)));

    if (we_created_adjacent_) {
      // We shortened but don't have a viable adjacent to lengthen, so we create one
      adjacent_ = new GapBlock();
      adjacent_->set_length_and_media_out(trim_diff_);
    } else {
      // Determine if we're removing the adjacent
      rational adjacent_length = adjacent_->length() + trim_diff_;
      we_removed_adjacent_ = adjacent_length.isNull();
    }
  }
}

}