/***

  Olive - Non-Linear Video Editor
  Copyright (C) 2022 Olive Team
  Modifications Copyright (C) 2025 mikesolar

  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 <utility>
#include "timelineundoripple.h"

#include "timelineundocommon.h"

namespace olive
{

//
// TrackRippleRemoveAreaCommand
//
TrackRippleRemoveAreaCommand::TrackRippleRemoveAreaCommand(
	Track *track, const TimeRange &range)
	: track_(track)
	, range_(range)
	, allow_splitting_gaps_(false)
	, splice_split_command_(nullptr)
{
	trim_out_.block = nullptr;
	trim_in_.block = nullptr;
}

TrackRippleRemoveAreaCommand::~TrackRippleRemoveAreaCommand()
{
	delete splice_split_command_;
	qDeleteAll(remove_block_commands_);
}

void TrackRippleRemoveAreaCommand::prepare()
{
	// Determine precisely what will be happening to these tracks
	Block *first_block = track_->nearest_block_before_or_at(range_.in());

	if (!first_block) {
		// No blocks at this time, nothing to be done on this track
		return;
	}

	// Determine if this first block is getting trimmed or removed
	bool first_block_is_out_trimmed = first_block->in() < range_.in();
	bool first_block_is_in_trimmed = first_block->out() > range_.out();

	// Set's the block that any insert command should insert AFTER. If the first block is not
	// getting out-trimmed, that means first block is either getting removed or in-trimmed, which
	// means any insert should happen before it
	insert_previous_ = first_block_is_out_trimmed ? first_block :
													first_block->previous();

	// If it's getting trimmed, determine if it's actually getting spliced
	if (first_block_is_out_trimmed && first_block_is_in_trimmed) {
		if (!allow_splitting_gaps_ && dynamic_cast<GapBlock *>(first_block)) {
			// As a rule, we don't split gaps, so we just treat it as a trim of the range requested
			trim_out_ = { first_block, first_block->length(),
						  first_block->length() - range_.length() };
		} else {
			// This block is getting spliced, so we'll handle that later
			splice_split_command_ =
				new BlockSplitCommand(first_block, range_.in());
		}
	} else {
		// It's just getting trimmed or removed, so we'll append that operation
		if (first_block_is_out_trimmed) {
			trim_out_ = { first_block, first_block->length(),
						  first_block->length() -
							  (first_block->out() - range_.in()) };
		} else if (first_block_is_in_trimmed) {
			// Block is getting in trimmed
			trim_in_ = { first_block, first_block->length(),
						 first_block->length() -
							 (range_.out() - first_block->in()) };
		} else {
			// We know for sure this block is within the range so it will be removed
			removals_.append(
				RemoveOperation({ first_block, first_block->previous() }));
		}

		// If the first block is getting in trimmed, we're already at the end of our range
		if (!first_block_is_in_trimmed) {
			// Loop through the rest of the blocks and determine what to do with those
			for (Block *next = first_block->next(); next; next = next->next()) {
				bool trimming = (next->out() > range_.out());

				if (trimming) {
					trim_in_ = { next, next->length(),
								 next->length() - (range_.out() - next->in()) };
					break;
				} else {
					removals_.append(
						RemoveOperation({ next, next->previous() }));

					if (next->out() == range_.out()) {
						break;
					}
				}
			}
		}
	}
}

void TrackRippleRemoveAreaCommand::redo()
{
	if (splice_split_command_) {
		// We're just splicing
		splice_split_command_->redo_now();

		// Trim the in of the split
		Block *split = splice_split_command_->new_block();
		split->set_length_and_media_in(split->length() -
									   (range_.out() - split->in()));
	} else {
		if (trim_out_.block) {
			trim_out_.block->set_length_and_media_out(trim_out_.new_length);
		}

		if (trim_in_.block) {
			trim_in_.block->set_length_and_media_in(trim_in_.new_length);
		}

		// Perform removals
		if (!removals_.isEmpty()) {
			foreach (auto op, removals_) {
				// Ripple remove them all first
				track_->ripple_remove_block(op.block);
			}

			// Create undo commands for node removals where possible
			if (remove_block_commands_.isEmpty()) {
				foreach (auto op, removals_) {
					if (node_can_be_removed(op.block)) {
						remove_block_commands_.append(
							create_remove_command(op.block));
					}
				}
			}

			foreach (UndoCommand *c, remove_block_commands_) {
				c->redo_now();
			}
		}
	}
}

void TrackRippleRemoveAreaCommand::undo()
{
	if (splice_split_command_) {
		splice_split_command_->undo_now();
	} else {
		if (trim_out_.block) {
			trim_out_.block->set_length_and_media_out(trim_out_.old_length);
		}

		if (trim_in_.block) {
			trim_in_.block->set_length_and_media_in(trim_in_.old_length);
		}

		// Un-remove any blocks
		for (int i = remove_block_commands_.size() - 1; i >= 0; i--) {
			remove_block_commands_.at(i)->undo_now();
		}

		foreach (auto op, removals_) {
			track_->insert_block_after(op.block, op.before);
		}
	}
}

//
// TrackListRippleRemoveAreaCommand
//
void TrackListRippleRemoveAreaCommand::prepare()
{
	foreach (Track *track, list_->get_tracks()) {
		if (track->is_locked()) {
			continue;
		}

		TrackRippleRemoveAreaCommand *c =
			new TrackRippleRemoveAreaCommand(track, range_);
		commands_.append(c);
		working_tracks_.append(track);
	}
}

void TrackListRippleRemoveAreaCommand::redo()
{
	foreach (TrackRippleRemoveAreaCommand *c, commands_) {
		c->redo_now();
	}
}

void TrackListRippleRemoveAreaCommand::undo()
{
	foreach (TrackRippleRemoveAreaCommand *c, commands_) {
		c->undo_now();
	}
}

//
// TimelineRippleRemoveAreaCommand
//
TimelineRippleRemoveAreaCommand::TimelineRippleRemoveAreaCommand(
	Sequence *timeline, Rational in, Rational out)
	: timeline_(timeline)
{
	for (int i = 0; i < Track::k_count; i++) {
		add_child(new TrackListRippleRemoveAreaCommand(
			timeline->track_list(static_cast<Track::Type>(i)), in, out));
	}
}

//
// TrackListRippleToolCommand
//
TrackListRippleToolCommand::TrackListRippleToolCommand(
	TrackList *track_list, const QHash<Track *, RippleInfo> &info,
	const Rational &ripple_movement,
	const Timeline::MovementMode &movement_mode)
	: track_list_(track_list)
	, info_(info)
	, ripple_movement_(ripple_movement)
	, movement_mode_(movement_mode)
{
}

void TrackListRippleToolCommand::ripple(bool redo)
{
	if (info_.isEmpty()) {
		return;
	}

	// The following variables are used to determine how much of the cache to invalidate

	// If we can shift, we will shift from the latest out before the ripple to the latest out after,
	// since those sections will be unchanged by this ripple
	Rational pre_latest_out = RATIONAL_MIN;
	Rational post_latest_out = RATIONAL_MIN;

	// Make timeline changes
	for (auto it = info_.cbegin(); it != info_.cend(); it++) {
		Track *track = it.key();
		const RippleInfo &info = it.value();
		WorkingData working_data = working_data_.value(track);
		Block *b = info.block;

		// Generate block length
		Rational new_block_length;
		Rational operation_movement = ripple_movement_;

		if (movement_mode_ == Timeline::k_trim_in) {
			operation_movement = -operation_movement;
		}

		if (!redo) {
			operation_movement = -operation_movement;
		}

		if (b) {
			new_block_length = b->length() + operation_movement;
		}

		Rational pre_shift;
		Rational post_shift;

		if (info.append_gap) {
			// Rather than rippling the referenced block, we'll insert a gap and ripple with that
			GapBlock *gap = working_data.created_gap;

			if (redo) {
				if (!gap) {
					gap = new GapBlock();
					gap->set_length_and_media_out(qAbs(ripple_movement_));
					working_data.created_gap = gap;
				}

				gap->setParent(track->parent());
				track->insert_block_before(gap, b);

				// As an insertion, we will shift from the gap's in to the gap's out
				pre_shift = gap->in();
				post_shift = gap->out();
				working_data.earliest_point_of_change = gap->in();
			} else {
				// As a removal, we will shift from the gap's out to the gap's in
				pre_shift = gap->out();
				post_shift = gap->in();

				track->ripple_remove_block(gap);
				gap->setParent(&memory_manager_);
			}

		} else if ((redo && new_block_length.isNull()) ||
				   (!redo && !b->track())) {
			// The ripple is the length of this block. We assume that for this to happen, it must have
			// been a gap that we will now remove.

			if (redo) {
				// The earliest point changes will happen is at the start of this block
				working_data.earliest_point_of_change = b->in();

				// As a removal, we will be shifting from the out point to the in point
				pre_shift = b->out();
				post_shift = b->in();

				// Remove gap from track and from graph
				working_data.removed_gap_after = b->previous();
				track->ripple_remove_block(b);
				b->setParent(&memory_manager_);
			} else {
				// Restore gap to graph and track
				b->setParent(track->parent());
				track->insert_block_after(b, working_data.removed_gap_after);

				// The earliest point changes will happen is at the start of this block
				working_data.earliest_point_of_change = b->in();

				// As an insert, we will be shifting from the block's in point to its out point
				pre_shift = b->in();
				post_shift = b->out();
			}

		} else {
			// Store old length
			working_data.old_length = b->length();

			if (movement_mode_ == Timeline::k_trim_in) {
				// The earliest point changes will occur is in point of this bloc
				working_data.earliest_point_of_change = b->in();

				// Undo the trim in inversion we do above, this will still be inverted accurately for
				// undoing where appropriate
				Rational inverted = -operation_movement;
				if (inverted > 0) {
					pre_shift = b->in() + inverted;
					post_shift = b->in();
				} else {
					pre_shift = b->in();
					post_shift = b->in() - inverted;
				}

				// Update length
				b->set_length_and_media_in(new_block_length);
			} else {
				// The earliest point changes will occur is the out point if trimming out or the in point
				// if trimming in
				working_data.earliest_point_of_change = b->out();

				// The latest out before the ripple is this block's current out point
				pre_shift = b->out();

				// Update length
				b->set_length_and_media_out(new_block_length);

				// The latest out after the ripple is this block's out point after the length change
				post_shift = b->out();
			}
		}

		working_data_.insert(it.key(), working_data);

		pre_latest_out = qMax(pre_latest_out, pre_shift);
		post_latest_out = qMax(post_latest_out, post_shift);
	}
}

//
// TimelineRippleDeleteGapsAtRegionsCommand
//
void TimelineRippleDeleteGapsAtRegionsCommand::prepare()
{
	int max_gaps = 0;
	QHash<Track *, QVector<RemovalRequest>> requested_gaps;

	// Convert regions to gaps
	for (const QPair<Track *, TimeRange> &region : std::as_const(regions_)) {
		Track *track = region.first;
		const TimeRange &range = region.second;

		GapBlock *gap =
			dynamic_cast<GapBlock *>(track->nearest_block_before_or_at(range.in()));

		if (gap) {
			QVector<RemovalRequest> &gaps_on_track = requested_gaps[track];

			RemovalRequest this_req = { gap, range };

			// Insertion sort
			bool inserted = false;
			for (int i = 0; i < gaps_on_track.size(); i++) {
				if (gaps_on_track.at(i).range.in() < range.in()) {
					gaps_on_track.insert(i, this_req);
					inserted = true;
					break;
				}
			}
			if (!inserted) {
				gaps_on_track.append(this_req);
			}

			max_gaps = qMax(max_gaps, gaps_on_track.size());
		} else {
			qWarning() << "Failed to find corresponding gap to region";
		}
	}

	// For each gap on each track, find a corresponding gap on every other track (which may include
	// a requested gap) to ripple in order to keep everything synchronized
	QHash<GapBlock *, Rational> gap_lengths;
	for (int gap_index = 0; gap_index < max_gaps; gap_index++) {
		Rational earliest_point = RATIONAL_MAX;
		Rational ripple_length = RATIONAL_MAX;
		Rational latest_point = RATIONAL_MIN;

		foreach (const QVector<RemovalRequest> &gaps_on_track, requested_gaps) {
			if (gap_index < gaps_on_track.size()) {
				const RemovalRequest &gap = gaps_on_track.at(gap_index);
				earliest_point = qMin(earliest_point, gap.range.in());
				ripple_length = qMin(ripple_length, gap.range.length());
				latest_point = qMax(latest_point, gap.range.out());
			}
		}

		// Determine which gaps will be involved in this operation
		QVector<GapBlock *> gaps;

		foreach (Track *track, timeline_->get_tracks()) {
			if (track->is_locked()) {
				continue;
			}

			const QVector<RemovalRequest> &requested_gaps_on_track =
				requested_gaps.value(track);
			GapBlock *gap = nullptr;
			if (gap_index < requested_gaps_on_track.size()) {
				// A requested gap was at this index, use it
				gap = requested_gaps_on_track.at(gap_index).gap;
			} else {
				// No requested gap was at this index, find one
				Block *block = track->nearest_block_after_or_at(earliest_point);

				if (block) {
					// Found a block, test if it's a gap
					gap = dynamic_cast<GapBlock *>(block);

					if (!gap) {
						if (block->in() == earliest_point) {
							if (block->next()) {
								gap = dynamic_cast<GapBlock *>(block->next());

								if (!gap) {
									ripple_length = 0;
								}
							}
						} else {
							gap = dynamic_cast<GapBlock *>(block->previous());

							if (!gap) {
								ripple_length = 0;
							}
						}
					}
				} else {
					// Assume track finishes here and track won't be affected by this operation
				}
			}

			if (gap) {
				gaps.append(gap);

				if (!gap_lengths.contains(gap)) {
					gap_lengths.insert(gap, gap->length());
				}

				ripple_length = qMin(ripple_length, gap_lengths.value(gap));
			}

			if (ripple_length == 0) {
				break;
			}
		}

		if (ripple_length > 0) {
			foreach (GapBlock *gap, gaps) {
				if (gap_lengths.value(gap) == ripple_length) {
					commands_.append(
						new TrackRippleRemoveBlockCommand(gap->track(), gap));
				} else {
					gap_lengths[gap] -= ripple_length;
					commands_.append(
						new BlockResizeCommand(gap, gap_lengths.value(gap)));
				}
			}
		}
	}
}

void TimelineRippleDeleteGapsAtRegionsCommand::redo()
{
	for (auto it = commands_.cbegin(); it != commands_.cend(); it++) {
		(*it)->redo_now();
	}
}

void TimelineRippleDeleteGapsAtRegionsCommand::undo()
{
	for (auto it = commands_.crbegin(); it != commands_.crend(); it++) {
		(*it)->undo_now();
	}
}

}