/***

  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 "widget/timelinewidget/timelinewidget.h"
#include "zoom.h"

namespace olive
{

ZoomTool::ZoomTool(TimelineWidget *parent)
	: TimelineTool(parent)
{
}

void ZoomTool::mouse_press(TimelineViewMouseEvent *event)
{
	Q_UNUSED(event)

	drag_global_start_ = QCursor::pos();
}

void ZoomTool::mouse_move(TimelineViewMouseEvent *event)
{
	Q_UNUSED(event)

	if (!dragging_) {
		parent()->start_rubber_band_select(drag_global_start_);

		dragging_ = true;
	}

	parent()->move_rubber_band_select(false, false);
}

void ZoomTool::mouse_release(TimelineViewMouseEvent *event)
{
	int scroll_value;

	if (dragging_) {
		// Zoom into the rubberband selection
		QRect screen_coords = parent()->get_rubber_band_geometry();

		parent()->end_rubber_band_select();

		TimelineView *reference_view = parent()->get_first_timeline_view();
		QPointF scene_topleft = reference_view->mapToScene(
			reference_view->mapFrom(parent(), screen_coords.topLeft()));
		QPointF scene_bottomright = reference_view->mapToScene(
			reference_view->mapFrom(parent(), screen_coords.bottomRight()));

		double scene_left = scene_topleft.x();
		double scene_right = scene_bottomright.x();

		// Normalize scale to 1.0 scale
		double scene_width = (scene_right - scene_left) / parent()->get_scale();

		double new_scale =
			qMin(parent()->get_first_timeline_view()->get_maximum_scale(),
				 static_cast<double>(reference_view->viewport()->width()) /
					 scene_width);

		parent()->SetScale(new_scale);

		scroll_value =
			qMax(0, qRound(scene_left / parent()->get_scale() * new_scale));

		dragging_ = false;
	} else {
		// Simple zoom in/out at the cursor position
		double scale = parent()->get_scale();

		if (event->get_modifiers() & Qt::AltModifier) {
			// Zoom out if the user clicks while holding Alt
			scale *= 0.5;
		} else {
			// Otherwise zoom in
			scale *= 2.0;
		}

		parent()->SetScale(scale);

		// Adjust scroll location for new scale
		double frame_x = event->get_frame().to_double() * scale;

		scroll_value = qMax(
			0,
			qRound(frame_x -
				   parent()->get_first_timeline_view()->viewport()->width() / 2));
	}

	parent()->queue_scroll(scroll_value);
}

}