/*
 * 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 "nodeviewminimap.h"

#include <QMouseEvent>

namespace olive
{

#define super QGraphicsView

NodeViewMiniMap::NodeViewMiniMap(NodeViewScene *scene, QWidget *parent)
	: super(parent)
	, resizing_(false)
{
	connect(scene, &QGraphicsScene::sceneRectChanged, this,
			&NodeViewMiniMap::SceneChanged);
	setScene(scene);

	setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
	setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
	setViewportUpdateMode(FullViewportUpdate);
	setFrameShape(QFrame::Panel);
	setFrameShadow(QFrame::Plain);
	setMouseTracking(true);

	QMetaObject::invokeMethod(this, &NodeViewMiniMap::SetDefaultSize,
							  Qt::QueuedConnection);

	resize_triangle_sz_ = fontMetrics().height() / 2;
}

void NodeViewMiniMap::SetViewportRect(const QPolygonF &rect)
{
	viewport_rect_ = rect;

	viewport()->update();
}

void NodeViewMiniMap::drawForeground(QPainter *painter, const QRectF &rect)
{
	super::drawForeground(painter, rect);

	QColor viewport_color = palette().text().color();

	// Draw resize triangle
	painter->save();
	painter->resetTransform();

	QPointF triangle[3] = { QPointF(0, 0), QPointF(resize_triangle_sz_, 0),
							QPointF(0, resize_triangle_sz_) };
	painter->setBrush(viewport_color);
	painter->setPen(viewport_color);
	painter->drawPolygon(triangle, 3);

	painter->restore();

	// Draw viewport rectangle
	viewport_color.setAlphaF(0.25);
	painter->setBrush(viewport_color);

	painter->drawPolygon(viewport_rect_);
}

void NodeViewMiniMap::resizeEvent(QResizeEvent *event)
{
	super::resizeEvent(event);

	emit Resized();

	SceneChanged(sceneRect());
}

void NodeViewMiniMap::mousePressEvent(QMouseEvent *event)
{
	if (event->button() == Qt::LeftButton) {
		if (MouseInsideResizeTriangle(event)) {
			// Resizing!
			resizing_ = true;
			resize_anchor_ = QCursor::pos();
		} else {
			EmitMoveSignal(event);
		}
	}
}

void NodeViewMiniMap::mouseMoveEvent(QMouseEvent *event)
{
	if (event->buttons() & Qt::LeftButton) {
		if (resizing_) {
			QPointF movement = QCursor::pos() - resize_anchor_;
			resize(QSize(width() - movement.x(), height() - movement.y()));
			resize_anchor_ = QCursor::pos();
		} else {
			EmitMoveSignal(event);
		}
	} else {
		if (MouseInsideResizeTriangle(event)) {
			setCursor(Qt::SizeFDiagCursor);
		} else {
			unsetCursor();
		}
	}
}

void NodeViewMiniMap::mouseReleaseEvent(QMouseEvent *event)
{
	resizing_ = false;
}

void NodeViewMiniMap::SceneChanged(const QRectF &bounding)
{
	double x_scale = double(this->width()) / bounding.width();
	double y_scale = double(this->height()) / bounding.height();

	double min_scale = qMin(x_scale, y_scale);

	QTransform transform;
	transform.scale(min_scale, min_scale);

	setTransform(transform);
}

void NodeViewMiniMap::SetDefaultSize()
{
	if (parentWidget()) {
		resize(parentWidget()->width() / 4, parentWidget()->height() / 4);
	}
}

bool NodeViewMiniMap::MouseInsideResizeTriangle(QMouseEvent *event)
{
	return event->pos().x() <= resize_triangle_sz_ &&
		   event->pos().y() <= resize_triangle_sz_;
}

void NodeViewMiniMap::EmitMoveSignal(QMouseEvent *event)
{
	emit MoveToScenePoint(mapToScene(event->pos()));
}

}
