/* SPDX-FileCopyrightText: 2026 Project Tick
 * SPDX-FileContributor: Project Tick
 * SPDX-License-Identifier: GPL-3.0-or-later WITH LicenseRef-MeshMC-MMCO-Module-Exception-1.0
 *
 *   MeshMC - A Custom Launcher for Minecraft
 *   Copyright (C) 2026 Project Tick
 *
 *   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, with the additional permission
 *   described in the MeshMC MMCO Module Exception 1.0.
 *
 *   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 <https://www.gnu.org/licenses/>.
 *
 *   You should have received a copy of the MeshMC MMCO Module Exception 1.0
 *   along with this program.  If not, see <https://projecttick.org/licenses/>.
 *
 *  This file incorporates work covered by the following copyright and
 *  permission notice:
 *
 * Copyright 2013-2021 MultiMC Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <QListView>
#include <QLineEdit>
#include <QScrollBar>
#include <QCache>
#include "VisualGroup.h"
#include <functional>

struct InstanceViewRoles {
	enum { GroupRole = Qt::UserRole, ProgressValueRole, ProgressMaximumRole };
};

class InstanceView : public QAbstractItemView
{
	Q_OBJECT

  public:
	InstanceView(QWidget* parent = 0);
	~InstanceView();

	QStyleOptionViewItem viewOptions() const
	{
		QStyleOptionViewItem option;
		initViewItemOption(&option);
		return option;
	}

	void setModel(QAbstractItemModel* model) override;

	using visibilityFunction = std::function<bool(const QString&)>;
	void setSourceOfGroupCollapseStatus(visibilityFunction f)
	{
		fVisibility = f;
	}

	/// return geometry rectangle occupied by the specified model item
	QRect geometryRect(const QModelIndex& index) const;
	/// return visual rectangle occupied by the specified model item
	virtual QRect visualRect(const QModelIndex& index) const override;
	/// get the model index at the specified visual point
	virtual QModelIndex indexAt(const QPoint& point) const override;
	QString groupNameAt(const QPoint& point);
	void
	setSelection(const QRect& rect,
				 const QItemSelectionModel::SelectionFlags commands) override;

	virtual int horizontalOffset() const override;
	virtual int verticalOffset() const override;
	virtual void scrollContentsBy(int dx, int dy) override;
	virtual void scrollTo(const QModelIndex& index,
						  ScrollHint hint = EnsureVisible) override;

	virtual QModelIndex moveCursor(CursorAction cursorAction,
								   Qt::KeyboardModifiers modifiers) override;

	virtual QRegion
	visualRegionForSelection(const QItemSelection& selection) const override;

	int spacing() const
	{
		return m_spacing;
	};

  public slots:
	virtual void updateGeometries() override;

  protected slots:
	virtual void dataChanged(const QModelIndex& topLeft,
							 const QModelIndex& bottomRight,
							 const QVector<int>& roles) override;
	virtual void rowsInserted(const QModelIndex& parent, int start,
							  int end) override;
	virtual void rowsAboutToBeRemoved(const QModelIndex& parent, int start,
									  int end) override;
	void modelReset();
	void rowsRemoved();
	void currentChanged(const QModelIndex& current,
						const QModelIndex& previous) override;

  signals:
	void droppedURLs(QList<QUrl> urls);
	void groupStateChanged(QString group, bool collapsed);

  protected:
	bool isIndexHidden(const QModelIndex& index) const override;
	void mousePressEvent(QMouseEvent* event) override;
	void mouseMoveEvent(QMouseEvent* event) override;
	void mouseReleaseEvent(QMouseEvent* event) override;
	void mouseDoubleClickEvent(QMouseEvent* event) override;
	void paintEvent(QPaintEvent* event) override;
	void resizeEvent(QResizeEvent* event) override;

	void dragEnterEvent(QDragEnterEvent* event) override;
	void dragMoveEvent(QDragMoveEvent* event) override;
	void dragLeaveEvent(QDragLeaveEvent* event) override;
	void dropEvent(QDropEvent* event) override;

	void startDrag(Qt::DropActions supportedActions) override;

	void updateScrollbar();

  private:
	friend struct VisualGroup;
	QList<VisualGroup*> m_groups;

	visibilityFunction fVisibility;

	// geometry
	int m_leftMargin = 5;
	int m_rightMargin = 5;
	int m_bottomMargin = 5;
	int m_categoryMargin = 5;
	int m_spacing = 5;
	int m_itemWidth = 100;
	int m_currentItemsPerRow = -1;
	int m_currentCursorColumn = -1;
	mutable QCache<int, QRect> geometryCache;

	// point where the currently active mouse action started in geometry
	// coordinates
	QPoint m_pressedPosition;
	QPersistentModelIndex m_pressedIndex;
	bool m_pressedAlreadySelected;
	VisualGroup* m_pressedCategory;
	QItemSelectionModel::SelectionFlag m_ctrlDragSelectionFlag;
	QPoint m_lastDragPosition;

	VisualGroup* category(const QModelIndex& index) const;
	VisualGroup* category(const QString& cat) const;
	VisualGroup* categoryAt(const QPoint& pos,
							VisualGroup::HitResults& result) const;

	int itemsPerRow() const
	{
		return m_currentItemsPerRow;
	};
	int contentWidth() const;

  private: /* methods */
	int itemWidth() const;
	int calculateItemsPerRow() const;
	int verticalScrollToValue(const QModelIndex& index, const QRect& rect,
							  QListView::ScrollHint hint) const;
	QPixmap renderToPixmap(const QModelIndexList& indices, QRect* r) const;
	QList<QPair<QRect, QModelIndex>>
	draggablePaintPairs(const QModelIndexList& indices, QRect* r) const;

	bool isDragEventAccepted(QDropEvent* event);

	QPair<VisualGroup*, VisualGroup::HitResults> rowDropPos(const QPoint& pos);

	QPoint offset() const;
};
