/* 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.
 */

#include <QHeaderView>
#include <QApplication>
#include <QMouseEvent>
#include <QDrag>
#include <QPainter>
#include "VersionListView.h"

VersionListView::VersionListView(QWidget* parent) : QTreeView(parent)
{
	m_emptyString = tr("No versions are currently available.");
}

void VersionListView::rowsInserted(const QModelIndex& parent, int start,
								   int end)
{
	m_itemCount += end - start + 1;
	updateEmptyViewPort();
	QTreeView::rowsInserted(parent, start, end);
}

void VersionListView::rowsAboutToBeRemoved(const QModelIndex& parent, int start,
										   int end)
{
	m_itemCount -= end - start + 1;
	updateEmptyViewPort();
	QTreeView::rowsAboutToBeRemoved(parent, start, end);
}

void VersionListView::setModel(QAbstractItemModel* model)
{
	m_itemCount = model->rowCount();
	updateEmptyViewPort();
	QTreeView::setModel(model);
}

void VersionListView::reset()
{
	if (model()) {
		m_itemCount = model()->rowCount();
	} else {
		m_itemCount = 0;
	}
	updateEmptyViewPort();
	QTreeView::reset();
}

void VersionListView::setEmptyString(QString emptyString)
{
	m_emptyString = emptyString;
	updateEmptyViewPort();
}

void VersionListView::setEmptyErrorString(QString emptyErrorString)
{
	m_emptyErrorString = emptyErrorString;
	updateEmptyViewPort();
}

void VersionListView::setEmptyMode(VersionListView::EmptyMode mode)
{
	m_emptyMode = mode;
	updateEmptyViewPort();
}

void VersionListView::updateEmptyViewPort()
{
#ifndef QT_NO_ACCESSIBILITY
	setAccessibleDescription(currentEmptyString());
#endif /* !QT_NO_ACCESSIBILITY */

	if (!m_itemCount) {
		viewport()->update();
	}
}

void VersionListView::paintEvent(QPaintEvent* event)
{
	if (m_itemCount) {
		QTreeView::paintEvent(event);
	} else {
		paintInfoLabel(event);
	}
}

QString VersionListView::currentEmptyString() const
{
	if (m_itemCount) {
		return QString();
	}
	switch (m_emptyMode) {
		default:
		case VersionListView::Empty:
			return QString();
		case VersionListView::String:
			return m_emptyString;
		case VersionListView::ErrorString:
			return m_emptyErrorString;
	}
}

void VersionListView::paintInfoLabel(QPaintEvent* event) const
{
	QString emptyString = currentEmptyString();

	// calculate the rect for the overlay
	QPainter painter(viewport());
	painter.setRenderHint(QPainter::Antialiasing, true);
	QFont font("sans", 20);
	font.setBold(true);

	QRect bounds = viewport()->geometry();
	bounds.moveTop(0);
	auto innerBounds = bounds;
	innerBounds.adjust(10, 10, -10, -10);

	QColor background = QApplication::palette().color(QPalette::Text);
	QColor foreground = QApplication::palette().color(QPalette::Base);
	foreground.setAlpha(190);
	painter.setFont(font);
	auto fontMetrics = painter.fontMetrics();
	auto textRect = fontMetrics.boundingRect(
		innerBounds, Qt::AlignHCenter | Qt::TextWordWrap, emptyString);
	textRect.moveCenter(bounds.center());

	auto wrapRect = textRect;
	wrapRect.adjust(-10, -10, 10, 10);

	// check if we are allowed to draw in our area
	if (!event->rect().intersects(wrapRect)) {
		return;
	}

	painter.setBrush(QBrush(background));
	painter.setPen(foreground);
	painter.drawRoundedRect(wrapRect, 5.0, 5.0);

	painter.setPen(foreground);
	painter.setFont(font);
	painter.drawText(textRect, Qt::AlignHCenter | Qt::TextWordWrap,
					 emptyString);
}
