/* Copyright 2013-2019 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 <QStyledItemDelegate>
#include <QEvent>
#include <QScrollBar>

class BasePage;
const int pageIconSize = 24;

class PageViewDelegate : public QStyledItemDelegate
{
public:
    PageViewDelegate(QObject *parent) : QStyledItemDelegate(parent)
    {
    }
    QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const
    {
        QSize size = QStyledItemDelegate::sizeHint(option, index);
        size.setHeight(qMax(size.height(), 32));
        return size;
    }
};

class PageModel : public QAbstractListModel
{
public:
    PageModel(QObject *parent = 0) : QAbstractListModel(parent)
    {
        QPixmap empty(pageIconSize, pageIconSize);
        empty.fill(Qt::transparent);
        m_emptyIcon = QIcon(empty);
    }
    virtual ~PageModel() {}

    int rowCount(const QModelIndex &parent = QModelIndex()) const
    {
        return parent.isValid() ? 0 : m_pages.size();
    }
    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const
    {
        switch (role)
        {
        case Qt::DisplayRole:
            return m_pages.at(index.row())->displayName();
        case Qt::DecorationRole:
        {
            QIcon icon = m_pages.at(index.row())->icon();
            if (icon.isNull())
                icon = m_emptyIcon;
            // HACK: fixes icon stretching on windows. TODO: report Qt bug for this
            return QIcon(icon.pixmap(QSize(48,48)));
        }
        }
        return QVariant();
    }

    void setPages(const QList<BasePage *> &pages)
    {
        beginResetModel();
        m_pages = pages;
        endResetModel();
    }
    const QList<BasePage *> &pages() const
    {
        return m_pages;
    }

    BasePage * findPageEntryById(QString id)
    {
        for(auto page: m_pages)
        {
            if (page->id() == id)
                return page;
        }
        return nullptr;
    }

    QList<BasePage *> m_pages;
    QIcon m_emptyIcon;
};

class PageView : public QListView
{
public:
    PageView(QWidget *parent = 0) : QListView(parent)
    {
        setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::Expanding);
        setItemDelegate(new PageViewDelegate(this));
        setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    }

    virtual QSize sizeHint() const
    {
        int width = sizeHintForColumn(0) + frameWidth() * 2 + 5;
        if (verticalScrollBar()->isVisible())
            width += verticalScrollBar()->width();
        return QSize(width, 100);
    }

    virtual bool eventFilter(QObject *obj, QEvent *event)
    {
        if (obj == verticalScrollBar() &&
            (event->type() == QEvent::Show || event->type() == QEvent::Hide))
            updateGeometry();
        return QListView::eventFilter(obj, event);
    }
};