/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing
**
** This file is part of Qt Creator.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company.  For licensing terms and
** conditions see http://www.qt.io/terms-conditions.  For further information
** use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, The Qt Company gives you certain additional
** rights.  These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
****************************************************************************/

#include "pluginview.h"
#include "pluginmanager.h"
#include "pluginspec.h"
#include "pluginspec_p.h"
#include "plugincollection.h"

#include <utils/algorithm.h>
#include <utils/itemviews.h>
#include <utils/treemodel.h>

#include <QDebug>
#include <QDir>
#include <QGridLayout>
#include <QHeaderView>
#include <QItemSelectionModel>
#include <QSet>
#include <QSortFilterProxyModel>

/*!
    \class ExtensionSystem::PluginView
    \brief The PluginView class implements a widget that shows a list of all
    plugins and their state.

    This class can be embedded for example in a dialog in the application that
    uses the plugin manager.
    The class also provides notifications for interaction with the list.

    \sa ExtensionSystem::PluginDetailsView
    \sa ExtensionSystem::PluginErrorView
*/

/*!
    \fn void PluginView::currentPluginChanged(ExtensionSystem::PluginSpec *spec)
    The current selection in the plugin list has changed to the
    plugin corresponding to \a spec.
*/

/*!
    \fn void PluginView::pluginActivated(ExtensionSystem::PluginSpec *spec)
    The plugin list entry corresponding to \a spec has been activated,
    for example by a double-click.
*/

Q_DECLARE_METATYPE(ExtensionSystem::PluginSpec*)
Q_DECLARE_METATYPE(ExtensionSystem::PluginCollection*)

using namespace Utils;

namespace ExtensionSystem {

enum Columns { NameColumn, LoadedColumn, VersionColumn, VendorColumn, };

enum IconIndex { OkIcon, ErrorIcon, NotLoadedIcon };

static const QIcon &icon(int num)
{
    static QIcon icons[] = {
        QIcon(QLatin1String(":/extensionsystem/images/ok.png")),
        QIcon(QLatin1String(":/extensionsystem/images/error.png")),
        QIcon(QLatin1String(":/extensionsystem/images/notloaded.png")),
    };
    return icons[num];
}

class PluginItem : public TreeItem
{
public:
    PluginItem(PluginSpec *spec, PluginView *view)
        : m_spec(spec), m_view(view)
    {}

    int columnCount() const { return 4; }

    QVariant data(int column, int role) const
    {
        switch (column) {
        case NameColumn:
            if (role == Qt::DisplayRole)
                return m_spec->name();
            if (role == Qt::ToolTipRole)
                return QDir::toNativeSeparators(m_spec->filePath());
            if (role == Qt::DecorationRole) {
                bool ok = !m_spec->hasError();
                QIcon i = icon(ok ? OkIcon : ErrorIcon);
                if (ok && m_spec->state() != PluginSpec::Running)
                    i = icon(NotLoadedIcon);
                return i;
            }
            break;

        case LoadedColumn:
            if (!m_spec->isAvailableForHostPlatform()) {
                if (role == Qt::CheckStateRole)
                    return Qt::Unchecked;
                if (role == Qt::ToolTipRole)
                    return PluginView::tr("Plugin is not available on this platform.");
            } else if (m_spec->isRequired()) {
                if (role == Qt::CheckStateRole)
                    return Qt::Checked;
                if (role == Qt::ToolTipRole)
                    return PluginView::tr("Plugin is required.");
            } else {
                if (role == Qt::CheckStateRole)
                    return m_spec->isEnabledBySettings() ? Qt::Checked : Qt::Unchecked;
                if (role == Qt::ToolTipRole)
                    return PluginView::tr("Load on startup");
            }
            break;

        case VersionColumn:
            if (role == Qt::DisplayRole)
                return QString::fromLatin1("%1 (%2)").arg(m_spec->version(), m_spec->compatVersion());
            break;

        case VendorColumn:
            if (role == Qt::DisplayRole)
                return m_spec->vendor();
            break;
        }

        return QVariant();
    }

    bool setData(int column, const QVariant &data, int role)
    {
        if (column == LoadedColumn && role == Qt::CheckStateRole) {
            m_spec->d->setEnabledBySettings(data.toBool());
            updateColumn(column);
            parent()->updateColumn(column);
            emit m_view->pluginSettingsChanged(m_spec);
            return true;
        }
        return false;
    }

    bool isEnabled() const
    {
        if (m_spec->isRequired() || !m_spec->isAvailableForHostPlatform())
            return false;
        foreach (PluginSpec *spec, m_view->m_pluginDependencies.value(m_spec))
            if (!spec->isEnabledBySettings())
                return false;
        return true;
    }

    Qt::ItemFlags flags(int column) const
    {
        Qt::ItemFlags ret = Qt::ItemIsSelectable;

        if (isEnabled())
            ret |= Qt::ItemIsEnabled;

        if (column == LoadedColumn) {
            if (m_spec->isAvailableForHostPlatform() && !m_spec->isRequired())
                ret |= Qt::ItemIsEditable | Qt ::ItemIsUserCheckable;
        }

        return ret;
    }

public:
    PluginSpec *m_spec; // Not owned.
    PluginView *m_view; // Not owned.
};

class CollectionItem : public TreeItem
{
public:
    CollectionItem(const QString &name, QList<PluginSpec *> plugins, PluginView *view)
        : m_name(name), m_plugins(plugins), m_view(view)
    {
        foreach (PluginSpec *spec, plugins)
            appendChild(new PluginItem(spec, view));
    }

    int columnCount() const { return 4; }

    QVariant data(int column, int role) const
    {
        if (column == NameColumn) {
            if (role == Qt::DisplayRole)
                return m_name;
            if (role == Qt::DecorationRole) {
                foreach (PluginSpec *spec, m_plugins) {
                    if (spec->hasError())
                        return icon(ErrorIcon);
                    if (!spec->isEnabledBySettings())
                        return icon(NotLoadedIcon);
                }
                return icon(OkIcon);
            }
        }

        if (column == LoadedColumn) {
            if (role == Qt::ToolTipRole)
                return PluginView::tr("Load on Startup");
            if (role == Qt::CheckStateRole) {
                int checkedCount = 0;
                foreach (PluginSpec *spec, m_plugins) {
                    if (spec->isEnabledBySettings())
                        ++checkedCount;
                }

                if (checkedCount == 0)
                    return Qt::Unchecked;
                if (checkedCount == m_plugins.length())
                    return Qt::Checked;
                return Qt::PartiallyChecked;
            }
        }

        return QVariant();
    }

    bool setData(int column, const QVariant &data, int role)
    {
        if (column == LoadedColumn && role == Qt::CheckStateRole) {
            foreach (TreeItem *item, children())
                static_cast<PluginItem *>(item)->setData(column, data, role);
            update();
            return true;
        }
        return false;
    }

    Qt::ItemFlags flags(int column) const
    {
        Qt::ItemFlags ret = Qt::ItemIsSelectable | Qt::ItemIsEnabled;
        if (column == LoadedColumn)
            ret |= Qt::ItemIsEditable | Qt::ItemIsUserCheckable;
        return ret;
    }

public:
    QString m_name;
    QList<PluginSpec *> m_plugins;
    PluginView *m_view; // Not owned.
};

/*!
    Constructs a PluginView that gets the list of plugins from the
    given plugin \a manager with a given \a parent widget.
*/
PluginView::PluginView(QWidget *parent)
    : QWidget(parent)
{
    m_categoryView = new TreeView(this);
    m_categoryView->setAlternatingRowColors(true);
    m_categoryView->setIndentation(20);
    m_categoryView->setUniformRowHeights(true);
    m_categoryView->setSortingEnabled(true);
    m_categoryView->setColumnWidth(LoadedColumn, 40);
    m_categoryView->header()->setDefaultSectionSize(120);
    m_categoryView->header()->setMinimumSectionSize(35);
    m_categoryView->header()->setSortIndicator(0, Qt::AscendingOrder);
    m_categoryView->setActivationMode(DoubleClickActivation);
    m_categoryView->setSelectionMode(QAbstractItemView::SingleSelection);
    m_categoryView->setSelectionBehavior(QAbstractItemView::SelectRows);

    m_model = new TreeModel(this);
    m_model->setHeader(QStringList() << tr("Name") << tr("Load") << tr("Version") << tr("Vendor"));

    m_sortModel = new QSortFilterProxyModel(this);
    m_sortModel->setSourceModel(m_model);
    m_categoryView->setModel(m_sortModel);

    QGridLayout *gridLayout = new QGridLayout(this);
    gridLayout->setContentsMargins(2, 2, 2, 2);
    gridLayout->addWidget(m_categoryView, 1, 0, 1, 1);

    QHeaderView *header = m_categoryView->header();
    header->setSectionResizeMode(0, QHeaderView::ResizeToContents);
    header->setSectionResizeMode(2, QHeaderView::ResizeToContents);

    connect(PluginManager::instance(), &PluginManager::pluginsChanged,
            this, &PluginView::updatePlugins);

    connect(m_categoryView, &QAbstractItemView::activated,
            [this](const QModelIndex &idx) { pluginActivated(pluginForIndex(idx)); });

    connect(m_categoryView->selectionModel(), &QItemSelectionModel::currentChanged,
            [this](const QModelIndex &idx) { currentPluginChanged(pluginForIndex(idx)); });

    updatePlugins();
}

/*!
    \internal
*/
PluginView::~PluginView()
{
}

/*!
    Returns the current selection in the list of plugins.
*/
PluginSpec *PluginView::currentPlugin() const
{
    return pluginForIndex(m_categoryView->currentIndex());
}

PluginSpec *PluginView::pluginForIndex(const QModelIndex &index) const
{
    const QModelIndex &sourceIndex = m_sortModel->mapToSource(index);
    auto item = dynamic_cast<PluginItem *>(m_model->itemFromIndex(sourceIndex));
    return item ? item->m_spec: 0;
}

static void queryDependendPlugins(PluginSpec *spec, QSet<PluginSpec *> *dependencies)
{
    QHashIterator<PluginDependency, PluginSpec *> it(spec->dependencySpecs());
    while (it.hasNext()) {
        it.next();
        PluginSpec *dep = it.value();
        if (!dependencies->contains(dep)) {
            dependencies->insert(dep);
            queryDependendPlugins(dep, dependencies);
        }
    }
}

void PluginView::updatePlugins()
{
    // Dependencies.
    m_pluginDependencies.clear();
    foreach (PluginSpec *spec, PluginManager::loadQueue()) {
        QSet<PluginSpec *> deps;
        queryDependendPlugins(spec, &deps);
        m_pluginDependencies[spec] = deps;
    }

    // Model.
    m_model->removeItems();

    PluginCollection *defaultCollection = 0;
    QList<CollectionItem *> collections;
    foreach (PluginCollection *collection, PluginManager::pluginCollections()) {
        if (collection->name().isEmpty() || collection->plugins().isEmpty()) {
            defaultCollection = collection;
            continue;
        }
        collections.append(new CollectionItem(collection->name(), collection->plugins(), this));
    }

    QList<PluginSpec *> plugins;
    if (defaultCollection)
        plugins = defaultCollection->plugins();

    if (!plugins.isEmpty()) {
        // add all non-categorized plugins into utilities. could also be added as root items
        // but that makes the tree ugly.
        collections.append(new CollectionItem(tr("Utilities"), plugins, this));
    }

    Utils::sort(collections, [](CollectionItem *a, CollectionItem *b) -> bool
        { return a->m_name < b->m_name; });

    foreach (CollectionItem *collection, collections)
        m_model->rootItem()->appendChild(collection);

    m_model->layoutChanged();
    m_categoryView->expandAll();
}

} // namespace ExtensionSystem