/*
    Copyright 2015 Milian Wolff <mail@milianw.de>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) version 3, or any
    later version accepted by the membership of KDE e.V. (or its
    successor approved by the membership of KDE e.V.), which shall
    act as a proxy defined in Section 6 of version 3 of the license.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "ktexteditorpluginintegration.h"

#include <QWidget>
#include <QVBoxLayout>
#include <QStackedLayout>

#include <KParts/MainWindow>
#include <KTextEditor/View>
#include <KTextEditor/Editor>
#include <KTextEditor/Application>

#include <sublime/area.h>
#include <sublime/view.h>
#include <sublime/viewbarcontainer.h>

#include "core.h"
#include "uicontroller.h"
#include "documentcontroller.h"
#include "plugincontroller.h"
#include "mainwindow.h"
#include "textdocument.h"

#include <util/objectlist.h>

using namespace KDevelop;

namespace {

KTextEditor::MainWindow *toKteWrapper(KParts::MainWindow *window)
{
    if (auto mainWindow = qobject_cast<KDevelop::MainWindow*>(window)) {
        return mainWindow->kateWrapper() ? mainWindow->kateWrapper()->interface() : nullptr;
    } else {
        return nullptr;
    }
}

KTextEditor::View *toKteView(Sublime::View *view)
{
    if (auto textView = qobject_cast<KDevelop::TextView*>(view)) {
        return textView->textView();
    } else {
        return nullptr;
    }
}

class ToolViewFactory;

/**
 * This HACK is required to massage the KTextEditor plugin API into the
 * GUI concepts we apply in KDevelop. Kate does not allow the user to
 * delete tool views and then readd them. We do. To support our use case
 * we prevent the widget we return to KTextEditor plugins from
 * MainWindow::createToolView from getting destroyed. This widget class
 * unsets the parent of the so called container in its dtor. The
 * ToolViewFactory handles the ownership and destroys the kate widget
 * as needed.
 */
class KeepAliveWidget : public QWidget
{
    Q_OBJECT
public:
    explicit KeepAliveWidget(ToolViewFactory *factory, QWidget *parent = nullptr)
        : QWidget(parent)
        , m_factory(factory)
    {
    }

    ~KeepAliveWidget() override;

private:
    ToolViewFactory* const m_factory;
};

class ToolViewFactory : public QObject, public KDevelop::IToolViewFactory
{
    Q_OBJECT
public:
    ToolViewFactory(const QString &text, const QIcon &icon, const QString &identifier,
                    KTextEditor::MainWindow::ToolViewPosition pos)
        : m_text(text)
        , m_icon(icon)
        , m_identifier(identifier)
        , m_container(new QWidget)
        , m_pos(pos)
    {
        m_container->setLayout(new QVBoxLayout);
    }

    ~ToolViewFactory() override
    {
        delete m_container;
    }

    QWidget *create(QWidget *parent = nullptr) override
    {
        auto widget = new KeepAliveWidget(this, parent);
        widget->setWindowTitle(m_text);
        widget->setWindowIcon(m_icon);
        widget->setLayout(new QVBoxLayout);
        widget->layout()->addWidget(m_container);
        widget->addActions(m_container->actions());
        return widget;
    }

    Qt::DockWidgetArea defaultPosition() override
    {
        switch (m_pos) {
            case KTextEditor::MainWindow::Left:
                return Qt::LeftDockWidgetArea;
            case KTextEditor::MainWindow::Right:
                return Qt::RightDockWidgetArea;
            case KTextEditor::MainWindow::Top:
                return Qt::TopDockWidgetArea;
            case KTextEditor::MainWindow::Bottom:
                return Qt::BottomDockWidgetArea;
        }
        Q_UNREACHABLE();
    }

    QString id() const override
    {
        return m_identifier;
    }

    QWidget *container() const
    {
        return m_container;
    }

private:
    const QString m_text;
    const QIcon m_icon;
    const QString m_identifier;
    QPointer<QWidget> m_container;
    const KTextEditor::MainWindow::ToolViewPosition m_pos;
    friend class KeepAliveWidget;
};

KeepAliveWidget::~KeepAliveWidget()
{
    // if the container is still valid, unparent it to prevent it from getting deleted
    // this happens when the user removes a tool view
    // on shutdown, the container does get deleted, thus we must guard against that.
    if (m_factory->container()) {
        Q_ASSERT(m_factory->container()->parentWidget() == this);
        m_factory->container()->setParent(nullptr);
    }
}

}

namespace KTextEditorIntegration {

Application::Application(QObject *parent)
    : QObject(parent)
{
}

Application::~Application()
{
    KTextEditor::Editor::instance()->setApplication(nullptr);
}

KTextEditor::MainWindow *Application::activeMainWindow() const
{
    return toKteWrapper(Core::self()->uiController()->activeMainWindow());
}

QList<KTextEditor::MainWindow *> Application::mainWindows() const
{
    return {activeMainWindow()};
}

bool Application::closeDocument(KTextEditor::Document *document) const
{
    const auto& openDocuments = Core::self()->documentControllerInternal()->openDocuments();
    for (auto doc : openDocuments) {
        if (doc->textDocument() == document) {
            return doc->close();
        }
    }
    return false;
}

KTextEditor::Plugin *Application::plugin(const QString &id) const
{
    auto kdevPlugin = Core::self()->pluginController()->loadPlugin(id);
    const auto plugin = dynamic_cast<Plugin*>(kdevPlugin);
    return plugin ? plugin->interface() : nullptr;
}

QList<KTextEditor::Document *> Application::documents()
{
    QList<KTextEditor::Document *> l;
    const auto openDocuments = Core::self()->documentControllerInternal()->openDocuments();
    l.reserve(openDocuments.size());
    for (auto* d : openDocuments) {
        l << d->textDocument();
    }
    return l;
}

KTextEditor::Document *Application::openUrl(const QUrl &url, const QString &encoding)
{
    Q_UNUSED(encoding);

    auto documentController = Core::self()->documentControllerInternal();
    auto doc = url.isEmpty() ? documentController->openDocumentFromText(QString()) : documentController->openDocument(url);
    return doc->textDocument();
}

MainWindow::MainWindow(KDevelop::MainWindow *mainWindow)
    : QObject(mainWindow)
    , m_mainWindow(mainWindow)
    , m_interface(new KTextEditor::MainWindow(this))
{
    connect(mainWindow, &Sublime::MainWindow::viewAdded, this, [this] (Sublime::View *view) {
        if (auto kteView = toKteView(view)) {
            emit m_interface->viewCreated(kteView);
        }
    });
    connect(mainWindow, &Sublime::MainWindow::activeViewChanged, this, [this] (Sublime::View *view) {
        auto kteView = toKteView(view);
        emit m_interface->viewChanged(kteView);

        if (auto viewBar = m_viewBars.value(kteView)) {
            m_mainWindow->viewBarContainer()->setCurrentViewBar(viewBar);
        }
    });
}

MainWindow::~MainWindow() = default;

QWidget *MainWindow::createToolView(KTextEditor::Plugin* plugin, const QString &identifier,
                                    KTextEditor::MainWindow::ToolViewPosition pos,
                                    const QIcon &icon, const QString &text)
{
    auto factory = new ToolViewFactory(text, icon, identifier, pos);
    Core::self()->uiController()->addToolView(text, factory);
    connect(plugin, &QObject::destroyed, this, [=] {
        Core::self()->uiController()->removeToolView(factory);
    });
    return factory->container();
}

KXMLGUIFactory *MainWindow::guiFactory() const
{
    return m_mainWindow->guiFactory();
}

QWidget *MainWindow::window() const
{
    return m_mainWindow;
}

QList<KTextEditor::View *> MainWindow::views() const
{
    QList<KTextEditor::View *> kteViews;
    const auto areas = m_mainWindow->areas();
    for (auto* area : areas) {
        const auto views = area->views();
        for (auto* view : views) {
            if (auto kteView = toKteView(view)) {
                kteViews << kteView;
            }
        }
    }
    return kteViews;
}

KTextEditor::View *MainWindow::activeView() const
{
    return toKteView(m_mainWindow->activeView());
}

KTextEditor::View *MainWindow::activateView(KTextEditor::Document *doc)
{
    const auto areas = m_mainWindow->areas();
    for (auto* area : areas) {
        const auto views = area->views();
        for (auto* view : views) {
            if (auto kteView = toKteView(view)) {
                if (kteView->document() == doc) {
                    m_mainWindow->activateView(view);
                    return kteView;
                }
            }
        }
    }

    return activeView();
}

QObject *MainWindow::pluginView(const QString &id) const
{
    return m_pluginViews.value(id);
}

QWidget *MainWindow::createViewBar(KTextEditor::View *view)
{
    Q_UNUSED(view);

    // we reuse the central view bar for every view
    return m_mainWindow->viewBarContainer();
}

void MainWindow::deleteViewBar(KTextEditor::View *view)
{
    auto viewBar = m_viewBars.take(view);
    m_mainWindow->viewBarContainer()->removeViewBar(viewBar);
    delete viewBar;
}

void MainWindow::showViewBar(KTextEditor::View *view)
{
    auto viewBar = m_viewBars.value(view);
    Q_ASSERT(viewBar);

    m_mainWindow->viewBarContainer()->showViewBar(viewBar);
}

void MainWindow::hideViewBar(KTextEditor::View *view)
{
    auto viewBar = m_viewBars.value(view);
    Q_ASSERT(viewBar);
    m_mainWindow->viewBarContainer()->hideViewBar(viewBar);
}

void MainWindow::addWidgetToViewBar(KTextEditor::View *view, QWidget *widget)
{
    Q_ASSERT(widget);
    m_viewBars[view] = widget;

    m_mainWindow->viewBarContainer()->addViewBar(widget);
}

KTextEditor::View *MainWindow::openUrl(const QUrl &url, const QString &encoding)
{
    return activateView(KTextEditor::Editor::instance()->application()->openUrl(url, encoding));
}

bool MainWindow::showToolView(QWidget *widget)
{
    if (widget->parentWidget()) {
        Core::self()->uiController()->raiseToolView(widget->parentWidget());
        return true;
    }
    return false;
}

KTextEditor::MainWindow *MainWindow::interface() const
{
    return m_interface;
}

void MainWindow::addPluginView(const QString &id, QObject *view)
{
    m_pluginViews.insert(id, view);
    emit m_interface->pluginViewCreated(id, view);
}

void MainWindow::removePluginView(const QString &id)
{
    auto view = m_pluginViews.take(id).data();
    delete view;
    emit m_interface->pluginViewDeleted(id, view);
}

Plugin::Plugin(KTextEditor::Plugin *plugin, QObject *parent)
    : IPlugin({}, parent)
    , m_plugin(plugin)
    , m_tracker(new ObjectListTracker(ObjectListTracker::CleanupWhenDone, this))
{
}

Plugin::~Plugin() = default;

void Plugin::unload()
{
    if (auto mainWindow = KTextEditor::Editor::instance()->application()->activeMainWindow()) {
        auto integration = qobject_cast<MainWindow*>(mainWindow->parent());
        if (integration) {
            integration->removePluginView(pluginId());
        }
    }
    m_tracker->deleteAll();
    delete m_plugin;
}

KXMLGUIClient *Plugin::createGUIForMainWindow(Sublime::MainWindow* window)
{
    auto ret = IPlugin::createGUIForMainWindow(window);
    auto mainWindow = qobject_cast<KDevelop::MainWindow*>(window);
    Q_ASSERT(mainWindow);

    auto wrapper = mainWindow->kateWrapper();
    auto view = m_plugin->createView(wrapper->interface());
    wrapper->addPluginView(pluginId(), view);
    // ensure that unloading the plugin kills all views
    m_tracker->append(view);

    return ret;
}

KTextEditor::Plugin *Plugin::interface() const
{
    return m_plugin.data();
}

QString Plugin::pluginId() const
{
    return Core::self()->pluginController()->pluginInfo(this).pluginId();
}

void initialize()
{
    auto app = new KTextEditor::Application(new Application(Core::self()));
    KTextEditor::Editor::instance()->setApplication(app);
}

void MainWindow::splitView(Qt::Orientation orientation)
{
    m_mainWindow->split(orientation);
}

}

#include "ktexteditorpluginintegration.moc"
