/*
 * Copyright (C) 2019 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#if ENABLE(FULLSCREEN_API)

#include "Document.h"
#include "GenericTaskQueue.h"
#include "LayoutRect.h"
#include <wtf/Deque.h>
#include <wtf/RefPtr.h>
#include <wtf/Vector.h>
#include <wtf/WeakHashSet.h>

namespace WebCore {

class RenderFullScreen;
class RenderTreeBuilder;
class RenderStyle;

class FullscreenManager final {
    WTF_MAKE_FAST_ALLOCATED;
public:
    FullscreenManager(Document&);
    ~FullscreenManager();

    Document& document() { return m_document; }
    const Document& document() const { return m_document; }
    Document& topDocument() const { return m_document.topDocument(); }
    Page* page() const { return m_document.page(); }
    Frame* frame() const { return m_document.frame(); }
    Element* documentElement() const { return m_document.documentElement(); }
    bool hasLivingRenderTree() const { return m_document.hasLivingRenderTree(); }
    Document::BackForwardCacheState backForwardCacheState() const { return m_document.backForwardCacheState(); }
    void scheduleFullStyleRebuild() { m_document.scheduleFullStyleRebuild(); }

    // W3C Fullscreen API
    Element* fullscreenElement() const { return !m_fullscreenElementStack.isEmpty() ? m_fullscreenElementStack.last().get() : nullptr; }
    WEBCORE_EXPORT bool isFullscreenEnabled() const;
    WEBCORE_EXPORT void exitFullscreen();

    // Mozilla versions.
    bool isFullscreen() const { return m_fullscreenElement.get(); }
    bool isFullscreenKeyboardInputAllowed() const { return m_fullscreenElement.get() && m_areKeysEnabledInFullscreen; }
    Element* currentFullscreenElement() const { return m_fullscreenElement.get(); }
    WEBCORE_EXPORT void cancelFullscreen();

    enum FullscreenCheckType {
        EnforceIFrameAllowFullscreenRequirement,
        ExemptIFrameAllowFullscreenRequirement,
    };
    void requestFullscreenForElement(Element*, FullscreenCheckType);

    WEBCORE_EXPORT void willEnterFullscreen(Element&);
    WEBCORE_EXPORT void didEnterFullscreen();
    WEBCORE_EXPORT void willExitFullscreen();
    WEBCORE_EXPORT void didExitFullscreen();

    void setFullscreenRenderer(RenderTreeBuilder&, RenderFullScreen&);
    RenderFullScreen* fullscreenRenderer() const;

    void dispatchFullscreenChangeEvents();
    bool fullscreenIsAllowedForElement(Element&) const;
    void fullscreenElementRemoved();

    void adjustFullscreenElementOnNodeRemoval(Node&, Document::NodeRemoval = Document::NodeRemoval::Node);

    WEBCORE_EXPORT bool isAnimatingFullscreen() const;
    WEBCORE_EXPORT void setAnimatingFullscreen(bool);

    WEBCORE_EXPORT bool areFullscreenControlsHidden() const;
    WEBCORE_EXPORT void setFullscreenControlsHidden(bool);

    void clear();
    void emptyEventQueue();

protected:
    friend class Document;

    void dispatchFullscreenChangeOrErrorEvent(Deque<RefPtr<Node>>&, const AtomString& eventName, bool shouldNotifyMediaElement);
    void clearFullscreenElementStack();
    void popFullscreenElementStack();
    void pushFullscreenElementStack(Element&);
    void addDocumentToFullscreenChangeEventQueue(Document&);

private:
    Document& m_document;

    RefPtr<Element> fullscreenOrPendingElement() const { return m_fullscreenElement ? m_fullscreenElement : m_pendingFullscreenElement; }

    RefPtr<Element> m_pendingFullscreenElement;
    RefPtr<Element> m_fullscreenElement;
    Vector<RefPtr<Element>> m_fullscreenElementStack;
    WeakPtr<RenderFullScreen> m_fullscreenRenderer { nullptr };
    GenericTaskQueue<Timer> m_fullscreenTaskQueue;
    Deque<RefPtr<Node>> m_fullscreenChangeEventTargetQueue;
    Deque<RefPtr<Node>> m_fullscreenErrorEventTargetQueue;
    LayoutRect m_savedPlaceholderFrameRect;
    std::unique_ptr<RenderStyle> m_savedPlaceholderRenderStyle;

    bool m_areKeysEnabledInFullscreen { false };
    bool m_isAnimatingFullscreen { false };
    bool m_areFullscreenControlsHidden { false };
};

}

#endif