/*
 * Copyright (C) 2016 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. ``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
 * 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.
 */

#include "config.h"
#include "SimulatedClick.h"

#include "DOMRect.h"
#include "DataTransfer.h"
#include "Element.h"
#include "EventNames.h"
#include "MouseEvent.h"
#include <wtf/IsoMallocInlines.h>
#include <wtf/NeverDestroyed.h>

namespace WebCore {

class SimulatedMouseEvent final : public MouseEvent {
    WTF_MAKE_ISO_ALLOCATED_INLINE(SimulatedMouseEvent);
public:
    static Ref<SimulatedMouseEvent> create(const AtomicString& eventType, RefPtr<WindowProxy>&& view, RefPtr<Event>&& underlyingEvent, Element& target, SimulatedClickSource source)
    {
        return adoptRef(*new SimulatedMouseEvent(eventType, WTFMove(view), WTFMove(underlyingEvent), target, source));
    }

private:
    SimulatedMouseEvent(const AtomicString& eventType, RefPtr<WindowProxy>&& view, RefPtr<Event>&& underlyingEvent, Element& target, SimulatedClickSource source)
        : MouseEvent(eventType, CanBubble::Yes, IsCancelable::Yes, IsComposed::Yes,
            underlyingEvent ? underlyingEvent->timeStamp() : MonotonicTime::now(), WTFMove(view), /* detail */ 0,
            { }, { }, { }, modifiersFromUnderlyingEvent(underlyingEvent), 0, 0, nullptr, 0, 0, nullptr, IsSimulated::Yes,
            source == SimulatedClickSource::UserAgent ? IsTrusted::Yes : IsTrusted::No)
    {
        setUnderlyingEvent(underlyingEvent.get());

        if (is<MouseEvent>(this->underlyingEvent())) {
            MouseEvent& mouseEvent = downcast<MouseEvent>(*this->underlyingEvent());
            m_screenLocation = mouseEvent.screenLocation();
            initCoordinates(mouseEvent.clientLocation());
        } else if (source == SimulatedClickSource::UserAgent) {
            // If there is no underlying event, we only populate the coordinates for events coming
            // from the user agent (e.g. accessibility). For those coming from JavaScript (e.g.
            // (element.click()), the coordinates will be 0, similarly to Firefox and Chrome.
            // Note that the call to screenRect() causes a synchronous IPC with the UI process.
            m_screenLocation = target.screenRect().center();
            initCoordinates(LayoutPoint(target.boundingClientRect().center()));
        }
    }

    static OptionSet<Modifier> modifiersFromUnderlyingEvent(const RefPtr<Event>& underlyingEvent)
    {
        UIEventWithKeyState* keyStateEvent = findEventWithKeyState(underlyingEvent.get());
        if (!keyStateEvent)
            return { };
        return keyStateEvent->modifierKeys();
    }
};

static void simulateMouseEvent(const AtomicString& eventType, Element& element, Event* underlyingEvent, SimulatedClickSource source)
{
    element.dispatchEvent(SimulatedMouseEvent::create(eventType, element.document().windowProxy(), underlyingEvent, element, source));
}

void simulateClick(Element& element, Event* underlyingEvent, SimulatedClickMouseEventOptions mouseEventOptions, SimulatedClickVisualOptions visualOptions, SimulatedClickSource creationOptions)
{
    if (element.isDisabledFormControl())
        return;

    static NeverDestroyed<HashSet<Element*>> elementsDispatchingSimulatedClicks;
    if (!elementsDispatchingSimulatedClicks.get().add(&element).isNewEntry)
        return;

    if (mouseEventOptions == SendMouseOverUpDownEvents)
        simulateMouseEvent(eventNames().mouseoverEvent, element, underlyingEvent, creationOptions);

    if (mouseEventOptions != SendNoEvents)
        simulateMouseEvent(eventNames().mousedownEvent, element, underlyingEvent, creationOptions);
    element.setActive(true, visualOptions == ShowPressedLook);
    if (mouseEventOptions != SendNoEvents)
        simulateMouseEvent(eventNames().mouseupEvent, element, underlyingEvent, creationOptions);
    element.setActive(false);

    simulateMouseEvent(eventNames().clickEvent, element, underlyingEvent, creationOptions);

    elementsDispatchingSimulatedClicks.get().remove(&element);
}

} // namespace WebCore