/*

 * Copyright (c) 2023, Andreas Kling <kling@serenityos.org>

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#include <LibWeb/Bindings/Intrinsics.h>

#include <LibWeb/Bindings/VisualViewportPrototype.h>

#include <LibWeb/CSS/VisualViewport.h>

#include <LibWeb/DOM/Document.h>

#include <LibWeb/DOM/EventDispatcher.h>

#include <LibWeb/DOM/IDLEventListener.h>

#include <LibWeb/HTML/EventHandler.h>

#include <LibWeb/HTML/EventNames.h>

namespace Web::CSS {

JS_DEFINE_ALLOCATOR(VisualViewport);

JS::NonnullGCPtr<VisualViewport> VisualViewport::create(DOM::Document& document)

{

    return document.heap().allocate<VisualViewport>(document.realm(), document);

}

VisualViewport::VisualViewport(DOM::Document& document)

    : DOM::EventTarget(document.realm())

    , m_document(document)

{

}

void VisualViewport::initialize(JS::Realm& realm)

{

    Base::initialize(realm);

    WEB_SET_PROTOTYPE_FOR_INTERFACE(VisualViewport);

}

void VisualViewport::visit_edges(Cell::Visitor& visitor)

{

    Base::visit_edges(visitor);

    visitor.visit(m_document);

}

// https://drafts.csswg.org/cssom-view/#dom-visualviewport-offsetleft

double VisualViewport::offset_left() const

{

    // 1. If the visual viewport’s associated document is not fully active, return 0.

    if (!m_document->is_fully_active())

        return 0;

    // 2. Otherwise, return the offset of the left edge of the visual viewport from the left edge of the layout viewport.

    VERIFY(m_document->navigable());

    return m_document->viewport_rect().left().to_double();

}

// https://drafts.csswg.org/cssom-view/#dom-visualviewport-offsettop

double VisualViewport::offset_top() const

{

    // 1. If the visual viewport’s associated document is not fully active, return 0.

    if (!m_document->is_fully_active())

        return 0;

    // 2. Otherwise, return the offset of the top edge of the visual viewport from the top edge of the layout viewport.

    VERIFY(m_document->navigable());

    return m_document->viewport_rect().top().to_double();

}

// https://drafts.csswg.org/cssom-view/#dom-visualviewport-pageleft

double VisualViewport::page_left() const

{

    // 1. If the visual viewport’s associated document is not fully active, return 0.

    if (!m_document->is_fully_active())

        return 0;

    // FIXME: 2. Otherwise, return the offset of the left edge of the visual viewport

    //           from the left edge of the initial containing block of the layout viewport’s document.

    return offset_left();

}

// https://drafts.csswg.org/cssom-view/#dom-visualviewport-pagetop

double VisualViewport::page_top() const

{

    // 1. If the visual viewport’s associated document is not fully active, return 0.

    if (!m_document->is_fully_active())

        return 0;

    // FIXME: 2. Otherwise, return the offset of the top edge of the visual viewport

    //           from the top edge of the initial containing block of the layout viewport’s document.

    return offset_top();

}

// https://drafts.csswg.org/cssom-view/#dom-visualviewport-width

double VisualViewport::width() const

{

    // 1. If the visual viewport’s associated document is not fully active, return 0.

    if (!m_document->is_fully_active())

        return 0;

    // 2. Otherwise, return the width of the visual viewport

    //    FIXME: excluding the width of any rendered vertical classic scrollbar that is fixed to the visual viewport.

    VERIFY(m_document->navigable());

    return m_document->viewport_rect().width().to_double();

}

// https://drafts.csswg.org/cssom-view/#dom-visualviewport-height

double VisualViewport::height() const

{

    // 1. If the visual viewport’s associated document is not fully active, return 0.

    if (!m_document->is_fully_active())

        return 0;

    // 2. Otherwise, return the height of the visual viewport

    //    FIXME: excluding the height of any rendered vertical classic scrollbar that is fixed to the visual viewport.

    VERIFY(m_document->navigable());

    return m_document->viewport_rect().height().to_double();

}

// https://drafts.csswg.org/cssom-view/#dom-visualviewport-scale

double VisualViewport::scale() const

{

    // FIXME: Implement.

    return 1;

}

void VisualViewport::set_onresize(WebIDL::CallbackType* event_handler)

{

    set_event_handler_attribute(HTML::EventNames::resize, event_handler);

}

WebIDL::CallbackType* VisualViewport::onresize()

{

    return event_handler_attribute(HTML::EventNames::resize);

}

void VisualViewport::set_onscroll(WebIDL::CallbackType* event_handler)

{

    set_event_handler_attribute(HTML::EventNames::scroll, event_handler);

}

WebIDL::CallbackType* VisualViewport::onscroll()

{

    return event_handler_attribute(HTML::EventNames::scroll);

}

void VisualViewport::set_onscrollend(WebIDL::CallbackType* event_handler)

{

    set_event_handler_attribute(HTML::EventNames::scrollend, event_handler);

}

WebIDL::CallbackType* VisualViewport::onscrollend()

{

    return event_handler_attribute(HTML::EventNames::scrollend);

}

}