/*

 * Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>

 * Copyright (c) 2023, Sam Atkins <atkinssj@serenityos.org>

 *

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

 */

#include <LibURL/Origin.h>

#include <LibWeb/Bindings/HTMLIFrameElementPrototype.h>

#include <LibWeb/DOM/Document.h>

#include <LibWeb/DOM/Event.h>

#include <LibWeb/HTML/BrowsingContext.h>

#include <LibWeb/HTML/HTMLIFrameElement.h>

#include <LibWeb/HTML/Navigable.h>

#include <LibWeb/HTML/Parser/HTMLParser.h>

#include <LibWeb/Layout/FrameBox.h>

namespace Web::HTML {

JS_DEFINE_ALLOCATOR(HTMLIFrameElement);

HTMLIFrameElement::HTMLIFrameElement(DOM::Document& document, DOM::QualifiedName qualified_name)

    : NavigableContainer(document, move(qualified_name))

{

}

HTMLIFrameElement::~HTMLIFrameElement() = default;

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

{

    Base::initialize(realm);

    WEB_SET_PROTOTYPE_FOR_INTERFACE(HTMLIFrameElement);

}

JS::GCPtr<Layout::Node> HTMLIFrameElement::create_layout_node(NonnullRefPtr<CSS::StyleProperties> style)

{

    return heap().allocate_without_realm<Layout::FrameBox>(document(), *this, move(style));

}

void HTMLIFrameElement::attribute_changed(FlyString const& name, Optional<String> const& old_value, Optional<String> const& value)

{

    HTMLElement::attribute_changed(name, old_value, value);

    // https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element:process-the-iframe-attributes-2

    // https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element:process-the-iframe-attributes-3

    // Whenever an iframe element with a non-null content navigable has its srcdoc attribute set, changed, or removed,

    // the user agent must process the iframe attributes.

    // Similarly, whenever an iframe element with a non-null content navigable but with no srcdoc attribute specified

    // has its src attribute set, changed, or removed, the user agent must process the iframe attributes.

    if (m_content_navigable) {

        if (name == AttributeNames::srcdoc || (name == AttributeNames::src && !has_attribute(AttributeNames::srcdoc)))

            process_the_iframe_attributes();

    }

}

// https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element:the-iframe-element-6

void HTMLIFrameElement::inserted()

{

    HTMLElement::inserted();

    // The iframe HTML element insertion steps, given insertedNode, are:

    // 1. If insertedNode's shadow-including root's browsing context is null, then return.

    if (!is<DOM::Document>(shadow_including_root()))

        return;

    DOM::Document& document = verify_cast<DOM::Document>(shadow_including_root());

    // NOTE: The check for "not fully active" is to prevent a crash on the dom/nodes/node-appendchild-crash.html WPT test.

    if (!document.browsing_context() || !document.is_fully_active())

        return;

    // 2. Create a new child navigable for insertedNode.

    MUST(create_new_child_navigable(JS::create_heap_function(realm().heap(), [this] {

        // FIXME: 3. If insertedNode has a sandbox attribute, then parse the sandboxing directive given the attribute's

        //           value and insertedNode's iframe sandboxing flag set.

        // 4. Process the iframe attributes for insertedNode, with initialInsertion set to true.

        process_the_iframe_attributes(true);

        set_content_navigable_initialized();

    })));

}

// https://html.spec.whatwg.org/multipage/iframe-embed-object.html#process-the-iframe-attributes

void HTMLIFrameElement::process_the_iframe_attributes(bool initial_insertion)

{

    if (!content_navigable())

        return;

    // 1. If element's srcdoc attribute is specified, then:

    if (has_attribute(HTML::AttributeNames::srcdoc)) {

        // 1. Set element's current navigation was lazy loaded boolean to false.

        set_current_navigation_was_lazy_loaded(false);

        // 2. If the will lazy load element steps given element return true, then:

        if (will_lazy_load_element()) {

            // 1. Set element's lazy load resumption steps to the rest of this algorithm starting with the step labeled navigate to the srcdoc resource.

            set_lazy_load_resumption_steps([this]() {

                // 3. Navigate to the srcdoc resource: navigate an iframe or frame given element, about:srcdoc, the empty string, and the value of element's srcdoc attribute.

                navigate_an_iframe_or_frame(URL::URL("about:srcdoc"sv), ReferrerPolicy::ReferrerPolicy::EmptyString, get_attribute(HTML::AttributeNames::srcdoc));

                // FIXME: The resulting Document must be considered an iframe srcdoc document.

            });

            // 2. Set element's current navigation was lazy loaded boolean to true.

            set_current_navigation_was_lazy_loaded(true);

            // 3. Start intersection-observing a lazy loading element for element.

            document().start_intersection_observing_a_lazy_loading_element(*this);

            // 4. Return.

            return;

        }

        // 3. Navigate to the srcdoc resource: navigate an iframe or frame given element, about:srcdoc, the empty string, and the value of element's srcdoc attribute.

        navigate_an_iframe_or_frame(URL::URL("about:srcdoc"sv), ReferrerPolicy::ReferrerPolicy::EmptyString, get_attribute(HTML::AttributeNames::srcdoc));

        // FIXME: The resulting Document must be considered an iframe srcdoc document.

        return;

    }

    // 1. Let url be the result of running the shared attribute processing steps for iframe and frame elements given element and initialInsertion.

    auto url = shared_attribute_processing_steps_for_iframe_and_frame(initial_insertion);

    // 2. If url is null, then return.

    if (!url.has_value()) {

        return;

    }

    // 3. If url matches about:blank and initialInsertion is true, then:

    if (url_matches_about_blank(*url) && initial_insertion) {

        // 1. Run the iframe load event steps given element.

        run_iframe_load_event_steps(*this);

        // 2. Return.

        return;

    }

    // 4. Let referrerPolicy be the current state of element's referrerpolicy content attribute.

    auto referrer_policy = ReferrerPolicy::from_string(get_attribute_value(HTML::AttributeNames::referrerpolicy)).value_or(ReferrerPolicy::ReferrerPolicy::EmptyString);

    // 5. Set element's current navigation was lazy loaded boolean to false.

    set_current_navigation_was_lazy_loaded(false);

    // 6. If the will lazy load element steps given element return true, then:

    if (will_lazy_load_element()) {

        // 1. Set element's lazy load resumption steps to the rest of this algorithm starting with the step labeled navigate.

        set_lazy_load_resumption_steps([this, url, referrer_policy]() {

            // 7. Navigate: navigate an iframe or frame given element, url, and referrerPolicy.

            navigate_an_iframe_or_frame(*url, referrer_policy);

        });

        // 2. Set element's current navigation was lazy loaded boolean to true.

        set_current_navigation_was_lazy_loaded(true);

        // 3. Start intersection-observing a lazy loading element for element.

        document().start_intersection_observing_a_lazy_loading_element(*this);

        // 4. Return.

        return;

    }

    // 7. Navigate: navigate an iframe or frame given element, url, and referrerPolicy.

    navigate_an_iframe_or_frame(*url, referrer_policy);

}

// https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element:the-iframe-element-7

void HTMLIFrameElement::removed_from(DOM::Node* node)

{

    HTMLElement::removed_from(node);

    // When an iframe element is removed from a document, the user agent must destroy the nested navigable of the element.

    destroy_the_child_navigable();

}

// https://html.spec.whatwg.org/multipage/iframe-embed-object.html#iframe-load-event-steps

void run_iframe_load_event_steps(HTML::HTMLIFrameElement& element)

{

    // FIXME: 1. Assert: element's content navigable is not null.

    if (!element.content_navigable()) {

        // FIXME: For some reason, we sometimes end up here in the middle of SunSpider.

        dbgln("FIXME: run_iframe_load_event_steps called with null nested browsing context");

        return;

    }

    // 2. Let childDocument be element's content navigable's active document.

    [[maybe_unused]] auto child_document = element.content_navigable()->active_document();

    // FIXME: 3. If childDocument has its mute iframe load flag set, then return.

    // FIXME: 4. Set childDocument's iframe load in progress flag.

    // 5. Fire an event named load at element.

    element.dispatch_event(DOM::Event::create(element.realm(), HTML::EventNames::load));

    // FIXME: 6. Unset childDocument's iframe load in progress flag.

}

// https://html.spec.whatwg.org/multipage/interaction.html#dom-tabindex

i32 HTMLIFrameElement::default_tab_index_value() const

{

    // See the base function for the spec comments.

    return 0;

}

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

{

    Base::visit_edges(visitor);

    visit_lazy_loading_element(visitor);

}

void HTMLIFrameElement::set_current_navigation_was_lazy_loaded(bool value)

{

    m_current_navigation_was_lazy_loaded = value;

    // An iframe element whose current navigation was lazy loaded boolean is false potentially delays the load event.

    // https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element:potentially-delays-the-load-event

    set_potentially_delays_the_load_event(!value);

}

}