/*

 * Copyright (c) 2020-2022, Andreas Kling <kling@serenityos.org>

 * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>

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

 *

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

 */

#include <LibURL/Origin.h>

#include <LibWeb/Bindings/MainThreadVM.h>

#include <LibWeb/DOM/Document.h>

#include <LibWeb/DOM/Event.h>

#include <LibWeb/Fetch/Infrastructure/HTTP/Requests.h>

#include <LibWeb/HTML/BrowsingContext.h>

#include <LibWeb/HTML/BrowsingContextGroup.h>

#include <LibWeb/HTML/DocumentState.h>

#include <LibWeb/HTML/HTMLIFrameElement.h>

#include <LibWeb/HTML/Navigable.h>

#include <LibWeb/HTML/NavigableContainer.h>

#include <LibWeb/HTML/NavigationParams.h>

#include <LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h>

#include <LibWeb/HTML/TraversableNavigable.h>

#include <LibWeb/HTML/Window.h>

#include <LibWeb/HighResolutionTime/TimeOrigin.h>

#include <LibWeb/Page/Page.h>

namespace Web::HTML {

HashTable<NavigableContainer*>& NavigableContainer::all_instances()

{

    static HashTable<NavigableContainer*> set;

    return set;

}

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

    : HTMLElement(document, move(qualified_name))

{

    all_instances().set(this);

}

NavigableContainer::~NavigableContainer()

{

    all_instances().remove(this);

}

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

{

    Base::visit_edges(visitor);

    visitor.visit(m_content_navigable);

}

JS::GCPtr<NavigableContainer> NavigableContainer::navigable_container_with_content_navigable(JS::NonnullGCPtr<Navigable> navigable)

{

    for (auto* navigable_container : all_instances()) {

        if (navigable_container->content_navigable() == navigable)

            return navigable_container;

    }

    return nullptr;

}

// https://html.spec.whatwg.org/multipage/document-sequences.html#create-a-new-child-navigable

WebIDL::ExceptionOr<void> NavigableContainer::create_new_child_navigable(JS::GCPtr<JS::HeapFunction<void()>> after_session_history_update)

{

    // 1. Let parentNavigable be element's node navigable.

    auto parent_navigable = navigable();

    // 2. Let group be element's node document's browsing context's top-level browsing context's group.

    VERIFY(document().browsing_context());

    auto group = document().browsing_context()->top_level_browsing_context()->group();

    VERIFY(group);

    // 3. Let browsingContext and document be the result of creating a new browsing context and document given element's node document, element, and group.

    auto& page = document().page();

    auto [browsing_context, document] = TRY(BrowsingContext::create_a_new_browsing_context_and_document(page, this->document(), *this, *group));

    // 4. Let targetName be null.

    Optional<String> target_name;

    // 5. If element has a name content attribute, then set targetName to the value of that attribute.

    if (name().has_value())

        target_name = name().value().to_string();

    // 6. Let documentState be a new document state, with

    //  - document: document

    //  - initiator origin: document's origin

    //  - origin: document's origin

    //  - navigable target name: targetName

    //  - about base URL: document's about base URL

    JS::NonnullGCPtr<DocumentState> document_state = *heap().allocate_without_realm<HTML::DocumentState>();

    document_state->set_document(document);

    document_state->set_initiator_origin(document->origin());

    document_state->set_origin(document->origin());

    if (target_name.has_value())

        document_state->set_navigable_target_name(*target_name);

    document_state->set_about_base_url(document->about_base_url());

    // 7. Let navigable be a new navigable.

    JS::NonnullGCPtr<Navigable> navigable = *heap().allocate_without_realm<Navigable>(page);

    // 8. Initialize the navigable navigable given documentState and parentNavigable.

    TRY_OR_THROW_OOM(vm(), navigable->initialize_navigable(document_state, parent_navigable));

    // 9. Set element's content navigable to navigable.

    m_content_navigable = navigable;

    // 10. Let historyEntry be navigable's active session history entry.

    auto history_entry = navigable->active_session_history_entry();

    // 11. Let traversable be parentNavigable's traversable navigable.

    auto traversable = parent_navigable->traversable_navigable();

    // 12. Append the following session history traversal steps to traversable:

    traversable->append_session_history_traversal_steps(JS::create_heap_function(heap(), [traversable, navigable, parent_navigable, history_entry, after_session_history_update] {

        // 1. Let parentDocState be parentNavigable's active session history entry's document state.

        auto parent_doc_state = parent_navigable->active_session_history_entry()->document_state();

        // 2. Let parentNavigableEntries be the result of getting session history entries for parentNavigable.

        auto parent_navigable_entries = parent_navigable->get_session_history_entries();

        // 3. Let targetStepSHE be the first session history entry in parentNavigableEntries whose document state equals parentDocState.

        auto target_step_she = *parent_navigable_entries.find_if([parent_doc_state](auto& entry) {

            return entry->document_state() == parent_doc_state;

        });

        // 4. Set historyEntry's step to targetStepSHE's step.

        history_entry->set_step(target_step_she->step());

        // 5. Let nestedHistory be a new nested history whose id is navigable's id and entries list is « historyEntry ».

        DocumentState::NestedHistory nested_history {

            .id = navigable->id(),

            .entries { *history_entry },

        };

        // 6. Append nestedHistory to parentDocState's nested histories.

        parent_doc_state->nested_histories().append(move(nested_history));

        // 7. Update for navigable creation/destruction given traversable

        traversable->update_for_navigable_creation_or_destruction();

        if (after_session_history_update) {

            after_session_history_update->function()();

        }

    }));

    return {};

}

// https://html.spec.whatwg.org/multipage/browsers.html#concept-bcc-content-document

const DOM::Document* NavigableContainer::content_document() const

{

    // 1. If container's content navigable is null, then return null.

    if (m_content_navigable == nullptr)

        return nullptr;

    // 2. Let document be container's content navigable's active document.

    auto document = m_content_navigable->active_document();

    // 4. If document's origin and container's node document's origin are not same origin-domain, then return null.

    if (!document->origin().is_same_origin_domain(m_document->origin()))

        return nullptr;

    // 5. Return document.

    return document;

}

DOM::Document const* NavigableContainer::content_document_without_origin_check() const

{

    if (!m_content_navigable)

        return nullptr;

    return m_content_navigable->active_document();

}

// https://html.spec.whatwg.org/multipage/embedded-content-other.html#dom-media-getsvgdocument

const DOM::Document* NavigableContainer::get_svg_document() const

{

    // 1. Let document be this element's content document.

    auto const* document = content_document();

    // 2. If document is non-null and was created by the page load processing model for XML files section because the computed type of the resource in the navigate algorithm was image/svg+xml, then return document.

    if (document && document->content_type() == "image/svg+xml"sv)

        return document;

    // 3. Return null.

    return nullptr;

}

HTML::WindowProxy* NavigableContainer::content_window()

{

    if (!m_content_navigable)

        return nullptr;

    return m_content_navigable->active_window_proxy();

}

// https://html.spec.whatwg.org/multipage/iframe-embed-object.html#shared-attribute-processing-steps-for-iframe-and-frame-elements

Optional<URL::URL> NavigableContainer::shared_attribute_processing_steps_for_iframe_and_frame(bool initial_insertion)

{

    // 1. Let url be the URL record about:blank.

    auto url = URL::URL("about:blank");

    // 2. If element has a src attribute specified, and its value is not the empty string,

    //    then parse the value of that attribute relative to element's node document.

    //    If this is successful, then set url to the resulting URL record.

    auto src_attribute_value = get_attribute_value(HTML::AttributeNames::src);

    if (!src_attribute_value.is_empty()) {

        auto parsed_src = document().parse_url(src_attribute_value);

        if (parsed_src.is_valid())

            url = parsed_src;

    }

    // 3. If the inclusive ancestor navigables of element's node navigable contains a navigable

    //    whose active document's URL equals url with exclude fragments set to true, then return null.

    if (m_content_navigable) {

        for (auto const& navigable : document().inclusive_ancestor_navigables()) {

            VERIFY(navigable->active_document());

            if (navigable->active_document()->url().equals(url, URL::ExcludeFragment::Yes))

                return {};

        }

    }

    // 4. If url matches about:blank and initialInsertion is true, then perform the URL and history update steps given element's content navigable's active document and url.

    if (url_matches_about_blank(url) && initial_insertion) {

        auto& document = *m_content_navigable->active_document();

        perform_url_and_history_update_steps(document, url);

    }

    // 5. Return url.

    return url;

}

// https://html.spec.whatwg.org/multipage/iframe-embed-object.html#navigate-an-iframe-or-frame

void NavigableContainer::navigate_an_iframe_or_frame(URL::URL url, ReferrerPolicy::ReferrerPolicy referrer_policy, Optional<String> srcdoc_string)

{

    // 1. Let historyHandling be "auto".

    auto history_handling = Bindings::NavigationHistoryBehavior::Auto;

    // 2. If element's content navigable's active document is not completely loaded, then set historyHandling to "replace".

    if (m_content_navigable->active_document() && !m_content_navigable->active_document()->is_completely_loaded()) {

        history_handling = Bindings::NavigationHistoryBehavior::Replace;

    }

    // FIXME: 3. If element is an iframe, then set element's pending resource-timing start time to the current high resolution

    //           time given element's node document's relevant global object.

    // 4. Navigate element's content navigable to url using element's node document, with historyHandling set to historyHandling,

    //    referrerPolicy set to referrerPolicy, and documentResource set to scrdocString.

    Variant<Empty, String, POSTResource> document_resource = Empty {};

    if (srcdoc_string.has_value())

        document_resource = srcdoc_string.value();

    MUST(m_content_navigable->navigate({ .url = url,

        .source_document = document(),

        .document_resource = document_resource,

        .history_handling = history_handling,

        .referrer_policy = referrer_policy }));

}

// https://html.spec.whatwg.org/multipage/document-sequences.html#destroy-a-child-navigable

void NavigableContainer::destroy_the_child_navigable()

{

    // 1. Let navigable be container's content navigable.

    auto navigable = content_navigable();

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

    if (!navigable)

        return;

    // Not in the spec:

    // Setting container's content navigable makes document *not* be "fully active".

    // Therefore, it is moved to run in afterAllDestruction callback of "destroy a document and its descendants"

    // when all queued tasks are done.

    // "Has been destroyed" flag is used instead to check whether navigable is already destroyed.

    if (navigable->has_been_destroyed())

        return;

    navigable->set_has_been_destroyed();

    // FIXME: 4. Inform the navigation API about child navigable destruction given navigable.

    // 5. Destroy a document and its descendants given navigable's active document.

    navigable->active_document()->destroy_a_document_and_its_descendants(JS::create_heap_function(heap(), [this, navigable] {

        // 3. Set container's content navigable to null.

        m_content_navigable = nullptr;

        // Not in the spec:

        HTML::all_navigables().remove(navigable);

        // 6. Let parentDocState be container's node navigable's active session history entry's document state.

        auto parent_doc_state = this->navigable()->active_session_history_entry()->document_state();

        // 7. Remove the nested history from parentDocState's nested histories whose id equals navigable's id.

        parent_doc_state->nested_histories().remove_all_matching([&](auto& nested_history) {

            return navigable->id() == nested_history.id;

        });

        // 8. Let traversable be container's node navigable's traversable navigable.

        auto traversable = this->navigable()->traversable_navigable();

        // 9. Append the following session history traversal steps to traversable:

        traversable->append_session_history_traversal_steps(JS::create_heap_function(heap(), [traversable] {

            // 1. Update for navigable creation/destruction given traversable.

            traversable->update_for_navigable_creation_or_destruction();

        }));

    }));

}

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

bool NavigableContainer::currently_delays_the_load_event() const

{

    if (!m_content_navigable_initialized)

        return true;

    if (!m_potentially_delays_the_load_event)

        return false;

    // If an element type potentially delays the load event, then for each element element of that type,

    // the user agent must delay the load event of element's node document if element's content navigable is non-null

    // and any of the following are true:

    if (!m_content_navigable)

        return false;

    // - element's content navigable's active document is not ready for post-load tasks;

    if (!m_content_navigable->active_document()->ready_for_post_load_tasks())

        return true;

    // - element's content navigable's is delaying load events is true; or

    if (m_content_navigable->is_delaying_load_events())

        return true;

    // - anything is delaying the load event of element's content navigable's active document.

    if (m_content_navigable->active_document()->anything_is_delaying_the_load_event())

        return true;

    return false;

}

}