/*
 * Copyright (c) 2020, the SerenityOS developers.
 * Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <LibWeb/Bindings/MainThreadVM.h>
#include <LibWeb/DOM/DOMImplementation.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/DOM/DocumentType.h>
#include <LibWeb/DOM/ElementFactory.h>
#include <LibWeb/DOM/Text.h>
#include <LibWeb/HTML/Origin.h>
#include <LibWeb/HTML/Window.h>
#include <LibWeb/Namespace.h>

namespace Web::DOM {

JS::NonnullGCPtr<DOMImplementation> DOMImplementation::create(Document& document)
{
    auto& window = document.window();
    return *window.heap().allocate<DOMImplementation>(document.realm(), document);
}

DOMImplementation::DOMImplementation(Document& document)
    : PlatformObject(document.window().cached_web_prototype("DOMImplementation"))
    , m_document(document)
{
}

DOMImplementation::~DOMImplementation() = default;

void DOMImplementation::visit_edges(Cell::Visitor& visitor)
{
    Base::visit_edges(visitor);
    visitor.visit(m_document);
}

// https://dom.spec.whatwg.org/#dom-domimplementation-createdocument
ExceptionOr<JS::NonnullGCPtr<Document>> DOMImplementation::create_document(String const& namespace_, String const& qualified_name, JS::GCPtr<DocumentType> doctype) const
{
    // FIXME: This should specifically be an XML document.
    auto xml_document = Document::create(Bindings::main_thread_internal_window_object());

    xml_document->set_ready_for_post_load_tasks(true);

    JS::GCPtr<Element> element;

    if (!qualified_name.is_empty())
        element = TRY(xml_document->create_element_ns(namespace_, qualified_name /* FIXME: and an empty dictionary */));

    if (doctype)
        xml_document->append_child(*doctype);

    if (element)
        xml_document->append_child(*element);

    xml_document->set_origin(document().origin());

    if (namespace_ == Namespace::HTML)
        xml_document->set_content_type("application/xhtml+xml");
    else if (namespace_ == Namespace::SVG)
        xml_document->set_content_type("image/svg+xml");
    else
        xml_document->set_content_type("application/xml");

    return xml_document;
}

// https://dom.spec.whatwg.org/#dom-domimplementation-createhtmldocument
JS::NonnullGCPtr<Document> DOMImplementation::create_html_document(String const& title) const
{
    auto html_document = Document::create(Bindings::main_thread_internal_window_object());

    html_document->set_content_type("text/html");
    html_document->set_ready_for_post_load_tasks(true);

    auto doctype = heap().allocate<DocumentType>(realm(), html_document);
    doctype->set_name("html");
    html_document->append_child(*doctype);

    auto html_element = create_element(html_document, HTML::TagNames::html, Namespace::HTML);
    html_document->append_child(html_element);

    auto head_element = create_element(html_document, HTML::TagNames::head, Namespace::HTML);
    html_element->append_child(head_element);

    if (!title.is_null()) {
        auto title_element = create_element(html_document, HTML::TagNames::title, Namespace::HTML);
        head_element->append_child(title_element);

        auto text_node = heap().allocate<Text>(realm(), html_document, title);
        title_element->append_child(*text_node);
    }

    auto body_element = create_element(html_document, HTML::TagNames::body, Namespace::HTML);
    html_element->append_child(body_element);

    html_document->set_origin(document().origin());

    return html_document;
}

// https://dom.spec.whatwg.org/#dom-domimplementation-createdocumenttype
ExceptionOr<JS::NonnullGCPtr<DocumentType>> DOMImplementation::create_document_type(String const& qualified_name, String const& public_id, String const& system_id)
{
    TRY(Document::validate_qualified_name(global_object(), qualified_name));
    auto document_type = DocumentType::create(document());
    document_type->set_name(qualified_name);
    document_type->set_public_id(public_id);
    document_type->set_system_id(system_id);
    return document_type;
}

}