/*
 * Copyright (c) 2018-2025, Andreas Kling <andreas@ladybird.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/DistinctNumeric.h>
#include <AK/FlyString.h>
#include <AK/Function.h>
#include <AK/GenericShorthands.h>
#include <AK/RefPtr.h>
#include <AK/TypeCasts.h>
#include <AK/Vector.h>
#include <LibWeb/Bindings/Node.h>
#include <LibWeb/CSS/InvalidationSet.h>
#include <LibWeb/DOM/EventTarget.h>
#include <LibWeb/DOM/FragmentSerializationMode.h>
#include <LibWeb/DOM/NodeType.h>
#include <LibWeb/DOM/Slottable.h>
#include <LibWeb/DOM/StyleInvalidationReason.h>
#include <LibWeb/Export.h>
#include <LibWeb/InvalidateDisplayList.h>
#include <LibWeb/TraversalDecision.h>
#include <LibWeb/TreeNode.h>
#include <LibWeb/WebIDL/ExceptionOr.h>

namespace Web::DOM {

class Document;

}

namespace Web::CSS {

class StyleScope;

}

namespace Web::DOM {

enum class NameOrDescription {
    Name,
    Description
};

enum class IsDescendant {
    No,
    Yes,
};

enum class ShouldComputeRole {
    No,
    Yes,
};

#define ENUMERATE_SET_NEEDS_LAYOUT_REASONS(X)         \
    X(CharacterDataReplaceData)                       \
    X(FinalizeACrossDocumentNavigation)               \
    X(GeneratedContentImageFinishedLoading)           \
    X(HTMLCanvasElementWidthOrHeightChange)           \
    X(HTMLImageElementReactToChangesInTheEnvironment) \
    X(HTMLImageElementUpdateTheImageData)             \
    X(HTMLVideoElementNaturalDimensionsChanged)       \
    X(HTMLVideoElementSetVideoTrack)                  \
    X(KeyframeEffect)                                 \
    X(LayoutTreeUpdate)                               \
    X(NavigableSetViewportSize)                       \
    X(SVGGraphicsElementTransformChange)              \
    X(SVGImageElementFetchTheDocument)                \
    X(SVGImageFilterFetch)                            \
    X(SVGViewBoxChange)                               \
    X(StyleChange)

enum class SetNeedsLayoutReason {
#define ENUMERATE_SET_NEEDS_LAYOUT_REASON(e) e,
    ENUMERATE_SET_NEEDS_LAYOUT_REASONS(ENUMERATE_SET_NEEDS_LAYOUT_REASON)
#undef ENUMERATE_SET_NEEDS_LAYOUT_REASON
};

[[nodiscard]] StringView to_string(SetNeedsLayoutReason);

#define ENUMERATE_SET_NEEDS_LAYOUT_TREE_UPDATE_REASONS(X) \
    X(ElementSetInnerHTML)                                \
    X(ElementSetShadowRoot)                               \
    X(DetailsElementOpenedOrClosed)                       \
    X(HTMLInputElementSrcAttribute)                       \
    X(HTMLOListElementOrdinalValues)                      \
    X(HTMLObjectElementUpdateLayoutAndChildObjects)       \
    X(KeyframeEffect)                                     \
    X(NodeInsertBefore)                                   \
    X(NodeInsertBeforeWithDisplayContents)                \
    X(NodeRemove)                                         \
    X(NodeSetTextContent)                                 \
    X(None)                                               \
    X(ShadowRootSetInnerHTML)                             \
    X(StyleChange)

enum class SetNeedsLayoutTreeUpdateReason {
#define ENUMERATE_SET_NEEDS_LAYOUT_TREE_UPDATE_REASON(e) e,
    ENUMERATE_SET_NEEDS_LAYOUT_TREE_UPDATE_REASONS(ENUMERATE_SET_NEEDS_LAYOUT_TREE_UPDATE_REASON)
#undef ENUMERATE_SET_NEEDS_LAYOUT_TREE_UPDATE_REASON
};

[[nodiscard]] StringView to_string(SetNeedsLayoutTreeUpdateReason);

class WEB_API Node : public EventTarget
    , public TreeNode<Node> {
    WEB_PLATFORM_OBJECT(Node, EventTarget);

public:
    static constexpr bool OVERRIDES_FINALIZE = true;

    ParentNode* parent_or_shadow_host();
    ParentNode const* parent_or_shadow_host() const { return const_cast<Node*>(this)->parent_or_shadow_host(); }
    Node const* parent_or_shadow_host_node() const;
    Element* parent_or_shadow_host_element();
    Element const* parent_or_shadow_host_element() const { return const_cast<Node*>(this)->parent_or_shadow_host_element(); }
    ParentNode* flat_tree_parent();
    ParentNode const* flat_tree_parent() const { return const_cast<Node*>(this)->flat_tree_parent(); }
    Element* flat_tree_parent_element();
    Element const* flat_tree_parent_element() const { return const_cast<Node*>(this)->flat_tree_parent_element(); }

    virtual ~Node();

    NodeType type() const { return m_type; }
    bool is_element() const { return type() == NodeType::ELEMENT_NODE; }
    bool is_text() const { return type() == NodeType::TEXT_NODE || type() == NodeType::CDATA_SECTION_NODE; }
    bool is_exclusive_text() const { return type() == NodeType::TEXT_NODE; }
    bool is_document() const { return type() == NodeType::DOCUMENT_NODE; }
    bool is_document_type() const { return type() == NodeType::DOCUMENT_TYPE_NODE; }
    bool is_comment() const { return type() == NodeType::COMMENT_NODE; }
    bool is_character_data() const { return first_is_one_of(type(), NodeType::TEXT_NODE, NodeType::COMMENT_NODE, NodeType::CDATA_SECTION_NODE, NodeType::PROCESSING_INSTRUCTION_NODE); }
    bool is_document_fragment() const { return type() == NodeType::DOCUMENT_FRAGMENT_NODE; }
    bool is_parent_node() const { return is_element() || is_document() || is_document_fragment(); }
    bool is_slottable() const { return is_element() || is_text() || is_cdata_section(); }
    bool is_attribute() const { return type() == NodeType::ATTRIBUTE_NODE; }
    bool is_cdata_section() const { return type() == NodeType::CDATA_SECTION_NODE; }
    virtual bool is_shadow_root() const { return false; }

    virtual bool requires_svg_container() const { return false; }
    virtual bool is_svg_container() const { return false; }
    virtual bool is_svg_element() const { return false; }
    virtual bool is_svg_graphics_element() const { return false; }
    virtual bool is_svg_mask_element() const { return false; }
    virtual bool is_svg_script_element() const { return false; }
    virtual bool is_svg_style_element() const { return false; }
    virtual bool is_svg_svg_element() const { return false; }
    virtual bool is_svg_symbol_element() const { return false; }
    virtual bool is_svg_use_element() const { return false; }
    virtual bool is_svg_view_element() const { return false; }
    virtual bool is_svg_a_element() const { return false; }
    virtual bool is_svg_g_element() const { return false; }
    virtual bool is_svg_foreign_object_element() const { return false; }

    bool in_a_document_tree() const;

    // NOTE: This is intended for the JS bindings.
    u16 node_type() const { return (u16)m_type; }

    bool is_editable() const;
    bool is_editing_host() const;
    bool is_editable_or_editing_host() const { return is_editable() || is_editing_host(); }
    GC::Ptr<Node> editing_host();

    bool in_editable_subtree() const { return m_in_editable_subtree; }
    void recompute_editable_subtree_flag();

    virtual bool is_dom_node() const final { return true; }
    virtual bool is_html_element() const { return false; }
    virtual bool is_html_html_element() const { return false; }
    virtual bool is_html_anchor_element() const { return false; }
    virtual bool is_html_area_element() const { return false; }
    virtual bool is_html_base_element() const { return false; }
    virtual bool is_html_body_element() const { return false; }
    virtual bool is_html_head_element() const { return false; }
    virtual bool is_html_heading_element() const { return false; }
    virtual bool is_html_input_element() const { return false; }
    virtual bool is_html_link_element() const { return false; }
    virtual bool is_html_media_element() const { return false; }
    virtual bool is_html_optgroup_element() const { return false; }
    virtual bool is_html_option_element() const { return false; }
    virtual bool is_html_progress_element() const { return false; }
    virtual bool is_html_script_element() const { return false; }
    virtual bool is_html_select_element() const { return false; }
    virtual bool is_html_style_element() const { return false; }
    virtual bool is_html_template_element() const { return false; }
    virtual bool is_html_table_element() const { return false; }
    virtual bool is_html_table_section_element() const { return false; }
    virtual bool is_html_table_row_element() const { return false; }
    virtual bool is_html_table_cell_element() const { return false; }
    virtual bool is_html_title_element() const { return false; }
    virtual bool is_html_br_element() const { return false; }
    virtual bool is_html_button_element() const { return false; }
    virtual bool is_html_slot_element() const { return false; }
    virtual bool is_html_embed_element() const { return false; }
    virtual bool is_html_object_element() const { return false; }
    virtual bool is_html_form_element() const { return false; }
    virtual bool is_html_image_element() const { return false; }
    virtual bool is_html_iframe_element() const { return false; }
    virtual bool is_html_div_element() const { return false; }
    virtual bool is_html_span_element() const { return false; }
    virtual bool is_html_textarea_element() const { return false; }
    virtual bool is_html_frameset_element() const { return false; }
    virtual bool is_html_fieldset_element() const { return false; }
    virtual bool is_html_li_element() const { return false; }
    virtual bool is_html_menu_element() const { return false; }
    virtual bool is_html_olist_element() const { return false; }
    virtual bool is_html_ulist_element() const { return false; }
    ALWAYS_INLINE bool is_html_ol_ul_menu_element() const
    {
        return is_html_olist_element() || is_html_ulist_element() || is_html_menu_element();
    }
    virtual bool is_navigable_container() const { return false; }
    virtual bool is_lazy_loading() const { return false; }

    WebIDL::ExceptionOr<GC::Ref<Node>> pre_insert(GC::Ref<Node>, GC::Ptr<Node>);
    WebIDL::ExceptionOr<GC::Ref<Node>> pre_remove(GC::Ref<Node>);

    WebIDL::ExceptionOr<GC::Ref<Node>> append_child(GC::Ref<Node>);
    WebIDL::ExceptionOr<GC::Ref<Node>> remove_child(GC::Ref<Node>);

    void insert_before(GC::Ref<Node> node, GC::Ptr<Node> child, bool suppress_observers = false);
    void remove(bool suppress_observers = false);
    void remove_all_children(bool suppress_observers = false);

    enum DocumentPosition : u16 {
        DOCUMENT_POSITION_EQUAL = 0,
        DOCUMENT_POSITION_DISCONNECTED = 1,
        DOCUMENT_POSITION_PRECEDING = 2,
        DOCUMENT_POSITION_FOLLOWING = 4,
        DOCUMENT_POSITION_CONTAINS = 8,
        DOCUMENT_POSITION_CONTAINED_BY = 16,
        DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC = 32,
    };

    u16 compare_document_position(GC::Ptr<Node> other);

    WebIDL::ExceptionOr<GC::Ref<Node>> replace_child(GC::Ref<Node> node, GC::Ref<Node> child);

    WebIDL::ExceptionOr<GC::Ref<Node>> clone_node(GC::Ptr<Document> document = nullptr, bool subtree = false, GC::Ptr<Node> parent = nullptr, GC::Ptr<HTML::CustomElementRegistry> fallback_registry = nullptr) const;
    WebIDL::ExceptionOr<GC::Ref<Node>> clone_single_node(Document&, GC::Ptr<HTML::CustomElementRegistry> fallback_registry) const;
    WebIDL::ExceptionOr<GC::Ref<Node>> clone_node_binding(bool subtree);

    WebIDL::ExceptionOr<void> move_node(Node& new_parent, Node* child);

    // NOTE: This is intended for the JS bindings.
    bool has_child_nodes() const { return has_children(); }
    GC::Ref<NodeList> child_nodes();
    Vector<GC::Root<Node>> children_as_vector() const;

    virtual FlyString node_name() const = 0;

    String base_uri() const;

    virtual Optional<String> alternative_text() const;

    Utf16String descendant_text_content() const;
    Optional<Utf16String> text_content() const;
    WebIDL::ExceptionOr<void> set_text_content(Optional<Utf16String> const&);

    WebIDL::ExceptionOr<void> normalize();

    Optional<String> node_value() const;
    WebIDL::ExceptionOr<void> set_node_value(Optional<String> const&);

    GC::Ptr<HTML::Navigable> navigable() const;

    Document& document() { return *m_document; }
    Document const& document() const { return *m_document; }

    GC::Ptr<Document> owner_document() const;

    HTML::HTMLAnchorElement const* enclosing_link_element() const;
    HTML::HTMLElement const* enclosing_html_element() const;
    HTML::HTMLElement const* enclosing_html_element_with_attribute(FlyString const&) const;

    Utf16String child_text_content() const;

    Node& shadow_including_root();
    Node const& shadow_including_root() const
    {
        return const_cast<Node*>(this)->shadow_including_root();
    }

    bool is_closed_shadow_hidden_from(Node const&) const;

    bool is_connected() const { return m_is_connected; }
    void set_is_connected(bool is_connected) { m_is_connected = is_connected; }

    [[nodiscard]] bool is_browsing_context_connected() const;

    Node* parent_node() { return parent(); }
    Node const* parent_node() const { return parent(); }

    GC::Ptr<Element> parent_element();
    GC::Ptr<Element const> parent_element() const;

    MUST_UPCALL virtual void inserted();
    virtual void post_connection();
    enum class IsSubtreeRoot : u8 {
        No,
        Yes,
    };
    MUST_UPCALL virtual void removed_from(IsSubtreeRoot, Node* old_ancestor, Node& old_root);
    MUST_UPCALL virtual void moved_from(IsSubtreeRoot, GC::Ptr<Node> old_ancestor);

    struct ChildrenChangedMetadata {
        enum class Type {
            Inserted,
            Removal,
            Mutation,
        };
        Type type {};
        GC::Ref<Node> node;
    };
    // FIXME: It would be good if we could always provide this metadata for use in optimizations.
    virtual void children_changed(ChildrenChangedMetadata const&) { }

    virtual void adopted_from(Document&) { }
    virtual WebIDL::ExceptionOr<void> cloned(Node&, bool) const { return {}; }

    Layout::Node const* layout_node() const;
    Layout::Node* layout_node();

    Layout::Node const* unsafe_layout_node() const { return m_layout_node; }
    Layout::Node* unsafe_layout_node() { return m_layout_node; }

    RefPtr<Painting::PaintableBox const> paintable_box() const;
    RefPtr<Painting::PaintableBox> paintable_box();
    RefPtr<Painting::Paintable const> paintable() const;
    RefPtr<Painting::Paintable> paintable();

    RefPtr<Painting::PaintableBox const> unsafe_paintable_box() const;
    RefPtr<Painting::PaintableBox> unsafe_paintable_box();
    RefPtr<Painting::Paintable const> unsafe_paintable() const;
    RefPtr<Painting::Paintable> unsafe_paintable();

    void set_paintable(WeakPtr<Painting::Paintable>);
    void clear_paintable();

    void set_needs_repaint(InvalidateDisplayList = InvalidateDisplayList::Yes);
    void set_needs_layout_update(SetNeedsLayoutReason);

    void clear_layout_node_and_paintable(Badge<Document>);
    void set_layout_node(Badge<Layout::Node>, GC::Ref<Layout::Node>);
    void detach_layout_node(Badge<Layout::TreeBuilder>);

    virtual bool is_child_allowed(Node const&) const { return true; }

    [[nodiscard]] bool needs_layout_tree_update() const { return m_needs_layout_tree_update; }
    void set_needs_layout_tree_update(bool, SetNeedsLayoutTreeUpdateReason);

    [[nodiscard]] bool child_needs_layout_tree_update() const { return m_child_needs_layout_tree_update; }
    void set_child_needs_layout_tree_update(bool b) { m_child_needs_layout_tree_update = b; }

    bool needs_style_update() const { return m_needs_style_update; }
    void set_needs_style_update(bool);
    void set_needs_style_update_internal(bool) { m_needs_style_update = true; }

    bool child_needs_style_update() const { return m_child_needs_style_update; }
    void set_child_needs_style_update(bool b) { m_child_needs_style_update = b; }

    [[nodiscard]] bool entire_subtree_needs_style_update() const { return m_entire_subtree_needs_style_update; }
    void set_entire_subtree_needs_style_update(bool b) { m_entire_subtree_needs_style_update = b; }

    void invalidate_style(StyleInvalidationReason);
    void invalidate_style(StyleInvalidationReason, Vector<CSS::InvalidationSet::Property> const&, StyleInvalidationOptions);
    CSS::StyleScope& style_scope();
    CSS::StyleScope const& style_scope() const { return const_cast<Node*>(this)->style_scope(); }
    void for_each_style_scope_which_may_observe_the_node(Function<void(CSS::StyleScope&)> const&);

    void set_document(Badge<Document>, Document&);
    void set_document(Badge<NamedNodeMap>, Document&);

    virtual EventTarget* get_parent(Event const&) override;

    template<typename T>
    bool fast_is() const = delete;

    WebIDL::ExceptionOr<void> ensure_pre_insertion_validity(JS::Realm&, GC::Ref<Node> node, GC::Ptr<Node> child) const;

    bool is_host_including_inclusive_ancestor_of(Node const&) const;

    bool is_scripting_enabled() const;
    bool is_scripting_disabled() const;

    // Used for dumping the DOM Tree
    void serialize_tree_as_json(JsonObjectSerializer<StringBuilder>&) const;
    IterationDecision serialize_child_as_json(JsonArraySerializer<StringBuilder>& children_array, Node const& child) const;

    bool is_shadow_including_descendant_of(Node const&) const;
    bool is_shadow_including_inclusive_descendant_of(Node const&) const;
    bool is_shadow_including_ancestor_of(Node const&) const;
    bool is_shadow_including_inclusive_ancestor_of(Node const&) const;

    [[nodiscard]] UniqueNodeID unique_id() const { return m_unique_id; }
    static Node* from_unique_id(UniqueNodeID);

    WebIDL::ExceptionOr<Utf16String> serialize_fragment(HTML::RequireWellFormed, FragmentSerializationMode = FragmentSerializationMode::Inner) const;

    WebIDL::ExceptionOr<void> unsafely_set_html(Element&, StringView);

    void replace_all(GC::Ptr<Node>);
    void string_replace_all(Utf16String);

    bool is_same_node(Node const*) const;
    bool is_equal_node(Node const*) const;

    GC::Ref<Node> get_root_node(Bindings::GetRootNodeOptions const& options = {});

    bool is_uninteresting_whitespace_node() const;

    String debug_description() const;

    size_t length() const;

    auto& registered_observer_list() { return m_registered_observer_list; }
    auto const& registered_observer_list() const { return m_registered_observer_list; }

    void add_registered_observer(RegisteredObserver&);

    void queue_mutation_record(FlyString const& type, Optional<FlyString> const& attribute_name, Optional<FlyString> const& attribute_namespace, Optional<String> const& old_value, Vector<GC::Root<Node>> added_nodes, Vector<GC::Root<Node>> removed_nodes, Node* previous_sibling, Node* next_sibling);

    // https://dom.spec.whatwg.org/#concept-shadow-including-inclusive-descendant
    template<typename Callback>
    TraversalDecision for_each_shadow_including_inclusive_descendant(Callback);

    // https://dom.spec.whatwg.org/#concept-shadow-including-descendant
    template<typename Callback>
    TraversalDecision for_each_shadow_including_descendant(Callback);

    Slottable as_slottable();

    template<typename U, typename Callback>
    WebIDL::ExceptionOr<void> for_each_child_of_type_fallible(Callback callback)
    {
        for (auto* node = first_child(); node; node = node->next_sibling()) {
            if (auto* maybe_node_of_type = as_if<U>(node)) {
                if (TRY(callback(*maybe_node_of_type)) == IterationDecision::Break)
                    return {};
            }
        }
        return {};
    }
    template<typename U>
    U const* first_flat_tree_ancestor_of_type() const
    {
        return const_cast<Node*>(this)->template first_flat_tree_ancestor_of_type<U>();
    }

    template<typename U>
    U* first_flat_tree_ancestor_of_type();

    template<typename Predicate>
    requires requires(Predicate& predicate, Node const& node) { { predicate(node) } -> ConvertibleTo<bool>; }
    Node const* find_in_shadow_including_ancestry(Predicate&& predicate) const
    {
        for (Node const* it = this; it; it = it->parent_or_shadow_host_node()) {
            if (predicate(*it))
                return it;
        }
        return nullptr;
    }

    ErrorOr<String> accessible_name(Document const&, ShouldComputeRole = ShouldComputeRole::Yes) const;
    ErrorOr<String> accessible_description(Document const&) const;

    Optional<String> locate_a_namespace(Optional<String> const& prefix) const;
    Optional<String> lookup_namespace_uri(Optional<String> prefix) const;
    Optional<String> lookup_prefix(Optional<String> namespace_) const;
    bool is_default_namespace(Optional<String> namespace_) const;
    Vector<FlyString> get_in_scope_prefixes() const;

    bool is_inert() const;

    bool has_inclusive_ancestor_with_display_none_ignoring_animations() const;
    bool has_inclusive_ancestor_with_event_listener(FlyString const& type) const;

    GC::Ptr<ShadowRoot> containing_shadow_root();
    GC::Ptr<ShadowRoot const> containing_shadow_root() const
    {
        return const_cast<Node*>(this)->containing_shadow_root();
    }

protected:
    Node(JS::Realm&, Document&, NodeType);
    Node(Document&, NodeType);

    void set_document(Document&);

    virtual void visit_edges(Cell::Visitor&) override;
    virtual void finalize() override;
    virtual size_t external_memory_size() const override;

    GC::Ptr<Document> m_document;
    GC::Ptr<Layout::Node> m_layout_node;
    WeakPtr<Painting::Paintable> m_paintable;
    NodeType m_type { NodeType::INVALID };
    bool m_needs_layout_tree_update { false };
    bool m_child_needs_layout_tree_update { false };

    bool m_needs_style_update { false };
    bool m_child_needs_style_update { false };
    bool m_entire_subtree_needs_style_update { false };
    bool m_in_editable_subtree { false };
    bool m_is_connected { false };

    UniqueNodeID m_unique_id;

    // https://dom.spec.whatwg.org/#registered-observer-list
    // "Nodes have a strong reference to registered observers in their registered observer list." https://dom.spec.whatwg.org/#garbage-collection
    OwnPtr<Vector<GC::Ref<RegisteredObserver>>> m_registered_observer_list;

    void build_accessibility_tree(AccessibilityTreeNode& parent);

    ErrorOr<String> name_or_description(NameOrDescription, Document const&, HashTable<UniqueNodeID>&, IsDescendant = IsDescendant::No, ShouldComputeRole = ShouldComputeRole::Yes) const;

private:
    void queue_tree_mutation_record(Vector<GC::Root<Node>> added_nodes, Vector<GC::Root<Node>> removed_nodes, Node* previous_sibling, Node* next_sibling);

    void live_range_pre_remove();

    void insert_before_impl(GC::Ref<Node>, GC::Ptr<Node> child);
    void append_child_impl(GC::Ref<Node>);
    void remove_child_impl(GC::Ref<Node>);

    static Optional<StringView> first_valid_id(StringView, Document const&);

    GC::Ptr<NodeList> m_child_nodes;
};

}

template<>
inline bool JS::Object::fast_is<Web::DOM::Node>() const { return is_dom_node(); }