/*
 * Copyright (c) 2018-2024, Andreas Kling <andreas@ladybird.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/HashMap.h>
#include <LibWeb/CSS/Selector.h>
#include <LibWeb/DOM/Element.h>

namespace Web::SelectorEngine {

enum class SelectorKind {
    Normal,
    Relative,
};

enum class HasMatchResult : u8 {
    Matched,
    NotMatched,
};

struct HasResultCacheKey {
    CSS::Selector const* selector;
    GC::Ptr<DOM::Element const> element;

    void visit_edges(GC::Cell::Visitor& visitor)
    {
        visitor.visit(element);
    }

    bool operator==(HasResultCacheKey const&) const = default;
};

struct HasResultCacheKeyTraits : Traits<HasResultCacheKey> {
    static unsigned hash(HasResultCacheKey const& key)
    {
        return pair_int_hash(ptr_hash(key.selector), ptr_hash(key.element.ptr()));
    }
};

using HasResultCache = HashMap<HasResultCacheKey, HasMatchResult, HasResultCacheKeyTraits>;

struct MatchContext {
    GC::Ptr<CSS::CSSStyleSheet const> style_sheet_for_rule {};
    GC::Ptr<DOM::Element const> subject {};
    GC::Ptr<DOM::Element const> slotted_element {};     // Only set when matching a ::slotted() pseudo-element
    GC::Ptr<DOM::Element const> part_owning_parent {};  // Only set temporarily when matching a ::part() pseudo-element
    GC::Ptr<DOM::ShadowRoot const> rule_shadow_root {}; // Shadow root the matched rule belongs to
    bool collect_per_element_selector_involvement_metadata { false };
    bool for_host_part_matching { false };
    // True while we are evaluating the argument of a :has() pseudo-class.
    // Elements visited by selector walks (descendants, siblings, etc.) while
    // this is set get marked as in_has_scope so the invalidation walker can
    // later terminate once it leaves the scope. Transparent to callers; set
    // by matches_has_pseudo_class with a ScopeGuard.
    bool inside_has_argument_match { false };
    CSS::PseudoClassBitmap attempted_pseudo_class_matches {};
    HasResultCache* has_result_cache { nullptr };
};

bool matches(CSS::Selector const&, DOM::AbstractElement const&, GC::Ptr<DOM::Element const> shadow_host, MatchContext& context, GC::Ptr<DOM::ParentNode const> scope = {}, SelectorKind selector_kind = SelectorKind::Normal, GC::Ptr<DOM::Element const> anchor = nullptr);

}