#include <AK/String.h>
#include <AK/Variant.h>
#include <LibGC/Heap.h>
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/FunctionObject.h>
#include <LibJS/Runtime/Iterator.h>
#include <LibJS/Runtime/Realm.h>
#include <LibJS/Runtime/VM.h>
#include <LibJS/Runtime/Value.h>
#include <LibJS/Runtime/ValueInlines.h>
#include <LibWeb/Bindings/ExceptionOrUtils.h>
#include <LibWeb/Bindings/IntersectionObserver.h>
#include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/Bindings/PlatformObject.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/DOM/Element.h>
#include <LibWeb/HTML/Scripting/Environments.h>
#include <LibWeb/IntersectionObserver/IntersectionObserver.h>
#include <LibWeb/IntersectionObserver/IntersectionObserverEntry.h>
#include <LibWeb/WebIDL/AbstractOperations.h>
#include <LibWeb/WebIDL/CallbackType.h>
#include <LibWeb/WebIDL/Tracing.h>
#include <LibWeb/WebIDL/Types.h>

namespace Web::Bindings {

void IntersectionObserverConstructor::initialize(JS::Realm& realm, JS::NativeFunction& object)
{
    auto& vm = realm.vm();
    [[maybe_unused]] u8 default_attributes = JS::Attribute::Enumerable;

    
    object.define_direct_property(vm.names.length, JS::Value(1), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.name, JS::PrimitiveString::create(vm, "IntersectionObserver"_utf16), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.prototype, &ensure_web_prototype<IntersectionObserverPrototype>(realm, "IntersectionObserver"_fly_string), 0);
}

JS::ThrowCompletionOr<GC::Ref<JS::Object>> IntersectionObserverConstructor::construct([[maybe_unused]] InterfaceConstructor& constructor, [[maybe_unused]] JS::FunctionObject& new_target)
{
    WebIDL::log_trace(constructor.vm(), "IntersectionObserverConstructor::construct");
    auto& vm = constructor.vm();
    [[maybe_unused]] auto& realm = *vm.current_realm();

    // To internally create a new object implementing the interface IntersectionObserver:

    // 3.2. Let prototype be ? Get(newTarget, "prototype").
    auto prototype = TRY(new_target.get(vm.names.prototype));

    // 3.3. If Type(prototype) is not Object, then:
    if (!prototype.is_object()) {
        // 1. Let targetRealm be ? GetFunctionRealm(newTarget).
        auto* target_realm = TRY(JS::get_function_realm(vm, new_target));

        // 2. Set prototype to the interface prototype object for interface in targetRealm.
        VERIFY(target_realm);
        prototype = &Bindings::ensure_web_prototype<IntersectionObserverPrototype>(*target_realm, "IntersectionObserver"_fly_string);
    }

    if (vm.argument_count() < 1)
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::BadArgCountOne, "IntersectionObserver");

    auto arg0 = vm.argument(0);
    auto callback = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<GC::Ref<WebIDL::CallbackType>> {

        if (!arg0.is_function())
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAFunction, arg0);

        return vm.heap().allocate<WebIDL::CallbackType>(arg0.as_object(),  HTML::incumbent_realm(), WebIDL::OperationReturnsPromise::No);
    }(); }));

    auto arg1 = vm.argument(1);
    IntersectionObserverInit options = IntersectionObserverInit {};
    if (!arg1.is_undefined())
        options = TRY(throw_dom_exception_if_needed(vm, [&] { return convert_to_idl_value_for_intersection_observer_init(vm, arg1); }));

    auto impl = TRY(throw_dom_exception_if_needed(vm, [&] { return IntersectionObserver::IntersectionObserver::construct_impl(realm, callback, options); }));

    // 7. Set instance.[[Prototype]] to prototype.
    VERIFY(prototype.is_object());
    impl->set_prototype(&prototype.as_object());

    // FIXME: Steps 8...11. of the "internally create a new object implementing the interface IntersectionObserver" algorithm
    // (https://webidl.spec.whatwg.org/#js-platform-objects) are currently not handled, or are handled within IntersectionObserver::IntersectionObserver::construct_impl().

    return *impl;
}

void IntersectionObserverPrototype::initialize(JS::Realm& realm, JS::Object& object)
{
    [[maybe_unused]] auto& vm = realm.vm();
    [[maybe_unused]] u8 default_attributes = JS::Attribute::Enumerable | JS::Attribute::Configurable | JS::Attribute::Writable;

    object.set_prototype(realm.intrinsics().object_prototype());

    auto root_id = "root"_utf16_fly_string;
    auto native_root_getter = JS::NativeFunction::create(realm, root_getter, 0, root_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_root_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto root_attributes = default_attributes;

    // 5. Let desc be the PropertyDescriptor{[[Get]]: getter, [[Set]]: setter, [[Enumerable]]: true, [[Configurable]]: configurable}.

    // 7. Perform ! DefinePropertyOrThrow(target, id, desc).
    object.define_direct_accessor(root_id, native_root_getter, native_root_setter, root_attributes);

    // 8. FIXME: If attr’s type is an observable array type with type argument T, then set target’s backing observable array exotic object for attr to the result of creating an observable array exotic object in realm, given T, attr’s set an indexed value algorithm, and attr’s delete an indexed value algorithm.
    auto root_margin_id = "rootMargin"_utf16_fly_string;
    auto native_root_margin_getter = JS::NativeFunction::create(realm, root_margin_getter, 0, root_margin_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_root_margin_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto root_margin_attributes = default_attributes;

    // 5. Let desc be the PropertyDescriptor{[[Get]]: getter, [[Set]]: setter, [[Enumerable]]: true, [[Configurable]]: configurable}.

    // 7. Perform ! DefinePropertyOrThrow(target, id, desc).
    object.define_direct_accessor(root_margin_id, native_root_margin_getter, native_root_margin_setter, root_margin_attributes);

    // 8. FIXME: If attr’s type is an observable array type with type argument T, then set target’s backing observable array exotic object for attr to the result of creating an observable array exotic object in realm, given T, attr’s set an indexed value algorithm, and attr’s delete an indexed value algorithm.
    auto scroll_margin_id = "scrollMargin"_utf16_fly_string;
    auto native_scroll_margin_getter = JS::NativeFunction::create(realm, scroll_margin_getter, 0, scroll_margin_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_scroll_margin_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto scroll_margin_attributes = default_attributes;

    // 5. Let desc be the PropertyDescriptor{[[Get]]: getter, [[Set]]: setter, [[Enumerable]]: true, [[Configurable]]: configurable}.

    // 7. Perform ! DefinePropertyOrThrow(target, id, desc).
    object.define_direct_accessor(scroll_margin_id, native_scroll_margin_getter, native_scroll_margin_setter, scroll_margin_attributes);

    // 8. FIXME: If attr’s type is an observable array type with type argument T, then set target’s backing observable array exotic object for attr to the result of creating an observable array exotic object in realm, given T, attr’s set an indexed value algorithm, and attr’s delete an indexed value algorithm.
    auto thresholds_id = "thresholds"_utf16_fly_string;
    auto native_thresholds_getter = JS::NativeFunction::create(realm, thresholds_getter, 0, thresholds_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_thresholds_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto thresholds_attributes = default_attributes;

    // 5. Let desc be the PropertyDescriptor{[[Get]]: getter, [[Set]]: setter, [[Enumerable]]: true, [[Configurable]]: configurable}.

    // 7. Perform ! DefinePropertyOrThrow(target, id, desc).
    object.define_direct_accessor(thresholds_id, native_thresholds_getter, native_thresholds_setter, thresholds_attributes);

    // 8. FIXME: If attr’s type is an observable array type with type argument T, then set target’s backing observable array exotic object for attr to the result of creating an observable array exotic object in realm, given T, attr’s set an indexed value algorithm, and attr’s delete an indexed value algorithm.
    auto delay_id = "delay"_utf16_fly_string;
    auto native_delay_getter = JS::NativeFunction::create(realm, delay_getter, 0, delay_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_delay_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto delay_attributes = default_attributes;

    // 5. Let desc be the PropertyDescriptor{[[Get]]: getter, [[Set]]: setter, [[Enumerable]]: true, [[Configurable]]: configurable}.

    // 7. Perform ! DefinePropertyOrThrow(target, id, desc).
    object.define_direct_accessor(delay_id, native_delay_getter, native_delay_setter, delay_attributes);

    // 8. FIXME: If attr’s type is an observable array type with type argument T, then set target’s backing observable array exotic object for attr to the result of creating an observable array exotic object in realm, given T, attr’s set an indexed value algorithm, and attr’s delete an indexed value algorithm.
    auto track_visibility_id = "trackVisibility"_utf16_fly_string;
    auto native_track_visibility_getter = JS::NativeFunction::create(realm, track_visibility_getter, 0, track_visibility_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_track_visibility_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto track_visibility_attributes = default_attributes;

    // 5. Let desc be the PropertyDescriptor{[[Get]]: getter, [[Set]]: setter, [[Enumerable]]: true, [[Configurable]]: configurable}.

    // 7. Perform ! DefinePropertyOrThrow(target, id, desc).
    object.define_direct_accessor(track_visibility_id, native_track_visibility_getter, native_track_visibility_setter, track_visibility_attributes);

    // 8. FIXME: If attr’s type is an observable array type with type argument T, then set target’s backing observable array exotic object for attr to the result of creating an observable array exotic object in realm, given T, attr’s set an indexed value algorithm, and attr’s delete an indexed value algorithm.
    object.define_native_function(realm, "observe"_utf16_fly_string, observe, 1, default_attributes);

    object.define_native_function(realm, "unobserve"_utf16_fly_string, unobserve, 1, default_attributes);

    object.define_native_function(realm, "disconnect"_utf16_fly_string, disconnect, 0, default_attributes);

    object.define_native_function(realm, "takeRecords"_utf16_fly_string, take_records, 0, default_attributes);

    object.define_direct_property(vm.well_known_symbol_to_string_tag(), JS::PrimitiveString::create(vm, "IntersectionObserver"_utf16), JS::Attribute::Configurable);
}

void IntersectionObserverPrototype::define_unforgeable_attributes(JS::Realm& realm, [[maybe_unused]] JS::Object& object)
{
    [[maybe_unused]] auto& vm = realm.vm();
    [[maybe_unused]] u8 default_attributes = JS::Attribute::Enumerable;
}

[[maybe_unused]] static JS::ThrowCompletionOr<IntersectionObserver::IntersectionObserver*> impl_from(JS::VM& vm, JS::Value js_value)
{

    if (auto impl = js_value.as_if<IntersectionObserver::IntersectionObserver>())
        return impl.ptr();
    return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "IntersectionObserver");
}

[[maybe_unused]] static JS::ThrowCompletionOr<IntersectionObserver::IntersectionObserver*> impl_from(JS::VM& vm)
{
    auto this_value = vm.this_value();
    if (this_value.is_nullish())
        this_value = &vm.current_realm()->global_object();
    return impl_from(vm, this_value);
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::root_getter)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::root_getter");
    [[maybe_unused]] auto& realm = *vm.current_realm();

    auto* idl_object = TRY(impl_from(vm));


    auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->root(); }));

    return R.visit(
        [&](GC::Ref<DOM::Element> const& visited_union_value0) -> JS::Value
        {
            return JS::Value(visited_union_value0);
        },
        [&](GC::Ref<DOM::Document> const& visited_union_value1) -> JS::Value
        {
            return JS::Value(visited_union_value1);
        },
        [](Empty) -> JS::Value
        {
            return JS::js_null();
        }
    );
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::root_margin_getter)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::root_margin_getter");
    [[maybe_unused]] auto& realm = *vm.current_realm();

    auto* idl_object = TRY(impl_from(vm));


    auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->root_margin(); }));

    return WebIDL::primitive_string_from_string(vm, R);
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::scroll_margin_getter)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::scroll_margin_getter");
    [[maybe_unused]] auto& realm = *vm.current_realm();

    auto* idl_object = TRY(impl_from(vm));


    auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->scroll_margin(); }));

    return WebIDL::primitive_string_from_string(vm, R);
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::thresholds_getter)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::thresholds_getter");
    [[maybe_unused]] auto& realm = *vm.current_realm();

    auto* idl_object = TRY(impl_from(vm));


    auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->thresholds(); }));

    return [&]() -> JS::Value {
        // An IDL sequence<T> value S is converted to a JavaScript value as follows:
        // 1. Let n be the length of S.
        auto sequence_length = R.size();

        // 2. Let A be a new Array object created as if by the expression [].
        auto sequence_array = MUST(JS::Array::create(realm, sequence_length));

        // 3. Initialize i to be 0.
        // 4. While i < n:
        for (size_t sequence_index = 0; sequence_index < sequence_length; ++sequence_index) {
            // 1. Let V be the value in S at index i.
            auto& sequence_element = R.at(sequence_index);

            // 2. Let E be the result of converting V to a JavaScript value.
            JS::Value js_sequence_element = JS::Value(sequence_element);

            // 3. Let P be the result of calling ! ToString(i).
            // 4. Perform ! CreateDataPropertyOrThrow(A, P, E).
            MUST(sequence_array->create_data_property(JS::PropertyKey { sequence_index }, js_sequence_element));

            // 5. Set i to i + 1.
        }

        MUST(sequence_array->set_integrity_level(JS::Object::IntegrityLevel::Frozen));

        // 5. Return A.
        return sequence_array;
    }();
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::delay_getter)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::delay_getter");
    [[maybe_unused]] auto& realm = *vm.current_realm();

    auto* idl_object = TRY(impl_from(vm));


    auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->delay(); }));

    return JS::Value(static_cast<WebIDL::Long>(R));
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::track_visibility_getter)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::track_visibility_getter");
    [[maybe_unused]] auto& realm = *vm.current_realm();

    auto* idl_object = TRY(impl_from(vm));


    auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->track_visibility(); }));

    return JS::Value(R);
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::observe)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::observe");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] IntersectionObserver::IntersectionObserver* idl_object = TRY(impl_from(vm));

    if (vm.argument_count() < 1)
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::BadArgCountOne, "observe");

    auto arg0 = vm.argument(0);
    auto target = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<GC::Ref<DOM::Element>> {
        if (auto impl = arg0.as_if<DOM::Element>())
            return *impl;
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "Element");
    }(); }));

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->observe(target); }));
    return JS::js_undefined();
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::unobserve)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::unobserve");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] IntersectionObserver::IntersectionObserver* idl_object = TRY(impl_from(vm));

    if (vm.argument_count() < 1)
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::BadArgCountOne, "unobserve");

    auto arg0 = vm.argument(0);
    auto target = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<GC::Ref<DOM::Element>> {
        if (auto impl = arg0.as_if<DOM::Element>())
            return *impl;
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "Element");
    }(); }));

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->unobserve(target); }));
    return JS::js_undefined();
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::disconnect)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::disconnect");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] IntersectionObserver::IntersectionObserver* idl_object = TRY(impl_from(vm));

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->disconnect(); }));
    return JS::js_undefined();
}

JS_DEFINE_NATIVE_FUNCTION(IntersectionObserverPrototype::take_records)
{
    WebIDL::log_trace(vm, "IntersectionObserverPrototype::take_records");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] IntersectionObserver::IntersectionObserver* idl_object = TRY(impl_from(vm));

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->take_records(); }));
    return [&]() -> JS::Value {
        // An IDL sequence<T> value S is converted to a JavaScript value as follows:
        // 1. Let n be the length of S.
        auto sequence_length = R.size();

        // 2. Let A be a new Array object created as if by the expression [].
        auto sequence_array = MUST(JS::Array::create(realm, sequence_length));

        // 3. Initialize i to be 0.
        // 4. While i < n:
        for (size_t sequence_index = 0; sequence_index < sequence_length; ++sequence_index) {
            // 1. Let V be the value in S at index i.
            auto& sequence_element = R.at(sequence_index);

            // 2. Let E be the result of converting V to a JavaScript value.
            JS::Value js_sequence_element = JS::Value(sequence_element);

            // 3. Let P be the result of calling ! ToString(i).
            // 4. Perform ! CreateDataPropertyOrThrow(A, P, E).
            MUST(sequence_array->create_data_property(JS::PropertyKey { sequence_index }, js_sequence_element));

            // 5. Set i to i + 1.
        }

        // 5. Return A.
        return sequence_array;
    }();
}

// https://webidl.spec.whatwg.org/#es-dictionary
JS::ThrowCompletionOr<IntersectionObserverInit> convert_to_idl_value_for_intersection_observer_init(JS::VM& vm, JS::Value js_dict)
{
    // 1. If jsDict is not an Object and jsDict is neither undefined nor null, then throw a TypeError.
    if (!js_dict.is_object() && !js_dict.is_nullish())
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "IntersectionObserverInit");

    // 2. Let idlDict be an empty ordered map, representing a dictionary of type D.
    // 3. Let dictionaries be a list consisting of D and all of D’s inherited dictionaries, in order from least to most derived.
    // 4. For each dictionary dictionary in dictionaries, in order:
    // NB: We defer construction until the return initializer because some members may not be default-constructible. Inherited dictionaries are represented by the generated C++ struct inheritance.

    // 5. Return idlDict.
    return IntersectionObserverInit {
        .delay = TRY([&]() -> JS::ThrowCompletionOr<WebIDL::Long> {
            // 1. Let key be the identifier of member.
            // 2. If jsDict is either undefined or null, then:
            //     1. Let jsMemberValue be undefined.
            // 3. Otherwise,
            //     1. Let jsMemberValue be ? Get(jsDict, key).
            auto js_member_value = JS::js_undefined();
            if (js_dict.is_object())
                js_member_value = TRY(js_dict.as_object().get("delay"_utf16_fly_string));

            // 4. If jsMemberValue is not undefined, then:
            if (!js_member_value.is_undefined()) {
                // 1. Let idlMemberValue be the result of converting jsMemberValue to an IDL value whose type is the type member is declared to be of.
                auto idl_member_value = TRY(throw_dom_exception_if_needed(vm, [&] { return WebIDL::convert_to_int<WebIDL::Long>(vm, js_member_value, WebIDL::EnforceRange::No, WebIDL::Clamp::No); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 5. Otherwise, if jsMemberValue is undefined but member has a default value, then:
            // 1. Let idlMemberValue be the result of converting member's default value to an IDL value whose type is the type member is declared to be of.
            auto idl_member_value = 0;

            // 2. Set idlDict[key] to idlMemberValue.
            return idl_member_value;
        }()),
        .root = TRY([&]() -> JS::ThrowCompletionOr<Variant<GC::Ref<DOM::Element>, GC::Ref<DOM::Document>, Empty>> {
            // 1. Let key be the identifier of member.
            // 2. If jsDict is either undefined or null, then:
            //     1. Let jsMemberValue be undefined.
            // 3. Otherwise,
            //     1. Let jsMemberValue be ? Get(jsDict, key).
            auto js_member_value = JS::js_undefined();
            if (js_dict.is_object())
                js_member_value = TRY(js_dict.as_object().get("root"_utf16_fly_string));

            // 4. If jsMemberValue is not undefined, then:
            if (!js_member_value.is_undefined()) {
                // 1. Let idlMemberValue be the result of converting jsMemberValue to an IDL value whose type is the type member is declared to be of.
                auto idl_member_value = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<Variant<GC::Ref<DOM::Element>, GC::Ref<DOM::Document>, Empty>> {
        Variant<GC::Ref<DOM::Element>, GC::Ref<DOM::Document>, Empty> value;

        if (!js_member_value.is_nullish()) {

            value = TRY([&]() -> JS::ThrowCompletionOr<Variant<GC::Ref<DOM::Element>, GC::Ref<DOM::Document>>> {

        if (js_member_value.is_object()) {
            [[maybe_unused]] auto& object = js_member_value.as_object();

            if (is<PlatformObject>(object)) {

                if (auto* result = as_if<DOM::Element>(object))
                    return Variant<GC::Ref<DOM::Element>, GC::Ref<DOM::Document>> { GC::Ref { *result } };

                if (auto* result = as_if<DOM::Document>(object))
                    return Variant<GC::Ref<DOM::Element>, GC::Ref<DOM::Document>> { GC::Ref { *result } };
            }
        }

        return vm.throw_completion<JS::TypeError>("No union types matched"_utf16);
    }());
        }
        return value;
    }(); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 5. Otherwise, if jsMemberValue is undefined but member has a default value, then:
            // 1. Let idlMemberValue be the result of converting member's default value to an IDL value whose type is the type member is declared to be of.
            auto idl_member_value = Variant<GC::Ref<DOM::Element>, GC::Ref<DOM::Document>, Empty> { Empty {} };

            // 2. Set idlDict[key] to idlMemberValue.
            return idl_member_value;
        }()),
        .root_margin = TRY([&]() -> JS::ThrowCompletionOr<String> {
            // 1. Let key be the identifier of member.
            // 2. If jsDict is either undefined or null, then:
            //     1. Let jsMemberValue be undefined.
            // 3. Otherwise,
            //     1. Let jsMemberValue be ? Get(jsDict, key).
            auto js_member_value = JS::js_undefined();
            if (js_dict.is_object())
                js_member_value = TRY(js_dict.as_object().get("rootMargin"_utf16_fly_string));

            // 4. If jsMemberValue is not undefined, then:
            if (!js_member_value.is_undefined()) {
                // 1. Let idlMemberValue be the result of converting jsMemberValue to an IDL value whose type is the type member is declared to be of.
                auto idl_member_value = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<String> {
        return TRY(WebIDL::to_string(vm, js_member_value));
    }(); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 5. Otherwise, if jsMemberValue is undefined but member has a default value, then:
            // 1. Let idlMemberValue be the result of converting member's default value to an IDL value whose type is the type member is declared to be of.
            auto idl_member_value = "0px"_string;

            // 2. Set idlDict[key] to idlMemberValue.
            return idl_member_value;
        }()),
        .scroll_margin = TRY([&]() -> JS::ThrowCompletionOr<String> {
            // 1. Let key be the identifier of member.
            // 2. If jsDict is either undefined or null, then:
            //     1. Let jsMemberValue be undefined.
            // 3. Otherwise,
            //     1. Let jsMemberValue be ? Get(jsDict, key).
            auto js_member_value = JS::js_undefined();
            if (js_dict.is_object())
                js_member_value = TRY(js_dict.as_object().get("scrollMargin"_utf16_fly_string));

            // 4. If jsMemberValue is not undefined, then:
            if (!js_member_value.is_undefined()) {
                // 1. Let idlMemberValue be the result of converting jsMemberValue to an IDL value whose type is the type member is declared to be of.
                auto idl_member_value = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<String> {
        return TRY(WebIDL::to_string(vm, js_member_value));
    }(); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 5. Otherwise, if jsMemberValue is undefined but member has a default value, then:
            // 1. Let idlMemberValue be the result of converting member's default value to an IDL value whose type is the type member is declared to be of.
            auto idl_member_value = "0px"_string;

            // 2. Set idlDict[key] to idlMemberValue.
            return idl_member_value;
        }()),
        .threshold = TRY([&]() -> JS::ThrowCompletionOr<Variant<double, Vector<double>>> {
            // 1. Let key be the identifier of member.
            // 2. If jsDict is either undefined or null, then:
            //     1. Let jsMemberValue be undefined.
            // 3. Otherwise,
            //     1. Let jsMemberValue be ? Get(jsDict, key).
            auto js_member_value = JS::js_undefined();
            if (js_dict.is_object())
                js_member_value = TRY(js_dict.as_object().get("threshold"_utf16_fly_string));

            // 4. If jsMemberValue is not undefined, then:
            if (!js_member_value.is_undefined()) {
                // 1. Let idlMemberValue be the result of converting jsMemberValue to an IDL value whose type is the type member is declared to be of.
                auto idl_member_value = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<Variant<double, Vector<double>>> {

        if (js_member_value.is_object()) {
            [[maybe_unused]] auto& object = js_member_value.as_object();

            // 1. Let method be ? GetMethod(V, @@iterator).
            auto method = TRY(js_member_value.get_method(vm, vm.well_known_symbol_iterator()));

            // 2. If method is not undefined, return the result of creating a sequence of that type from V and method.
            if (method) {
                auto sequence_union_type = TRY([&]() -> JS::ThrowCompletionOr<Vector<double>> {
        // To create an IDL value of type sequence<T> given an iterable iterable and an iterator getter method, perform the following steps:
        // 1. Let iteratorRecord be ? GetIteratorFromMethod(iterable, method).
        auto iterator = TRY(JS::get_iterator_from_method(vm, js_member_value, *method));

        Vector<double> sequence;

        // 2. Initialize i to be 0.
        // 3. Repeat
        for (;;) {
            // 1. Let next be ? IteratorStepValue(iteratorRecord).
            auto next = TRY(JS::iterator_step_value(vm, iterator));

            // 2. If next is done, then return an IDL sequence value of type sequence<T> of length i, where the value of the element at index j is Sj.
            if (!next.has_value())
                break;

            // 3. Initialize Si to the result of converting next to an IDL value of type T.
            auto next_value = next.release_value();
            auto sequence_item = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<double> {
        auto x = TRY(next_value.to_double(vm));
        if (isinf(x) || isnan(x))
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidRestrictedFloatingPointParameter, "threshold");
        return x;
    }(); }));

            // 4. Set i to i + 1.
            sequence.append(sequence_item);
        }

        return sequence;
    }());
                return Variant<double, Vector<double>> { sequence_union_type };
            }

        }

        if (js_member_value.is_number()) {
            auto threshold_number = TRY([&]() -> JS::ThrowCompletionOr<double> {
        auto x = TRY(js_member_value.to_double(vm));
        if (isinf(x) || isnan(x))
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidRestrictedFloatingPointParameter, "threshold");
        return x;
    }());
            return Variant<double, Vector<double>> { threshold_number };
        }

        auto threshold_number_fallback = TRY([&]() -> JS::ThrowCompletionOr<double> {
        auto x = TRY(js_member_value.to_double(vm));
        if (isinf(x) || isnan(x))
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidRestrictedFloatingPointParameter, "threshold");
        return x;
    }());
        return Variant<double, Vector<double>> { threshold_number_fallback };

        return vm.throw_completion<JS::TypeError>("No union types matched"_utf16);
    }(); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 5. Otherwise, if jsMemberValue is undefined but member has a default value, then:
            // 1. Let idlMemberValue be the result of converting member's default value to an IDL value whose type is the type member is declared to be of.
            auto idl_member_value = Variant<double, Vector<double>> { 0 };

            // 2. Set idlDict[key] to idlMemberValue.
            return idl_member_value;
        }()),
        .track_visibility = TRY([&]() -> JS::ThrowCompletionOr<bool> {
            // 1. Let key be the identifier of member.
            // 2. If jsDict is either undefined or null, then:
            //     1. Let jsMemberValue be undefined.
            // 3. Otherwise,
            //     1. Let jsMemberValue be ? Get(jsDict, key).
            auto js_member_value = JS::js_undefined();
            if (js_dict.is_object())
                js_member_value = TRY(js_dict.as_object().get("trackVisibility"_utf16_fly_string));

            // 4. If jsMemberValue is not undefined, then:
            if (!js_member_value.is_undefined()) {
                // 1. Let idlMemberValue be the result of converting jsMemberValue to an IDL value whose type is the type member is declared to be of.
                auto idl_member_value = TRY(throw_dom_exception_if_needed(vm, [&] { return js_member_value.to_boolean(); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 5. Otherwise, if jsMemberValue is undefined but member has a default value, then:
            // 1. Let idlMemberValue be the result of converting member's default value to an IDL value whose type is the type member is declared to be of.
            auto idl_member_value = false;

            // 2. Set idlDict[key] to idlMemberValue.
            return idl_member_value;
        }()),
    };
}

} // namespace Web::Bindings