#include <AK/String.h>
#include <AK/TypeCasts.h>
#include <LibGC/Heap.h>
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/FunctionObject.h>
#include <LibJS/Runtime/PrimitiveString.h>
#include <LibJS/Runtime/Promise.h>
#include <LibJS/Runtime/Set.h>
#include <LibJS/Runtime/SetIterator.h>
#include <LibJS/Runtime/VM.h>
#include <LibJS/Runtime/Value.h>
#include <LibJS/Runtime/ValueInlines.h>
#include <LibWeb/Bindings/EventTarget.h>
#include <LibWeb/Bindings/ExceptionOrUtils.h>
#include <LibWeb/Bindings/FontFaceSet.h>
#include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/CSS/FontFace.h>
#include <LibWeb/CSS/FontFaceSet.h>
#include <LibWeb/HTML/Scripting/Environments.h>
#include <LibWeb/WebIDL/AbstractOperations.h>
#include <LibWeb/WebIDL/CallbackType.h>
#include <LibWeb/WebIDL/Promise.h>
#include <LibWeb/WebIDL/Tracing.h>

namespace Web::Bindings {

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

    object.set_prototype(&ensure_web_constructor<EventTargetPrototype>(realm, "EventTarget"_fly_string));
    object.define_direct_property(vm.names.length, JS::Value(0), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.name, JS::PrimitiveString::create(vm, "FontFaceSet"_utf16), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.prototype, &ensure_web_prototype<FontFaceSetPrototype>(realm, "FontFaceSet"_fly_string), 0);
}

JS::ThrowCompletionOr<GC::Ref<JS::Object>> FontFaceSetConstructor::construct([[maybe_unused]] InterfaceConstructor& constructor, [[maybe_unused]] JS::FunctionObject& new_target)
{
    WebIDL::log_trace(constructor.vm(), "FontFaceSetConstructor::construct");
    return constructor.vm().throw_completion<JS::TypeError>(JS::ErrorType::NotAConstructor, "FontFaceSet");
}

GC_DEFINE_ALLOCATOR(FontFaceSetPrototype);

FontFaceSetPrototype::FontFaceSetPrototype([[maybe_unused]] JS::Realm& realm)
    : Object(ConstructWithPrototypeTag::Tag, GC::Ref { ensure_web_prototype<EventTargetPrototype>(realm, "EventTarget"_fly_string) })
{
}

FontFaceSetPrototype::~FontFaceSetPrototype()
{
}


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

    object.set_prototype(GC::Ref { ensure_web_prototype<EventTargetPrototype>(realm, "EventTarget"_fly_string) });

    auto onloading_id = "onloading"_utf16_fly_string;
    auto native_onloading_getter = JS::NativeFunction::create(realm, onloading_getter, 0, onloading_id, &realm, "get"sv);
    auto native_onloading_setter = JS::NativeFunction::create(realm, onloading_setter, 1, onloading_id, &realm, "set"sv);

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto onloading_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(onloading_id, native_onloading_getter, native_onloading_setter, onloading_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 onloadingdone_id = "onloadingdone"_utf16_fly_string;
    auto native_onloadingdone_getter = JS::NativeFunction::create(realm, onloadingdone_getter, 0, onloadingdone_id, &realm, "get"sv);
    auto native_onloadingdone_setter = JS::NativeFunction::create(realm, onloadingdone_setter, 1, onloadingdone_id, &realm, "set"sv);

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto onloadingdone_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(onloadingdone_id, native_onloadingdone_getter, native_onloadingdone_setter, onloadingdone_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 onloadingerror_id = "onloadingerror"_utf16_fly_string;
    auto native_onloadingerror_getter = JS::NativeFunction::create(realm, onloadingerror_getter, 0, onloadingerror_id, &realm, "get"sv);
    auto native_onloadingerror_setter = JS::NativeFunction::create(realm, onloadingerror_setter, 1, onloadingerror_id, &realm, "set"sv);

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto onloadingerror_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(onloadingerror_id, native_onloadingerror_getter, native_onloadingerror_setter, onloadingerror_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 ready_id = "ready"_utf16_fly_string;
    auto native_ready_getter = JS::NativeFunction::create(realm, ready_getter, 0, ready_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_ready_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto ready_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(ready_id, native_ready_getter, native_ready_setter, ready_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 status_id = "status"_utf16_fly_string;
    auto native_status_getter = JS::NativeFunction::create(realm, status_getter, 0, status_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_status_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto status_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(status_id, native_status_getter, native_status_setter, status_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, "add"_utf16_fly_string, add, 1, default_attributes);

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

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

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

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

    object.define_native_accessor(realm, vm.names.size, get_size, nullptr, JS::Attribute::Enumerable | JS::Attribute::Configurable);
    object.define_native_function(realm, vm.names.entries, entries, 0, default_attributes);
    object.define_native_function(realm, vm.names.keys, values, 0, default_attributes);
    object.define_native_function(realm, vm.names.values, values, 0, default_attributes);
    object.define_direct_property(vm.well_known_symbol_iterator(), object.get_without_side_effects(vm.names.values), JS::Attribute::Configurable | JS::Attribute::Writable);
    object.define_native_function(realm, vm.names.forEach, for_each, 1, default_attributes);
    object.define_native_function(realm, vm.names.has, has, 1, default_attributes);

    object.define_direct_property(vm.well_known_symbol_to_string_tag(), JS::PrimitiveString::create(vm, "FontFaceSet"_utf16), JS::Attribute::Configurable);
    Base::initialize(realm);
}

void FontFaceSetPrototype::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<CSS::FontFaceSet*> impl_from(JS::VM& vm, JS::Value js_value)
{

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

[[maybe_unused]] static JS::ThrowCompletionOr<CSS::FontFaceSet*> 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(FontFaceSetPrototype::onloading_getter)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::onloading_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->onloading(); }));

    return [&]() -> JS::Value {
        // 1. If the IDL nullable type T? value is null, then the JavaScript value is null.
        if (!R)
            return JS::js_null();

        // 2. Otherwise, the JavaScript value is the result of converting the IDL nullable type value to the inner IDL type T.
        return JS::Value(R->callback);
    }();
}

JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::onloadingdone_getter)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::onloadingdone_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->onloadingdone(); }));

    return [&]() -> JS::Value {
        // 1. If the IDL nullable type T? value is null, then the JavaScript value is null.
        if (!R)
            return JS::js_null();

        // 2. Otherwise, the JavaScript value is the result of converting the IDL nullable type value to the inner IDL type T.
        return JS::Value(R->callback);
    }();
}

JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::onloadingerror_getter)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::onloadingerror_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->onloadingerror(); }));

    return [&]() -> JS::Value {
        // 1. If the IDL nullable type T? value is null, then the JavaScript value is null.
        if (!R)
            return JS::js_null();

        // 2. Otherwise, the JavaScript value is the result of converting the IDL nullable type value to the inner IDL type T.
        return JS::Value(R->callback);
    }();
}

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

    auto steps = [&]() -> JS::ThrowCompletionOr<GC::Ptr<WebIDL::Promise>> {
        // 1. Let idlObject be null.
        [[maybe_unused]] auto* idl_object = TRY(impl_from(vm));
        auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->ready(); }));
        return R;
    };

    auto maybe_R = steps();

    // 2. And then, if an exception E was thrown:

    // 1. If attribute’s type is a promise type, then return ! Call(%Promise.reject%, %Promise%, «E»).
    if (maybe_R.is_throw_completion())
        return WebIDL::create_rejected_promise(realm, maybe_R.error_value())->promise();

    // 2. Otherwise, end these steps and allow the exception to propagate.
    auto R = maybe_R.release_value();

    // 4. Return the result of converting R to a JavaScript value of the type attribute is declared as.
    return GC::Ref { as<JS::Promise>(*R->promise()) };
}

JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::status_getter)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::status_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->status(); }));

    return JS::PrimitiveString::create(vm, idl_enum_to_string(R));
}

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

    // 1. Let V be undefined.
    auto V = JS::js_undefined();

    // 2. If any arguments were passed, then set V to the value of the first argument passed.
    if (vm.argument_count() > 0)
        V = vm.argument(0);

    // 3. Let id be attribute’s identifier.

    // 4. Let idlObject be null.
    [[maybe_unused]] CSS::FontFaceSet* idl_object = nullptr;

    // 5. If attribute is a regular attribute:

    // 1. Let jsValue be the this value, if it is not null or undefined, or realm’s global object otherwise. (This will subsequently cause a TypeError in a few steps, if the global object does not implement target and [LegacyLenientThis] is not specified.)
    auto js_value = vm.this_value();
    if (js_value.is_nullish())
        js_value = &realm.global_object();

    // 2. FIXME: If jsValue is a platform object, then perform a security check, passing jsValue, attribute’s identifier, and "setter".

    // 3. Let validThis be true if jsValue implements target, or false otherwise.
    auto maybe_idl_object = impl_from(vm, js_value);

    // 4. If validThis is false and attribute was not specified with the [LegacyLenientThis] extended attribute, then throw a TypeError.
    idl_object = TRY(maybe_idl_object);

    auto original_steps = [&]() -> JS::ThrowCompletionOr<JS::Value> {
        // 6. Let idlValue be determined as follows:
        // -> Otherwise, idlValue is the result of converting V to an IDL value of attribute’s type.
        auto idl_value = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<GC::Ptr<WebIDL::CallbackType>> {
        GC::Ptr<WebIDL::CallbackType> value;
        if (V.is_object()) {

        if (!V.is_nullish()) {

            value = TRY([&]() -> JS::ThrowCompletionOr<GC::Ptr<WebIDL::CallbackType>> {

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

        // 7. Run the setter steps of attribute with idlObject as this and idlValue as the value.
        auto setter_result = [&]() -> JS::ThrowCompletionOr<void> {
            TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->set_onloading(idl_value); }));
    return {};
        }();

        if (setter_result.is_error())
            return setter_result.release_error();

        return JS::js_undefined();
    };

    // 8. Return undefined.
    return TRY(original_steps());
}

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

    // 1. Let V be undefined.
    auto V = JS::js_undefined();

    // 2. If any arguments were passed, then set V to the value of the first argument passed.
    if (vm.argument_count() > 0)
        V = vm.argument(0);

    // 3. Let id be attribute’s identifier.

    // 4. Let idlObject be null.
    [[maybe_unused]] CSS::FontFaceSet* idl_object = nullptr;

    // 5. If attribute is a regular attribute:

    // 1. Let jsValue be the this value, if it is not null or undefined, or realm’s global object otherwise. (This will subsequently cause a TypeError in a few steps, if the global object does not implement target and [LegacyLenientThis] is not specified.)
    auto js_value = vm.this_value();
    if (js_value.is_nullish())
        js_value = &realm.global_object();

    // 2. FIXME: If jsValue is a platform object, then perform a security check, passing jsValue, attribute’s identifier, and "setter".

    // 3. Let validThis be true if jsValue implements target, or false otherwise.
    auto maybe_idl_object = impl_from(vm, js_value);

    // 4. If validThis is false and attribute was not specified with the [LegacyLenientThis] extended attribute, then throw a TypeError.
    idl_object = TRY(maybe_idl_object);

    auto original_steps = [&]() -> JS::ThrowCompletionOr<JS::Value> {
        // 6. Let idlValue be determined as follows:
        // -> Otherwise, idlValue is the result of converting V to an IDL value of attribute’s type.
        auto idl_value = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<GC::Ptr<WebIDL::CallbackType>> {
        GC::Ptr<WebIDL::CallbackType> value;
        if (V.is_object()) {

        if (!V.is_nullish()) {

            value = TRY([&]() -> JS::ThrowCompletionOr<GC::Ptr<WebIDL::CallbackType>> {

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

        // 7. Run the setter steps of attribute with idlObject as this and idlValue as the value.
        auto setter_result = [&]() -> JS::ThrowCompletionOr<void> {
            TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->set_onloadingdone(idl_value); }));
    return {};
        }();

        if (setter_result.is_error())
            return setter_result.release_error();

        return JS::js_undefined();
    };

    // 8. Return undefined.
    return TRY(original_steps());
}

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

    // 1. Let V be undefined.
    auto V = JS::js_undefined();

    // 2. If any arguments were passed, then set V to the value of the first argument passed.
    if (vm.argument_count() > 0)
        V = vm.argument(0);

    // 3. Let id be attribute’s identifier.

    // 4. Let idlObject be null.
    [[maybe_unused]] CSS::FontFaceSet* idl_object = nullptr;

    // 5. If attribute is a regular attribute:

    // 1. Let jsValue be the this value, if it is not null or undefined, or realm’s global object otherwise. (This will subsequently cause a TypeError in a few steps, if the global object does not implement target and [LegacyLenientThis] is not specified.)
    auto js_value = vm.this_value();
    if (js_value.is_nullish())
        js_value = &realm.global_object();

    // 2. FIXME: If jsValue is a platform object, then perform a security check, passing jsValue, attribute’s identifier, and "setter".

    // 3. Let validThis be true if jsValue implements target, or false otherwise.
    auto maybe_idl_object = impl_from(vm, js_value);

    // 4. If validThis is false and attribute was not specified with the [LegacyLenientThis] extended attribute, then throw a TypeError.
    idl_object = TRY(maybe_idl_object);

    auto original_steps = [&]() -> JS::ThrowCompletionOr<JS::Value> {
        // 6. Let idlValue be determined as follows:
        // -> Otherwise, idlValue is the result of converting V to an IDL value of attribute’s type.
        auto idl_value = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<GC::Ptr<WebIDL::CallbackType>> {
        GC::Ptr<WebIDL::CallbackType> value;
        if (V.is_object()) {

        if (!V.is_nullish()) {

            value = TRY([&]() -> JS::ThrowCompletionOr<GC::Ptr<WebIDL::CallbackType>> {

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

        // 7. Run the setter steps of attribute with idlObject as this and idlValue as the value.
        auto setter_result = [&]() -> JS::ThrowCompletionOr<void> {
            TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->set_onloadingerror(idl_value); }));
    return {};
        }();

        if (setter_result.is_error())
            return setter_result.release_error();

        return JS::js_undefined();
    };

    // 8. Return undefined.
    return TRY(original_steps());
}

JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::add)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::add");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] CSS::FontFaceSet* idl_object = TRY(impl_from(vm));

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

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

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

JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::delete_)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::delete_");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] CSS::FontFaceSet* idl_object = TRY(impl_from(vm));

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

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

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

JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::clear)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::clear");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] CSS::FontFaceSet* idl_object = TRY(impl_from(vm));

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

JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::load)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::load");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    auto steps = [&realm, &vm]() -> JS::ThrowCompletionOr<GC::Ref<WebIDL::Promise>> {
        (void)realm;
    [[maybe_unused]] CSS::FontFaceSet* idl_object = TRY(impl_from(vm));

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

    auto arg0 = vm.argument(0);
    auto font = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<String> {
        return TRY(WebIDL::to_string(vm, arg0));
    }(); }));

    auto arg1 = vm.argument(1);
    String text = " "_string;
    if (!arg1.is_undefined())
        text = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<String> {
        return TRY(WebIDL::to_string(vm, arg1));
    }(); }));

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->load(font, text); }));
        return R;
    };

    auto maybe_R = steps();

    // And then, if an exception E was thrown:
    // 1. If op has a return type that is a promise type, then return ! Call(%Promise.reject%, %Promise%, «E»).
    // 2. Otherwise, end these steps and allow the exception to propagate.
    if (maybe_R.is_throw_completion())
        return WebIDL::create_rejected_promise(realm, maybe_R.error_value())->promise();

    return GC::Ref { as<JS::Promise>(*maybe_R.release_value()->promise()) };
}

JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::check)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::check");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] CSS::FontFaceSet* idl_object = TRY(impl_from(vm));

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

    auto arg0 = vm.argument(0);
    auto font = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<String> {
        return TRY(WebIDL::to_string(vm, arg0));
    }(); }));

    auto arg1 = vm.argument(1);
    String text = " "_string;
    if (!arg1.is_undefined())
        text = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<String> {
        return TRY(WebIDL::to_string(vm, arg1));
    }(); }));

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->check(font, text); }));
    return JS::Value(R);
}

// https://webidl.spec.whatwg.org/#js-set-size
JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::get_size)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::size");

    // 1. Let O be the this value, implementation-checked against A with identifier "size" and type "getter".
    auto* this_impl = TRY(impl_from(vm));

    // 2. Let set be the set entries of the IDL value that represents a reference to O.
    GC::Ref<JS::Set> set = this_impl->set_entries();

    // 3. Return set’s size, converted to a JavaScript value.
    return set->set_size();
}

// https://webidl.spec.whatwg.org/#js-set-entries
JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::entries)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::values");
    auto& realm = *vm.current_realm();

    // 1. Let O be the this value, implementation-checked against A with identifier "entries" and type "method".
    auto* this_impl = TRY(impl_from(vm));

    // 2. Let set be the set entries of the IDL value that represents a reference to O.
    GC::Ref<JS::Set> set = this_impl->set_entries();

    // 3. Return the result of creating a set iterator from set with kind "key+value".
    return JS::SetIterator::create(realm, *set, PropertyKind::KeyAndValue);
}

// https://webidl.spec.whatwg.org/#js-set-values
JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::values)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::values");
    auto& realm = *vm.current_realm();

    // 1. Let O be the this value, implementation-checked against A with identifier "values" and type "method".
    auto* this_impl = TRY(impl_from(vm));

    // 2. Let set be the set entries of the IDL value that represents a reference to O.
    GC::Ref<JS::Set> set = this_impl->set_entries();

    // 3. Return the result of creating a set iterator from set with kind "value".
    return JS::SetIterator::create(realm, *set, PropertyKind::Value);
}

// https://webidl.spec.whatwg.org/#js-set-forEach
JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::for_each)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::for_each");

    // 1. Let O be the this value, implementation-checked against A with identifier "forEach" and type "method".
    auto* this_impl = TRY(impl_from(vm));

    // 2. Let set be the set entries of the IDL value that represents a reference to O.
    GC::Ref<JS::Set> set = this_impl->set_entries();

    // 3. Let callbackFn be the first argument passed to the function, or undefined if not supplied.
    // 4. If IsCallable(callbackFn) is false, throw a TypeError.
    auto callback = vm.argument(0);
    if (!callback.is_function())
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAFunction, callback);

    // 5. Let thisArg be the second argument passed to the function, or undefined if not supplied.
    auto this_arg = vm.argument(1);

    // 6. For each value of set:
    for (auto value : *set) {
        // 1. Let jsValue be value converted to a JavaScript value.

        // 2. Perform ? Call(callbackFn, thisArg, « jsValue, jsValue, O»).
        TRY(JS::call(vm, callback.as_function(), this_arg, value, value, this_impl));
    }

    // 7. Return undefined.
    return JS::js_undefined();
}

// https://webidl.spec.whatwg.org/#js-set-has
JS_DEFINE_NATIVE_FUNCTION(FontFaceSetPrototype::has)
{
    WebIDL::log_trace(vm, "FontFaceSetPrototype::has");

    // 1. Let O be the this value, implementation-checked against A with identifier "has" and type "method".
    auto* this_impl = TRY(impl_from(vm));

    // 2. Let set be the set entries of the IDL value that represents a reference to O.
    GC::Ref<JS::Set> set = this_impl->set_entries();

    // 3. Let valueType be the value type specified in the setlike declaration.
    // 4. Let valueArg be the first argument passed to this function, or undefined if not supplied.
    // 5. Let value be valueArg converted to an IDL value of type valueType.
    // FIXME: 6. If value is -0, set value to +0.
    auto value = vm.argument(0);
        if (!value.is<CSS::FontFace>())
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "CSS::FontFace");


    // 7. If set contains value, then return true, otherwise return false.
    return set->set_has(value);
}

// https://webidl.spec.whatwg.org/#idl-enumeration
JS::ThrowCompletionOr<FontFaceSetLoadStatus> convert_to_idl_value_for_font_face_set_load_status(JS::VM& vm, JS::Value value)
{
    // 1. Let S be the result of calling ? ToString(V).
    auto value_as_string = TRY(value.to_utf16_string(vm));

    // 2. If S is not one of E’s enumeration values, then throw a TypeError.
    // 3. Return the enumeration value of type E that is equal to S.
    if (value_as_string == "loading"sv)
        return FontFaceSetLoadStatus::Loading;
    if (value_as_string == "loaded"sv)
        return FontFaceSetLoadStatus::Loaded;
    return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidEnumerationValue, value_as_string, "FontFaceSetLoadStatus");
}

// https://webidl.spec.whatwg.org/#idl-enumeration
Utf16String idl_enum_to_string(FontFaceSetLoadStatus value)
{
    // The result of converting an IDL enumeration type value to a JavaScript value is the String value that represents the same sequence of code units as the enumeration value.
    switch (value) {
    case FontFaceSetLoadStatus::Loading:
        return "loading"_utf16;
    case FontFaceSetLoadStatus::Loaded:
        return "loaded"_utf16;
    }
    VERIFY_NOT_REACHED();
}

} // namespace Web::Bindings