#include <AK/String.h>
#include <AK/TypeCasts.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/Iterator.h>
#include <LibJS/Runtime/Promise.h>
#include <LibJS/Runtime/VM.h>
#include <LibJS/Runtime/Value.h>
#include <LibJS/Runtime/ValueInlines.h>
#include <LibWeb/Bindings/ExceptionOrUtils.h>
#include <LibWeb/Bindings/FakeXRDevice.h>
#include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/Bindings/XRSystem.h>
#include <LibWeb/Internals/FakeXRDevice.h>
#include <LibWeb/WebIDL/AbstractOperations.h>
#include <LibWeb/WebIDL/Promise.h>
#include <LibWeb/WebIDL/Tracing.h>

namespace Web::Bindings {

void FakeXRDeviceConstructor::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(0), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.name, JS::PrimitiveString::create(vm, "FakeXRDevice"_utf16), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.prototype, &ensure_web_prototype<FakeXRDevicePrototype>(realm, "FakeXRDevice"_fly_string), 0);
}

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

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

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

void FakeXRDevicePrototype::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<Internals::FakeXRDevice*> impl_from(JS::VM& vm, JS::Value js_value)
{

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

[[maybe_unused]] static JS::ThrowCompletionOr<Internals::FakeXRDevice*> 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(FakeXRDevicePrototype::disconnect)
{
    WebIDL::log_trace(vm, "FakeXRDevicePrototype::disconnect");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    auto steps = [&realm, &vm]() -> JS::ThrowCompletionOr<GC::Ref<WebIDL::Promise>> {
        (void)realm;
    [[maybe_unused]] Internals::FakeXRDevice* idl_object = TRY(impl_from(vm));

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

// https://webidl.spec.whatwg.org/#es-dictionary
JS::ThrowCompletionOr<FakeXRDeviceInit> convert_to_idl_value_for_fake_xr_device_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, "FakeXRDeviceInit");

    // 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 FakeXRDeviceInit {
        .supported_features = TRY([&]() -> JS::ThrowCompletionOr<Optional<Vector<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("supportedFeatures"_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<Vector<String>> {
        if (!js_member_value.is_object())
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObject, js_member_value);

        auto method = TRY(js_member_value.get_method(vm, vm.well_known_symbol_iterator()));
        if (!method)
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotIterable, js_member_value);

        return TRY([&]() -> JS::ThrowCompletionOr<Vector<String>> {
        // 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<String> 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<String> {
        return TRY(WebIDL::to_string(vm, next_value));
    }(); }));

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

        return sequence;
    }());
    }(); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 7. Otherwise, jsMemberValue is undefined and the member is optional.
            return OptionalNone {};
        }()),
        .supported_modes = TRY([&]() -> JS::ThrowCompletionOr<Optional<Vector<XRSessionMode>>> {
            // 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("supportedModes"_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<Vector<XRSessionMode>> {
        if (!js_member_value.is_object())
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObject, js_member_value);

        auto method = TRY(js_member_value.get_method(vm, vm.well_known_symbol_iterator()));
        if (!method)
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotIterable, js_member_value);

        return TRY([&]() -> JS::ThrowCompletionOr<Vector<XRSessionMode>> {
        // 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<XRSessionMode> 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 convert_to_idl_value_for_xr_session_mode(vm, next_value); }));

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

        return sequence;
    }());
    }(); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 7. Otherwise, jsMemberValue is undefined and the member is optional.
            return OptionalNone {};
        }()),
    };
}

} // namespace Web::Bindings