#include <AK/String.h>
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/Realm.h>
#include <LibJS/Runtime/VM.h>
#include <LibJS/Runtime/Value.h>
#include <LibJS/Runtime/ValueInlines.h>
#include <LibWeb/Bindings/Event.h>
#include <LibWeb/Bindings/ExceptionOrUtils.h>
#include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/Bindings/UIEvent.h>
#include <LibWeb/HTML/WindowProxy.h>
#include <LibWeb/UIEvents/UIEvent.h>
#include <LibWeb/WebIDL/AbstractOperations.h>
#include <LibWeb/WebIDL/Tracing.h>
#include <LibWeb/WebIDL/Types.h>

namespace Web::Bindings {

void UIEventConstructor::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<EventPrototype>(realm, "Event"_fly_string));
    object.define_direct_property(vm.names.length, JS::Value(1), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.name, JS::PrimitiveString::create(vm, "UIEvent"_utf16), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.prototype, &ensure_web_prototype<UIEventPrototype>(realm, "UIEvent"_fly_string), 0);
}

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

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

    // 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<UIEventPrototype>(*target_realm, "UIEvent"_fly_string);
    }

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

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

    auto arg1 = vm.argument(1);
    UIEventInit event_init_dict = UIEventInit {};
    if (!arg1.is_undefined())
        event_init_dict = TRY(throw_dom_exception_if_needed(vm, [&] { return convert_to_idl_value_for_ui_event_init(vm, arg1); }));

    auto impl = TRY(throw_dom_exception_if_needed(vm, [&] { return UIEvents::UIEvent::construct_impl(realm, type, event_init_dict); }));

    // 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 UIEvent" algorithm
    // (https://webidl.spec.whatwg.org/#js-platform-objects) are currently not handled, or are handled within UIEvents::UIEvent::construct_impl().

    return *impl;
}

void UIEventPrototype::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(GC::Ref { ensure_web_prototype<EventPrototype>(realm, "Event"_fly_string) });

    auto view_id = "view"_utf16_fly_string;
    auto native_view_getter = JS::NativeFunction::create(realm, view_getter, 0, view_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_view_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto view_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(view_id, native_view_getter, native_view_setter, view_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 detail_id = "detail"_utf16_fly_string;
    auto native_detail_getter = JS::NativeFunction::create(realm, detail_getter, 0, detail_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_detail_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto detail_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(detail_id, native_detail_getter, native_detail_setter, detail_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 which_id = "which"_utf16_fly_string;
    auto native_which_getter = JS::NativeFunction::create(realm, which_getter, 0, which_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_which_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto which_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(which_id, native_which_getter, native_which_setter, which_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, "initUIEvent"_utf16_fly_string, init_ui_event, 1, default_attributes);

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

void UIEventPrototype::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<UIEvents::UIEvent*> impl_from(JS::VM& vm, JS::Value js_value)
{

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

[[maybe_unused]] static JS::ThrowCompletionOr<UIEvents::UIEvent*> 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(UIEventPrototype::view_getter)
{
    WebIDL::log_trace(vm, "UIEventPrototype::view_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->view(); }));

    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(JS::Value(R));
    }();
}

JS_DEFINE_NATIVE_FUNCTION(UIEventPrototype::detail_getter)
{
    WebIDL::log_trace(vm, "UIEventPrototype::detail_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->detail(); }));

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

JS_DEFINE_NATIVE_FUNCTION(UIEventPrototype::which_getter)
{
    WebIDL::log_trace(vm, "UIEventPrototype::which_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->which(); }));

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

JS_DEFINE_NATIVE_FUNCTION(UIEventPrototype::init_ui_event)
{
    WebIDL::log_trace(vm, "UIEventPrototype::init_ui_event");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] UIEvents::UIEvent* idl_object = TRY(impl_from(vm));

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

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

    auto arg1 = vm.argument(1);
    bool bubbles_arg = false;
    if (!arg1.is_undefined())
        bubbles_arg = TRY(throw_dom_exception_if_needed(vm, [&] { return arg1.to_boolean(); }));

    auto arg2 = vm.argument(2);
    bool cancelable_arg = false;
    if (!arg2.is_undefined())
        cancelable_arg = TRY(throw_dom_exception_if_needed(vm, [&] { return arg2.to_boolean(); }));

    auto arg3 = vm.argument(3);
    GC::Ptr<HTML::WindowProxy> view_arg = nullptr;
    if (!arg3.is_undefined())
        view_arg = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<GC::Ptr<HTML::WindowProxy>> {
        GC::Ptr<HTML::WindowProxy> value;

        if (!arg3.is_nullish()) {

            value = TRY([&]() -> JS::ThrowCompletionOr<GC::Ref<HTML::WindowProxy>> {
        if (auto impl = arg3.as_if<HTML::WindowProxy>())
            return *impl;
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "WindowProxy");
    }());
        }
        return value;
    }(); }));

    auto arg4 = vm.argument(4);
    WebIDL::Long detail_arg = 0;
    if (!arg4.is_undefined())
        detail_arg = TRY(throw_dom_exception_if_needed(vm, [&] { return WebIDL::convert_to_int<WebIDL::Long>(vm, arg4, WebIDL::EnforceRange::No, WebIDL::Clamp::No); }));

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return idl_object->init_ui_event(type_arg, bubbles_arg, cancelable_arg, view_arg, detail_arg); }));
    return JS::js_undefined();
}

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

    // 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 UIEventInit {
        TRY(convert_to_idl_value_for_event_init(vm, js_dict)),
        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("detail"_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;
        }()),
        TRY([&]() -> JS::ThrowCompletionOr<GC::Ptr<HTML::WindowProxy>> {
            // 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("view"_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<GC::Ptr<HTML::WindowProxy>> {
        GC::Ptr<HTML::WindowProxy> value;

        if (!js_member_value.is_nullish()) {

            value = TRY([&]() -> JS::ThrowCompletionOr<GC::Ref<HTML::WindowProxy>> {
        if (auto impl = js_member_value.as_if<HTML::WindowProxy>())
            return *impl;
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "WindowProxy");
    }());
        }
        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 = nullptr;

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

} // namespace Web::Bindings