#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/PrimitiveString.h>
#include <LibJS/Runtime/Realm.h>
#include <LibJS/Runtime/VM.h>
#include <LibJS/Runtime/Value.h>
#include <LibJS/Runtime/ValueInlines.h>
#include <LibWeb/Animations/ScrollTimeline.h>
#include <LibWeb/Bindings/AnimationTimeline.h>
#include <LibWeb/Bindings/ExceptionOrUtils.h>
#include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/Bindings/ScrollTimeline.h>
#include <LibWeb/DOM/Element.h>
#include <LibWeb/WebIDL/Tracing.h>

namespace Web::Bindings {

void ScrollTimelineConstructor::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<AnimationTimelinePrototype>(realm, "AnimationTimeline"_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, "ScrollTimeline"_utf16), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.prototype, &ensure_web_prototype<ScrollTimelinePrototype>(realm, "ScrollTimeline"_fly_string), 0);
}

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

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

    // 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<ScrollTimelinePrototype>(*target_realm, "ScrollTimeline"_fly_string);
    }

    auto arg0 = vm.argument(0);
    ScrollTimelineOptions options = ScrollTimelineOptions {};
    if (!arg0.is_undefined())
        options = TRY(throw_dom_exception_if_needed(vm, [&] { return convert_to_idl_value_for_scroll_timeline_options(vm, arg0); }));

    auto impl = TRY(throw_dom_exception_if_needed(vm, [&] { return Animations::ScrollTimeline::construct_impl(realm, 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 ScrollTimeline" algorithm
    // (https://webidl.spec.whatwg.org/#js-platform-objects) are currently not handled, or are handled within Animations::ScrollTimeline::construct_impl().

    return *impl;
}

void ScrollTimelinePrototype::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<AnimationTimelinePrototype>(realm, "AnimationTimeline"_fly_string) });

    auto source_id = "source"_utf16_fly_string;
    auto native_source_getter = JS::NativeFunction::create(realm, source_getter, 0, source_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_source_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto source_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(source_id, native_source_getter, native_source_setter, source_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 axis_id = "axis"_utf16_fly_string;
    auto native_axis_getter = JS::NativeFunction::create(realm, axis_getter, 0, axis_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_axis_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto axis_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(axis_id, native_axis_getter, native_axis_setter, axis_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_direct_property(vm.well_known_symbol_to_string_tag(), JS::PrimitiveString::create(vm, "ScrollTimeline"_utf16), JS::Attribute::Configurable);
}

void ScrollTimelinePrototype::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<Animations::ScrollTimeline*> impl_from(JS::VM& vm, JS::Value js_value)
{

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

[[maybe_unused]] static JS::ThrowCompletionOr<Animations::ScrollTimeline*> 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(ScrollTimelinePrototype::source_getter)
{
    WebIDL::log_trace(vm, "ScrollTimelinePrototype::source_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->source(); }));

    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(ScrollTimelinePrototype::axis_getter)
{
    WebIDL::log_trace(vm, "ScrollTimelinePrototype::axis_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->axis(); }));

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

// https://webidl.spec.whatwg.org/#idl-enumeration
JS::ThrowCompletionOr<ScrollAxis> convert_to_idl_value_for_scroll_axis(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 == "block"sv)
        return ScrollAxis::Block;
    if (value_as_string == "inline"sv)
        return ScrollAxis::Inline;
    if (value_as_string == "x"sv)
        return ScrollAxis::X;
    if (value_as_string == "y"sv)
        return ScrollAxis::Y;
    return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidEnumerationValue, value_as_string, "ScrollAxis");
}

// https://webidl.spec.whatwg.org/#idl-enumeration
Utf16String idl_enum_to_string(ScrollAxis 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 ScrollAxis::Block:
        return "block"_utf16;
    case ScrollAxis::Inline:
        return "inline"_utf16;
    case ScrollAxis::X:
        return "x"_utf16;
    case ScrollAxis::Y:
        return "y"_utf16;
    }
    VERIFY_NOT_REACHED();
}

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

    // 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 ScrollTimelineOptions {
        .axis = TRY([&]() -> JS::ThrowCompletionOr<ScrollAxis> {
            // 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("axis"_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 convert_to_idl_value_for_scroll_axis(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 = ScrollAxis::Block;

            // 2. Set idlDict[key] to idlMemberValue.
            return idl_member_value;
        }()),
        .source = TRY([&]() -> JS::ThrowCompletionOr<Optional<GC::Ptr<DOM::Element>>> {
            // 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("source"_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<Optional<GC::Ptr<DOM::Element>>> {
        GC::Ptr<DOM::Element> value;

        if (!js_member_value.is_nullish()) {

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

                // 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