#include <LibGC/Heap.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/FunctionObject.h>
#include <LibJS/Runtime/Iterator.h>
#include <LibJS/Runtime/Value.h>
#include <LibJS/Runtime/ValueInlines.h>
#include <LibWeb/Bindings/AbortSignal.h>
#include <LibWeb/Bindings/EventTarget.h>
#include <LibWeb/Bindings/ExceptionOrUtils.h>
#include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/DOM/AbortSignal.h>
#include <LibWeb/HTML/Scripting/Environments.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 AbortSignalConstructor::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, "AbortSignal"_utf16), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.prototype, &ensure_web_prototype<AbortSignalPrototype>(realm, "AbortSignal"_fly_string), 0);
    object.define_native_function(realm, "abort"_utf16_fly_string, abort, 0, JS::Attribute::Enumerable | JS::Attribute::Configurable | JS::Attribute::Writable);

    object.define_native_function(realm, "timeout"_utf16_fly_string, timeout, 1, JS::Attribute::Enumerable | JS::Attribute::Configurable | JS::Attribute::Writable);

    object.define_native_function(realm, "any"_utf16_fly_string, any, 1, JS::Attribute::Enumerable | JS::Attribute::Configurable | JS::Attribute::Writable);

}

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

void AbortSignalPrototype::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<EventTargetPrototype>(realm, "EventTarget"_fly_string) });

    auto aborted_id = "aborted"_utf16_fly_string;
    auto native_aborted_getter = JS::NativeFunction::create(realm, aborted_getter, 0, aborted_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_aborted_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto aborted_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(aborted_id, native_aborted_getter, native_aborted_setter, aborted_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 reason_id = "reason"_utf16_fly_string;
    auto native_reason_getter = JS::NativeFunction::create(realm, reason_getter, 0, reason_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_reason_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto reason_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(reason_id, native_reason_getter, native_reason_setter, reason_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 onabort_id = "onabort"_utf16_fly_string;
    auto native_onabort_getter = JS::NativeFunction::create(realm, onabort_getter, 0, onabort_id, &realm, "get"sv);
    auto native_onabort_setter = JS::NativeFunction::create(realm, onabort_setter, 1, onabort_id, &realm, "set"sv);

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto onabort_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(onabort_id, native_onabort_getter, native_onabort_setter, onabort_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, "throwIfAborted"_utf16_fly_string, throw_if_aborted, 0, default_attributes);

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

void AbortSignalPrototype::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<DOM::AbortSignal*> impl_from(JS::VM& vm, JS::Value js_value)
{

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

[[maybe_unused]] static JS::ThrowCompletionOr<DOM::AbortSignal*> 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(AbortSignalConstructor::abort)
{
    WebIDL::log_trace(vm, "AbortSignalConstructor::abort");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    auto arg0 = vm.argument(0);
    Optional<JS::Value> reason {};
    if (!arg0.is_undefined())
        reason = TRY(throw_dom_exception_if_needed(vm, [&] { return arg0; }));

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return DOM::AbortSignal::abort(vm, reason); }));
    return JS::Value(R);
}

JS_DEFINE_NATIVE_FUNCTION(AbortSignalConstructor::timeout)
{
    WebIDL::log_trace(vm, "AbortSignalConstructor::timeout");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    if (vm.argument_count() < 1)
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::BadArgCountOne, "timeout");

    auto arg0 = vm.argument(0);
    auto milliseconds = TRY(throw_dom_exception_if_needed(vm, [&] { return WebIDL::convert_to_int<WebIDL::UnsignedLongLong>(vm, arg0, WebIDL::EnforceRange::Yes, WebIDL::Clamp::No); }));

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return DOM::AbortSignal::timeout(vm, milliseconds); }));
    return JS::Value(R);
}

JS_DEFINE_NATIVE_FUNCTION(AbortSignalConstructor::any)
{
    WebIDL::log_trace(vm, "AbortSignalConstructor::any");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    if (vm.argument_count() < 1)
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::BadArgCountOne, "any");

    auto arg0 = vm.argument(0);
    auto signals = TRY(throw_dom_exception_if_needed(vm, [&] { return [&]() -> JS::ThrowCompletionOr<GC::RootVector<GC::Ref<DOM::AbortSignal>>> {
        if (!arg0.is_object())
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObject, arg0);

        auto method = TRY(arg0.get_method(vm, vm.well_known_symbol_iterator()));
        if (!method)
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotIterable, arg0);

        return TRY([&]() -> JS::ThrowCompletionOr<GC::RootVector<GC::Ref<DOM::AbortSignal>>> {
        // 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, arg0, *method));

        GC::RootVector<GC::Ref<DOM::AbortSignal>> 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<GC::Ref<DOM::AbortSignal>> {
        if (auto impl = next_value.as_if<DOM::AbortSignal>())
            return *impl;
        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "AbortSignal");
    }(); }));

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

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

    [[maybe_unused]] auto R = TRY(throw_dom_exception_if_needed(vm, [&] { return DOM::AbortSignal::any(vm, signals); }));
    return JS::Value(R);
}

JS_DEFINE_NATIVE_FUNCTION(AbortSignalPrototype::aborted_getter)
{
    WebIDL::log_trace(vm, "AbortSignalPrototype::aborted_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->aborted(); }));

    return JS::Value(R);
}

JS_DEFINE_NATIVE_FUNCTION(AbortSignalPrototype::reason_getter)
{
    WebIDL::log_trace(vm, "AbortSignalPrototype::reason_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->reason(); }));

    return R;
}

JS_DEFINE_NATIVE_FUNCTION(AbortSignalPrototype::onabort_getter)
{
    WebIDL::log_trace(vm, "AbortSignalPrototype::onabort_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->onabort(); }));

    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(AbortSignalPrototype::onabort_setter)
{
    WebIDL::log_trace(vm, "AbortSignalPrototype::onabort_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]] DOM::AbortSignal* 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_onabort(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(AbortSignalPrototype::throw_if_aborted)
{
    WebIDL::log_trace(vm, "AbortSignalPrototype::throw_if_aborted");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] DOM::AbortSignal* idl_object = TRY(impl_from(vm));

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

} // namespace Web::Bindings