#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/ExceptionOrUtils.h>
#include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/Bindings/Table.h>
#include <LibWeb/WebAssembly/Table.h>
#include <LibWeb/WebIDL/Tracing.h>

namespace Web::Bindings {

void TableConstructor::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(1), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.name, JS::PrimitiveString::create(vm, "Table"_utf16), JS::Attribute::Configurable);
    object.define_direct_property(vm.names.prototype, &ensure_web_prototype<TablePrototype>(realm, "WebAssembly.Table"_fly_string), 0);
}

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

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

    // 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<TablePrototype>(*target_realm, "WebAssembly.Table"_fly_string);
    }

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

    auto arg0 = vm.argument(0);
    auto descriptor = TRY(throw_dom_exception_if_needed(vm, [&] { return convert_to_idl_value_for_table_descriptor(vm, arg0); }));

    auto arg1 = vm.argument(1);
    Optional<JS::Value> value {};
    if (!arg1.is_undefined())
        value = TRY(throw_dom_exception_if_needed(vm, [&] { return arg1; }));

    auto impl = TRY(throw_dom_exception_if_needed(vm, [&] { return WebAssembly::Table::construct_impl(realm, descriptor, value); }));

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

    return *impl;
}

void TablePrototype::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());

    auto length_id = "length"_utf16_fly_string;
    auto native_length_getter = JS::NativeFunction::create(realm, length_getter, 0, length_id, &realm, "get"sv);
    GC::Ptr<JS::NativeFunction> native_length_setter;

    // 4. Let configurable be false if attr is unforgeable and true otherwise.
    auto length_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(length_id, native_length_getter, native_length_setter, length_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, "grow"_utf16_fly_string, grow, 1, default_attributes);

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

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

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

void TablePrototype::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<WebAssembly::Table*> impl_from(JS::VM& vm, JS::Value js_value)
{

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

[[maybe_unused]] static JS::ThrowCompletionOr<WebAssembly::Table*> 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(TablePrototype::length_getter)
{
    WebIDL::log_trace(vm, "TablePrototype::length_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->length(); }));

    return R;
}

JS_DEFINE_NATIVE_FUNCTION(TablePrototype::grow)
{
    WebIDL::log_trace(vm, "TablePrototype::grow");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] WebAssembly::Table* idl_object = TRY(impl_from(vm));

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

    auto arg0 = vm.argument(0);
    auto delta = TRY(throw_dom_exception_if_needed(vm, [&] { return arg0; }));

    auto arg1 = vm.argument(1);
    Optional<JS::Value> value {};
    if (!arg1.is_undefined())
        value = TRY(throw_dom_exception_if_needed(vm, [&] { return arg1; }));

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

JS_DEFINE_NATIVE_FUNCTION(TablePrototype::get)
{
    WebIDL::log_trace(vm, "TablePrototype::get");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] WebAssembly::Table* idl_object = TRY(impl_from(vm));

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

    auto arg0 = vm.argument(0);
    auto index = TRY(throw_dom_exception_if_needed(vm, [&] { return arg0; }));

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

JS_DEFINE_NATIVE_FUNCTION(TablePrototype::set)
{
    WebIDL::log_trace(vm, "TablePrototype::set");
    [[maybe_unused]] auto& realm = *vm.current_realm();
    [[maybe_unused]] WebAssembly::Table* idl_object = TRY(impl_from(vm));

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

    auto arg0 = vm.argument(0);
    auto index = TRY(throw_dom_exception_if_needed(vm, [&] { return arg0; }));

    auto arg1 = vm.argument(1);
    Optional<JS::Value> value {};
    if (!arg1.is_undefined())
        value = TRY(throw_dom_exception_if_needed(vm, [&] { return arg1; }));

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

// https://webidl.spec.whatwg.org/#idl-enumeration
JS::ThrowCompletionOr<AddressType> convert_to_idl_value_for_address_type(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 == "i32"sv)
        return AddressType::I32;
    if (value_as_string == "i64"sv)
        return AddressType::I64;
    return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidEnumerationValue, value_as_string, "AddressType");
}

// https://webidl.spec.whatwg.org/#idl-enumeration
Utf16String idl_enum_to_string(AddressType 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 AddressType::I32:
        return "i32"_utf16;
    case AddressType::I64:
        return "i64"_utf16;
    }
    VERIFY_NOT_REACHED();
}

// https://webidl.spec.whatwg.org/#idl-enumeration
JS::ThrowCompletionOr<TableKind> convert_to_idl_value_for_table_kind(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 == "externref"sv)
        return TableKind::Externref;
    if (value_as_string == "anyfunc"sv)
        return TableKind::Anyfunc;
    return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidEnumerationValue, value_as_string, "TableKind");
}

// https://webidl.spec.whatwg.org/#idl-enumeration
Utf16String idl_enum_to_string(TableKind 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 TableKind::Externref:
        return "externref"_utf16;
    case TableKind::Anyfunc:
        return "anyfunc"_utf16;
    }
    VERIFY_NOT_REACHED();
}

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

    // 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 TableDescriptor {
        .address = TRY([&]() -> JS::ThrowCompletionOr<Optional<AddressType>> {
            // 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("address"_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_address_type(vm, js_member_value); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 7. Otherwise, jsMemberValue is undefined and the member is optional.
            return OptionalNone {};
        }()),
        .element = TRY([&]() -> JS::ThrowCompletionOr<TableKind> {
            // 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("element"_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_table_kind(vm, js_member_value); }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 6. Otherwise, if jsMemberValue is undefined and member is required, then throw a TypeError.
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::MissingRequiredProperty, "element");
        }()),
        .initial = TRY([&]() -> JS::ThrowCompletionOr<JS::Value> {
            // 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("initial"_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_member_value; }));

                // 2. Set idlDict[key] to idlMemberValue.
                return idl_member_value;
            }
            // 6. Otherwise, if jsMemberValue is undefined and member is required, then throw a TypeError.
            return vm.throw_completion<JS::TypeError>(JS::ErrorType::MissingRequiredProperty, "initial");
        }()),
        .maximum = TRY([&]() -> JS::ThrowCompletionOr<Optional<JS::Value>> {
            // 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("maximum"_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_member_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