/*
 * Copyright (c) 2022, Tim Flynn <trflynn89@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <AK/Array.h>
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/Intl/AbstractOperations.h>
#include <LibJS/Runtime/Intl/NumberFormatConstructor.h>
#include <LibJS/Runtime/Intl/PluralRules.h>
#include <LibJS/Runtime/Intl/PluralRulesConstructor.h>

namespace JS::Intl {

// 16.1 The Intl.PluralRules Constructor, https://tc39.es/ecma402/#sec-intl-pluralrules-constructor
PluralRulesConstructor::PluralRulesConstructor(Realm& realm)
    : NativeFunction(realm.vm().names.PluralRules.as_string(), *realm.intrinsics().function_prototype())
{
}

void PluralRulesConstructor::initialize(Realm& realm)
{
    NativeFunction::initialize(realm);

    auto& vm = this->vm();

    // 16.2.1 Intl.PluralRules.prototype, https://tc39.es/ecma402/#sec-intl.pluralrules.prototype
    define_direct_property(vm.names.prototype, realm.intrinsics().intl_plural_rules_prototype(), 0);
    define_direct_property(vm.names.length, Value(0), Attribute::Configurable);

    u8 attr = Attribute::Writable | Attribute::Configurable;
    define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
}

// 16.1.1 Intl.PluralRules ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.pluralrules
ThrowCompletionOr<Value> PluralRulesConstructor::call()
{
    // 1. If NewTarget is undefined, throw a TypeError exception.
    return vm().throw_completion<TypeError>(ErrorType::ConstructorWithoutNew, "Intl.PluralRules");
}

// 16.1.1 Intl.PluralRules ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.pluralrules
ThrowCompletionOr<NonnullGCPtr<Object>> PluralRulesConstructor::construct(FunctionObject& new_target)
{
    auto& vm = this->vm();

    auto locales = vm.argument(0);
    auto options = vm.argument(1);

    // 2. Let pluralRules be ? OrdinaryCreateFromConstructor(NewTarget, "%PluralRules.prototype%", « [[InitializedPluralRules]], [[Locale]], [[Type]], [[MinimumIntegerDigits]], [[MinimumFractionDigits]], [[MaximumFractionDigits]], [[MinimumSignificantDigits]], [[MaximumSignificantDigits]], [[RoundingType]] »).
    auto plural_rules = TRY(ordinary_create_from_constructor<PluralRules>(vm, new_target, &Intrinsics::intl_plural_rules_prototype));

    // 3. Return ? InitializePluralRules(pluralRules, locales, options).
    return *TRY(initialize_plural_rules(vm, plural_rules, locales, options));
}

// 16.2.2 Intl.PluralRules.supportedLocalesOf ( locales [ , options ] ), https://tc39.es/ecma402/#sec-intl.pluralrules.supportedlocalesof
JS_DEFINE_NATIVE_FUNCTION(PluralRulesConstructor::supported_locales_of)
{
    auto locales = vm.argument(0);
    auto options = vm.argument(1);

    // 1. Let availableLocales be %PluralRules%.[[AvailableLocales]].

    // 2. Let requestedLocales be ? CanonicalizeLocaleList(locales).
    auto requested_locales = TRY(canonicalize_locale_list(vm, locales));

    // 3. Return ? SupportedLocales(availableLocales, requestedLocales, options).
    return TRY(supported_locales(vm, requested_locales, options));
}

// 16.1.2 InitializePluralRules ( pluralRules, locales, options ), https://tc39.es/ecma402/#sec-initializepluralrules
ThrowCompletionOr<PluralRules*> initialize_plural_rules(VM& vm, PluralRules& plural_rules, Value locales_value, Value options_value)
{
    // 1. Let requestedLocales be ? CanonicalizeLocaleList(locales).
    auto requested_locales = TRY(canonicalize_locale_list(vm, locales_value));

    // 2. Set options to ? CoerceOptionsToObject(options).
    auto* options = TRY(coerce_options_to_object(vm, options_value));

    // 3. Let opt be a new Record.
    LocaleOptions opt {};

    // 4. Let matcher be ? GetOption(options, "localeMatcher", "string", « "lookup", "best fit" », "best fit").
    auto matcher = TRY(get_option(vm, *options, vm.names.localeMatcher, OptionType::String, AK::Array { "lookup"sv, "best fit"sv }, "best fit"sv));

    // 5. Set opt.[[localeMatcher]] to matcher.
    opt.locale_matcher = matcher;

    // 6. Let t be ? GetOption(options, "type", "string", « "cardinal", "ordinal" », "cardinal").
    auto type = TRY(get_option(vm, *options, vm.names.type, OptionType::String, AK::Array { "cardinal"sv, "ordinal"sv }, "cardinal"sv));

    // 7. Set pluralRules.[[Type]] to t.
    plural_rules.set_type(type.as_string().deprecated_string());

    // 8. Perform ? SetNumberFormatDigitOptions(pluralRules, options, +0𝔽, 3𝔽, "standard").
    TRY(set_number_format_digit_options(vm, plural_rules, *options, 0, 3, NumberFormat::Notation::Standard));

    // 9. Let localeData be %PluralRules%.[[LocaleData]].
    // 10. Let r be ResolveLocale(%PluralRules%.[[AvailableLocales]], requestedLocales, opt, %PluralRules%.[[RelevantExtensionKeys]], localeData).
    auto result = resolve_locale(requested_locales, opt, {});

    // 11. Set pluralRules.[[Locale]] to r.[[locale]].
    plural_rules.set_locale(move(result.locale));

    // Non-standard, the data locale is used by our NumberFormat implementation.
    plural_rules.set_data_locale(move(result.data_locale));

    // 12. Return pluralRules.
    return &plural_rules;
}

}
