/*
 * Copyright (c) 2021, Tim Flynn <trflynn89@pm.me>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/Intl/AbstractOperations.h>
#include <LibJS/Runtime/Intl/NumberFormat.h>
#include <LibJS/Runtime/Intl/NumberFormatConstructor.h>
#include <LibUnicode/CurrencyCode.h>
#include <LibUnicode/Locale.h>

namespace JS::Intl {

static Vector<StringView> const& number_format_relevant_extension_keys()
{
    // 15.3.3 Internal slots, https://tc39.es/ecma402/#sec-intl.numberformat-internal-slots
    // The value of the [[RelevantExtensionKeys]] internal slot is « "nu" ».
    static Vector<StringView> relevant_extension_keys { "nu"sv };
    return relevant_extension_keys;
}

// 15.1.1 SetNumberFormatDigitOptions ( intlObj, options, mnfdDefault, mxfdDefault, notation ), https://tc39.es/ecma402/#sec-setnfdigitoptions
static void set_number_format_digit_options(GlobalObject& global_object, NumberFormat& intl_object, Object& options, int default_min_fraction_digits, int default_max_fraction_digits, NumberFormat::Notation notation)
{
    auto& vm = global_object.vm();

    // 1. Assert: Type(intlObj) is Object.
    // 2. Assert: Type(options) is Object.
    // 3. Assert: Type(mnfdDefault) is Number.
    // 4. Assert: Type(mxfdDefault) is Number.

    // 5. Let mnid be ? GetNumberOption(options, "minimumIntegerDigits,", 1, 21, 1).
    auto min_integer_digits = get_number_option(global_object, options, vm.names.minimumIntegerDigits, 1, 21, 1);
    if (vm.exception())
        return;

    // 6. Let mnfd be ? Get(options, "minimumFractionDigits").
    auto min_fraction_digits = options.get(vm.names.minimumFractionDigits);
    if (vm.exception())
        return;

    // 7. Let mxfd be ? Get(options, "maximumFractionDigits").
    auto max_fraction_digits = options.get(vm.names.maximumFractionDigits);
    if (vm.exception())
        return;

    // 8. Let mnsd be ? Get(options, "minimumSignificantDigits").
    auto min_significant_digits = options.get(vm.names.minimumSignificantDigits);
    if (vm.exception())
        return;

    // 9. Let mxsd be ? Get(options, "maximumSignificantDigits").
    auto max_significant_digits = options.get(vm.names.maximumSignificantDigits);
    if (vm.exception())
        return;

    // 10. Set intlObj.[[MinimumIntegerDigits]] to mnid.
    intl_object.set_min_integer_digits(*min_integer_digits);

    // 11. If mnsd is not undefined or mxsd is not undefined, then
    if (!min_significant_digits.is_undefined() || !max_significant_digits.is_undefined()) {
        // a. Set intlObj.[[RoundingType]] to significantDigits.
        intl_object.set_rounding_type(NumberFormat::RoundingType::SignificantDigits);

        // b. Let mnsd be ? DefaultNumberOption(mnsd, 1, 21, 1).
        auto min_digits = default_number_option(global_object, min_significant_digits, 1, 21, 1);
        if (vm.exception())
            return;

        // c. Let mxsd be ? DefaultNumberOption(mxsd, mnsd, 21, 21).
        auto max_digits = default_number_option(global_object, max_significant_digits, *min_digits, 21, 21);
        if (vm.exception())
            return;

        // d. Set intlObj.[[MinimumSignificantDigits]] to mnsd.
        intl_object.set_min_significant_digits(*min_digits);

        // e. Set intlObj.[[MaximumSignificantDigits]] to mxsd.
        intl_object.set_max_significant_digits(*max_digits);
    }
    // 12. Else if mnfd is not undefined or mxfd is not undefined, then
    else if (!min_fraction_digits.is_undefined() || !max_fraction_digits.is_undefined()) {
        // a. Set intlObj.[[RoundingType]] to fractionDigits.
        intl_object.set_rounding_type(NumberFormat::RoundingType::FractionDigits);

        // b. Let mnfd be ? DefaultNumberOption(mnfd, 0, 20, undefined).
        auto min_digits = default_number_option(global_object, min_fraction_digits, 0, 20, {});
        if (vm.exception())
            return;

        // c. Let mxfd be ? DefaultNumberOption(mxfd, 0, 20, undefined).
        auto max_digits = default_number_option(global_object, max_fraction_digits, 0, 20, {});
        if (vm.exception())
            return;

        // d. If mnfd is undefined, set mnfd to min(mnfdDefault, mxfd).
        if (!min_digits.has_value()) {
            min_digits = min(default_min_fraction_digits, *max_digits);
        }
        // e. Else if mxfd is undefined, set mxfd to max(mxfdDefault, mnfd).
        else if (!max_digits.has_value()) {
            max_digits = max(default_max_fraction_digits, *min_digits);
        }
        // f. Else if mnfd is greater than mxfd, throw a RangeError exception.
        else if (*min_digits > *max_digits) {
            vm.throw_exception<RangeError>(global_object, ErrorType::IntlMinimumExceedsMaximum, *min_digits, *max_digits);
            return;
        }

        // g. Set intlObj.[[MinimumFractionDigits]] to mnfd.
        intl_object.set_min_fraction_digits(*min_digits);

        // h. Set intlObj.[[MaximumFractionDigits]] to mxfd.
        intl_object.set_max_fraction_digits(*max_digits);
    }
    // 13. Else if notation is "compact", then
    else if (notation == NumberFormat::Notation::Compact) {
        // a. Set intlObj.[[RoundingType]] to compactRounding.
        intl_object.set_rounding_type(NumberFormat::RoundingType::CompactRounding);

    }
    // 14. Else,
    else {
        // a. Set intlObj.[[RoundingType]] to fractionDigits.
        intl_object.set_rounding_type(NumberFormat::RoundingType::FractionDigits);

        // b. Set intlObj.[[MinimumFractionDigits]] to mnfdDefault.
        intl_object.set_min_fraction_digits(default_min_fraction_digits);

        // c. Set intlObj.[[MaximumFractionDigits]] to mxfdDefault.
        intl_object.set_max_fraction_digits(default_max_fraction_digits);
    }
}

// 15.1.3 CurrencyDigits ( currency ), https://tc39.es/ecma402/#sec-currencydigits
static int currency_digits(StringView currency)
{
    // 1. If the ISO 4217 currency and funds code list contains currency as an alphabetic code, return the minor
    //    unit value corresponding to the currency from the list; otherwise, return 2.
    if (auto currency_code = Unicode::get_currency_code(currency); currency_code.has_value())
        return currency_code->minor_unit.value_or(2);
    return 2;
}

// 15.1.13 SetNumberFormatUnitOptions ( intlObj, options ), https://tc39.es/ecma402/#sec-setnumberformatunitoptions
static void set_number_format_unit_options(GlobalObject& global_object, NumberFormat& intl_object, Object& options)
{
    auto& vm = global_object.vm();

    // 1. Assert: Type(intlObj) is Object.
    // 2. Assert: Type(options) is Object.

    // 3. Let style be ? GetOption(options, "style", "string", « "decimal", "percent", "currency", "unit" », "decimal").
    auto style = get_option(global_object, &options, vm.names.style, Value::Type::String, { "decimal"sv, "percent"sv, "currency"sv, "unit"sv }, "decimal"sv);
    if (vm.exception())
        return;

    // 4. Set intlObj.[[Style]] to style.
    intl_object.set_style(style.as_string().string());

    // 5. Let currency be ? GetOption(options, "currency", "string", undefined, undefined).
    auto currency = get_option(global_object, &options, vm.names.currency, Value::Type::String, {}, Empty {});
    if (vm.exception())
        return;

    // 6. If currency is undefined, then
    if (currency.is_undefined()) {
        // a. If style is "currency", throw a TypeError exception.
        if (intl_object.style() == NumberFormat::Style::Currency) {
            vm.throw_exception<TypeError>(global_object, ErrorType::IntlOptionUndefined, "currency"sv, "style"sv, style);
            return;
        }
    }
    // 7. Else,
    //     a. If the result of IsWellFormedCurrencyCode(currency) is false, throw a RangeError exception.
    else if (!is_well_formed_currency_code(currency.as_string().string())) {
        vm.throw_exception<RangeError>(global_object, ErrorType::OptionIsNotValidValue, currency, "currency"sv);
        return;
    }

    // 8. Let currencyDisplay be ? GetOption(options, "currencyDisplay", "string", « "code", "symbol", "narrowSymbol", "name" », "symbol").
    auto currency_display = get_option(global_object, &options, vm.names.currencyDisplay, Value::Type::String, { "code"sv, "symbol"sv, "narrowSymbol"sv, "name"sv }, "symbol"sv);
    if (vm.exception())
        return;

    // 9. Let currencySign be ? GetOption(options, "currencySign", "string", « "standard", "accounting" », "standard").
    auto currency_sign = get_option(global_object, &options, vm.names.currencySign, Value::Type::String, { "standard"sv, "accounting"sv }, "standard"sv);
    if (vm.exception())
        return;

    // 10. Let unit be ? GetOption(options, "unit", "string", undefined, undefined).
    auto unit = get_option(global_object, &options, vm.names.unit, Value::Type::String, {}, Empty {});
    if (vm.exception())
        return;

    // 11. If unit is undefined, then
    if (unit.is_undefined()) {
        // a. If style is "unit", throw a TypeError exception.
        if (intl_object.style() == NumberFormat::Style::Unit) {
            vm.throw_exception<TypeError>(global_object, ErrorType::IntlOptionUndefined, "unit"sv, "style"sv, style);
            return;
        }
    }
    // 12. Else,
    //     a. If the result of IsWellFormedUnitIdentifier(unit) is false, throw a RangeError exception.
    else if (!is_well_formed_unit_identifier(unit.as_string().string())) {
        vm.throw_exception<RangeError>(global_object, ErrorType::OptionIsNotValidValue, unit, "unit"sv);
        return;
    }

    // 13. Let unitDisplay be ? GetOption(options, "unitDisplay", "string", « "short", "narrow", "long" », "short").
    auto unit_display = get_option(global_object, &options, vm.names.unitDisplay, Value::Type::String, { "short"sv, "narrow"sv, "long"sv }, "short"sv);
    if (vm.exception())
        return;

    // 14. If style is "currency", then
    if (intl_object.style() == NumberFormat::Style::Currency) {
        // a. Let currency be the result of converting currency to upper case as specified in 6.1.
        // b. Set intlObj.[[Currency]] to currency.
        intl_object.set_currency(currency.as_string().string().to_uppercase());

        // c. Set intlObj.[[CurrencyDisplay]] to currencyDisplay.
        intl_object.set_currency_display(currency_display.as_string().string());

        // d. Set intlObj.[[CurrencySign]] to currencySign.
        intl_object.set_currency_sign(currency_sign.as_string().string());
    }

    // 15. If style is "unit", then
    if (intl_object.style() == NumberFormat::Style::Unit) {
        // a. Set intlObj.[[Unit]] to unit.
        intl_object.set_unit(unit.as_string().string());

        // b. Set intlObj.[[UnitDisplay]] to unitDisplay.
        intl_object.set_unit_display(unit_display.as_string().string());
    }
}

// 15.1.2 InitializeNumberFormat ( numberFormat, locales, options ), https://tc39.es/ecma402/#sec-initializenumberformat
static NumberFormat* initialize_number_format(GlobalObject& global_object, NumberFormat& number_format, Value locales, Value options)
{
    auto& vm = global_object.vm();

    // 1. Let requestedLocales be ? CanonicalizeLocaleList(locales).
    auto requested_locales = canonicalize_locale_list(global_object, locales);
    if (vm.exception())
        return {};

    // 2. Set options to ? CoerceOptionsToObject(options).
    options = coerce_options_to_object(global_object, options);
    if (vm.exception())
        return {};

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

    // 4. Let matcher be ? GetOption(options, "localeMatcher", "string", « "lookup", "best fit" », "best fit").
    auto matcher = get_option(global_object, options, vm.names.localeMatcher, Value::Type::String, { "lookup"sv, "best fit"sv }, "best fit"sv);
    if (vm.exception())
        return {};

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

    // 6. Let numberingSystem be ? GetOption(options, "numberingSystem", "string", undefined, undefined).
    auto numbering_system = get_option(global_object, options, vm.names.numberingSystem, Value::Type::String, {}, Empty {});
    if (vm.exception())
        return {};

    // 7. If numberingSystem is not undefined, then
    if (!numbering_system.is_undefined()) {
        // a. If numberingSystem does not match the Unicode Locale Identifier type nonterminal, throw a RangeError exception.
        if (!Unicode::is_type_identifier(numbering_system.as_string().string())) {
            vm.throw_exception<RangeError>(global_object, ErrorType::OptionIsNotValidValue, numbering_system, "numberingSystem"sv);
            return {};
        }

        // 8. Set opt.[[nu]] to numberingSystem.
        opt.nu = numbering_system.as_string().string();
    }

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

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

    // 12. Set numberFormat.[[DataLocale]] to r.[[dataLocale]].
    number_format.set_data_locale(move(result.data_locale));

    // 13. Set numberFormat.[[NumberingSystem]] to r.[[nu]].
    number_format.set_numbering_system(result.nu.release_value());

    // 14. Perform ? SetNumberFormatUnitOptions(numberFormat, options).
    set_number_format_unit_options(global_object, number_format, options.as_object());
    if (vm.exception())
        return {};

    // 15. Let style be numberFormat.[[Style]].
    auto style = number_format.style();

    int default_min_fraction_digits = 0;
    int default_max_fraction_digits = 0;

    // 16. If style is "currency", then
    if (style == NumberFormat::Style::Currency) {
        // a. Let currency be numberFormat.[[Currency]].
        auto const& currency = number_format.currency();

        // b. Let cDigits be CurrencyDigits(currency).
        int digits = currency_digits(currency);

        // c. Let mnfdDefault be cDigits.
        default_min_fraction_digits = digits;

        // d. Let mxfdDefault be cDigits.
        default_max_fraction_digits = digits;
    }
    // 17. Else,
    else {
        // a. Let mnfdDefault be 0.
        default_min_fraction_digits = 0;

        // b. If style is "percent", then
        //     i. Let mxfdDefault be 0.
        // c. Else,
        //     i. Let mxfdDefault be 3.
        default_max_fraction_digits = style == NumberFormat::Style::Percent ? 0 : 3;
    }

    // 18. Let notation be ? GetOption(options, "notation", "string", « "standard", "scientific", "engineering", "compact" », "standard").
    auto notation = get_option(global_object, options, vm.names.notation, Value::Type::String, { "standard"sv, "scientific"sv, "engineering"sv, "compact"sv }, "standard"sv);
    if (vm.exception())
        return {};

    // 19. Set numberFormat.[[Notation]] to notation.
    number_format.set_notation(notation.as_string().string());

    // 20. Perform ? SetNumberFormatDigitOptions(numberFormat, options, mnfdDefault, mxfdDefault, notation).
    set_number_format_digit_options(global_object, number_format, options.as_object(), default_min_fraction_digits, default_max_fraction_digits, number_format.notation());
    if (vm.exception())
        return {};

    // 21. Let compactDisplay be ? GetOption(options, "compactDisplay", "string", « "short", "long" », "short").
    auto compact_display = get_option(global_object, options, vm.names.compactDisplay, Value::Type::String, { "short"sv, "long"sv }, "short"sv);
    if (vm.exception())
        return {};

    // 22. If notation is "compact", then
    if (number_format.notation() == NumberFormat::Notation::Compact) {
        // a. Set numberFormat.[[CompactDisplay]] to compactDisplay.
        number_format.set_compact_display(compact_display.as_string().string());
    }

    // 23. Let useGrouping be ? GetOption(options, "useGrouping", "boolean", undefined, true).
    auto use_grouping = get_option(global_object, options, vm.names.useGrouping, Value::Type::Boolean, {}, true);
    if (vm.exception())
        return {};

    // 24. Set numberFormat.[[UseGrouping]] to useGrouping.
    number_format.set_use_grouping(use_grouping.as_bool());

    // 25. Let signDisplay be ? GetOption(options, "signDisplay", "string", « "auto", "never", "always", "exceptZero" », "auto").
    auto sign_display = get_option(global_object, options, vm.names.signDisplay, Value::Type::String, { "auto"sv, "never"sv, "always"sv, "exceptZero"sv }, "auto"sv);
    if (vm.exception())
        return {};

    // 26. Set numberFormat.[[SignDisplay]] to signDisplay.
    number_format.set_sign_display(sign_display.as_string().string());

    // 27. Return numberFormat.
    return &number_format;
}

// 15.2 The Intl.NumberFormat Constructor, https://tc39.es/ecma402/#sec-intl-numberformat-constructor
NumberFormatConstructor::NumberFormatConstructor(GlobalObject& global_object)
    : NativeFunction(vm().names.NumberFormat.as_string(), *global_object.function_prototype())
{
}

void NumberFormatConstructor::initialize(GlobalObject& global_object)
{
    NativeFunction::initialize(global_object);

    auto& vm = this->vm();

    // 15.3.1 Intl.NumberFormat.prototype, https://tc39.es/ecma402/#sec-intl.numberformat.prototype
    define_direct_property(vm.names.prototype, global_object.intl_number_format_prototype(), 0);
    define_direct_property(vm.names.length, Value(0), Attribute::Configurable);
}

// 15.2.1 Intl.NumberFormat ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.numberformat
Value NumberFormatConstructor::call()
{
    // 1. If NewTarget is undefined, let newTarget be the active function object, else let newTarget be NewTarget.
    return construct(*this);
}

// 15.2.1 Intl.NumberFormat ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.numberformat
Value NumberFormatConstructor::construct(FunctionObject& new_target)
{
    auto& vm = this->vm();
    auto& global_object = this->global_object();

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

    // 2. Let numberFormat be ? OrdinaryCreateFromConstructor(newTarget, "%NumberFormat.prototype%", « [[InitializedNumberFormat]], [[Locale]], [[DataLocale]], [[NumberingSystem]], [[Style]], [[Unit]], [[UnitDisplay]], [[Currency]], [[CurrencyDisplay]], [[CurrencySign]], [[MinimumIntegerDigits]], [[MinimumFractionDigits]], [[MaximumFractionDigits]], [[MinimumSignificantDigits]], [[MaximumSignificantDigits]], [[RoundingType]], [[Notation]], [[CompactDisplay]], [[UseGrouping]], [[SignDisplay]], [[BoundFormat]] »).
    auto* number_format = ordinary_create_from_constructor<NumberFormat>(global_object, new_target, &GlobalObject::intl_number_format_prototype);
    if (vm.exception())
        return {};

    // 3. Perform ? InitializeNumberFormat(numberFormat, locales, options).
    initialize_number_format(global_object, *number_format, locales, options);
    if (vm.exception())
        return {};

    // 4. If the implementation supports the normative optional constructor mode of 4.3 Note 1, then
    //     a. Let this be the this value.
    //     b. Return ? ChainNumberFormat(numberFormat, NewTarget, this).

    // 5. Return numberFormat.
    return number_format;
}

}