// © 2017 and later: Unicode, Inc. and others.

// License & terms of use: http://www.unicode.org/copyright.html

#include "unicode/utypes.h"

#if !UCONFIG_NO_FORMATTING

#include "unicode/numberformatter.h"

#include "number_patternstring.h"

#include "uresimp.h"

using namespace icu;

using namespace icu::number;

using namespace icu::number::impl;

namespace {

int16_t getMinGroupingForLocale(const Locale& locale) {

    // TODO: Cache this?

    UErrorCode localStatus = U_ZERO_ERROR;

    LocalUResourceBundlePointer bundle(ures_open(nullptr, locale.getName(), &localStatus));

    int32_t resultLen = 0;

    const char16_t* result = ures_getStringByKeyWithFallback(

        bundle.getAlias(),

        "NumberElements/minimumGroupingDigits",

        &resultLen,

        &localStatus);

    // TODO: Is it safe to assume resultLen == 1? Would locales set minGrouping >= 10?

    if (U_FAILURE(localStatus) || resultLen != 1) {

        return 1;

    }

    return result[0] - u'0';

}

}

Grouper Grouper::forStrategy(UNumberGroupingStrategy grouping) {

    switch (grouping) {

    case UNUM_GROUPING_OFF:

        return {-1, -1, -2, grouping};

    case UNUM_GROUPING_AUTO:

        return {-2, -2, -2, grouping};

    case UNUM_GROUPING_MIN2:

        return {-2, -2, -3, grouping};

    case UNUM_GROUPING_ON_ALIGNED:

        return {-4, -4, 1, grouping};

    case UNUM_GROUPING_THOUSANDS:

        return {3, 3, 1, grouping};

    default:

        UPRV_UNREACHABLE_EXIT;

    }

}

Grouper Grouper::forProperties(const DecimalFormatProperties& properties) {

    if (!properties.groupingUsed) {

        return forStrategy(UNUM_GROUPING_OFF);

    }

    auto grouping1 = static_cast<int16_t>(properties.groupingSize);

    auto grouping2 = static_cast<int16_t>(properties.secondaryGroupingSize);

    auto minGrouping = static_cast<int16_t>(properties.minimumGroupingDigits);

    grouping1 = grouping1 > 0 ? grouping1 : grouping2 > 0 ? grouping2 : grouping1;

    grouping2 = grouping2 > 0 ? grouping2 : grouping1;

    return {grouping1, grouping2, minGrouping, UNUM_GROUPING_COUNT};

}

void Grouper::setLocaleData(const impl::ParsedPatternInfo &patternInfo, const Locale& locale) {

    if (fMinGrouping == -2) {

        fMinGrouping = getMinGroupingForLocale(locale);

    } else if (fMinGrouping == -3) {

        fMinGrouping = static_cast<int16_t>(uprv_max(2, getMinGroupingForLocale(locale)));

    } else {

        // leave fMinGrouping alone

    }

    if (fGrouping1 != -2 && fGrouping2 != -4) {

        return;

    }

    auto grouping1 = static_cast<int16_t> (patternInfo.positive.groupingSizes & 0xffff);

    auto grouping2 = static_cast<int16_t> ((patternInfo.positive.groupingSizes >> 16) & 0xffff);

    auto grouping3 = static_cast<int16_t> ((patternInfo.positive.groupingSizes >> 32) & 0xffff);

    if (grouping2 == -1) {

        grouping1 = fGrouping1 == -4 ? static_cast<short>(3) : static_cast<short>(-1);

    }

    if (grouping3 == -1) {

        grouping2 = grouping1;

    }

    fGrouping1 = grouping1;

    fGrouping2 = grouping2;

}

bool Grouper::groupAtPosition(int32_t position, const impl::DecimalQuantity &value) const {

    U_ASSERT(fGrouping1 > -2);

    if (fGrouping1 == -1 || fGrouping1 == 0) {

        // Either -1 or 0 means "no grouping"

        return false;

    }

    position -= fGrouping1;

    return position >= 0 && (position % fGrouping2) == 0

           && value.getUpperDisplayMagnitude() - fGrouping1 + 1 >= fMinGrouping;

}

int16_t Grouper::getPrimary() const {

    return fGrouping1;

}

int16_t Grouper::getSecondary() const {

    return fGrouping2;

}

#endif /* #if !UCONFIG_NO_FORMATTING */