/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "ICULocale.h"

#include <wtf/PassOwnPtr.h>
#include <wtf/text/StringBuilder.h>

using namespace icu;

namespace WebCore {

ICULocale::ICULocale(const char* locale)
    : m_locale(locale)
    , m_numberFormat(0)
    , m_didCreateDecimalFormat(false)
{
}

ICULocale::~ICULocale()
{
    unum_close(m_numberFormat);
}

PassOwnPtr<ICULocale> ICULocale::create(const char* localeString)
{
    return adoptPtr(new ICULocale(localeString));
}

PassOwnPtr<ICULocale> ICULocale::createForCurrentLocale()
{
    return adoptPtr(new ICULocale(0));
}

ICULocale* ICULocale::currentLocale()
{
    static ICULocale* currentICULocale = ICULocale::createForCurrentLocale().leakPtr();
    return currentICULocale;
}

void ICULocale::setDecimalSymbol(unsigned index, UNumberFormatSymbol symbol)
{
    UErrorCode status = U_ZERO_ERROR;
    int32_t bufferLength = unum_getSymbol(m_numberFormat, symbol, 0, 0, &status);
    ASSERT(U_SUCCESS(status) || status == U_BUFFER_OVERFLOW_ERROR);
    if (U_FAILURE(status) && status != U_BUFFER_OVERFLOW_ERROR)
        return;
    Vector<UChar> buffer(bufferLength);
    status = U_ZERO_ERROR;
    unum_getSymbol(m_numberFormat, symbol, buffer.data(), bufferLength, &status);
    if (U_FAILURE(status))
        return;
    m_decimalSymbols[index] = String::adopt(buffer);
}

void ICULocale::setDecimalTextAttribute(String& destination, UNumberFormatTextAttribute tag)
{
    UErrorCode status = U_ZERO_ERROR;
    int32_t bufferLength = unum_getTextAttribute(m_numberFormat, tag, 0, 0, &status);
    ASSERT(U_SUCCESS(status) || status == U_BUFFER_OVERFLOW_ERROR);
    if (U_FAILURE(status) && status != U_BUFFER_OVERFLOW_ERROR)
        return;
    Vector<UChar> buffer(bufferLength);
    status = U_ZERO_ERROR;
    unum_getTextAttribute(m_numberFormat, tag, buffer.data(), bufferLength, &status);
    ASSERT(U_SUCCESS(status));
    if (U_FAILURE(status))
        return;
    destination = String::adopt(buffer);
}

void ICULocale::initializeDecimalFormat()
{
    if (m_didCreateDecimalFormat)
        return;
    m_didCreateDecimalFormat = true;
    UErrorCode status = U_ZERO_ERROR;
    m_numberFormat = unum_open(UNUM_DECIMAL, 0, 0, m_locale.data(), 0, &status);
    if (!U_SUCCESS(status))
        return;

    setDecimalSymbol(0, UNUM_ZERO_DIGIT_SYMBOL);
    setDecimalSymbol(1, UNUM_ONE_DIGIT_SYMBOL);
    setDecimalSymbol(2, UNUM_TWO_DIGIT_SYMBOL);
    setDecimalSymbol(3, UNUM_THREE_DIGIT_SYMBOL);
    setDecimalSymbol(4, UNUM_FOUR_DIGIT_SYMBOL);
    setDecimalSymbol(5, UNUM_FIVE_DIGIT_SYMBOL);
    setDecimalSymbol(6, UNUM_SIX_DIGIT_SYMBOL);
    setDecimalSymbol(7, UNUM_SEVEN_DIGIT_SYMBOL);
    setDecimalSymbol(8, UNUM_EIGHT_DIGIT_SYMBOL);
    setDecimalSymbol(9, UNUM_NINE_DIGIT_SYMBOL);
    setDecimalSymbol(DecimalSeparatorIndex, UNUM_DECIMAL_SEPARATOR_SYMBOL);
    setDecimalSymbol(GroupSeparatorIndex, UNUM_GROUPING_SEPARATOR_SYMBOL);
    setDecimalTextAttribute(m_positivePrefix, UNUM_POSITIVE_PREFIX);
    setDecimalTextAttribute(m_positiveSuffix, UNUM_POSITIVE_SUFFIX);
    setDecimalTextAttribute(m_negativePrefix, UNUM_NEGATIVE_PREFIX);
    setDecimalTextAttribute(m_negativeSuffix, UNUM_NEGATIVE_SUFFIX);
    ASSERT(!m_positivePrefix.isEmpty() || !m_positiveSuffix.isEmpty() || !m_negativePrefix.isEmpty() || !m_negativeSuffix.isEmpty());
}

String ICULocale::convertToLocalizedNumber(const String& input)
{
    initializeDecimalFormat();
    if (!m_numberFormat || input.isEmpty())
        return input;

    unsigned i = 0;
    bool isNegative = false;
    UnicodeString ustring;
    StringBuilder builder;
    builder.reserveCapacity(input.length());

    if (input[0] == '-') {
        ++i;
        isNegative = true;
        builder.append(m_negativePrefix);
    } else
        builder.append(m_positivePrefix);

    for (; i < input.length(); ++i) {
        switch (input[i]) {
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            builder.append(m_decimalSymbols[input[i] - '0']);
            break;
        case '.':
            builder.append(m_decimalSymbols[DecimalSeparatorIndex]);
            break;
        default:
            ASSERT_NOT_REACHED();
        }
    }

    builder.append(isNegative ? m_negativeSuffix : m_positiveSuffix);

    return builder.toString();
}

static bool matches(const String& text, unsigned position, const String& part)
{
    if (part.isEmpty())
        return true;
    if (position + part.length() > text.length())
        return false;
    for (unsigned i = 0; i < part.length(); ++i) {
        if (text[position + i] != part[i])
            return false;
    }
    return true;
}

bool ICULocale::detectSignAndGetDigitRange(const String& input, bool& isNegative, unsigned& startIndex, unsigned& endIndex)
{
    startIndex = 0;
    endIndex = input.length();
    if (m_negativePrefix.isEmpty() && m_negativeSuffix.isEmpty()) {
        if (input.startsWith(m_positivePrefix) && input.endsWith(m_positiveSuffix)) {
            isNegative = false;
            startIndex = m_positivePrefix.length();
            endIndex -= m_positiveSuffix.length();
        } else
            isNegative = true;
    } else {
        if (input.startsWith(m_negativePrefix) && input.endsWith(m_negativeSuffix)) {
            isNegative = true;
            startIndex = m_negativePrefix.length();
            endIndex -= m_negativeSuffix.length();
        } else {
            isNegative = false;
            if (input.startsWith(m_positivePrefix) && input.endsWith(m_positiveSuffix)) {
                startIndex = m_positivePrefix.length();
                endIndex -= m_positiveSuffix.length();
            } else
                return false;
        }
    }
    return true;
}

unsigned ICULocale::matchedDecimalSymbolIndex(const String& input, unsigned& position)
{
    for (unsigned symbolIndex = 0; symbolIndex < DecimalSymbolsSize; ++symbolIndex) {
        if (m_decimalSymbols[symbolIndex].length() && matches(input, position, m_decimalSymbols[symbolIndex])) {
            position += m_decimalSymbols[symbolIndex].length();
            return symbolIndex;
        }
    }
    return DecimalSymbolsSize;
}

String ICULocale::convertFromLocalizedNumber(const String& localized)
{
    initializeDecimalFormat();
    String input = localized.stripWhiteSpace();
    if (!m_numberFormat || input.isEmpty())
        return input;

    bool isNegative;
    unsigned startIndex;
    unsigned endIndex;
    if (!detectSignAndGetDigitRange(input, isNegative, startIndex, endIndex)) {
        // Input is broken. Returning an invalid number string.
        return "*";
    }

    StringBuilder builder;
    builder.reserveCapacity(input.length());
    if (isNegative)
        builder.append("-");
    for (unsigned i = startIndex; i < endIndex;) {
        unsigned symbolIndex = matchedDecimalSymbolIndex(input, i);
        if (symbolIndex >= DecimalSymbolsSize)
            return "*";
        if (symbolIndex == DecimalSeparatorIndex)
            builder.append('.');
        else if (symbolIndex == GroupSeparatorIndex) {
            // Ignore group separators.

        } else
            builder.append(static_cast<UChar>('0' + symbolIndex));
    }
    return builder.toString();
}

} // namespace WebCore