// © 2018 and later: Unicode, Inc. and others.

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

#include "unicode/utypes.h"

#if !UCONFIG_NO_FORMATTING

// Allow implicit conversion from char16_t* to UnicodeString for this file:

// Helpful in toString methods and elsewhere.

#define UNISTR_FROM_STRING_EXPLICIT

#include <typeinfo>

#include <array>

#include "number_types.h"

#include "number_patternstring.h"

#include "numparse_types.h"

#include "numparse_impl.h"

#include "numparse_symbols.h"

#include "numparse_decimal.h"

#include "unicode/numberformatter.h"

#include "cstr.h"

#include "number_mapper.h"

#include "static_unicode_sets.h"

using namespace icu;

using namespace icu::number;

using namespace icu::number::impl;

using namespace icu::numparse;

using namespace icu::numparse::impl;

NumberParseMatcher::~NumberParseMatcher() = default;

NumberParserImpl*

NumberParserImpl::createSimpleParser(const Locale& locale, const UnicodeString& patternString,

                                     parse_flags_t parseFlags, UErrorCode& status) {

    LocalPointer<NumberParserImpl> parser(new NumberParserImpl(parseFlags));

    DecimalFormatSymbols symbols(locale, status);

    parser->fLocalMatchers.ignorables = {parseFlags};

    IgnorablesMatcher& ignorables = parser->fLocalMatchers.ignorables;

    DecimalFormatSymbols dfs(locale, status);

    dfs.setSymbol(DecimalFormatSymbols::kCurrencySymbol, u"IU$");

    dfs.setSymbol(DecimalFormatSymbols::kIntlCurrencySymbol, u"ICU");

    CurrencySymbols currencySymbols({u"ICU", status}, locale, dfs, status);

    ParsedPatternInfo patternInfo;

    PatternParser::parseToPatternInfo(patternString, patternInfo, status);

    // The following statements set up the affix matchers.

    AffixTokenMatcherSetupData affixSetupData = {

            currencySymbols, symbols, ignorables, locale, parseFlags};

    parser->fLocalMatchers.affixTokenMatcherWarehouse = {&affixSetupData};

    parser->fLocalMatchers.affixMatcherWarehouse = {&parser->fLocalMatchers.affixTokenMatcherWarehouse};

    parser->fLocalMatchers.affixMatcherWarehouse.createAffixMatchers(

            patternInfo, *parser, ignorables, parseFlags, status);

    Grouper grouper = Grouper::forStrategy(UNUM_GROUPING_AUTO);

    grouper.setLocaleData(patternInfo, locale);

    parser->addMatcher(parser->fLocalMatchers.ignorables);

    parser->addMatcher(parser->fLocalMatchers.decimal = {symbols, grouper, parseFlags});

    parser->addMatcher(parser->fLocalMatchers.minusSign = {symbols, false});

    parser->addMatcher(parser->fLocalMatchers.plusSign = {symbols, false});

    parser->addMatcher(parser->fLocalMatchers.approximatelySign = {symbols, false});

    parser->addMatcher(parser->fLocalMatchers.percent = {symbols});

    parser->addMatcher(parser->fLocalMatchers.permille = {symbols});

    parser->addMatcher(parser->fLocalMatchers.nan = {symbols});

    parser->addMatcher(parser->fLocalMatchers.infinity = {symbols});

    parser->addMatcher(parser->fLocalMatchers.padding = {u"@"});

    parser->addMatcher(parser->fLocalMatchers.scientific = {symbols, grouper});

    parser->addMatcher(parser->fLocalMatchers.currency = {currencySymbols, symbols, parseFlags, status});

    parser->addMatcher(parser->fLocalValidators.number = {});

    parser->freeze();

    return parser.orphan();

}

NumberParserImpl*

NumberParserImpl::createParserFromProperties(const number::impl::DecimalFormatProperties& properties,

                                             const DecimalFormatSymbols& symbols, bool parseCurrency,

                                             UErrorCode& status) {

    Locale locale = symbols.getLocale();

    AutoAffixPatternProvider affixProvider(properties, status);

    if (U_FAILURE(status)) { return nullptr; }

    CurrencyUnit currency = resolveCurrency(properties, locale, status);

    CurrencySymbols currencySymbols(currency, locale, symbols, status);

    bool isStrict = properties.parseMode.getOrDefault(PARSE_MODE_STRICT) == PARSE_MODE_STRICT;

    Grouper grouper = Grouper::forProperties(properties);

    int parseFlags = 0;

    if (U_FAILURE(status)) { return nullptr; }

    if (!properties.parseCaseSensitive) {

        parseFlags |= PARSE_FLAG_IGNORE_CASE;

    }

    if (properties.parseIntegerOnly) {

        parseFlags |= PARSE_FLAG_INTEGER_ONLY;

    }

    if (properties.signAlwaysShown) {

        parseFlags |= PARSE_FLAG_PLUS_SIGN_ALLOWED;

    }

    if (isStrict) {

        parseFlags |= PARSE_FLAG_STRICT_GROUPING_SIZE;

        parseFlags |= PARSE_FLAG_STRICT_SEPARATORS;

        parseFlags |= PARSE_FLAG_USE_FULL_AFFIXES;

        parseFlags |= PARSE_FLAG_EXACT_AFFIX;

        parseFlags |= PARSE_FLAG_STRICT_IGNORABLES;

    } else {

        parseFlags |= PARSE_FLAG_INCLUDE_UNPAIRED_AFFIXES;

    }

    if (grouper.getPrimary() <= 0) {

        parseFlags |= PARSE_FLAG_GROUPING_DISABLED;

    }

    if (parseCurrency || affixProvider.get().hasCurrencySign()) {

        parseFlags |= PARSE_FLAG_MONETARY_SEPARATORS;

    }

    if (!parseCurrency) {

        parseFlags |= PARSE_FLAG_NO_FOREIGN_CURRENCY;

    }

    LocalPointer<NumberParserImpl> parser(new NumberParserImpl(parseFlags));

    parser->fLocalMatchers.ignorables = {parseFlags};

    IgnorablesMatcher& ignorables = parser->fLocalMatchers.ignorables;

    //////////////////////

    /// AFFIX MATCHERS ///

    //////////////////////

    // The following statements set up the affix matchers.

    AffixTokenMatcherSetupData affixSetupData = {

            currencySymbols, symbols, ignorables, locale, parseFlags};

    parser->fLocalMatchers.affixTokenMatcherWarehouse = {&affixSetupData};

    parser->fLocalMatchers.affixMatcherWarehouse = {&parser->fLocalMatchers.affixTokenMatcherWarehouse};

    parser->fLocalMatchers.affixMatcherWarehouse.createAffixMatchers(

            affixProvider.get(), *parser, ignorables, parseFlags, status);

    ////////////////////////

    /// CURRENCY MATCHER ///

    ////////////////////////

    if (parseCurrency || affixProvider.get().hasCurrencySign()) {

        parser->addMatcher(parser->fLocalMatchers.currency = {currencySymbols, symbols, parseFlags, status});

    }

    ///////////////

    /// PERCENT ///

    ///////////////

    // ICU-TC meeting, April 11, 2018: accept percent/permille only if it is in the pattern,

    // and to maintain regressive behavior, divide by 100 even if no percent sign is present.

    if (!isStrict && affixProvider.get().containsSymbolType(AffixPatternType::TYPE_PERCENT, status)) {

        parser->addMatcher(parser->fLocalMatchers.percent = {symbols});

    }

    if (!isStrict && affixProvider.get().containsSymbolType(AffixPatternType::TYPE_PERMILLE, status)) {

        parser->addMatcher(parser->fLocalMatchers.permille = {symbols});

    }

    ///////////////////////////////

    /// OTHER STANDARD MATCHERS ///

    ///////////////////////////////

    if (!isStrict) {

        parser->addMatcher(parser->fLocalMatchers.plusSign = {symbols, false});

        parser->addMatcher(parser->fLocalMatchers.minusSign = {symbols, false});

        parser->addMatcher(parser->fLocalMatchers.approximatelySign = {symbols, false});

    }

    parser->addMatcher(parser->fLocalMatchers.nan = {symbols});

    parser->addMatcher(parser->fLocalMatchers.infinity = {symbols});

    UnicodeString padString = properties.padString;

    if (!padString.isBogus() && !ignorables.getSet()->contains(padString)) {

        parser->addMatcher(parser->fLocalMatchers.padding = {padString});

    }

    parser->addMatcher(parser->fLocalMatchers.ignorables);

    parser->addMatcher(parser->fLocalMatchers.decimal = {symbols, grouper, parseFlags});

    // NOTE: parseNoExponent doesn't disable scientific parsing if we have a scientific formatter

    if (!properties.parseNoExponent || properties.minimumExponentDigits > 0) {

        parser->addMatcher(parser->fLocalMatchers.scientific = {symbols, grouper});

    }

    //////////////////

    /// VALIDATORS ///

    //////////////////

    parser->addMatcher(parser->fLocalValidators.number = {});

    if (isStrict) {

        parser->addMatcher(parser->fLocalValidators.affix = {});

    }

    if (parseCurrency) {

        parser->addMatcher(parser->fLocalValidators.currency = {});

    }

    if (properties.decimalPatternMatchRequired) {

        bool patternHasDecimalSeparator =

                properties.decimalSeparatorAlwaysShown || properties.maximumFractionDigits != 0;

        parser->addMatcher(parser->fLocalValidators.decimalSeparator = {patternHasDecimalSeparator});

    }

    // The multiplier takes care of scaling percentages.

    Scale multiplier = scaleFromProperties(properties);

    if (multiplier.isValid()) {

        parser->addMatcher(parser->fLocalValidators.multiplier = {multiplier});

    }

    parser->freeze();

    return parser.orphan();

}

NumberParserImpl::NumberParserImpl(parse_flags_t parseFlags)

        : fParseFlags(parseFlags) {

}

NumberParserImpl::~NumberParserImpl() {

    fNumMatchers = 0;

}

void NumberParserImpl::addMatcher(NumberParseMatcher& matcher) {

    if (fNumMatchers + 1 > fMatchers.getCapacity()) {

        fMatchers.resize(fNumMatchers * 2, fNumMatchers);

    }

    fMatchers[fNumMatchers] = &matcher;

    fNumMatchers++;

}

void NumberParserImpl::freeze() {

    fFrozen = true;

}

parse_flags_t NumberParserImpl::getParseFlags() const {

    return fParseFlags;

}

void NumberParserImpl::parse(const UnicodeString& input, bool greedy, ParsedNumber& result,

                             UErrorCode& status) const {

    return parse(input, 0, greedy, result, status);

}

void NumberParserImpl::parse(const UnicodeString& input, int32_t start, bool greedy, ParsedNumber& result,

                             UErrorCode& status) const {

    if (U_FAILURE(status)) {

        return;

    }

    U_ASSERT(fFrozen);

    // TODO: Check start >= 0 and start < input.length()

    StringSegment segment(input, 0 != (fParseFlags & PARSE_FLAG_IGNORE_CASE));

    segment.adjustOffset(start);

    if (greedy) {

        parseGreedy(segment, result, status);

    } else if (0 != (fParseFlags & PARSE_FLAG_ALLOW_INFINITE_RECURSION)) {

        // Start at 1 so that recursionLevels never gets to 0

        parseLongestRecursive(segment, result, 1, status);

    } else {

        // Arbitrary recursion safety limit: 100 levels.

        parseLongestRecursive(segment, result, -100, status);

    }

    for (int32_t i = 0; i < fNumMatchers; i++) {

        fMatchers[i]->postProcess(result);

    }

    result.postProcess();

}

void NumberParserImpl::parseGreedy(StringSegment& segment, ParsedNumber& result,

                                            UErrorCode& status) const {

    // Note: this method is not recursive in order to avoid stack overflow.

    for (int i = 0; i <fNumMatchers;) {

        // Base Case

        if (segment.length() == 0) {

            return;

        }

        const NumberParseMatcher* matcher = fMatchers[i];

        if (!matcher->smokeTest(segment)) {

            // Matcher failed smoke test: try the next one

            i++;

            continue;

        }

        int32_t initialOffset = segment.getOffset();

        matcher->match(segment, result, status);

        if (U_FAILURE(status)) {

            return;

        }

        if (segment.getOffset() != initialOffset) {

            // Greedy heuristic: accept the match and loop back

            i = 0;

            continue;

        } else {

            // Matcher did not match: try the next one

            i++;

            continue;

        }

        UPRV_UNREACHABLE_EXIT;

    }

    // NOTE: If we get here, the greedy parse completed without consuming the entire string.

}

void NumberParserImpl::parseLongestRecursive(StringSegment& segment, ParsedNumber& result,

                                             int32_t recursionLevels,

                                             UErrorCode& status) const {

    // Base Case

    if (segment.length() == 0) {

        return;

    }

    // Safety against stack overflow

    if (recursionLevels == 0) {

        return;

    }

    // TODO: Give a nice way for the matcher to reset the ParsedNumber?

    ParsedNumber initial(result);

    ParsedNumber candidate;

    int initialOffset = segment.getOffset();

    for (int32_t i = 0; i < fNumMatchers; i++) {

        const NumberParseMatcher* matcher = fMatchers[i];

        if (!matcher->smokeTest(segment)) {

            continue;

        }

        // In a non-greedy parse, we attempt all possible matches and pick the best.

        for (int32_t charsToConsume = 0; charsToConsume < segment.length();) {

            charsToConsume += U16_LENGTH(segment.codePointAt(charsToConsume));

            // Run the matcher on a segment of the current length.

            candidate = initial;

            segment.setLength(charsToConsume);

            bool maybeMore = matcher->match(segment, candidate, status);

            segment.resetLength();

            if (U_FAILURE(status)) {

                return;

            }

            // If the entire segment was consumed, recurse.

            if (segment.getOffset() - initialOffset == charsToConsume) {

                parseLongestRecursive(segment, candidate, recursionLevels + 1, status);

                if (U_FAILURE(status)) {

                    return;

                }

                if (candidate.isBetterThan(result)) {

                    result = candidate;

                }

            }

            // Since the segment can be re-used, reset the offset.

            // This does not have an effect if the matcher did not consume any chars.

            segment.setOffset(initialOffset);

            // Unless the matcher wants to see the next char, continue to the next matcher.

            if (!maybeMore) {

                break;

            }

        }

    }

}

UnicodeString NumberParserImpl::toString() const {

    UnicodeString result(u"<NumberParserImpl matchers:[");

    for (int32_t i = 0; i < fNumMatchers; i++) {

        result.append(u' ');

        result.append(fMatchers[i]->toString());

    }

    result.append(u" ]>", -1);

    return result;

}

#endif /* #if !UCONFIG_NO_FORMATTING */