// © 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 "numparse_types.h"

#include "numparse_decimal.h"

#include "static_unicode_sets.h"

#include "numparse_utils.h"

#include "unicode/uchar.h"

#include "putilimp.h"

#include "number_decimalquantity.h"

#include "string_segment.h"

using namespace icu;

using namespace icu::numparse;

using namespace icu::numparse::impl;

DecimalMatcher::DecimalMatcher(const DecimalFormatSymbols& symbols, const Grouper& grouper,

                               parse_flags_t parseFlags) {

    if (0 != (parseFlags & PARSE_FLAG_MONETARY_SEPARATORS)) {

        groupingSeparator = symbols.getConstSymbol(DecimalFormatSymbols::kMonetaryGroupingSeparatorSymbol);

        decimalSeparator = symbols.getConstSymbol(DecimalFormatSymbols::kMonetarySeparatorSymbol);

    } else {

        groupingSeparator = symbols.getConstSymbol(DecimalFormatSymbols::kGroupingSeparatorSymbol);

        decimalSeparator = symbols.getConstSymbol(DecimalFormatSymbols::kDecimalSeparatorSymbol);

    }

    bool strictSeparators = 0 != (parseFlags & PARSE_FLAG_STRICT_SEPARATORS);

    unisets::Key groupingKey = strictSeparators ? unisets::STRICT_ALL_SEPARATORS

                                                : unisets::ALL_SEPARATORS;

    // Attempt to find separators in the static cache

    groupingUniSet = unisets::get(groupingKey);

    unisets::Key decimalKey = unisets::chooseFrom(

            decimalSeparator,

            strictSeparators ? unisets::STRICT_COMMA : unisets::COMMA,

            strictSeparators ? unisets::STRICT_PERIOD : unisets::PERIOD);

    if (decimalKey >= 0) {

        decimalUniSet = unisets::get(decimalKey);

    } else if (!decimalSeparator.isEmpty()) {

        auto* set = new UnicodeSet();

        set->add(decimalSeparator.char32At(0));

        set->freeze();

        decimalUniSet = set;

        fLocalDecimalUniSet.adoptInstead(set);

    } else {

        decimalUniSet = unisets::get(unisets::EMPTY);

    }

    if (groupingKey >= 0 && decimalKey >= 0) {

        // Everything is available in the static cache

        separatorSet = groupingUniSet;

        leadSet = unisets::get(

                strictSeparators ? unisets::DIGITS_OR_ALL_SEPARATORS

                                 : unisets::DIGITS_OR_STRICT_ALL_SEPARATORS);

    } else {

        auto* set = new UnicodeSet();

        set->addAll(*groupingUniSet);

        set->addAll(*decimalUniSet);

        set->freeze();

        separatorSet = set;

        fLocalSeparatorSet.adoptInstead(set);

        leadSet = nullptr;

    }

    UChar32 cpZero = symbols.getCodePointZero();

    if (cpZero == -1 || !u_isdigit(cpZero) || u_digit(cpZero, 10) != 0) {

        // Uncommon case: okay to allocate.

        auto* digitStrings = new UnicodeString[10];

        fLocalDigitStrings.adoptInstead(digitStrings);

        for (int32_t i = 0; i <= 9; i++) {

            digitStrings[i] = symbols.getConstDigitSymbol(i);

        }

    }

    requireGroupingMatch = 0 != (parseFlags & PARSE_FLAG_STRICT_GROUPING_SIZE);

    groupingDisabled = 0 != (parseFlags & PARSE_FLAG_GROUPING_DISABLED);

    integerOnly = 0 != (parseFlags & PARSE_FLAG_INTEGER_ONLY);

    grouping1 = grouper.getPrimary();

    grouping2 = grouper.getSecondary();

    // Fraction grouping parsing is disabled for now but could be enabled later.

    // See https://unicode-org.atlassian.net/browse/ICU-10794

    // fractionGrouping = 0 != (parseFlags & PARSE_FLAG_FRACTION_GROUPING_ENABLED);

}

bool DecimalMatcher::match(StringSegment& segment, ParsedNumber& result, UErrorCode& status) const {

    return match(segment, result, 0, status);

}

bool DecimalMatcher::match(StringSegment& segment, ParsedNumber& result, int8_t exponentSign,

                           UErrorCode&) const {

    if (result.seenNumber() && exponentSign == 0) {

        // A number has already been consumed.

        return false;

    } else if (exponentSign != 0) {

        // scientific notation always comes after the number

        U_ASSERT(!result.quantity.bogus);

    }

    // Initial offset before any character consumption.

    int32_t initialOffset = segment.getOffset();

    // Return value: whether to ask for more characters.

    bool maybeMore = false;

    // All digits consumed so far.

    number::impl::DecimalQuantity digitsConsumed;

    digitsConsumed.bogus = true;

    // The total number of digits after the decimal place, used for scaling the result.

    int32_t digitsAfterDecimalPlace = 0;

    // The actual grouping and decimal separators used in the string.

    // If non-null, we have seen that token.

    UnicodeString actualGroupingString;

    UnicodeString actualDecimalString;

    actualGroupingString.setToBogus();

    actualDecimalString.setToBogus();

    // Information for two groups: the previous group and the current group.

    //

    // Each group has three pieces of information:

    //

    // Offset: the string position of the beginning of the group, including a leading separator

    // if there was a leading separator. This is needed in case we need to rewind the parse to

    // that position.

    //

    // Separator type:

    // 0 => beginning of string

    // 1 => lead separator is a grouping separator

    // 2 => lead separator is a decimal separator

    //

    // Count: the number of digits in the group. If -1, the group has been validated.

    int32_t currGroupOffset = 0;

    int32_t currGroupSepType = 0;

    int32_t currGroupCount = 0;

    int32_t prevGroupOffset = -1;

    int32_t prevGroupSepType = -1;

    int32_t prevGroupCount = -1;

    while (segment.length() > 0) {

        maybeMore = false;

        // Attempt to match a digit.

        int8_t digit = -1;

        // Try by code point digit value.

        UChar32 cp = segment.getCodePoint();

        if (u_isdigit(cp)) {

            segment.adjustOffset(U16_LENGTH(cp));

            digit = static_cast<int8_t>(u_digit(cp, 10));

        }

        // Try by digit string.

        if (digit == -1 && !fLocalDigitStrings.isNull()) {

            for (int32_t i = 0; i < 10; i++) {

                const UnicodeString& str = fLocalDigitStrings[i];

                if (str.isEmpty()) {

                    continue;

                }

                int32_t overlap = segment.getCommonPrefixLength(str);

                if (overlap == str.length()) {

                    segment.adjustOffset(overlap);

                    digit = static_cast<int8_t>(i);

                    break;

                }

                maybeMore = maybeMore || (overlap == segment.length());

            }

        }

        if (digit >= 0) {

            // Digit was found.

            if (digitsConsumed.bogus) {

                digitsConsumed.bogus = false;

                digitsConsumed.clear();

            }

            digitsConsumed.appendDigit(digit, 0, true);

            currGroupCount++;

            if (!actualDecimalString.isBogus()) {

                digitsAfterDecimalPlace++;

            }

            continue;

        }

        // Attempt to match a literal grouping or decimal separator.

        bool isDecimal = false;

        bool isGrouping = false;

        // 1) Attempt the decimal separator string literal.

        // if (we have not seen a decimal separator yet) { ... }

        if (actualDecimalString.isBogus() && !decimalSeparator.isEmpty()) {

            int32_t overlap = segment.getCommonPrefixLength(decimalSeparator);

            maybeMore = maybeMore || (overlap == segment.length());

            if (overlap == decimalSeparator.length()) {

                isDecimal = true;

                actualDecimalString = decimalSeparator;

            }

        }

        // 2) Attempt to match the actual grouping string literal.

        if (!actualGroupingString.isBogus()) {

            int32_t overlap = segment.getCommonPrefixLength(actualGroupingString);

            maybeMore = maybeMore || (overlap == segment.length());

            if (overlap == actualGroupingString.length()) {

                isGrouping = true;

            }

        }

        // 2.5) Attempt to match a new the grouping separator string literal.

        // if (we have not seen a grouping or decimal separator yet) { ... }

        if (!groupingDisabled && actualGroupingString.isBogus() && actualDecimalString.isBogus() &&

            !groupingSeparator.isEmpty()) {

            int32_t overlap = segment.getCommonPrefixLength(groupingSeparator);

            maybeMore = maybeMore || (overlap == segment.length());

            if (overlap == groupingSeparator.length()) {

                isGrouping = true;

                actualGroupingString = groupingSeparator;

            }

        }

        // 3) Attempt to match a decimal separator from the equivalence set.

        // if (we have not seen a decimal separator yet) { ... }

        // The !isGrouping is to confirm that we haven't yet matched the current character.

        if (!isGrouping && actualDecimalString.isBogus()) {

            if (decimalUniSet->contains(cp)) {

                isDecimal = true;

                actualDecimalString = UnicodeString(cp);

            }

        }

        // 4) Attempt to match a grouping separator from the equivalence set.

        // if (we have not seen a grouping or decimal separator yet) { ... }

        if (!groupingDisabled && actualGroupingString.isBogus() && actualDecimalString.isBogus()) {

            if (groupingUniSet->contains(cp)) {

                isGrouping = true;

                actualGroupingString = UnicodeString(cp);

            }

        }

        // Leave if we failed to match this as a separator.

        if (!isDecimal && !isGrouping) {

            break;

        }

        // Check for conditions when we don't want to accept the separator.

        if (isDecimal && integerOnly) {

            break;

        } else if (currGroupSepType == 2 && isGrouping) {

            // Fraction grouping

            break;

        }

        // Validate intermediate grouping sizes.

        bool prevValidSecondary = validateGroup(prevGroupSepType, prevGroupCount, false);

        bool currValidPrimary = validateGroup(currGroupSepType, currGroupCount, true);

        if (!prevValidSecondary || (isDecimal && !currValidPrimary)) {

            // Invalid grouping sizes.

            if (isGrouping && currGroupCount == 0) {

                // Trailing grouping separators: these are taken care of below

                U_ASSERT(currGroupSepType == 1);

            } else if (requireGroupingMatch) {

                // Strict mode: reject the parse

                digitsConsumed.clear();

                digitsConsumed.bogus = true;

            }

            break;

        } else if (requireGroupingMatch && currGroupCount == 0 && currGroupSepType == 1) {

            break;

        } else {

            // Grouping sizes OK so far.

            prevGroupOffset = currGroupOffset;

            prevGroupCount = currGroupCount;

            if (isDecimal) {

                // Do not validate this group any more.

                prevGroupSepType = -1;

            } else {

                prevGroupSepType = currGroupSepType;

            }

        }

        // OK to accept the separator.

        // Special case: don't update currGroup if it is empty; this allows two grouping

        // separators in a row in lenient mode.

        if (currGroupCount != 0) {

            currGroupOffset = segment.getOffset();

        }

        currGroupSepType = isGrouping ? 1 : 2;

        currGroupCount = 0;

        if (isGrouping) {

            segment.adjustOffset(actualGroupingString.length());

        } else {

            segment.adjustOffset(actualDecimalString.length());

        }

    }

    // End of main loop.

    // Back up if there was a trailing grouping separator.

    // Shift prev -> curr so we can check it as a final group.

    if (currGroupSepType != 2 && currGroupCount == 0) {

        maybeMore = true;

        segment.setOffset(currGroupOffset);

        currGroupOffset = prevGroupOffset;

        currGroupSepType = prevGroupSepType;

        currGroupCount = prevGroupCount;

        prevGroupOffset = -1;

        prevGroupSepType = 0;

        prevGroupCount = 1;

    }

    // Validate final grouping sizes.

    bool prevValidSecondary = validateGroup(prevGroupSepType, prevGroupCount, false);

    bool currValidPrimary = validateGroup(currGroupSepType, currGroupCount, true);

    if (!requireGroupingMatch) {

        // The cases we need to handle here are lone digits.

        // Examples: "1,1"  "1,1,"  "1,1,1"  "1,1,1,"  ",1" (all parse as 1)

        // See more examples in numberformattestspecification.txt

        int32_t digitsToRemove = 0;

        if (!prevValidSecondary) {

            segment.setOffset(prevGroupOffset);

            digitsToRemove += prevGroupCount;

            digitsToRemove += currGroupCount;

        } else if (!currValidPrimary && (prevGroupSepType != 0 || prevGroupCount != 0)) {

            maybeMore = true;

            segment.setOffset(currGroupOffset);

            digitsToRemove += currGroupCount;

        }

        if (digitsToRemove != 0) {

            digitsConsumed.adjustMagnitude(-digitsToRemove);

            digitsConsumed.truncate();

        }

        prevValidSecondary = true;

        currValidPrimary = true;

    }

    if (currGroupSepType != 2 && (!prevValidSecondary || !currValidPrimary)) {

        // Grouping failure.

        digitsConsumed.bogus = true;

    }

    // Strings that start with a separator but have no digits,

    // or strings that failed a grouping size check.

    if (digitsConsumed.bogus) {

        maybeMore = maybeMore || (segment.length() == 0);

        segment.setOffset(initialOffset);

        return maybeMore;

    }

    // We passed all inspections. Start post-processing.

    // Adjust for fraction part.

    digitsConsumed.adjustMagnitude(-digitsAfterDecimalPlace);

    // Set the digits, either normal or exponent.

    if (exponentSign != 0 && segment.getOffset() != initialOffset) {

        bool overflow = false;

        if (digitsConsumed.fitsInLong()) {

            int64_t exponentLong = digitsConsumed.toLong(false);

            U_ASSERT(exponentLong >= 0);

            if (exponentLong <= INT32_MAX) {

                auto exponentInt = static_cast<int32_t>(exponentLong);

                if (result.quantity.adjustMagnitude(exponentSign * exponentInt)) {

                    overflow = true;

                }

            } else {

                overflow = true;

            }

        } else {

            overflow = true;

        }

        if (overflow) {

            if (exponentSign == -1) {

                // Set to zero

                result.quantity.clear();

            } else {

                // Set to infinity

                result.quantity.bogus = true;

                result.flags |= FLAG_INFINITY;

            }

        }

    } else {

        result.quantity = digitsConsumed;

    }

    // Set other information into the result and return.

    if (!actualDecimalString.isBogus()) {

        result.flags |= FLAG_HAS_DECIMAL_SEPARATOR;

    }

    result.setCharsConsumed(segment);

    return segment.length() == 0 || maybeMore;

}

bool DecimalMatcher::validateGroup(int32_t sepType, int32_t count, bool isPrimary) const {

    if (requireGroupingMatch) {

        if (sepType == -1) {

            // No such group (prevGroup before first shift).

            return true;

        } else if (sepType == 0) {

            // First group.

            if (isPrimary) {

                // No grouping separators is OK.

                return true;

            } else {

                return count != 0 && count <= grouping2;

            }

        } else if (sepType == 1) {

            // Middle group.

            if (isPrimary) {

                return count == grouping1;

            } else {

                return count == grouping2;

            }

        } else {

            U_ASSERT(sepType == 2);

            // After the decimal separator.

            return true;

        }

    } else {

        if (sepType == 1) {

            // #11230: don't accept middle groups with only 1 digit.

            return count != 1;

        } else {

            return true;

        }

    }

}

bool DecimalMatcher::smokeTest(const StringSegment& segment) const {

    // The common case uses a static leadSet for efficiency.

    if (fLocalDigitStrings.isNull() && leadSet != nullptr) {

        return segment.startsWith(*leadSet);

    }

    if (segment.startsWith(*separatorSet) || u_isdigit(segment.getCodePoint())) {

        return true;

    }

    if (fLocalDigitStrings.isNull()) {

        return false;

    }

    for (int32_t i = 0; i < 10; i++) {

        if (segment.startsWith(fLocalDigitStrings[i])) {

            return true;

        }

    }

    return false;

}

UnicodeString DecimalMatcher::toString() const {

    return u"<Decimal>";

}

#endif /* #if !UCONFIG_NO_FORMATTING */