// © 2016 and later: Unicode, Inc. and others.

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

/*

***************************************************************************

* Copyright (C) 2008-2015, International Business Machines Corporation

* and others. All Rights Reserved.

***************************************************************************

*   file name:  uspoof.cpp

*   encoding:   UTF-8

*   tab size:   8 (not used)

*   indentation:4

*

*   created on: 2008Feb13

*   created by: Andy Heninger

*

*   Unicode Spoof Detection

*/

#include "unicode/utypes.h"

#include "unicode/normalizer2.h"

#include "unicode/uspoof.h"

#include "unicode/ustring.h"

#include "unicode/utf16.h"

#include "cmemory.h"

#include "cstring.h"

#include "mutex.h"

#include "scriptset.h"

#include "uassert.h"

#include "ucln_in.h"

#include "uspoof_impl.h"

#include "umutex.h"

#if !UCONFIG_NO_NORMALIZATION

U_NAMESPACE_USE

//

// Static Objects used by the spoof impl, their thread safe initialization and their cleanup.

//

static UnicodeSet *gInclusionSet = NULL;

static UnicodeSet *gRecommendedSet = NULL;

static const Normalizer2 *gNfdNormalizer = NULL;

static UInitOnce gSpoofInitStaticsOnce = U_INITONCE_INITIALIZER;

static UBool U_CALLCONV

uspoof_cleanup(void) {

    delete gInclusionSet;

    gInclusionSet = NULL;

    delete gRecommendedSet;

    gRecommendedSet = NULL;

    gNfdNormalizer = NULL;

    gSpoofInitStaticsOnce.reset();

    return TRUE;

}

static void U_CALLCONV initializeStatics(UErrorCode &status) {

    static const char16_t *inclusionPat =

        u"['\\-.\\:\\u00B7\\u0375\\u058A\\u05F3\\u05F4\\u06FD\\u06FE\\u0F0B\\u200C"

        u"\\u200D\\u2010\\u2019\\u2027\\u30A0\\u30FB]";

    gInclusionSet = new UnicodeSet(UnicodeString(inclusionPat), status);

    if (gInclusionSet == NULL) {

        status = U_MEMORY_ALLOCATION_ERROR;

        return;

    }

    gInclusionSet->freeze();

    // Note: data from IdentifierStatus.txt & IdentifierType.txt

    // There is tooling to generate this constant in the unicodetools project:

    //      org.unicode.text.tools.RecommendedSetGenerator

    // It will print the Java and C++ code to the console for easy copy-paste into this file.

    // Note: concatenated string constants do not work with UNICODE_STRING_SIMPLE on all platforms.

    static const char16_t *recommendedPat =

        u"[0-9A-Z_a-z\\u00C0-\\u00D6\\u00D8-\\u00F6\\u00F8-\\u0131\\u0134-\\u013E"

        u"\\u0141-\\u0148\\u014A-\\u017E\\u018F\\u01A0\\u01A1\\u01AF\\u01B0\\u01CD-"

        u"\\u01DC\\u01DE-\\u01E3\\u01E6-\\u01F0\\u01F4\\u01F5\\u01F8-\\u021B\\u021E"

        u"\\u021F\\u0226-\\u0233\\u0259\\u02BB\\u02BC\\u02EC\\u0300-\\u0304\\u0306-"

        u"\\u030C\\u030F-\\u0311\\u0313\\u0314\\u031B\\u0323-\\u0328\\u032D\\u032E"

        u"\\u0330\\u0331\\u0335\\u0338\\u0339\\u0342\\u0345\\u037B-\\u037D\\u0386"

        u"\\u0388-\\u038A\\u038C\\u038E-\\u03A1\\u03A3-\\u03CE\\u03FC-\\u045F\\u048A-"

        u"\\u0529\\u052E\\u052F\\u0531-\\u0556\\u0559\\u0560-\\u0586\\u0588\\u05B4"

        u"\\u05D0-\\u05EA\\u05EF-\\u05F2\\u0620-\\u063F\\u0641-\\u0655\\u0660-\\u0669"

        u"\\u0670-\\u0672\\u0674\\u0679-\\u068D\\u068F-\\u06D3\\u06D5\\u06E5\\u06E6"

        u"\\u06EE-\\u06FC\\u06FF\\u0750-\\u07B1\\u08A0-\\u08AC\\u08B2\\u08B6-\\u08BD"

        u"\\u0901-\\u094D\\u094F\\u0950\\u0956\\u0957\\u0960-\\u0963\\u0966-\\u096F"

        u"\\u0971-\\u0977\\u0979-\\u097F\\u0981-\\u0983\\u0985-\\u098C\\u098F\\u0990"

        u"\\u0993-\\u09A8\\u09AA-\\u09B0\\u09B2\\u09B6-\\u09B9\\u09BC-\\u09C4\\u09C7"

        u"\\u09C8\\u09CB-\\u09CE\\u09D7\\u09E0-\\u09E3\\u09E6-\\u09F1\\u09FC\\u09FE"

        u"\\u0A01-\\u0A03\\u0A05-\\u0A0A\\u0A0F\\u0A10\\u0A13-\\u0A28\\u0A2A-\\u0A30"

        u"\\u0A32\\u0A35\\u0A38\\u0A39\\u0A3C\\u0A3E-\\u0A42\\u0A47\\u0A48\\u0A4B-"

        u"\\u0A4D\\u0A5C\\u0A66-\\u0A74\\u0A81-\\u0A83\\u0A85-\\u0A8D\\u0A8F-\\u0A91"

        u"\\u0A93-\\u0AA8\\u0AAA-\\u0AB0\\u0AB2\\u0AB3\\u0AB5-\\u0AB9\\u0ABC-\\u0AC5"

        u"\\u0AC7-\\u0AC9\\u0ACB-\\u0ACD\\u0AD0\\u0AE0-\\u0AE3\\u0AE6-\\u0AEF\\u0AFA-"

        u"\\u0AFF\\u0B01-\\u0B03\\u0B05-\\u0B0C\\u0B0F\\u0B10\\u0B13-\\u0B28\\u0B2A-"

        u"\\u0B30\\u0B32\\u0B33\\u0B35-\\u0B39\\u0B3C-\\u0B43\\u0B47\\u0B48\\u0B4B-"

        u"\\u0B4D\\u0B56\\u0B57\\u0B5F-\\u0B61\\u0B66-\\u0B6F\\u0B71\\u0B82\\u0B83"

        u"\\u0B85-\\u0B8A\\u0B8E-\\u0B90\\u0B92-\\u0B95\\u0B99\\u0B9A\\u0B9C\\u0B9E"

        u"\\u0B9F\\u0BA3\\u0BA4\\u0BA8-\\u0BAA\\u0BAE-\\u0BB9\\u0BBE-\\u0BC2\\u0BC6-"

        u"\\u0BC8\\u0BCA-\\u0BCD\\u0BD0\\u0BD7\\u0BE6-\\u0BEF\\u0C01-\\u0C0C\\u0C0E-"

        u"\\u0C10\\u0C12-\\u0C28\\u0C2A-\\u0C33\\u0C35-\\u0C39\\u0C3D-\\u0C44\\u0C46-"

        u"\\u0C48\\u0C4A-\\u0C4D\\u0C55\\u0C56\\u0C60\\u0C61\\u0C66-\\u0C6F\\u0C80"

        u"\\u0C82\\u0C83\\u0C85-\\u0C8C\\u0C8E-\\u0C90\\u0C92-\\u0CA8\\u0CAA-\\u0CB3"

        u"\\u0CB5-\\u0CB9\\u0CBC-\\u0CC4\\u0CC6-\\u0CC8\\u0CCA-\\u0CCD\\u0CD5\\u0CD6"

        u"\\u0CE0-\\u0CE3\\u0CE6-\\u0CEF\\u0CF1\\u0CF2\\u0D00\\u0D02\\u0D03\\u0D05-"

        u"\\u0D0C\\u0D0E-\\u0D10\\u0D12-\\u0D43\\u0D46-\\u0D48\\u0D4A-\\u0D4E\\u0D54-"

        u"\\u0D57\\u0D60\\u0D61\\u0D66-\\u0D6F\\u0D7A-\\u0D7F\\u0D82\\u0D83\\u0D85-"

        u"\\u0D8E\\u0D91-\\u0D96\\u0D9A-\\u0DA5\\u0DA7-\\u0DB1\\u0DB3-\\u0DBB\\u0DBD"

        u"\\u0DC0-\\u0DC6\\u0DCA\\u0DCF-\\u0DD4\\u0DD6\\u0DD8-\\u0DDE\\u0DF2\\u0E01-"

        u"\\u0E32\\u0E34-\\u0E3A\\u0E40-\\u0E4E\\u0E50-\\u0E59\\u0E81\\u0E82\\u0E84"

        u"\\u0E87\\u0E88\\u0E8A\\u0E8D\\u0E94-\\u0E97\\u0E99-\\u0E9F\\u0EA1-\\u0EA3"

        u"\\u0EA5\\u0EA7\\u0EAA\\u0EAB\\u0EAD-\\u0EB2\\u0EB4-\\u0EB9\\u0EBB-\\u0EBD"

        u"\\u0EC0-\\u0EC4\\u0EC6\\u0EC8-\\u0ECD\\u0ED0-\\u0ED9\\u0EDE\\u0EDF\\u0F00"

        u"\\u0F20-\\u0F29\\u0F35\\u0F37\\u0F3E-\\u0F42\\u0F44-\\u0F47\\u0F49-\\u0F4C"

        u"\\u0F4E-\\u0F51\\u0F53-\\u0F56\\u0F58-\\u0F5B\\u0F5D-\\u0F68\\u0F6A-\\u0F6C"

        u"\\u0F71\\u0F72\\u0F74\\u0F7A-\\u0F80\\u0F82-\\u0F84\\u0F86-\\u0F92\\u0F94-"

        u"\\u0F97\\u0F99-\\u0F9C\\u0F9E-\\u0FA1\\u0FA3-\\u0FA6\\u0FA8-\\u0FAB\\u0FAD-"

        u"\\u0FB8\\u0FBA-\\u0FBC\\u0FC6\\u1000-\\u1049\\u1050-\\u109D\\u10C7\\u10CD"

        u"\\u10D0-\\u10F0\\u10F7-\\u10FA\\u10FD-\\u10FF\\u1200-\\u1248\\u124A-\\u124D"

        u"\\u1250-\\u1256\\u1258\\u125A-\\u125D\\u1260-\\u1288\\u128A-\\u128D\\u1290-"

        u"\\u12B0\\u12B2-\\u12B5\\u12B8-\\u12BE\\u12C0\\u12C2-\\u12C5\\u12C8-\\u12D6"

        u"\\u12D8-\\u1310\\u1312-\\u1315\\u1318-\\u135A\\u135D-\\u135F\\u1380-\\u138F"

        u"\\u1780-\\u17A2\\u17A5-\\u17A7\\u17A9-\\u17B3\\u17B6-\\u17CA\\u17D2\\u17D7"

        u"\\u17DC\\u17E0-\\u17E9\\u1C80-\\u1C88\\u1C90-\\u1CBA\\u1CBD-\\u1CBF\\u1E00-"

        u"\\u1E99\\u1E9E\\u1EA0-\\u1EF9\\u1F00-\\u1F15\\u1F18-\\u1F1D\\u1F20-\\u1F45"

        u"\\u1F48-\\u1F4D\\u1F50-\\u1F57\\u1F59\\u1F5B\\u1F5D\\u1F5F-\\u1F70\\u1F72"

        u"\\u1F74\\u1F76\\u1F78\\u1F7A\\u1F7C\\u1F80-\\u1FB4\\u1FB6-\\u1FBA\\u1FBC"

        u"\\u1FC2-\\u1FC4\\u1FC6-\\u1FC8\\u1FCA\\u1FCC\\u1FD0-\\u1FD2\\u1FD6-\\u1FDA"

        u"\\u1FE0-\\u1FE2\\u1FE4-\\u1FEA\\u1FEC\\u1FF2-\\u1FF4\\u1FF6-\\u1FF8\\u1FFA"

        u"\\u1FFC\\u2D27\\u2D2D\\u2D80-\\u2D96\\u2DA0-\\u2DA6\\u2DA8-\\u2DAE\\u2DB0-"

        u"\\u2DB6\\u2DB8-\\u2DBE\\u2DC0-\\u2DC6\\u2DC8-\\u2DCE\\u2DD0-\\u2DD6\\u2DD8-"

        u"\\u2DDE\\u3005-\\u3007\\u3041-\\u3096\\u3099\\u309A\\u309D\\u309E\\u30A1-"

        u"\\u30FA\\u30FC-\\u30FE\\u3105-\\u312F\\u31A0-\\u31BA\\u3400-\\u4DB5\\u4E00-"

        u"\\u9FEF\\uA660\\uA661\\uA674-\\uA67B\\uA67F\\uA69F\\uA717-\\uA71F\\uA788"

        u"\\uA78D\\uA78E\\uA790-\\uA793\\uA7A0-\\uA7AA\\uA7AE\\uA7AF\\uA7B8\\uA7B9"

        u"\\uA7FA\\uA9E7-\\uA9FE\\uAA60-\\uAA76\\uAA7A-\\uAA7F\\uAB01-\\uAB06\\uAB09-"

        u"\\uAB0E\\uAB11-\\uAB16\\uAB20-\\uAB26\\uAB28-\\uAB2E\\uAC00-\\uD7A3\\uFA0E"

        u"\\uFA0F\\uFA11\\uFA13\\uFA14\\uFA1F\\uFA21\\uFA23\\uFA24\\uFA27-\\uFA29"

        u"\\U0001133B\\U0001B002-\\U0001B11E\\U00020000-\\U0002A6D6\\U0002A700-"

        u"\\U0002B734\\U0002B740-\\U0002B81D\\U0002B820-\\U0002CEA1\\U0002CEB0-"

        u"\\U0002EBE0]";

    gRecommendedSet = new UnicodeSet(UnicodeString(recommendedPat), status);

    if (gRecommendedSet == NULL) {

        status = U_MEMORY_ALLOCATION_ERROR;

        delete gInclusionSet;

        return;

    }

    gRecommendedSet->freeze();

    gNfdNormalizer = Normalizer2::getNFDInstance(status);

    ucln_i18n_registerCleanup(UCLN_I18N_SPOOF, uspoof_cleanup);

}

U_CFUNC void uspoof_internalInitStatics(UErrorCode *status) {

    umtx_initOnce(gSpoofInitStaticsOnce, &initializeStatics, *status);

}

U_CAPI USpoofChecker * U_EXPORT2

uspoof_open(UErrorCode *status) {

    umtx_initOnce(gSpoofInitStaticsOnce, &initializeStatics, *status);

    if (U_FAILURE(*status)) {

        return NULL;

    }

    SpoofImpl *si = new SpoofImpl(*status);

    if (si == NULL) {

        *status = U_MEMORY_ALLOCATION_ERROR;

        return NULL;

    }

    if (U_FAILURE(*status)) {

        delete si;

        return NULL;

    }

    return si->asUSpoofChecker();

}

U_CAPI USpoofChecker * U_EXPORT2

uspoof_openFromSerialized(const void *data, int32_t length, int32_t *pActualLength,

                          UErrorCode *status) {

    if (U_FAILURE(*status)) {

        return NULL;

    }

    if (data == NULL) {

        *status = U_ILLEGAL_ARGUMENT_ERROR;

        return NULL;

    }

    umtx_initOnce(gSpoofInitStaticsOnce, &initializeStatics, *status);

    if (U_FAILURE(*status))

    {

        return NULL;

    }

    SpoofData *sd = new SpoofData(data, length, *status);

    if (sd == NULL) {

        *status = U_MEMORY_ALLOCATION_ERROR;

        return NULL;

    }

    if (U_FAILURE(*status)) {

        delete sd;

        return NULL;

    }

    SpoofImpl *si = new SpoofImpl(sd, *status);

    if (si == NULL) {

        *status = U_MEMORY_ALLOCATION_ERROR;

        delete sd; // explicit delete as the destructor for si won't be called.

        return NULL;

    }

    if (U_FAILURE(*status)) {

        delete si; // no delete for sd, as the si destructor will delete it.

        return NULL;

    }

    if (pActualLength != NULL) {

        *pActualLength = sd->size();

    }

    return si->asUSpoofChecker();

}

U_CAPI USpoofChecker * U_EXPORT2

uspoof_clone(const USpoofChecker *sc, UErrorCode *status) {

    const SpoofImpl *src = SpoofImpl::validateThis(sc, *status);

    if (src == NULL) {

        return NULL;

    }

    SpoofImpl *result = new SpoofImpl(*src, *status);   // copy constructor

    if (result == NULL) {

        *status = U_MEMORY_ALLOCATION_ERROR;

        return NULL;

    }

    if (U_FAILURE(*status)) {

        delete result;

        result = NULL;

    }

    return result->asUSpoofChecker();

}

U_CAPI void U_EXPORT2

uspoof_close(USpoofChecker *sc) {

    UErrorCode status = U_ZERO_ERROR;

    SpoofImpl *This = SpoofImpl::validateThis(sc, status);

    delete This;

}

U_CAPI void U_EXPORT2

uspoof_setChecks(USpoofChecker *sc, int32_t checks, UErrorCode *status) {

    SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (This == NULL) {

        return;

    }

    // Verify that the requested checks are all ones (bits) that 

    //   are acceptable, known values.

    if (checks & ~(USPOOF_ALL_CHECKS | USPOOF_AUX_INFO)) {

        *status = U_ILLEGAL_ARGUMENT_ERROR; 

        return;

    }

    This->fChecks = checks;

}

U_CAPI int32_t U_EXPORT2

uspoof_getChecks(const USpoofChecker *sc, UErrorCode *status) {

    const SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (This == NULL) {

        return 0;

    }

    return This->fChecks;

}

U_CAPI void U_EXPORT2

uspoof_setRestrictionLevel(USpoofChecker *sc, URestrictionLevel restrictionLevel) {

    UErrorCode status = U_ZERO_ERROR;

    SpoofImpl *This = SpoofImpl::validateThis(sc, status);

    if (This != NULL) {

        This->fRestrictionLevel = restrictionLevel;

        This->fChecks |= USPOOF_RESTRICTION_LEVEL;

    }

}

U_CAPI URestrictionLevel U_EXPORT2

uspoof_getRestrictionLevel(const USpoofChecker *sc) {

    UErrorCode status = U_ZERO_ERROR;

    const SpoofImpl *This = SpoofImpl::validateThis(sc, status);

    if (This == NULL) {

        return USPOOF_UNRESTRICTIVE;

    }

    return This->fRestrictionLevel;

}

U_CAPI void U_EXPORT2

uspoof_setAllowedLocales(USpoofChecker *sc, const char *localesList, UErrorCode *status) {

    SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (This == NULL) {

        return;

    }

    This->setAllowedLocales(localesList, *status);

}

U_CAPI const char * U_EXPORT2

uspoof_getAllowedLocales(USpoofChecker *sc, UErrorCode *status) {

    SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (This == NULL) {

        return NULL;

    }

    return This->getAllowedLocales(*status);

}

U_CAPI const USet * U_EXPORT2

uspoof_getAllowedChars(const USpoofChecker *sc, UErrorCode *status) {

    const UnicodeSet *result = uspoof_getAllowedUnicodeSet(sc, status);

    return result->toUSet();

}

U_CAPI const UnicodeSet * U_EXPORT2

uspoof_getAllowedUnicodeSet(const USpoofChecker *sc, UErrorCode *status) {

    const SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (This == NULL) {

        return NULL;

    }

    return This->fAllowedCharsSet;

}

U_CAPI void U_EXPORT2

uspoof_setAllowedChars(USpoofChecker *sc, const USet *chars, UErrorCode *status) {

    const UnicodeSet *set = UnicodeSet::fromUSet(chars);

    uspoof_setAllowedUnicodeSet(sc, set, status);

}

U_CAPI void U_EXPORT2

uspoof_setAllowedUnicodeSet(USpoofChecker *sc, const UnicodeSet *chars, UErrorCode *status) {

    SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (This == NULL) {

        return;

    }

    if (chars->isBogus()) {

        *status = U_ILLEGAL_ARGUMENT_ERROR;

        return;

    }

    UnicodeSet *clonedSet = static_cast<UnicodeSet *>(chars->clone());

    if (clonedSet == NULL || clonedSet->isBogus()) {

        *status = U_MEMORY_ALLOCATION_ERROR;

        return;

    }

    clonedSet->freeze();

    delete This->fAllowedCharsSet;

    This->fAllowedCharsSet = clonedSet;

    This->fChecks |= USPOOF_CHAR_LIMIT;

}

U_CAPI int32_t U_EXPORT2

uspoof_check(const USpoofChecker *sc,

             const UChar *id, int32_t length,

             int32_t *position,

             UErrorCode *status) {

    // Backwards compatibility:

    if (position != NULL) {

        *position = 0;

    }

    // Delegate to uspoof_check2

    return uspoof_check2(sc, id, length, NULL, status);

}

U_CAPI int32_t U_EXPORT2

uspoof_check2(const USpoofChecker *sc,

    const UChar* id, int32_t length,

    USpoofCheckResult* checkResult,

    UErrorCode *status) {

    const SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (This == NULL) {

        return 0;

    }

    if (length < -1) {

        *status = U_ILLEGAL_ARGUMENT_ERROR;

        return 0;

    }

    UnicodeString idStr((length == -1), id, length);  // Aliasing constructor.

    int32_t result = uspoof_check2UnicodeString(sc, idStr, checkResult, status);

    return result;

}

U_CAPI int32_t U_EXPORT2

uspoof_checkUTF8(const USpoofChecker *sc,

                 const char *id, int32_t length,

                 int32_t *position,

                 UErrorCode *status) {

    // Backwards compatibility:

    if (position != NULL) {

        *position = 0;

    }

    // Delegate to uspoof_check2

    return uspoof_check2UTF8(sc, id, length, NULL, status);

}

U_CAPI int32_t U_EXPORT2

uspoof_check2UTF8(const USpoofChecker *sc,

    const char *id, int32_t length,

    USpoofCheckResult* checkResult,

    UErrorCode *status) {

    if (U_FAILURE(*status)) {

        return 0;

    }

    UnicodeString idStr = UnicodeString::fromUTF8(StringPiece(id, length>=0 ? length : static_cast<int32_t>(uprv_strlen(id))));

    int32_t result = uspoof_check2UnicodeString(sc, idStr, checkResult, status);

    return result;

}

U_CAPI int32_t U_EXPORT2

uspoof_areConfusable(const USpoofChecker *sc,

                     const UChar *id1, int32_t length1,

                     const UChar *id2, int32_t length2,

                     UErrorCode *status) {

    SpoofImpl::validateThis(sc, *status);

    if (U_FAILURE(*status)) {

        return 0;

    }

    if (length1 < -1 || length2 < -1) {

        *status = U_ILLEGAL_ARGUMENT_ERROR;

        return 0;

    }

    UnicodeString id1Str((length1==-1), id1, length1);  // Aliasing constructor

    UnicodeString id2Str((length2==-1), id2, length2);  // Aliasing constructor

    return uspoof_areConfusableUnicodeString(sc, id1Str, id2Str, status);

}

U_CAPI int32_t U_EXPORT2

uspoof_areConfusableUTF8(const USpoofChecker *sc,

                         const char *id1, int32_t length1,

                         const char *id2, int32_t length2,

                         UErrorCode *status) {

    SpoofImpl::validateThis(sc, *status);

    if (U_FAILURE(*status)) {

        return 0;

    }

    if (length1 < -1 || length2 < -1) {

        *status = U_ILLEGAL_ARGUMENT_ERROR;

        return 0;

    }

    UnicodeString id1Str = UnicodeString::fromUTF8(StringPiece(id1, length1>=0? length1 : static_cast<int32_t>(uprv_strlen(id1))));

    UnicodeString id2Str = UnicodeString::fromUTF8(StringPiece(id2, length2>=0? length2 : static_cast<int32_t>(uprv_strlen(id2))));

    int32_t results = uspoof_areConfusableUnicodeString(sc, id1Str, id2Str, status);

    return results;

}

U_CAPI int32_t U_EXPORT2

uspoof_areConfusableUnicodeString(const USpoofChecker *sc,

                                  const icu::UnicodeString &id1,

                                  const icu::UnicodeString &id2,

                                  UErrorCode *status) {

    const SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (U_FAILURE(*status)) {

        return 0;

    }

    //

    // See section 4 of UAX 39 for the algorithm for checking whether two strings are confusable,

    //   and for definitions of the types (single, whole, mixed-script) of confusables.

    // We only care about a few of the check flags.  Ignore the others.

    // If no tests relavant to this function have been specified, return an error.

    // TODO:  is this really the right thing to do?  It's probably an error on the caller's part,

    //        but logically we would just return 0 (no error).

    if ((This->fChecks & USPOOF_CONFUSABLE) == 0) {

        *status = U_INVALID_STATE_ERROR;

        return 0;

    }

    // Compute the skeletons and check for confusability.

    UnicodeString id1Skeleton;

    uspoof_getSkeletonUnicodeString(sc, 0 /* deprecated */, id1, id1Skeleton, status);

    UnicodeString id2Skeleton;

    uspoof_getSkeletonUnicodeString(sc, 0 /* deprecated */, id2, id2Skeleton, status);

    if (U_FAILURE(*status)) { return 0; }

    if (id1Skeleton != id2Skeleton) {

        return 0;

    }

    // If we get here, the strings are confusable.  Now we just need to set the flags for the appropriate classes

    // of confusables according to UTS 39 section 4.

    // Start by computing the resolved script sets of id1 and id2.

    ScriptSet id1RSS;

    This->getResolvedScriptSet(id1, id1RSS, *status);

    ScriptSet id2RSS;

    This->getResolvedScriptSet(id2, id2RSS, *status);

    // Turn on all applicable flags

    int32_t result = 0;

    if (id1RSS.intersects(id2RSS)) {

        result |= USPOOF_SINGLE_SCRIPT_CONFUSABLE;

    } else {

        result |= USPOOF_MIXED_SCRIPT_CONFUSABLE;

        if (!id1RSS.isEmpty() && !id2RSS.isEmpty()) {

            result |= USPOOF_WHOLE_SCRIPT_CONFUSABLE;

        }

    }

    // Turn off flags that the user doesn't want

    if ((This->fChecks & USPOOF_SINGLE_SCRIPT_CONFUSABLE) == 0) {

        result &= ~USPOOF_SINGLE_SCRIPT_CONFUSABLE;

    }

    if ((This->fChecks & USPOOF_MIXED_SCRIPT_CONFUSABLE) == 0) {

        result &= ~USPOOF_MIXED_SCRIPT_CONFUSABLE;

    }

    if ((This->fChecks & USPOOF_WHOLE_SCRIPT_CONFUSABLE) == 0) {

        result &= ~USPOOF_WHOLE_SCRIPT_CONFUSABLE;

    }

    return result;

}

U_CAPI int32_t U_EXPORT2

uspoof_checkUnicodeString(const USpoofChecker *sc,

                          const icu::UnicodeString &id,

                          int32_t *position,

                          UErrorCode *status) {

    // Backwards compatibility:

    if (position != NULL) {

        *position = 0;

    }

    // Delegate to uspoof_check2

    return uspoof_check2UnicodeString(sc, id, NULL, status);

}

int32_t checkImpl(const SpoofImpl* This, const UnicodeString& id, CheckResult* checkResult, UErrorCode* status) {

    U_ASSERT(This != NULL);

    U_ASSERT(checkResult != NULL);

    checkResult->clear();

    int32_t result = 0;

    if (0 != (This->fChecks & USPOOF_RESTRICTION_LEVEL)) {

        URestrictionLevel idRestrictionLevel = This->getRestrictionLevel(id, *status);

        if (idRestrictionLevel > This->fRestrictionLevel) {

            result |= USPOOF_RESTRICTION_LEVEL;

        }

        checkResult->fRestrictionLevel = idRestrictionLevel;

    }

    if (0 != (This->fChecks & USPOOF_MIXED_NUMBERS)) {

        UnicodeSet numerics;

        This->getNumerics(id, numerics, *status);

        if (numerics.size() > 1) {

            result |= USPOOF_MIXED_NUMBERS;

        }

        checkResult->fNumerics = numerics;  // UnicodeSet::operator=

    }

    if (0 != (This->fChecks & USPOOF_HIDDEN_OVERLAY)) {

        int32_t index = This->findHiddenOverlay(id, *status);

        if (index != -1) {

            result |= USPOOF_HIDDEN_OVERLAY;

        }

    }

    if (0 != (This->fChecks & USPOOF_CHAR_LIMIT)) {

        int32_t i;

        UChar32 c;

        int32_t length = id.length();

        for (i=0; i<length ;) {

            c = id.char32At(i);

            i += U16_LENGTH(c);

            if (!This->fAllowedCharsSet->contains(c)) {

                result |= USPOOF_CHAR_LIMIT;

                break;

            }

        }

    }

    if (0 != (This->fChecks & USPOOF_INVISIBLE)) {

        // This check needs to be done on NFD input

        UnicodeString nfdText;

        gNfdNormalizer->normalize(id, nfdText, *status);

        int32_t nfdLength = nfdText.length();

        // scan for more than one occurence of the same non-spacing mark

        // in a sequence of non-spacing marks.

        int32_t     i;

        UChar32     c;

        UChar32     firstNonspacingMark = 0;

        UBool       haveMultipleMarks = FALSE;  

        UnicodeSet  marksSeenSoFar;   // Set of combining marks in a single combining sequence.

        for (i=0; i<nfdLength ;) {

            c = nfdText.char32At(i);

            i += U16_LENGTH(c);

            if (u_charType(c) != U_NON_SPACING_MARK) {

                firstNonspacingMark = 0;

                if (haveMultipleMarks) {

                    marksSeenSoFar.clear();

                    haveMultipleMarks = FALSE;

                }

                continue;

            }

            if (firstNonspacingMark == 0) {

                firstNonspacingMark = c;

                continue;

            }

            if (!haveMultipleMarks) {

                marksSeenSoFar.add(firstNonspacingMark);

                haveMultipleMarks = TRUE;

            }

            if (marksSeenSoFar.contains(c)) {

                // report the error, and stop scanning.

                // No need to find more than the first failure.

                result |= USPOOF_INVISIBLE;

                break;

            }

            marksSeenSoFar.add(c);

        }

    }

    checkResult->fChecks = result;

    return checkResult->toCombinedBitmask(This->fChecks);

}

U_CAPI int32_t U_EXPORT2

uspoof_check2UnicodeString(const USpoofChecker *sc,

                          const icu::UnicodeString &id,

                          USpoofCheckResult* checkResult,

                          UErrorCode *status) {

    const SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (This == NULL) {

        return FALSE;

    }

    if (checkResult != NULL) {

        CheckResult* ThisCheckResult = CheckResult::validateThis(checkResult, *status);

        if (ThisCheckResult == NULL) {

            return FALSE;

        }

        return checkImpl(This, id, ThisCheckResult, status);

    } else {

        // Stack-allocate the checkResult since this method doesn't return it

        CheckResult stackCheckResult;

        return checkImpl(This, id, &stackCheckResult, status);

    }

}

U_CAPI int32_t U_EXPORT2

uspoof_getSkeleton(const USpoofChecker *sc,

                   uint32_t type,

                   const UChar *id,  int32_t length,

                   UChar *dest, int32_t destCapacity,

                   UErrorCode *status) {

    SpoofImpl::validateThis(sc, *status);

    if (U_FAILURE(*status)) {

        return 0;

    }

    if (length<-1 || destCapacity<0 || (destCapacity==0 && dest!=NULL)) {

        *status = U_ILLEGAL_ARGUMENT_ERROR;

        return 0;

    }

    UnicodeString idStr((length==-1), id, length);  // Aliasing constructor

    UnicodeString destStr;

    uspoof_getSkeletonUnicodeString(sc, type, idStr, destStr, status);

    destStr.extract(dest, destCapacity, *status);

    return destStr.length();

}

U_I18N_API UnicodeString &  U_EXPORT2

uspoof_getSkeletonUnicodeString(const USpoofChecker *sc,

                                uint32_t /*type*/,

                                const UnicodeString &id,

                                UnicodeString &dest,

                                UErrorCode *status) {

    const SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (U_FAILURE(*status)) {

        return dest;

    }

    UnicodeString nfdId;

    gNfdNormalizer->normalize(id, nfdId, *status);

    // Apply the skeleton mapping to the NFD normalized input string

    // Accumulate the skeleton, possibly unnormalized, in a UnicodeString.

    int32_t inputIndex = 0;

    UnicodeString skelStr;

    int32_t normalizedLen = nfdId.length();

    for (inputIndex=0; inputIndex < normalizedLen; ) {

        UChar32 c = nfdId.char32At(inputIndex);

        inputIndex += U16_LENGTH(c);

        This->fSpoofData->confusableLookup(c, skelStr);

    }

    gNfdNormalizer->normalize(skelStr, dest, *status);

    return dest;

}

U_CAPI int32_t U_EXPORT2

uspoof_getSkeletonUTF8(const USpoofChecker *sc,

                       uint32_t type,

                       const char *id,  int32_t length,

                       char *dest, int32_t destCapacity,

                       UErrorCode *status) {

    SpoofImpl::validateThis(sc, *status);

    if (U_FAILURE(*status)) {

        return 0;

    }

    if (length<-1 || destCapacity<0 || (destCapacity==0 && dest!=NULL)) {

        *status = U_ILLEGAL_ARGUMENT_ERROR;

        return 0;

    }

    UnicodeString srcStr = UnicodeString::fromUTF8(StringPiece(id, length>=0 ? length : static_cast<int32_t>(uprv_strlen(id))));

    UnicodeString destStr;

    uspoof_getSkeletonUnicodeString(sc, type, srcStr, destStr, status);

    if (U_FAILURE(*status)) {

        return 0;

    }

    int32_t lengthInUTF8 = 0;

    u_strToUTF8(dest, destCapacity, &lengthInUTF8,

                destStr.getBuffer(), destStr.length(), status);

    return lengthInUTF8;

}

U_CAPI int32_t U_EXPORT2

uspoof_serialize(USpoofChecker *sc,void *buf, int32_t capacity, UErrorCode *status) {

    SpoofImpl *This = SpoofImpl::validateThis(sc, *status);

    if (This == NULL) {

        U_ASSERT(U_FAILURE(*status));

        return 0;

    }

    return This->fSpoofData->serialize(buf, capacity, *status);

}

U_CAPI const USet * U_EXPORT2

uspoof_getInclusionSet(UErrorCode *status) {

    umtx_initOnce(gSpoofInitStaticsOnce, &initializeStatics, *status);

    return gInclusionSet->toUSet();

}

U_CAPI const USet * U_EXPORT2

uspoof_getRecommendedSet(UErrorCode *status) {

    umtx_initOnce(gSpoofInitStaticsOnce, &initializeStatics, *status);

    return gRecommendedSet->toUSet();

}

U_I18N_API const UnicodeSet * U_EXPORT2

uspoof_getInclusionUnicodeSet(UErrorCode *status) {

    umtx_initOnce(gSpoofInitStaticsOnce, &initializeStatics, *status);

    return gInclusionSet;

}

U_I18N_API const UnicodeSet * U_EXPORT2

uspoof_getRecommendedUnicodeSet(UErrorCode *status) {

    umtx_initOnce(gSpoofInitStaticsOnce, &initializeStatics, *status);

    return gRecommendedSet;

}

//------------------

// CheckResult APIs

//------------------

U_CAPI USpoofCheckResult* U_EXPORT2

uspoof_openCheckResult(UErrorCode *status) {

    CheckResult* checkResult = new CheckResult();

    if (checkResult == NULL) {

        *status = U_MEMORY_ALLOCATION_ERROR;

        return NULL;

    }

    return checkResult->asUSpoofCheckResult();

}

U_CAPI void U_EXPORT2

uspoof_closeCheckResult(USpoofCheckResult* checkResult) {

    UErrorCode status = U_ZERO_ERROR;

    CheckResult* This = CheckResult::validateThis(checkResult, status);

    delete This;

}

U_CAPI int32_t U_EXPORT2

uspoof_getCheckResultChecks(const USpoofCheckResult *checkResult, UErrorCode *status) {

    const CheckResult* This = CheckResult::validateThis(checkResult, *status);

    if (U_FAILURE(*status)) { return 0; }

    return This->fChecks;

}

U_CAPI URestrictionLevel U_EXPORT2

uspoof_getCheckResultRestrictionLevel(const USpoofCheckResult *checkResult, UErrorCode *status) {

    const CheckResult* This = CheckResult::validateThis(checkResult, *status);

    if (U_FAILURE(*status)) { return USPOOF_UNRESTRICTIVE; }

    return This->fRestrictionLevel;

}

U_CAPI const USet* U_EXPORT2

uspoof_getCheckResultNumerics(const USpoofCheckResult *checkResult, UErrorCode *status) {

    const CheckResult* This = CheckResult::validateThis(checkResult, *status);

    if (U_FAILURE(*status)) { return NULL; }

    return This->fNumerics.toUSet();

}

#endif // !UCONFIG_NO_NORMALIZATION