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

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

/*

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

* Copyright (C) 2008-2013, International Business Machines Corporation

* and others. All Rights Reserved.

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

*

*  uspoof_impl.h

*

*    Implemenation header for spoof detection

*

*/

#ifndef USPOOFIM_H

#define USPOOFIM_H

#include "uassert.h"

#include "unicode/utypes.h"

#include "unicode/uspoof.h"

#include "unicode/uscript.h"

#include "unicode/udata.h"

#include "utrie2.h"

#if !UCONFIG_NO_NORMALIZATION

#ifdef __cplusplus

U_NAMESPACE_BEGIN

// The maximium length (in UTF-16 UChars) of the skeleton replacement string resulting from

//   a single input code point.  This is function of the unicode.org data.

#define USPOOF_MAX_SKELETON_EXPANSION 20

// The default stack buffer size for copies or conversions or normalizations

// of input strings being checked.  (Used in multiple places.)

#define USPOOF_STACK_BUFFER_SIZE 100

// Magic number for sanity checking spoof data.

#define USPOOF_MAGIC 0x3845fdef

// Magic number for sanity checking spoof checkers.

#define USPOOF_CHECK_MAGIC 0x2734ecde

class ScriptSet;

class SpoofData;

struct SpoofDataHeader;

class ConfusableDataUtils;

/**

  *  Class SpoofImpl corresponds directly to the plain C API opaque type

  *  USpoofChecker.  One can be cast to the other.

  */

class SpoofImpl : public UObject  {

public:

    SpoofImpl(SpoofData *data, UErrorCode& status);

    SpoofImpl(UErrorCode& status);

    SpoofImpl();

    void construct(UErrorCode& status);

    virtual ~SpoofImpl();

    /** Copy constructor, used by the user level uspoof_clone() function.

     */

    SpoofImpl(const SpoofImpl &src, UErrorCode &status);

    USpoofChecker *asUSpoofChecker();

    static SpoofImpl *validateThis(USpoofChecker *sc, UErrorCode &status);

    static const SpoofImpl *validateThis(const USpoofChecker *sc, UErrorCode &status);

    /** Set and Get AllowedLocales, implementations of the corresponding API */

    void setAllowedLocales(const char *localesList, UErrorCode &status);

    const char * getAllowedLocales(UErrorCode &status);

    // Add (union) to the UnicodeSet all of the characters for the scripts used for

    // the specified locale.  Part of the implementation of setAllowedLocales.

    void addScriptChars(const char *locale, UnicodeSet *allowedChars, UErrorCode &status);

    // Functions implementing the features of UTS 39 section 5.

    static void getAugmentedScriptSet(UChar32 codePoint, ScriptSet& result, UErrorCode& status);

    void getResolvedScriptSet(const UnicodeString& input, ScriptSet& result, UErrorCode& status) const;

    void getResolvedScriptSetWithout(const UnicodeString& input, UScriptCode script, ScriptSet& result, UErrorCode& status) const;

    void getNumerics(const UnicodeString& input, UnicodeSet& result, UErrorCode& status) const;

    URestrictionLevel getRestrictionLevel(const UnicodeString& input, UErrorCode& status) const;

    int32_t findHiddenOverlay(const UnicodeString& input, UErrorCode& status) const;

    bool isIllegalCombiningDotLeadCharacter(UChar32 cp) const;

    /** parse a hex number.  Untility used by the builders.   */

    static UChar32 ScanHex(const UChar *s, int32_t start, int32_t limit, UErrorCode &status);

    static UClassID U_EXPORT2 getStaticClassID(void);

    virtual UClassID getDynamicClassID(void) const;

    //

    // Data Members

    //

    int32_t           fMagic;             // Internal sanity check.

    int32_t           fChecks;            // Bit vector of checks to perform.

    SpoofData        *fSpoofData;

    const UnicodeSet *fAllowedCharsSet;   // The UnicodeSet of allowed characters.

                                          //   for this Spoof Checker.  Defaults to all chars.

    const char       *fAllowedLocales;    // The list of allowed locales.

    URestrictionLevel fRestrictionLevel;  // The maximum restriction level for an acceptable identifier.

};

/**

 *  Class CheckResult corresponds directly to the plain C API opaque type

 *  USpoofCheckResult.  One can be cast to the other.

 */

class CheckResult : public UObject {

public:

    CheckResult();

    virtual ~CheckResult();

    USpoofCheckResult *asUSpoofCheckResult();

    static CheckResult *validateThis(USpoofCheckResult *ptr, UErrorCode &status);

    static const CheckResult *validateThis(const USpoofCheckResult *ptr, UErrorCode &status);

    void clear();

    // Used to convert this CheckResult to the older int32_t return value API

    int32_t toCombinedBitmask(int32_t expectedChecks);

    // Data Members

    int32_t fMagic;                        // Internal sanity check.

    int32_t fChecks;                       // Bit vector of checks that were failed.

    UnicodeSet fNumerics;                  // Set of numerics found in the string.

    URestrictionLevel fRestrictionLevel;   // The restriction level of the string.

};

//

//  Confusable Mappings Data Structures, version 2.0

//

//    For the confusable data, we are essentially implementing a map,

//       key:    a code point

//       value:  a string.  Most commonly one char in length, but can be more.

//

//    The keys are stored as a sorted array of 32 bit ints.

//             bits 0-23    a code point value

//             bits 24-31   length of value string, in UChars (between 1 and 256 UChars).

//        The key table is sorted in ascending code point order.  (not on the

//        32 bit int value, the flag bits do not participate in the sorting.)

//

//        Lookup is done by means of a binary search in the key table.

//

//    The corresponding values are kept in a parallel array of 16 bit ints.

//        If the value string is of length 1, it is literally in the value array.

//        For longer strings, the value array contains an index into the strings table.

//

//    String Table:

//       The strings table contains all of the value strings (those of length two or greater)

//       concatentated together into one long UChar (UTF-16) array.

//

//       There is no nul character or other mark between adjacent strings.

//

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

//

//  Changes from format version 1 to format version 2:

//      1) Removal of the whole-script confusable data tables.

//      2) Removal of the SL/SA/ML/MA and multi-table flags in the key bitmask.

//      3) Expansion of string length value in the key bitmask from 2 bits to 8 bits.

//      4) Removal of the string lengths table since 8 bits is sufficient for the

//         lengths of all entries in confusables.txt.

// Internal functions for manipulating confusable data table keys

#define USPOOF_CONFUSABLE_DATA_FORMAT_VERSION 2  // version for ICU 58

class ConfusableDataUtils {

public:

    inline static UChar32 keyToCodePoint(int32_t key) {

        return key & 0x00ffffff;

    }

    inline static int32_t keyToLength(int32_t key) {

        return ((key & 0xff000000) >> 24) + 1;

    }

    inline static int32_t codePointAndLengthToKey(UChar32 codePoint, int32_t length) {

        U_ASSERT((codePoint & 0x00ffffff) == codePoint);

        U_ASSERT(length <= 256);

        return codePoint | ((length - 1) << 24);

    }

};

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

//

//  SpoofData

//

//    A small class that wraps the raw (usually memory mapped) spoof data.

//    Serves two primary functions:

//      1.  Convenience.  Contains real pointers to the data, to avoid dealing with

//          the offsets in the raw data.

//      2.  Reference counting.  When a spoof checker is cloned, the raw data is shared

//          and must be retained until all checkers using the data are closed.

//    Nothing in this struct includes state that is specific to any particular

//    USpoofDetector object.

//

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

class SpoofData: public UMemory {

  public:

    static SpoofData* getDefault(UErrorCode &status);   // Get standard ICU spoof data.

    static void releaseDefault();   // Cleanup reference to default spoof data.

    SpoofData(UErrorCode &status);   // Create new spoof data wrapper.

                                     // Only used when building new data from rules.

    // Constructor for use when creating from prebuilt default data.

    //   A UDataMemory is what the ICU internal data loading functions provide.

    //   The udm is adopted by the SpoofData.

    SpoofData(UDataMemory *udm, UErrorCode &status);

    // Constructor for use when creating from serialized data.

    //

    SpoofData(const void *serializedData, int32_t length, UErrorCode &status);

    //  Check raw Spoof Data Version compatibility.

    //  Return TRUE it looks good.

    UBool validateDataVersion(UErrorCode &status) const;

    ~SpoofData();                    // Destructor not normally used.

                                     // Use removeReference() instead.

    // Reference Counting functions.

    //    Clone of a user-level spoof detector increments the ref count on the data.

    //    Close of a user-level spoof detector decrements the ref count.

    //    If the data is owned by us, it will be deleted when count goes to zero.

    SpoofData *addReference(); 

    void removeReference();

    // Reset all fields to an initial state.

    // Called from the top of all constructors.

    void reset();

    // Copy this instance's raw data buffer to the specified address.

    int32_t serialize(void *buf, int32_t capacity, UErrorCode &status) const;

    // Get the total number of bytes of data backed by this SpoofData.

    // Not to be confused with length, which returns the number of confusable entries.

    int32_t size() const;

    // Get the confusable skeleton transform for a single code point.

    // The result is a string with a length between 1 and 18 as of Unicode 9.

    // This is the main public endpoint for this class.

    // @return   The length in UTF-16 code units of the substition string.

    int32_t confusableLookup(UChar32 inChar, UnicodeString &dest) const;

    // Get the number of confusable entries in this SpoofData.

    int32_t length() const;

    // Get the code point (key) at the specified index.

    UChar32 codePointAt(int32_t index) const;

    // Get the confusable skeleton (value) at the specified index.

    // Append it to the specified UnicodeString&.

    // @return   The length in UTF-16 code units of the skeleton string.

    int32_t appendValueTo(int32_t index, UnicodeString& dest) const;

  private:

    // Reserve space in the raw data.  For use by builder when putting together a

    //   new set of data.  Init the new storage to zero, to prevent inconsistent

    //   results if it is not all otherwise set by the requester.

    //  Return:

    //    pointer to the new space that was added by this function.

    void *reserveSpace(int32_t numBytes, UErrorCode &status);

    // initialize the pointers from this object to the raw data.

    void initPtrs(UErrorCode &status);

    SpoofDataHeader             *fRawData;          // Ptr to the raw memory-mapped data

    UBool                       fDataOwned;         // True if the raw data is owned, and needs

                                                    //  to be deleted when refcount goes to zero.

    UDataMemory                 *fUDM;              // If not NULL, our data came from a

                                                    //   UDataMemory, which we must close when

                                                    //   we are done.

    uint32_t                    fMemLimit;          // Limit of available raw data space

    u_atomic_int32_t            fRefCount;

    // Confusable data

    int32_t                     *fCFUKeys;

    uint16_t                    *fCFUValues;

    UChar                       *fCFUStrings;

    friend class ConfusabledataBuilder;

};

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

//

//  Raw Binary Data Formats, as loaded from the ICU data file,

//    or as built by the builder.

//

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

struct SpoofDataHeader {

    int32_t       fMagic;                // (0x3845fdef)

    uint8_t       fFormatVersion[4];     // Data Format. Same as the value in struct UDataInfo

                                         //   if there is one associated with this data.

    int32_t       fLength;               // Total lenght in bytes of this spoof data,

                                         //   including all sections, not just the header.

    // The following four sections refer to data representing the confusable data

    //   from the Unicode.org data from "confusables.txt"

    int32_t       fCFUKeys;               // byte offset to Keys table (from SpoofDataHeader *)

    int32_t       fCFUKeysSize;           // number of entries in keys table  (32 bits each)

    // TODO: change name to fCFUValues, for consistency.

    int32_t       fCFUStringIndex;        // byte offset to String Indexes table

    int32_t       fCFUStringIndexSize;    // number of entries in String Indexes table (16 bits each)

                                          //     (number of entries must be same as in Keys table

    int32_t       fCFUStringTable;        // byte offset of String table

    int32_t       fCFUStringTableLen;     // length of string table (in 16 bit UChars)

    // The following sections are for data from xidmodifications.txt

    int32_t       unused[15];              // Padding, Room for Expansion

};

U_NAMESPACE_END

#endif /* __cplusplus */

/**

  * Endianness swap function for binary spoof data.

  * @internal

  */

U_CAPI int32_t U_EXPORT2

uspoof_swap(const UDataSwapper *ds, const void *inData, int32_t length, void *outData,

            UErrorCode *status);

#endif

#endif  /* USPOOFIM_H */