/*

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

 * Copyright (C) 1996-2005, International Business Machines Corporation and    *

 * others. All Rights Reserved.                                                *

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

 */

#ifndef CANITER_H

#define CANITER_H

#include "unicode/utypes.h"

#if !UCONFIG_NO_NORMALIZATION

#include "unicode/uobject.h"

#include "unicode/unistr.h"

/**

 * \file

 * \brief C++ API: Canonical Iterator

 */

/** Should permutation skip characters with combining class zero

 *  Should be either TRUE or FALSE. This is a compile time option

 *  @stable ICU 2.4

 */

#ifndef CANITER_SKIP_ZEROES

#define CANITER_SKIP_ZEROES TRUE

#endif

U_NAMESPACE_BEGIN

class Hashtable;

/**

 * This class allows one to iterate through all the strings that are canonically equivalent to a given

 * string. For example, here are some sample results:

Results for: {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}

1: \\u0041\\u030A\\u0064\\u0307\\u0327

 = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}

2: \\u0041\\u030A\\u0064\\u0327\\u0307

 = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}

3: \\u0041\\u030A\\u1E0B\\u0327

 = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}

4: \\u0041\\u030A\\u1E11\\u0307

 = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}

5: \\u00C5\\u0064\\u0307\\u0327

 = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}

6: \\u00C5\\u0064\\u0327\\u0307

 = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}

7: \\u00C5\\u1E0B\\u0327

 = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}

8: \\u00C5\\u1E11\\u0307

 = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}

9: \\u212B\\u0064\\u0307\\u0327

 = {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}

10: \\u212B\\u0064\\u0327\\u0307

 = {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}

11: \\u212B\\u1E0B\\u0327

 = {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}

12: \\u212B\\u1E11\\u0307

 = {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}

 *<br>Note: the code is intended for use with small strings, and is not suitable for larger ones,

 * since it has not been optimized for that situation.

 * Note, CanonicalIterator is not intended to be subclassed.

 * @author M. Davis

 * @author C++ port by V. Weinstein

 * @stable ICU 2.4

 */

class U_COMMON_API CanonicalIterator : public UObject {

public:

    /**

     * Construct a CanonicalIterator object

     * @param source    string to get results for

     * @param status    Fill-in parameter which receives the status of this operation.

     * @stable ICU 2.4

     */

    CanonicalIterator(const UnicodeString &source, UErrorCode &status);

    /** Destructor

     *  Cleans pieces

     * @stable ICU 2.4

     */

    virtual ~CanonicalIterator();

    /**

     * Gets the NFD form of the current source we are iterating over.

     * @return gets the source: NOTE: it is the NFD form of source

     * @stable ICU 2.4

     */

    UnicodeString getSource();

    /**

     * Resets the iterator so that one can start again from the beginning.

     * @stable ICU 2.4

     */

    void reset();

    /**

     * Get the next canonically equivalent string.

     * <br><b>Warning: The strings are not guaranteed to be in any particular order.</b>

     * @return the next string that is canonically equivalent. A bogus string is returned when

     * the iteration is done.

     * @stable ICU 2.4

     */

    UnicodeString next();

    /**

     * Set a new source for this iterator. Allows object reuse.

     * @param newSource     the source string to iterate against. This allows the same iterator to be used

     *                     while changing the source string, saving object creation.

     * @param status        Fill-in parameter which receives the status of this operation.

     * @stable ICU 2.4

     */

    void setSource(const UnicodeString &newSource, UErrorCode &status);

    /**

     * Dumb recursive implementation of permutation.

     * TODO: optimize

     * @param source     the string to find permutations for

     * @param skipZeros  determine if skip zeros

     * @param result     the results in a set.

     * @param status       Fill-in parameter which receives the status of this operation.

     * @internal

     */

    static void U_EXPORT2 permute(UnicodeString &source, UBool skipZeros, Hashtable *result, UErrorCode &status);

    /**

     * ICU "poor man's RTTI", returns a UClassID for this class.

     *

     * @stable ICU 2.2

     */

    static UClassID U_EXPORT2 getStaticClassID();

    /**

     * ICU "poor man's RTTI", returns a UClassID for the actual class.

     *

     * @stable ICU 2.2

     */

    virtual UClassID getDynamicClassID() const;

private:

    // ===================== PRIVATES ==============================

    // private default constructor

    CanonicalIterator();

    /**

     * Copy constructor. Private for now.

     * @internal

     */

    CanonicalIterator(const CanonicalIterator& other);

    /**

     * Assignment operator. Private for now.

     * @internal

     */

    CanonicalIterator& operator=(const CanonicalIterator& other);

    // fields

    UnicodeString source;

    UBool done;

    // 2 dimensional array holds the pieces of the string with

    // their different canonically equivalent representations

    UnicodeString **pieces;

    int32_t pieces_length;

    int32_t *pieces_lengths;

    // current is used in iterating to combine pieces

    int32_t *current;

    int32_t current_length;

    // transient fields

    UnicodeString buffer;

    // we have a segment, in NFD. Find all the strings that are canonically equivalent to it.

    UnicodeString *getEquivalents(const UnicodeString &segment, int32_t &result_len, UErrorCode &status); //private String[] getEquivalents(String segment)

    //Set getEquivalents2(String segment);

    Hashtable *getEquivalents2(const UChar *segment, int32_t segLen, UErrorCode &status);

    //Hashtable *getEquivalents2(const UnicodeString &segment, int32_t segLen, UErrorCode &status);

    /**

     * See if the decomposition of cp2 is at segment starting at segmentPos

     * (with canonical rearrangment!)

     * If so, take the remainder, and return the equivalents

     */

    //Set extract(int comp, String segment, int segmentPos, StringBuffer buffer);

    Hashtable *extract(UChar32 comp, const UChar *segment, int32_t segLen, int32_t segmentPos, UErrorCode &status);

    //Hashtable *extract(UChar32 comp, const UnicodeString &segment, int32_t segLen, int32_t segmentPos, UErrorCode &status);

    void cleanPieces();

};

U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_NORMALIZATION */

#endif