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

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

/*

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

*

*   Copyright (C) 2011, International Business Machines

*   Corporation and others.  All Rights Reserved.

*

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

*   file name:  uniset_closure.cpp

*   encoding:   UTF-8

*   tab size:   8 (not used)

*   indentation:4

*

*   created on: 2011may30

*   created by: Markus W. Scherer

*

*   UnicodeSet::closeOver() and related methods moved here from uniset_props.cpp

*   to simplify dependencies.

*   In particular, this depends on the BreakIterator, but the BreakIterator

*   code also builds UnicodeSets from patterns and needs uniset_props.

*/

#include "unicode/brkiter.h"

#include "unicode/locid.h"

#include "unicode/parsepos.h"

#include "unicode/uniset.h"

#include "unicode/utf16.h"

#include "cmemory.h"

#include "ruleiter.h"

#include "ucase.h"

#include "uprops.h"

#include "util.h"

#include "uvector.h"

U_NAMESPACE_BEGIN

// TODO memory debugging provided inside uniset.cpp

// could be made available here but probably obsolete with use of modern

// memory leak checker tools

#define _dbgct(me)

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

// Constructors &c

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

UnicodeSet::UnicodeSet(const UnicodeString& pattern,

                       uint32_t options,

                       const SymbolTable* symbols,

                       UErrorCode& status) {

    applyPattern(pattern, options, symbols, status);

    _dbgct(this);

}

UnicodeSet::UnicodeSet(const UnicodeString& pattern, ParsePosition& pos,

                       uint32_t options,

                       const SymbolTable* symbols,

                       UErrorCode& status) {

    applyPattern(pattern, pos, options, symbols, status);

    _dbgct(this);

}

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

// Public API

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

UnicodeSet& UnicodeSet::applyPattern(const UnicodeString& pattern,

                                     uint32_t options,

                                     const SymbolTable* symbols,

                                     UErrorCode& status) U_LIFETIME_BOUND {

    ParsePosition pos(0);

    applyPattern(pattern, pos, options, symbols, status);

    if (U_FAILURE(status)) return *this;

    int32_t i = pos.getIndex();

    if (options & USET_IGNORE_SPACE) {

        // Skip over trailing whitespace

        ICU_Utility::skipWhitespace(pattern, i, true);

    }

    if (i != pattern.length()) {

        status = U_ILLEGAL_ARGUMENT_ERROR;

    }

    return *this;

}

UnicodeSet& UnicodeSet::applyPattern(const UnicodeString& pattern,

                                     ParsePosition& pos,

                                     uint32_t options,

                                     const SymbolTable* symbols,

                                     UErrorCode& status) U_LIFETIME_BOUND {

    if (U_FAILURE(status)) {

        return *this;

    }

    if (isFrozen()) {

        status = U_NO_WRITE_PERMISSION;

        return *this;

    }

    // Need to build the pattern in a temporary string because

    // _applyPattern calls add() etc., which set pat to empty.

    UnicodeString rebuiltPat;

    RuleCharacterIterator chars(pattern, symbols, pos);

    applyPattern(pattern, pos, chars, symbols, rebuiltPat, options, &UnicodeSet::closeOver, status);

    if (U_FAILURE(status)) return *this;

    if (chars.inVariable()) {

        // syntaxError(chars, "Extra chars in variable value");

        status = U_MALFORMED_SET;

        return *this;

    }

    setPattern(rebuiltPat);

    return *this;

}

// USetAdder implementation

// Does not use uset.h to reduce code dependencies

static void U_CALLCONV

_set_add(USet *set, UChar32 c) {

    reinterpret_cast<UnicodeSet*>(set)->add(c);

}

static void U_CALLCONV

_set_addRange(USet *set, UChar32 start, UChar32 end) {

    reinterpret_cast<UnicodeSet*>(set)->add(start, end);

}

static void U_CALLCONV

_set_addString(USet *set, const char16_t *str, int32_t length) {

    reinterpret_cast<UnicodeSet*>(set)->add(UnicodeString(static_cast<UBool>(length < 0), str, length));

}

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

// Case folding API

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

// add the result of a full case mapping to the set

// use str as a temporary string to avoid constructing one

static inline void

addCaseMapping(UnicodeSet &set, int32_t result, const char16_t *full, UnicodeString &str) {

    if(result >= 0) {

        if(result > UCASE_MAX_STRING_LENGTH) {

            // add a single-code point case mapping

            set.add(result);

        } else {

            // add a string case mapping from full with length result

            str.setTo(static_cast<UBool>(false), full, result);

            set.add(str);

        }

    }

    // result < 0: the code point mapped to itself, no need to add it

    // see ucase.h

}

namespace {

/** For case closure on a large set, look only at code points with relevant properties. */

const UnicodeSet &maybeOnlyCaseSensitive(const UnicodeSet &src U_LIFETIME_BOUND,

                                         UnicodeSet &subset U_LIFETIME_BOUND) {

    // The subset must have been constructed with all code points,

    // so that the retainAll() intersection effectively copies all single code points from src.

    U_ASSERT(subset.contains(0, 0x10ffff));

    if (src.size() < 30) {

        return src;

    }

    // Return the intersection of the src code points with Case_Sensitive ones.

    UErrorCode errorCode = U_ZERO_ERROR;

    const UnicodeSet *sensitive =

        CharacterProperties::getBinaryPropertySet(UCHAR_CASE_SENSITIVE, errorCode);

    if (U_FAILURE(errorCode)) {

        return src;

    }

    // Start by copying the "smaller" set.

    // (We "copy" by intersecting all Unicode *code points* with the first set,

    // which omits any strings.)

    if (src.getRangeCount() > sensitive->getRangeCount()) {

        subset.retainAll(*sensitive);

        subset.retainAll(src);

    } else {

        subset.retainAll(src);

        subset.retainAll(*sensitive);

    }

    return subset;

}

// Per-character scf = Simple_Case_Folding of a string.

// (Normally when we case-fold a string we use full case foldings.)

bool scfString(const UnicodeString &s, UnicodeString &scf) {

    // Iterate over the raw buffer for best performance.

    const char16_t *p = s.getBuffer();

    int32_t length = s.length();

    // Loop while not needing modification.

    for (int32_t i = 0; i < length;) {

        UChar32 c;

        U16_NEXT(p, i, length, c);  // post-increments i

        UChar32 scfChar = u_foldCase(c, U_FOLD_CASE_DEFAULT);

        if (scfChar != c) {

            // Copy the characters before c.

            scf.setTo(p, i - U16_LENGTH(c));

            // Loop over the rest of the string and keep case-folding.

            for (;;) {

                scf.append(scfChar);

                if (i == length) {

                    return true;

                }

                U16_NEXT(p, i, length, c);  // post-increments i

                scfChar = u_foldCase(c, U_FOLD_CASE_DEFAULT);

            }

        }

    }

    return false;

}

}  // namespace

UnicodeSet& UnicodeSet::closeOver(int32_t attribute) U_LIFETIME_BOUND {

    if (isFrozen() || isBogus()) {

        return *this;

    }

    switch (attribute & USET_CASE_MASK) {

    case 0:

        break;

    case USET_CASE_INSENSITIVE:

        closeOverCaseInsensitive(/* simple= */ false);

        break;

    case USET_ADD_CASE_MAPPINGS:

        closeOverAddCaseMappings();

        break;

    case USET_SIMPLE_CASE_INSENSITIVE:

        closeOverCaseInsensitive(/* simple= */ true);

        break;

    default:

        // bad option (unreachable)

        break;

    }

    return *this;

}

void UnicodeSet::closeOverCaseInsensitive(bool simple) {

    // Start with input set to guarantee inclusion.

    UnicodeSet foldSet(*this);

    // Full case mappings closure:

    // Remove strings because the strings will actually be reduced (folded);

    // therefore, start with no strings and add only those needed.

    // Do this before processing code points, because they may add strings.

    if (!simple && foldSet.hasStrings()) {

        foldSet.strings_->removeAllElements();

    }

    USetAdder sa = {

        foldSet.toUSet(),

        _set_add,

        _set_addRange,

        _set_addString,

        nullptr, // don't need remove()

        nullptr // don't need removeRange()

    };

    UnicodeSet subset(0, 0x10ffff);

    const UnicodeSet &codePoints = maybeOnlyCaseSensitive(*this, subset);

    // Iterate over the ranges of single code points. Nested loop for each code point.

    int32_t n = codePoints.getRangeCount();

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

        UChar32 start = codePoints.getRangeStart(i);

        UChar32 end   = codePoints.getRangeEnd(i);

        if (simple) {

            for (UChar32 cp=start; cp<=end; ++cp) {

                ucase_addSimpleCaseClosure(cp, &sa);

            }

        } else {

            for (UChar32 cp=start; cp<=end; ++cp) {

                ucase_addCaseClosure(cp, &sa);

            }

        }

    }

    if (hasStrings()) {

        UnicodeString str;

        for (int32_t j=0; j<strings_->size(); ++j) {

            const UnicodeString* pStr = static_cast<const UnicodeString*>(strings_->elementAt(j));

            if (simple) {

                if (scfString(*pStr, str)) {

                    foldSet.remove(*pStr).add(str);

                }

            } else {

                str = *pStr;

                str.foldCase();

                if(!ucase_addStringCaseClosure(str.getBuffer(), str.length(), &sa)) {

                    foldSet.add(str); // does not map to code points: add the folded string itself

                }

            }

        }

    }

    *this = foldSet;

}

void UnicodeSet::closeOverAddCaseMappings() {

    // Start with input set to guarantee inclusion.

    UnicodeSet foldSet(*this);

    UnicodeSet subset(0, 0x10ffff);

    const UnicodeSet &codePoints = maybeOnlyCaseSensitive(*this, subset);

    // Iterate over the ranges of single code points. Nested loop for each code point.

    int32_t n = codePoints.getRangeCount();

    UChar32 result;

    const char16_t *full;

    UnicodeString str;

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

        UChar32 start = codePoints.getRangeStart(i);

        UChar32 end   = codePoints.getRangeEnd(i);

        // add case mappings

        // (does not add long s for regular s, or Kelvin for k, for example)

        for (UChar32 cp=start; cp<=end; ++cp) {

            result = ucase_toFullLower(cp, nullptr, nullptr, &full, UCASE_LOC_ROOT);

            addCaseMapping(foldSet, result, full, str);

            result = ucase_toFullTitle(cp, nullptr, nullptr, &full, UCASE_LOC_ROOT);

            addCaseMapping(foldSet, result, full, str);

            result = ucase_toFullUpper(cp, nullptr, nullptr, &full, UCASE_LOC_ROOT);

            addCaseMapping(foldSet, result, full, str);

            result = ucase_toFullFolding(cp, &full, 0);

            addCaseMapping(foldSet, result, full, str);

        }

    }

    if (hasStrings()) {

        Locale root("");

#if !UCONFIG_NO_BREAK_ITERATION

        UErrorCode status = U_ZERO_ERROR;

        BreakIterator *bi = BreakIterator::createWordInstance(root, status);

        if (U_SUCCESS(status)) {

#endif

            for (int32_t j=0; j<strings_->size(); ++j) {

                const UnicodeString* pStr = static_cast<const UnicodeString*>(strings_->elementAt(j));

                (str = *pStr).toLower(root);

                foldSet.add(str);

#if !UCONFIG_NO_BREAK_ITERATION

                (str = *pStr).toTitle(bi, root);

                foldSet.add(str);

#endif

                (str = *pStr).toUpper(root);

                foldSet.add(str);

                (str = *pStr).foldCase();

                foldSet.add(str);

            }

#if !UCONFIG_NO_BREAK_ITERATION

        }

        delete bi;

#endif

    }

    *this = foldSet;

}

U_NAMESPACE_END