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

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

/*

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

 * Copyright (C) 2006-2016, International Business Machines Corporation

 * and others. All Rights Reserved.

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

 */

#include "unicode/utypes.h"

#if !UCONFIG_NO_BREAK_ITERATION

#include "unicode/uchar.h"

#include "unicode/uniset.h"

#include "unicode/chariter.h"

#include "unicode/ures.h"

#include "unicode/udata.h"

#include "unicode/putil.h"

#include "unicode/ustring.h"

#include "unicode/uscript.h"

#include "unicode/ucharstrie.h"

#include "unicode/bytestrie.h"

#include "brkeng.h"

#include "cmemory.h"

#include "dictbe.h"

#include "lstmbe.h"

#include "charstr.h"

#include "dictionarydata.h"

#include "mutex.h"

#include "uvector.h"

#include "umutex.h"

#include "uresimp.h"

#include "ubrkimpl.h"

U_NAMESPACE_BEGIN

/*

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

 */

LanguageBreakEngine::LanguageBreakEngine() {

}

LanguageBreakEngine::~LanguageBreakEngine() {

}

/*

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

 */

LanguageBreakFactory::LanguageBreakFactory() {

}

LanguageBreakFactory::~LanguageBreakFactory() {

}

/*

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

 */

UnhandledEngine::UnhandledEngine(UErrorCode &status) : fHandled(nullptr) {

    (void)status;

}

UnhandledEngine::~UnhandledEngine() {

    delete fHandled;

    fHandled = nullptr;

}

UBool

UnhandledEngine::handles(UChar32 c) const {

    return fHandled && fHandled->contains(c);

}

int32_t

UnhandledEngine::findBreaks( UText *text,

                             int32_t /* startPos */,

                             int32_t endPos,

                             UVector32 &/*foundBreaks*/,

                             UErrorCode &status) const {

    if (U_FAILURE(status)) return 0;

    UChar32 c = utext_current32(text); 

    while((int32_t)utext_getNativeIndex(text) < endPos && fHandled->contains(c)) {

        utext_next32(text);            // TODO:  recast loop to work with post-increment operations.

        c = utext_current32(text);

    }

    return 0;

}

void

UnhandledEngine::handleCharacter(UChar32 c) {

    if (fHandled == nullptr) {

        fHandled = new UnicodeSet();

        if (fHandled == nullptr) {

            return;

        }

    }

    if (!fHandled->contains(c)) {

        UErrorCode status = U_ZERO_ERROR;

        // Apply the entire script of the character.

        int32_t script = u_getIntPropertyValue(c, UCHAR_SCRIPT);

        fHandled->applyIntPropertyValue(UCHAR_SCRIPT, script, status);

    }

}

/*

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

 */

ICULanguageBreakFactory::ICULanguageBreakFactory(UErrorCode &/*status*/) {

    fEngines = 0;

}

ICULanguageBreakFactory::~ICULanguageBreakFactory() {

    if (fEngines != 0) {

        delete fEngines;

    }

}

U_NAMESPACE_END

U_CDECL_BEGIN

static void U_CALLCONV _deleteEngine(void *obj) {

    delete (const icu::LanguageBreakEngine *) obj;

}

U_CDECL_END

U_NAMESPACE_BEGIN

const LanguageBreakEngine *

ICULanguageBreakFactory::getEngineFor(UChar32 c) {

    const LanguageBreakEngine *lbe = NULL;

    UErrorCode  status = U_ZERO_ERROR;

    static UMutex gBreakEngineMutex;

    Mutex m(&gBreakEngineMutex);

    if (fEngines == NULL) {

        UStack  *engines = new UStack(_deleteEngine, NULL, status);

        if (U_FAILURE(status) || engines == NULL) {

            // Note: no way to return error code to caller.

            delete engines;

            return NULL;

        }

        fEngines = engines;

    } else {

        int32_t i = fEngines->size();

        while (--i >= 0) {

            lbe = (const LanguageBreakEngine *)(fEngines->elementAt(i));

            if (lbe != NULL && lbe->handles(c)) {

                return lbe;

            }

        }

    }

    // We didn't find an engine. Create one.

    lbe = loadEngineFor(c);

    if (lbe != NULL) {

        fEngines->push((void *)lbe, status);

    }

    return lbe;

}

const LanguageBreakEngine *

ICULanguageBreakFactory::loadEngineFor(UChar32 c) {

    UErrorCode status = U_ZERO_ERROR;

    UScriptCode code = uscript_getScript(c, &status);

    if (U_SUCCESS(status)) {

        const LanguageBreakEngine *engine = nullptr;

        // Try to use LSTM first

        const LSTMData *data = CreateLSTMDataForScript(code, status);

        if (U_SUCCESS(status)) {

            if (data != nullptr) {

                engine = CreateLSTMBreakEngine(code, data, status);

                if (U_SUCCESS(status) && engine != nullptr) {

                    return engine;

                }

                if (engine != nullptr) {

                    delete engine;

                    engine = nullptr;

                } else {

                    DeleteLSTMData(data);

                }

            }

        }

        status = U_ZERO_ERROR;  // fallback to dictionary based

        DictionaryMatcher *m = loadDictionaryMatcherFor(code);

        if (m != NULL) {

            switch(code) {

            case USCRIPT_THAI:

                engine = new ThaiBreakEngine(m, status);

                break;

            case USCRIPT_LAO:

                engine = new LaoBreakEngine(m, status);

                break;

            case USCRIPT_MYANMAR:

                engine = new BurmeseBreakEngine(m, status);

                break;

            case USCRIPT_KHMER:

                engine = new KhmerBreakEngine(m, status);

                break;

#if !UCONFIG_NO_NORMALIZATION

                // CJK not available w/o normalization

            case USCRIPT_HANGUL:

                engine = new CjkBreakEngine(m, kKorean, status);

                break;

            // use same BreakEngine and dictionary for both Chinese and Japanese

            case USCRIPT_HIRAGANA:

            case USCRIPT_KATAKANA:

            case USCRIPT_HAN:

                engine = new CjkBreakEngine(m, kChineseJapanese, status);

                break;

#if 0

            // TODO: Have to get some characters with script=common handled

            // by CjkBreakEngine (e.g. U+309B). Simply subjecting

            // them to CjkBreakEngine does not work. The engine has to

            // special-case them.

            case USCRIPT_COMMON:

            {

                UBlockCode block = ublock_getCode(code);

                if (block == UBLOCK_HIRAGANA || block == UBLOCK_KATAKANA)

                   engine = new CjkBreakEngine(dict, kChineseJapanese, status);

                break;

            }

#endif

#endif

            default:

                break;

            }

            if (engine == NULL) {

                delete m;

            }

            else if (U_FAILURE(status)) {

                delete engine;

                engine = NULL;

            }

            return engine;

        }

    }

    return NULL;

}

DictionaryMatcher *

ICULanguageBreakFactory::loadDictionaryMatcherFor(UScriptCode script) { 

    UErrorCode status = U_ZERO_ERROR;

    // open root from brkitr tree.

    UResourceBundle *b = ures_open(U_ICUDATA_BRKITR, "", &status);

    b = ures_getByKeyWithFallback(b, "dictionaries", b, &status);

    int32_t dictnlength = 0;

    const UChar *dictfname =

        ures_getStringByKeyWithFallback(b, uscript_getShortName(script), &dictnlength, &status);

    if (U_FAILURE(status)) {

        ures_close(b);

        return NULL;

    }

    CharString dictnbuf;

    CharString ext;

    const UChar *extStart = u_memrchr(dictfname, 0x002e, dictnlength);  // last dot

    if (extStart != NULL) {

        int32_t len = (int32_t)(extStart - dictfname);

        ext.appendInvariantChars(UnicodeString(FALSE, extStart + 1, dictnlength - len - 1), status);

        dictnlength = len;

    }

    dictnbuf.appendInvariantChars(UnicodeString(FALSE, dictfname, dictnlength), status);

    ures_close(b);

    UDataMemory *file = udata_open(U_ICUDATA_BRKITR, ext.data(), dictnbuf.data(), &status);

    if (U_SUCCESS(status)) {

        // build trie

        const uint8_t *data = (const uint8_t *)udata_getMemory(file);

        const int32_t *indexes = (const int32_t *)data;

        const int32_t offset = indexes[DictionaryData::IX_STRING_TRIE_OFFSET];

        const int32_t trieType = indexes[DictionaryData::IX_TRIE_TYPE] & DictionaryData::TRIE_TYPE_MASK;

        DictionaryMatcher *m = NULL;

        if (trieType == DictionaryData::TRIE_TYPE_BYTES) {

            const int32_t transform = indexes[DictionaryData::IX_TRANSFORM];

            const char *characters = (const char *)(data + offset);

            m = new BytesDictionaryMatcher(characters, transform, file);

        }

        else if (trieType == DictionaryData::TRIE_TYPE_UCHARS) {

            const UChar *characters = (const UChar *)(data + offset);

            m = new UCharsDictionaryMatcher(characters, file);

        }

        if (m == NULL) {

            // no matcher exists to take ownership - either we are an invalid 

            // type or memory allocation failed

            udata_close(file);

        }

        return m;

    } else if (dictfname != NULL) {

        // we don't have a dictionary matcher.

        // returning NULL here will cause us to fail to find a dictionary break engine, as expected

        status = U_ZERO_ERROR;

        return NULL;

    }

    return NULL;

}

U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_BREAK_ITERATION */