/*
*******************************************************************************
* Copyright (C) 2011-2014, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*
* File TZNAMES_IMPL.CPP
*
*******************************************************************************
*/

#include "unicode/utypes.h"

#if !UCONFIG_NO_FORMATTING

#include "starboard/client_porting/poem/assert_poem.h"
#include "unicode/ustring.h"
#include "unicode/timezone.h"

#include "tznames_impl.h"
#include "cmemory.h"
#include "cstring.h"
#include "uassert.h"
#include "mutex.h"
#include "uresimp.h"
#include "ureslocs.h"
#include "zonemeta.h"
#include "ucln_in.h"
#include "uvector.h"
#include "olsontz.h"


U_NAMESPACE_BEGIN

#define ZID_KEY_MAX  128
#define MZ_PREFIX_LEN 5

static const char gZoneStrings[]        = "zoneStrings";
static const char gMZPrefix[]           = "meta:";

static const char* KEYS[]               = {"lg", "ls", "ld", "sg", "ss", "sd"};
static const int32_t KEYS_SIZE = (sizeof KEYS / sizeof KEYS[0]);

static const char gEcTag[]              = "ec";

static const char EMPTY[]               = "<empty>";   // place holder for empty ZNames/TZNames

static const UTimeZoneNameType ALL_NAME_TYPES[] = {
    UTZNM_LONG_GENERIC, UTZNM_LONG_STANDARD, UTZNM_LONG_DAYLIGHT,
    UTZNM_SHORT_GENERIC, UTZNM_SHORT_STANDARD, UTZNM_SHORT_DAYLIGHT,
    UTZNM_EXEMPLAR_LOCATION,
    UTZNM_UNKNOWN // unknown as the last one
};

// stuff for TZDBTimeZoneNames
static const char* TZDBNAMES_KEYS[]               = {"ss", "sd"};
static const int32_t TZDBNAMES_KEYS_SIZE = (sizeof TZDBNAMES_KEYS / sizeof TZDBNAMES_KEYS[0]);

static UMutex gTZDBNamesMapLock = U_MUTEX_INITIALIZER;

static UHashtable* gTZDBNamesMap = NULL;
static icu::UInitOnce gTZDBNamesMapInitOnce = U_INITONCE_INITIALIZER;

static TextTrieMap* gTZDBNamesTrie = NULL;
static icu::UInitOnce gTZDBNamesTrieInitOnce = U_INITONCE_INITIALIZER;

U_CDECL_BEGIN
static UBool U_CALLCONV tzdbTimeZoneNames_cleanup(void) {
    if (gTZDBNamesMap != NULL) {
        uhash_close(gTZDBNamesMap);
        gTZDBNamesMap = NULL;
    }
    gTZDBNamesMapInitOnce.reset();

    if (gTZDBNamesTrie != NULL) {
        delete gTZDBNamesTrie;
        gTZDBNamesTrie = NULL;
    }
    gTZDBNamesTrieInitOnce.reset();

    return TRUE;
}
U_CDECL_END

#define DEFAULT_CHARACTERNODE_CAPACITY 1

// ---------------------------------------------------
// CharacterNode class implementation
// ---------------------------------------------------
void CharacterNode::clear() {
    uprv_memset(this, 0, sizeof(*this));
}

void CharacterNode::deleteValues(UObjectDeleter *valueDeleter) {
    if (fValues == NULL) {
        // Do nothing.
    } else if (!fHasValuesVector) {
        if (valueDeleter) {
            valueDeleter(fValues);
        }
    } else {
        delete (UVector *)fValues;
    }
}

void
CharacterNode::addValue(void *value, UObjectDeleter *valueDeleter, UErrorCode &status) {
    if (U_FAILURE(status)) {
        if (valueDeleter) {
            valueDeleter(value);
        }
        return;
    }
    if (fValues == NULL) {
        fValues = value;
    } else {
        // At least one value already.
        if (!fHasValuesVector) {
            // There is only one value so far, and not in a vector yet.
            // Create a vector and add the old value.
            UVector *values = new UVector(valueDeleter, NULL, DEFAULT_CHARACTERNODE_CAPACITY, status);
            if (U_FAILURE(status)) {
                if (valueDeleter) {
                    valueDeleter(value);
                }
                return;
            }
            values->addElement(fValues, status);
            fValues = values;
            fHasValuesVector = TRUE;
        }
        // Add the new value.
        ((UVector *)fValues)->addElement(value, status);
    }
}

// ---------------------------------------------------
// TextTrieMapSearchResultHandler class implementation
// ---------------------------------------------------
TextTrieMapSearchResultHandler::~TextTrieMapSearchResultHandler(){
}

// ---------------------------------------------------
// TextTrieMap class implementation
// ---------------------------------------------------
TextTrieMap::TextTrieMap(UBool ignoreCase, UObjectDeleter *valueDeleter)
: fIgnoreCase(ignoreCase), fNodes(NULL), fNodesCapacity(0), fNodesCount(0), 
  fLazyContents(NULL), fIsEmpty(TRUE), fValueDeleter(valueDeleter) {
}

TextTrieMap::~TextTrieMap() {
    int32_t index;
    for (index = 0; index < fNodesCount; ++index) {
        fNodes[index].deleteValues(fValueDeleter);
    }
    uprv_free(fNodes);
    if (fLazyContents != NULL) {
        for (int32_t i=0; i<fLazyContents->size(); i+=2) {
            if (fValueDeleter) {
                fValueDeleter(fLazyContents->elementAt(i+1));
            }
        } 
        delete fLazyContents;
    }
}

int32_t TextTrieMap::isEmpty() const {
    // Use a separate field for fIsEmpty because it will remain unchanged once the
    //   Trie is built, while fNodes and fLazyContents change with the lazy init
    //   of the nodes structure.  Trying to test the changing fields has
    //   thread safety complications.
    return fIsEmpty;
}


//  We defer actually building the TextTrieMap node structure until the first time a
//     search is performed.  put() simply saves the parameters in case we do
//     eventually need to build it.
//     
void
TextTrieMap::put(const UnicodeString &key, void *value, ZNStringPool &sp, UErrorCode &status) {
    const UChar *s = sp.get(key, status);
    put(s, value, status);
}

// This method is for designed for a persistent key, such as string key stored in
// resource bundle.
void
TextTrieMap::put(const UChar *key, void *value, UErrorCode &status) {
    fIsEmpty = FALSE;
    if (fLazyContents == NULL) {
        fLazyContents = new UVector(status);
        if (fLazyContents == NULL) {
            status = U_MEMORY_ALLOCATION_ERROR;
        }
    }
    if (U_FAILURE(status)) {
        return;
    }
    U_ASSERT(fLazyContents != NULL);
    UChar *s = const_cast<UChar *>(key);
    fLazyContents->addElement(s, status);
    fLazyContents->addElement(value, status);
}

void
TextTrieMap::putImpl(const UnicodeString &key, void *value, UErrorCode &status) {
    if (fNodes == NULL) {
        fNodesCapacity = 512;
        fNodes = (CharacterNode *)uprv_malloc(fNodesCapacity * sizeof(CharacterNode));
        fNodes[0].clear();  // Init root node.
        fNodesCount = 1;
    }

    UnicodeString foldedKey;
    const UChar *keyBuffer;
    int32_t keyLength;
    if (fIgnoreCase) {
        // Ok to use fastCopyFrom() because we discard the copy when we return.
        foldedKey.fastCopyFrom(key).foldCase();
        keyBuffer = foldedKey.getBuffer();
        keyLength = foldedKey.length();
    } else {
        keyBuffer = key.getBuffer();
        keyLength = key.length();
    }

    CharacterNode *node = fNodes;
    int32_t index;
    for (index = 0; index < keyLength; ++index) {
        node = addChildNode(node, keyBuffer[index], status);
    }
    node->addValue(value, fValueDeleter, status);
}

UBool
TextTrieMap::growNodes() {
    if (fNodesCapacity == 0xffff) {
        return FALSE;  // We use 16-bit node indexes.
    }
    int32_t newCapacity = fNodesCapacity + 1000;
    if (newCapacity > 0xffff) {
        newCapacity = 0xffff;
    }
    CharacterNode *newNodes = (CharacterNode *)uprv_malloc(newCapacity * sizeof(CharacterNode));
    if (newNodes == NULL) {
        return FALSE;
    }
    uprv_memcpy(newNodes, fNodes, fNodesCount * sizeof(CharacterNode));
    uprv_free(fNodes);
    fNodes = newNodes;
    fNodesCapacity = newCapacity;
    return TRUE;
}

CharacterNode*
TextTrieMap::addChildNode(CharacterNode *parent, UChar c, UErrorCode &status) {
    if (U_FAILURE(status)) {
        return NULL;
    }
    // Linear search of the sorted list of children.
    uint16_t prevIndex = 0;
    uint16_t nodeIndex = parent->fFirstChild;
    while (nodeIndex > 0) {
        CharacterNode *current = fNodes + nodeIndex;
        UChar childCharacter = current->fCharacter;
        if (childCharacter == c) {
            return current;
        } else if (childCharacter > c) {
            break;
        }
        prevIndex = nodeIndex;
        nodeIndex = current->fNextSibling;
    }

    // Ensure capacity. Grow fNodes[] if needed.
    if (fNodesCount == fNodesCapacity) {
        int32_t parentIndex = (int32_t)(parent - fNodes);
        if (!growNodes()) {
            status = U_MEMORY_ALLOCATION_ERROR;
            return NULL;
        }
        parent = fNodes + parentIndex;
    }

    // Insert a new child node with c in sorted order.
    CharacterNode *node = fNodes + fNodesCount;
    node->clear();
    node->fCharacter = c;
    node->fNextSibling = nodeIndex;
    if (prevIndex == 0) {
        parent->fFirstChild = (uint16_t)fNodesCount;
    } else {
        fNodes[prevIndex].fNextSibling = (uint16_t)fNodesCount;
    }
    ++fNodesCount;
    return node;
}

CharacterNode*
TextTrieMap::getChildNode(CharacterNode *parent, UChar c) const {
    // Linear search of the sorted list of children.
    uint16_t nodeIndex = parent->fFirstChild;
    while (nodeIndex > 0) {
        CharacterNode *current = fNodes + nodeIndex;
        UChar childCharacter = current->fCharacter;
        if (childCharacter == c) {
            return current;
        } else if (childCharacter > c) {
            break;
        }
        nodeIndex = current->fNextSibling;
    }
    return NULL;
}

// Mutex for protecting the lazy creation of the Trie node structure on the first call to search().
static UMutex TextTrieMutex = U_MUTEX_INITIALIZER;

// buildTrie() - The Trie node structure is needed.  Create it from the data that was
//               saved at the time the ZoneStringFormatter was created.  The Trie is only
//               needed for parsing operations, which are less common than formatting,
//               and the Trie is big, which is why its creation is deferred until first use.
void TextTrieMap::buildTrie(UErrorCode &status) {
    if (fLazyContents != NULL) {
        for (int32_t i=0; i<fLazyContents->size(); i+=2) {
            const UChar *key = (UChar *)fLazyContents->elementAt(i);
            void  *val = fLazyContents->elementAt(i+1);
            UnicodeString keyString(TRUE, key, -1);  // Aliasing UnicodeString constructor.
            putImpl(keyString, val, status);
        }
        delete fLazyContents;
        fLazyContents = NULL; 
    }
}

void
TextTrieMap::search(const UnicodeString &text, int32_t start,
                  TextTrieMapSearchResultHandler *handler, UErrorCode &status) const {
    {
        // TODO: if locking the mutex for each check proves to be a performance problem,
        //       add a flag of type atomic_int32_t to class TextTrieMap, and use only
        //       the ICU atomic safe functions for assigning and testing.
        //       Don't test the pointer fLazyContents.
        //       Don't do unless it's really required.
        Mutex lock(&TextTrieMutex);
        if (fLazyContents != NULL) {
            TextTrieMap *nonConstThis = const_cast<TextTrieMap *>(this);
            nonConstThis->buildTrie(status);
        }
    }
    if (fNodes == NULL) {
        return;
    }
    search(fNodes, text, start, start, handler, status);
}

void
TextTrieMap::search(CharacterNode *node, const UnicodeString &text, int32_t start,
                  int32_t index, TextTrieMapSearchResultHandler *handler, UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return;
    }
    if (node->hasValues()) {
        if (!handler->handleMatch(index - start, node, status)) {
            return;
        }
        if (U_FAILURE(status)) {
            return;
        }
    }
    UChar32 c = text.char32At(index);
    if (fIgnoreCase) {
        // size of character may grow after fold operation
        UnicodeString tmp(c);
        tmp.foldCase();
        int32_t tmpidx = 0;
        while (tmpidx < tmp.length()) {
            c = tmp.char32At(tmpidx);
            node = getChildNode(node, c);
            if (node == NULL) {
                break;
            }
            tmpidx = tmp.moveIndex32(tmpidx, 1);
        }
    } else {
        node = getChildNode(node, c);
    }
    if (node != NULL) {
        search(node, text, start, index+1, handler, status);
    }
}

// ---------------------------------------------------
// ZNStringPool class implementation
// ---------------------------------------------------
static const int32_t POOL_CHUNK_SIZE = 2000;
struct ZNStringPoolChunk: public UMemory {
    ZNStringPoolChunk    *fNext;                       // Ptr to next pool chunk
    int32_t               fLimit;                       // Index to start of unused area at end of fStrings
    UChar                 fStrings[POOL_CHUNK_SIZE];    //  Strings array
    ZNStringPoolChunk();
};

ZNStringPoolChunk::ZNStringPoolChunk() {
    fNext = NULL;
    fLimit = 0;
}

ZNStringPool::ZNStringPool(UErrorCode &status) {
    fChunks = NULL;
    fHash   = NULL;
    if (U_FAILURE(status)) {
        return;
    }
    fChunks = new ZNStringPoolChunk;
    if (fChunks == NULL) {
        status = U_MEMORY_ALLOCATION_ERROR;
        return;
    }

    fHash   = uhash_open(uhash_hashUChars      /* keyHash */, 
                         uhash_compareUChars   /* keyComp */, 
                         uhash_compareUChars   /* valueComp */, 
                         &status);
    if (U_FAILURE(status)) {
        return;
    }
}

ZNStringPool::~ZNStringPool() {
    if (fHash != NULL) {
        uhash_close(fHash);
        fHash = NULL;
    }

    while (fChunks != NULL) {
        ZNStringPoolChunk *nextChunk = fChunks->fNext;
        delete fChunks;
        fChunks = nextChunk;
    }
}

static const UChar EmptyString = 0;

const UChar *ZNStringPool::get(const UChar *s, UErrorCode &status) {
    const UChar *pooledString;
    if (U_FAILURE(status)) {
        return &EmptyString;
    }

    pooledString = static_cast<UChar *>(uhash_get(fHash, s));
    if (pooledString != NULL) {
        return pooledString;
    }

    int32_t length = u_strlen(s);
    int32_t remainingLength = POOL_CHUNK_SIZE - fChunks->fLimit;
    if (remainingLength <= length) {
        U_ASSERT(length < POOL_CHUNK_SIZE);
        if (length >= POOL_CHUNK_SIZE) {
            status = U_INTERNAL_PROGRAM_ERROR;
            return &EmptyString;
        }
        ZNStringPoolChunk *oldChunk = fChunks;
        fChunks = new ZNStringPoolChunk;
        if (fChunks == NULL) {
            status = U_MEMORY_ALLOCATION_ERROR;
            return &EmptyString;
        }
        fChunks->fNext = oldChunk;
    }
    
    UChar *destString = &fChunks->fStrings[fChunks->fLimit];
    u_strcpy(destString, s);
    fChunks->fLimit += (length + 1);
    uhash_put(fHash, destString, destString, &status);
    return destString;
}        


//
//  ZNStringPool::adopt()    Put a string into the hash, but do not copy the string data
//                           into the pool's storage.  Used for strings from resource bundles,
//                           which will perisist for the life of the zone string formatter, and
//                           therefore can be used directly without copying.
const UChar *ZNStringPool::adopt(const UChar * s, UErrorCode &status) {
    const UChar *pooledString;
    if (U_FAILURE(status)) {
        return &EmptyString;
    }
    if (s != NULL) {
        pooledString = static_cast<UChar *>(uhash_get(fHash, s));
        if (pooledString == NULL) {
            UChar *ncs = const_cast<UChar *>(s);
            uhash_put(fHash, ncs, ncs, &status);
        }
    }
    return s;
}

    
const UChar *ZNStringPool::get(const UnicodeString &s, UErrorCode &status) {
    UnicodeString &nonConstStr = const_cast<UnicodeString &>(s);
    return this->get(nonConstStr.getTerminatedBuffer(), status);
}

/*
 * freeze().   Close the hash table that maps to the pooled strings.
 *             After freezing, the pool can not be searched or added to,
 *             but all existing references to pooled strings remain valid.
 *
 *             The main purpose is to recover the storage used for the hash.
 */
void ZNStringPool::freeze() {
    uhash_close(fHash);
    fHash = NULL;
}


// ---------------------------------------------------
// ZNames - names common for time zone and meta zone
// ---------------------------------------------------
class ZNames : public UMemory {
public:
    virtual ~ZNames();

    static ZNames* createInstance(UResourceBundle* rb, const char* key);
    virtual const UChar* getName(UTimeZoneNameType type);

protected:
    ZNames(const UChar** names);
    static const UChar** loadData(UResourceBundle* rb, const char* key);

private:
    const UChar** fNames;
};

ZNames::ZNames(const UChar** names)
: fNames(names) {
}

ZNames::~ZNames() {
    if (fNames != NULL) {
        uprv_free(fNames);
    }
}

ZNames*
ZNames::createInstance(UResourceBundle* rb, const char* key) {
    const UChar** names = loadData(rb, key);
    if (names == NULL) {
        // No names data available
        return NULL; 
    }
    return new ZNames(names);
}

const UChar*
ZNames::getName(UTimeZoneNameType type) {
    if (fNames == NULL) {
        return NULL;
    }
    const UChar *name = NULL;
    switch(type) {
    case UTZNM_LONG_GENERIC:
        name = fNames[0];
        break;
    case UTZNM_LONG_STANDARD:
        name = fNames[1];
        break;
    case UTZNM_LONG_DAYLIGHT:
        name = fNames[2];
        break;
    case UTZNM_SHORT_GENERIC:
        name = fNames[3];
        break;
    case UTZNM_SHORT_STANDARD:
        name = fNames[4];
        break;
    case UTZNM_SHORT_DAYLIGHT:
        name = fNames[5];
        break;
    case UTZNM_EXEMPLAR_LOCATION:   // implemeted by subclass
    default:
        name = NULL;
    }
    return name;
}

const UChar**
ZNames::loadData(UResourceBundle* rb, const char* key) {
    if (rb == NULL || key == NULL || *key == 0) {
        return NULL;
    }

    UErrorCode status = U_ZERO_ERROR;
    const UChar **names = NULL;

    UResourceBundle* rbTable = NULL;
    rbTable = ures_getByKeyWithFallback(rb, key, rbTable, &status);
    if (U_SUCCESS(status)) {
        names = (const UChar **)uprv_malloc(sizeof(const UChar*) * KEYS_SIZE);
        if (names != NULL) {
            UBool isEmpty = TRUE;
            for (int32_t i = 0; i < KEYS_SIZE; i++) {
                status = U_ZERO_ERROR;
                int32_t len = 0;
                const UChar *value = ures_getStringByKeyWithFallback(rbTable, KEYS[i], &len, &status);
                if (U_FAILURE(status) || len == 0) {
                    names[i] = NULL;
                } else {
                    names[i] = value;
                    isEmpty = FALSE;
                }
            }
            if (isEmpty) {
                // No need to keep the names array
                uprv_free(names);
                names = NULL;
            }
        }
    }
    ures_close(rbTable);
    return names;
}

// ---------------------------------------------------
// TZNames - names for a time zone
// ---------------------------------------------------
class TZNames : public ZNames {
public:
    virtual ~TZNames();

    static TZNames* createInstance(UResourceBundle* rb, const char* key, const UnicodeString& tzID);
    virtual const UChar* getName(UTimeZoneNameType type);

private:
    TZNames(const UChar** names);
    const UChar* fLocationName;
    UChar* fLocationNameOwned;
};

TZNames::TZNames(const UChar** names)
: ZNames(names), fLocationName(NULL), fLocationNameOwned(NULL) {
}

TZNames::~TZNames() {
    if (fLocationNameOwned) {
        uprv_free(fLocationNameOwned);
    }
}

const UChar*
TZNames::getName(UTimeZoneNameType type) {
    if (type == UTZNM_EXEMPLAR_LOCATION) {
        return fLocationName;
    }
    return ZNames::getName(type);
}

TZNames*
TZNames::createInstance(UResourceBundle* rb, const char* key, const UnicodeString& tzID) {
    if (rb == NULL || key == NULL || *key == 0) {
        return NULL;
    }

    const UChar** names = loadData(rb, key);
    const UChar* locationName = NULL;
    UChar* locationNameOwned = NULL;

    UErrorCode status = U_ZERO_ERROR;
    int32_t len = 0;

    UResourceBundle* table = ures_getByKeyWithFallback(rb, key, NULL, &status);
    locationName = ures_getStringByKeyWithFallback(table, gEcTag, &len, &status);
    // ignore missing resource here
    status = U_ZERO_ERROR;

    ures_close(table);

    if (locationName == NULL) {
        UnicodeString tmpName;
        int32_t tmpNameLen = 0;
        TimeZoneNamesImpl::getDefaultExemplarLocationName(tzID, tmpName);
        tmpNameLen = tmpName.length();

        if (tmpNameLen > 0) {
            locationNameOwned = (UChar*) uprv_malloc(sizeof(UChar) * (tmpNameLen + 1));
            if (locationNameOwned) {
                tmpName.extract(locationNameOwned, tmpNameLen + 1, status);
                locationName = locationNameOwned;
            }
        }
    }

    TZNames* tznames = NULL;
    if (locationName != NULL || names != NULL) {
        tznames = new TZNames(names);
        if (tznames == NULL) {
            if (locationNameOwned) {
                uprv_free(locationNameOwned);
            }
        }
        tznames->fLocationName = locationName;
        tznames->fLocationNameOwned = locationNameOwned;
    }

    return tznames;
}

// ---------------------------------------------------
// The meta zone ID enumeration class
// ---------------------------------------------------
class MetaZoneIDsEnumeration : public StringEnumeration {
public:
    MetaZoneIDsEnumeration();
    MetaZoneIDsEnumeration(const UVector& mzIDs);
    MetaZoneIDsEnumeration(UVector* mzIDs);
    virtual ~MetaZoneIDsEnumeration();
    static UClassID U_EXPORT2 getStaticClassID(void);
    virtual UClassID getDynamicClassID(void) const;
    virtual const UnicodeString* snext(UErrorCode& status);
    virtual void reset(UErrorCode& status);
    virtual int32_t count(UErrorCode& status) const;
private:
    int32_t fLen;
    int32_t fPos;
    const UVector* fMetaZoneIDs;
    UVector *fLocalVector;
};

UOBJECT_DEFINE_RTTI_IMPLEMENTATION(MetaZoneIDsEnumeration)

MetaZoneIDsEnumeration::MetaZoneIDsEnumeration() 
: fLen(0), fPos(0), fMetaZoneIDs(NULL), fLocalVector(NULL) {
}

MetaZoneIDsEnumeration::MetaZoneIDsEnumeration(const UVector& mzIDs) 
: fPos(0), fMetaZoneIDs(&mzIDs), fLocalVector(NULL) {
    fLen = fMetaZoneIDs->size();
}

MetaZoneIDsEnumeration::MetaZoneIDsEnumeration(UVector *mzIDs)
: fLen(0), fPos(0), fMetaZoneIDs(mzIDs), fLocalVector(mzIDs) {
    if (fMetaZoneIDs) {
        fLen = fMetaZoneIDs->size();
    }
}

const UnicodeString*
MetaZoneIDsEnumeration::snext(UErrorCode& status) {
    if (U_SUCCESS(status) && fMetaZoneIDs != NULL && fPos < fLen) {
        unistr.setTo((const UChar*)fMetaZoneIDs->elementAt(fPos++), -1);
        return &unistr;
    }
    return NULL;
}

void
MetaZoneIDsEnumeration::reset(UErrorCode& /*status*/) {
    fPos = 0;
}

int32_t
MetaZoneIDsEnumeration::count(UErrorCode& /*status*/) const {
    return fLen;
}

MetaZoneIDsEnumeration::~MetaZoneIDsEnumeration() {
    if (fLocalVector) {
        delete fLocalVector;
    }
}

U_CDECL_BEGIN
/**
 * ZNameInfo stores zone name information in the trie
 */
typedef struct ZNameInfo {
    UTimeZoneNameType   type;
    const UChar*        tzID;
    const UChar*        mzID;
} ZNameInfo;

/**
 * ZMatchInfo stores zone name match information used by find method
 */
typedef struct ZMatchInfo {
    const ZNameInfo*    znameInfo;
    int32_t             matchLength;
} ZMatchInfo;
U_CDECL_END


// ---------------------------------------------------
// ZNameSearchHandler
// ---------------------------------------------------
class ZNameSearchHandler : public TextTrieMapSearchResultHandler {
public:
    ZNameSearchHandler(uint32_t types);
    virtual ~ZNameSearchHandler();

    UBool handleMatch(int32_t matchLength, const CharacterNode *node, UErrorCode &status);
    TimeZoneNames::MatchInfoCollection* getMatches(int32_t& maxMatchLen);

private:
    uint32_t fTypes;
    int32_t fMaxMatchLen;
    TimeZoneNames::MatchInfoCollection* fResults;
};

ZNameSearchHandler::ZNameSearchHandler(uint32_t types) 
: fTypes(types), fMaxMatchLen(0), fResults(NULL) {
}

ZNameSearchHandler::~ZNameSearchHandler() {
    if (fResults != NULL) {
        delete fResults;
    }
}

UBool
ZNameSearchHandler::handleMatch(int32_t matchLength, const CharacterNode *node, UErrorCode &status) {
    if (U_FAILURE(status)) {
        return FALSE;
    }
    if (node->hasValues()) {
        int32_t valuesCount = node->countValues();
        for (int32_t i = 0; i < valuesCount; i++) {
            ZNameInfo *nameinfo = (ZNameInfo *)node->getValue(i);
            if (nameinfo == NULL) {
                continue;
            }
            if ((nameinfo->type & fTypes) != 0) {
                // matches a requested type
                if (fResults == NULL) {
                    fResults = new TimeZoneNames::MatchInfoCollection();
                    if (fResults == NULL) {
                        status = U_MEMORY_ALLOCATION_ERROR;
                    }
                }
                if (U_SUCCESS(status)) {
                    U_ASSERT(fResults != NULL);
                    if (nameinfo->tzID) {
                        fResults->addZone(nameinfo->type, matchLength, UnicodeString(nameinfo->tzID, -1), status);
                    } else {
                        U_ASSERT(nameinfo->mzID);
                        fResults->addMetaZone(nameinfo->type, matchLength, UnicodeString(nameinfo->mzID, -1), status);
                    }
                    if (U_SUCCESS(status) && matchLength > fMaxMatchLen) {
                        fMaxMatchLen = matchLength;
                    }
                }
            }
        }
    }
    return TRUE;
}

TimeZoneNames::MatchInfoCollection*
ZNameSearchHandler::getMatches(int32_t& maxMatchLen) {
    // give the ownership to the caller
    TimeZoneNames::MatchInfoCollection* results = fResults;
    maxMatchLen = fMaxMatchLen;

    // reset
    fResults = NULL;
    fMaxMatchLen = 0;
    return results;
}

// ---------------------------------------------------
// TimeZoneNamesImpl
//
// TimeZoneNames implementation class. This is the main
// part of this module.
// ---------------------------------------------------

U_CDECL_BEGIN
/**
 * Deleter for ZNames
 */
static void U_CALLCONV
deleteZNames(void *obj) {
    if (obj != EMPTY) {
        delete (ZNames *)obj;
    }
}
/**
 * Deleter for TZNames
 */
static void U_CALLCONV
deleteTZNames(void *obj) {
    if (obj != EMPTY) {
        delete (TZNames *)obj;
    }
}

/**
 * Deleter for ZNameInfo
 */
static void U_CALLCONV
deleteZNameInfo(void *obj) {
    uprv_free(obj);
}

U_CDECL_END

static UMutex gLock = U_MUTEX_INITIALIZER;

TimeZoneNamesImpl::TimeZoneNamesImpl(const Locale& locale, UErrorCode& status)
: fLocale(locale),
  fZoneStrings(NULL),
  fTZNamesMap(NULL),
  fMZNamesMap(NULL),
  fNamesTrieFullyLoaded(FALSE),
  fNamesTrie(TRUE, deleteZNameInfo) {
    initialize(locale, status);
}

void
TimeZoneNamesImpl::initialize(const Locale& locale, UErrorCode& status) {
    if (U_FAILURE(status)) {
        return;
    }

    // Load zoneStrings bundle
    UErrorCode tmpsts = U_ZERO_ERROR;   // OK with fallback warning..
    fZoneStrings = ures_open(U_ICUDATA_ZONE, locale.getName(), &tmpsts);
    fZoneStrings = ures_getByKeyWithFallback(fZoneStrings, gZoneStrings, fZoneStrings, &tmpsts);
    if (U_FAILURE(tmpsts)) {
        status = tmpsts;
        cleanup();
        return;
    }

    // Initialize hashtables holding time zone/meta zone names
    fMZNamesMap = uhash_open(uhash_hashUChars, uhash_compareUChars, NULL, &status);
    fTZNamesMap = uhash_open(uhash_hashUChars, uhash_compareUChars, NULL, &status);
    if (U_FAILURE(status)) {
        cleanup();
        return;
    }

    uhash_setValueDeleter(fMZNamesMap, deleteZNames);
    uhash_setValueDeleter(fTZNamesMap, deleteTZNames);
    // no key deleters for name maps

    // preload zone strings for the default zone
    TimeZone *tz = TimeZone::createDefault();
    const UChar *tzID = ZoneMeta::getCanonicalCLDRID(*tz);
    if (tzID != NULL) {
        loadStrings(UnicodeString(tzID));
    }
    delete tz;

    return;
}

/*
 * This method updates the cache and must be called with a lock,
 * except initializer.
 */
void
TimeZoneNamesImpl::loadStrings(const UnicodeString& tzCanonicalID) {
    loadTimeZoneNames(tzCanonicalID);

    UErrorCode status = U_ZERO_ERROR;
    StringEnumeration *mzIDs = getAvailableMetaZoneIDs(tzCanonicalID, status);
    if (U_SUCCESS(status) && mzIDs != NULL) {
        const UnicodeString *mzID;
        while ((mzID = mzIDs->snext(status))) {
            if (U_FAILURE(status)) {
                break;
            }
            loadMetaZoneNames(*mzID);
        }
        delete mzIDs;
    }
}

TimeZoneNamesImpl::~TimeZoneNamesImpl() {
    cleanup();
}

void
TimeZoneNamesImpl::cleanup() {
    if (fZoneStrings != NULL) {
        ures_close(fZoneStrings);
        fZoneStrings = NULL;
    }
    if (fMZNamesMap != NULL) {
        uhash_close(fMZNamesMap);
        fMZNamesMap = NULL;
    }
    if (fTZNamesMap != NULL) {
        uhash_close(fTZNamesMap);
        fTZNamesMap = NULL;
    }
}

UBool
TimeZoneNamesImpl::operator==(const TimeZoneNames& other) const {
    if (this == &other) {
        return TRUE;
    }
    // No implementation for now
    return FALSE;
}

TimeZoneNames*
TimeZoneNamesImpl::clone() const {
    UErrorCode status = U_ZERO_ERROR;
    return new TimeZoneNamesImpl(fLocale, status);
}

StringEnumeration*
TimeZoneNamesImpl::getAvailableMetaZoneIDs(UErrorCode& status) const {
    return TimeZoneNamesImpl::_getAvailableMetaZoneIDs(status);
}

// static implementation of getAvailableMetaZoneIDs(UErrorCode&)
StringEnumeration*
TimeZoneNamesImpl::_getAvailableMetaZoneIDs(UErrorCode& status) {
    if (U_FAILURE(status)) {
        return NULL;
    }
    const UVector* mzIDs = ZoneMeta::getAvailableMetazoneIDs();
    if (mzIDs == NULL) {
        return new MetaZoneIDsEnumeration();
    }
    return new MetaZoneIDsEnumeration(*mzIDs);
}

StringEnumeration*
TimeZoneNamesImpl::getAvailableMetaZoneIDs(const UnicodeString& tzID, UErrorCode& status) const {
    return TimeZoneNamesImpl::_getAvailableMetaZoneIDs(tzID, status);
}

// static implementation of getAvailableMetaZoneIDs(const UnicodeString&, UErrorCode&)
StringEnumeration*
TimeZoneNamesImpl::_getAvailableMetaZoneIDs(const UnicodeString& tzID, UErrorCode& status) {
    if (U_FAILURE(status)) {
        return NULL;
    }
    const UVector* mappings = ZoneMeta::getMetazoneMappings(tzID);
    if (mappings == NULL) {
        return new MetaZoneIDsEnumeration();
    }

    MetaZoneIDsEnumeration *senum = NULL;
    UVector* mzIDs = new UVector(NULL, uhash_compareUChars, status);
    if (mzIDs == NULL) {
        status = U_MEMORY_ALLOCATION_ERROR;
    }
    if (U_SUCCESS(status)) {
        U_ASSERT(mzIDs != NULL);
        for (int32_t i = 0; U_SUCCESS(status) && i < mappings->size(); i++) {

            OlsonToMetaMappingEntry *map = (OlsonToMetaMappingEntry *)mappings->elementAt(i);
            const UChar *mzID = map->mzid;
            if (!mzIDs->contains((void *)mzID)) {
                mzIDs->addElement((void *)mzID, status);
            }
        }
        if (U_SUCCESS(status)) {
            senum = new MetaZoneIDsEnumeration(mzIDs);
        } else {
            delete mzIDs;
        }
    }
    return senum;
}

UnicodeString&
TimeZoneNamesImpl::getMetaZoneID(const UnicodeString& tzID, UDate date, UnicodeString& mzID) const {
    return TimeZoneNamesImpl::_getMetaZoneID(tzID, date, mzID);
}

// static implementation of getMetaZoneID
UnicodeString&
TimeZoneNamesImpl::_getMetaZoneID(const UnicodeString& tzID, UDate date, UnicodeString& mzID) {
    ZoneMeta::getMetazoneID(tzID, date, mzID);
    return mzID;
}

UnicodeString&
TimeZoneNamesImpl::getReferenceZoneID(const UnicodeString& mzID, const char* region, UnicodeString& tzID) const {
    return TimeZoneNamesImpl::_getReferenceZoneID(mzID, region, tzID);
}

// static implementaion of getReferenceZoneID
UnicodeString&
TimeZoneNamesImpl::_getReferenceZoneID(const UnicodeString& mzID, const char* region, UnicodeString& tzID) {
    ZoneMeta::getZoneIdByMetazone(mzID, UnicodeString(region, -1, US_INV), tzID);
    return tzID;
}


UnicodeString&
TimeZoneNamesImpl::getMetaZoneDisplayName(const UnicodeString& mzID,
                                          UTimeZoneNameType type,
                                          UnicodeString& name) const {
    name.setToBogus();  // cleanup result.
    if (mzID.isEmpty()) {
        return name;
    }

    ZNames *znames = NULL;
    TimeZoneNamesImpl *nonConstThis = const_cast<TimeZoneNamesImpl *>(this);

    umtx_lock(&gLock);
    {
        znames = nonConstThis->loadMetaZoneNames(mzID);
    }
    umtx_unlock(&gLock);

    if (znames != NULL) {
        const UChar* s = znames->getName(type);
        if (s != NULL) {
            name.setTo(TRUE, s, -1);
        }
    }
    return name;
}

UnicodeString&
TimeZoneNamesImpl::getTimeZoneDisplayName(const UnicodeString& tzID, UTimeZoneNameType type, UnicodeString& name) const {
    name.setToBogus();  // cleanup result.
    if (tzID.isEmpty()) {
        return name;
    }

    TZNames *tznames = NULL;
    TimeZoneNamesImpl *nonConstThis = const_cast<TimeZoneNamesImpl *>(this);

    umtx_lock(&gLock);
    {
        tznames = nonConstThis->loadTimeZoneNames(tzID);
    }
    umtx_unlock(&gLock);

    if (tznames != NULL) {
        const UChar *s = tznames->getName(type);
        if (s != NULL) {
            name.setTo(TRUE, s, -1);
        }
    }
    return name;
}

UnicodeString&
TimeZoneNamesImpl::getExemplarLocationName(const UnicodeString& tzID, UnicodeString& name) const {
    name.setToBogus();  // cleanup result.
    const UChar* locName = NULL;
    TZNames *tznames = NULL;
    TimeZoneNamesImpl *nonConstThis = const_cast<TimeZoneNamesImpl *>(this);

    umtx_lock(&gLock);
    {
        tznames = nonConstThis->loadTimeZoneNames(tzID);
    }
    umtx_unlock(&gLock);

    if (tznames != NULL) {
        locName = tznames->getName(UTZNM_EXEMPLAR_LOCATION);
    }
    if (locName != NULL) {
        name.setTo(TRUE, locName, -1);
    }

    return name;
}


// Merge the MZ_PREFIX and mzId
static void mergeTimeZoneKey(const UnicodeString& mzID, char* result) {
    if (mzID.isEmpty()) {
        result[0] = '\0';
        return;
    }

    char mzIdChar[ZID_KEY_MAX + 1];
    int32_t keyLen;
    int32_t prefixLen = uprv_strlen(gMZPrefix);
    keyLen = mzID.extract(0, mzID.length(), mzIdChar, ZID_KEY_MAX + 1, US_INV);
    uprv_memcpy((void *)result, (void *)gMZPrefix, prefixLen);
    uprv_memcpy((void *)(result + prefixLen), (void *)mzIdChar, keyLen);
    result[keyLen + prefixLen] = '\0';
}

/*
 * This method updates the cache and must be called with a lock
 */
ZNames*
TimeZoneNamesImpl::loadMetaZoneNames(const UnicodeString& mzID) {
    if (mzID.length() > (ZID_KEY_MAX - MZ_PREFIX_LEN)) {
        return NULL;
    }

    ZNames *znames = NULL;

    UErrorCode status = U_ZERO_ERROR;
    UChar mzIDKey[ZID_KEY_MAX + 1];
    mzID.extract(mzIDKey, ZID_KEY_MAX + 1, status);
    U_ASSERT(status == U_ZERO_ERROR);   // already checked length above
    mzIDKey[mzID.length()] = 0;

    void *cacheVal = uhash_get(fMZNamesMap, mzIDKey);
    if (cacheVal == NULL) {
        char key[ZID_KEY_MAX + 1];
        mergeTimeZoneKey(mzID, key);
        znames = ZNames::createInstance(fZoneStrings, key);

        if (znames == NULL) {
            cacheVal = (void *)EMPTY;
        } else {
            cacheVal = znames;
        }
        // Use the persistent ID as the resource key, so we can
        // avoid duplications.
        const UChar* newKey = ZoneMeta::findMetaZoneID(mzID);
        if (newKey != NULL) {
            uhash_put(fMZNamesMap, (void *)newKey, cacheVal, &status);
            if (U_FAILURE(status)) {
                if (znames != NULL) {
                    delete znames;
                    znames = NULL;
                }
            } else if (znames != NULL) {
                // put the name info into the trie
                for (int32_t i = 0; ALL_NAME_TYPES[i] != UTZNM_UNKNOWN; i++) {
                    const UChar* name = znames->getName(ALL_NAME_TYPES[i]);
                    if (name != NULL) {
                        ZNameInfo *nameinfo = (ZNameInfo *)uprv_malloc(sizeof(ZNameInfo));
                        if (nameinfo != NULL) {
                            nameinfo->type = ALL_NAME_TYPES[i];
                            nameinfo->tzID = NULL;
                            nameinfo->mzID = newKey;
                            fNamesTrie.put(name, nameinfo, status);
                        }
                    }
                }
            }

        } else {
            // Should never happen with a valid input
            if (znames != NULL) {
                // It's not possible that we get a valid ZNames with unknown ID.
                // But just in case..
                delete znames;
                znames = NULL;
            }
        }
    } else if (cacheVal != EMPTY) {
        znames = (ZNames *)cacheVal;
    }

    return znames;
}

/*
 * This method updates the cache and must be called with a lock
 */
TZNames*
TimeZoneNamesImpl::loadTimeZoneNames(const UnicodeString& tzID) {
    if (tzID.length() > ZID_KEY_MAX) {
        return NULL;
    }

    TZNames *tznames = NULL;

    UErrorCode status = U_ZERO_ERROR;
    UChar tzIDKey[ZID_KEY_MAX + 1];
    int32_t tzIDKeyLen = tzID.extract(tzIDKey, ZID_KEY_MAX + 1, status);
    U_ASSERT(status == U_ZERO_ERROR);   // already checked length above
    tzIDKey[tzIDKeyLen] = 0;

    void *cacheVal = uhash_get(fTZNamesMap, tzIDKey);
    if (cacheVal == NULL) {
        char key[ZID_KEY_MAX + 1];
        UErrorCode status = U_ZERO_ERROR;
        // Replace "/" with ":".
        UnicodeString uKey(tzID);
        for (int32_t i = 0; i < uKey.length(); i++) {
            if (uKey.charAt(i) == (UChar)0x2F) {
                uKey.setCharAt(i, (UChar)0x3A);
            }
        }
        uKey.extract(0, uKey.length(), key, sizeof(key), US_INV);
        tznames = TZNames::createInstance(fZoneStrings, key, tzID);

        if (tznames == NULL) {
            cacheVal = (void *)EMPTY;
        } else {
            cacheVal = tznames;
        }
        // Use the persistent ID as the resource key, so we can
        // avoid duplications.
        const UChar* newKey = ZoneMeta::findTimeZoneID(tzID);
        if (newKey != NULL) {
            uhash_put(fTZNamesMap, (void *)newKey, cacheVal, &status);
            if (U_FAILURE(status)) {
                if (tznames != NULL) {
                    delete tznames;
                    tznames = NULL;
                }
            } else if (tznames != NULL) {
                // put the name info into the trie
                for (int32_t i = 0; ALL_NAME_TYPES[i] != UTZNM_UNKNOWN; i++) {
                    const UChar* name = tznames->getName(ALL_NAME_TYPES[i]);
                    if (name != NULL) {
                        ZNameInfo *nameinfo = (ZNameInfo *)uprv_malloc(sizeof(ZNameInfo));
                        if (nameinfo != NULL) {
                            nameinfo->type = ALL_NAME_TYPES[i];
                            nameinfo->tzID = newKey;
                            nameinfo->mzID = NULL;
                            fNamesTrie.put(name, nameinfo, status);
                        }
                    }
                }
            }
        } else {
            // Should never happen with a valid input
            if (tznames != NULL) {
                // It's not possible that we get a valid TZNames with unknown ID.
                // But just in case..
                delete tznames;
                tznames = NULL;
            }
        }
    } else if (cacheVal != EMPTY) {
        tznames = (TZNames *)cacheVal;
    }

    return tznames;
}

TimeZoneNames::MatchInfoCollection*
TimeZoneNamesImpl::find(const UnicodeString& text, int32_t start, uint32_t types, UErrorCode& status) const {
    ZNameSearchHandler handler(types);

    TimeZoneNamesImpl *nonConstThis = const_cast<TimeZoneNamesImpl *>(this);

    umtx_lock(&gLock);
    {
        fNamesTrie.search(text, start, (TextTrieMapSearchResultHandler *)&handler, status);
    }
    umtx_unlock(&gLock);

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

    int32_t maxLen = 0;
    TimeZoneNames::MatchInfoCollection* matches = handler.getMatches(maxLen);
    if (matches != NULL && ((maxLen == (text.length() - start)) || fNamesTrieFullyLoaded)) {
        // perfect match
        return matches;
    }

    delete matches;

    // All names are not yet loaded into the trie
    umtx_lock(&gLock);
    {
        if (!fNamesTrieFullyLoaded) {
            const UnicodeString *id;

            // load strings for all zones
            StringEnumeration *tzIDs = TimeZone::createTimeZoneIDEnumeration(UCAL_ZONE_TYPE_CANONICAL, NULL, NULL, status);
            if (U_SUCCESS(status)) {
                while ((id = tzIDs->snext(status))) {
                    if (U_FAILURE(status)) {
                        break;
                    }
                    // loadStrings also load related metazone strings
                    nonConstThis->loadStrings(*id);
                }
            }
            if (tzIDs != NULL) {
                delete tzIDs;
            }
            if (U_SUCCESS(status)) {
                nonConstThis->fNamesTrieFullyLoaded = TRUE;
            }
        }
    }
    umtx_unlock(&gLock);

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

    umtx_lock(&gLock);
    {
        // now try it again
        fNamesTrie.search(text, start, (TextTrieMapSearchResultHandler *)&handler, status);
    }
    umtx_unlock(&gLock);

    return handler.getMatches(maxLen);
}

static const UChar gEtcPrefix[]         = { 0x45, 0x74, 0x63, 0x2F }; // "Etc/"
static const int32_t gEtcPrefixLen      = 4;
static const UChar gSystemVPrefix[]     = { 0x53, 0x79, 0x73, 0x74, 0x65, 0x6D, 0x56, 0x2F }; // "SystemV/
static const int32_t gSystemVPrefixLen  = 8;
static const UChar gRiyadh8[]           = { 0x52, 0x69, 0x79, 0x61, 0x64, 0x68, 0x38 }; // "Riyadh8"
static const int32_t gRiyadh8Len       = 7;

UnicodeString& U_EXPORT2
TimeZoneNamesImpl::getDefaultExemplarLocationName(const UnicodeString& tzID, UnicodeString& name) {
    if (tzID.isEmpty() || tzID.startsWith(gEtcPrefix, gEtcPrefixLen)
        || tzID.startsWith(gSystemVPrefix, gSystemVPrefixLen) || tzID.indexOf(gRiyadh8, gRiyadh8Len, 0) > 0) {
        name.setToBogus();
        return name;
    }

    int32_t sep = tzID.lastIndexOf((UChar)0x2F /* '/' */);
    if (sep > 0 && sep + 1 < tzID.length()) {
        name.setTo(tzID, sep + 1);
        name.findAndReplace(UnicodeString((UChar)0x5f /* _ */),
                            UnicodeString((UChar)0x20 /* space */));
    } else {
        name.setToBogus();
    }
    return name;
}

// ---------------------------------------------------
// TZDBTimeZoneNames and its supporting classes
//
// TZDBTimeZoneNames is an implementation class of
// TimeZoneNames holding the IANA tz database abbreviations.
// ---------------------------------------------------

class TZDBNames : public UMemory {
public:
    virtual ~TZDBNames();

    static TZDBNames* createInstance(UResourceBundle* rb, const char* key);
    const UChar* getName(UTimeZoneNameType type) const;
    const char** getParseRegions(int32_t& numRegions) const;

protected:
    TZDBNames(const UChar** names, char** regions, int32_t numRegions);

private:
    const UChar** fNames;
    char** fRegions;
    int32_t fNumRegions;
};

TZDBNames::TZDBNames(const UChar** names, char** regions, int32_t numRegions)
    :   fNames(names),
        fRegions(regions),
        fNumRegions(numRegions) {
}

TZDBNames::~TZDBNames() {
    if (fNames != NULL) {
        uprv_free(fNames);
    }
    if (fRegions != NULL) {
        char **p = fRegions;
        for (int32_t i = 0; i < fNumRegions; p++, i++) {
            uprv_free(*p);
        }
        uprv_free(fRegions);
    }
}

TZDBNames*
TZDBNames::createInstance(UResourceBundle* rb, const char* key) {
    if (rb == NULL || key == NULL || *key == 0) {
        return NULL;
    }

    UErrorCode status = U_ZERO_ERROR;

    const UChar **names = NULL;
    char** regions = NULL;
    int32_t numRegions = 0;

    int32_t len = 0;

    UResourceBundle* rbTable = NULL;
    rbTable = ures_getByKey(rb, key, rbTable, &status);
    if (U_FAILURE(status)) {
        return NULL;
    }

    names = (const UChar **)uprv_malloc(sizeof(const UChar*) * TZDBNAMES_KEYS_SIZE);
    UBool isEmpty = TRUE;
    if (names != NULL) {
        for (int32_t i = 0; i < TZDBNAMES_KEYS_SIZE; i++) {
            status = U_ZERO_ERROR;
            const UChar *value = ures_getStringByKey(rbTable, TZDBNAMES_KEYS[i], &len, &status);
            if (U_FAILURE(status) || len == 0) {
                names[i] = NULL;
            } else {
                names[i] = value;
                isEmpty = FALSE;
            }
        }
    }

    if (isEmpty) {
        if (names != NULL) {
            uprv_free(names);
        }
        return NULL;
    }

    UResourceBundle *regionsRes = ures_getByKey(rbTable, "parseRegions", NULL, &status);
    UBool regionError = FALSE;
    if (U_SUCCESS(status)) {
        numRegions = ures_getSize(regionsRes);
        if (numRegions > 0) {
            regions = (char**)uprv_malloc(sizeof(char*) * numRegions);
            if (regions != NULL) {
                char **pRegion = regions;
                for (int32_t i = 0; i < numRegions; i++, pRegion++) {
                    *pRegion = NULL;
                }
                // filling regions
                pRegion = regions;
                for (int32_t i = 0; i < numRegions; i++, pRegion++) {
                    status = U_ZERO_ERROR;
                    const UChar *uregion = ures_getStringByIndex(regionsRes, i, &len, &status);
                    if (U_FAILURE(status)) {
                        regionError = TRUE;
                        break;
                    }
                    *pRegion = (char*)uprv_malloc(sizeof(char) * (len + 1));
                    if (*pRegion == NULL) {
                        regionError = TRUE;
                        break;
                    }
                    u_UCharsToChars(uregion, *pRegion, len);
                    (*pRegion)[len] = 0;
                }
            }
        }
    }
    ures_close(regionsRes);
    ures_close(rbTable);

    if (regionError) {
        if (names != NULL) {
            uprv_free(names);
        }
        if (regions != NULL) {
            char **p = regions;
            for (int32_t i = 0; i < numRegions; p++, i++) {
                uprv_free(p);
            }
            uprv_free(regions);
        }
        return NULL;
    }

    return new TZDBNames(names, regions, numRegions);
}

const UChar*
TZDBNames::getName(UTimeZoneNameType type) const {
    if (fNames == NULL) {
        return NULL;
    }
    const UChar *name = NULL;
    switch(type) {
    case UTZNM_SHORT_STANDARD:
        name = fNames[0];
        break;
    case UTZNM_SHORT_DAYLIGHT:
        name = fNames[1];
        break;
    default:
        name = NULL;
    }
    return name;
}

const char**
TZDBNames::getParseRegions(int32_t& numRegions) const {
    if (fRegions == NULL) {
        numRegions = 0;
    } else {
        numRegions = fNumRegions;
    }
    return (const char**)fRegions;
}

U_CDECL_BEGIN
/**
 * TZDBNameInfo stores metazone name information for the IANA abbreviations
 * in the trie
 */
typedef struct TZDBNameInfo {
    const UChar*        mzID;
    UTimeZoneNameType   type;
    UBool               ambiguousType;
    const char**        parseRegions;
    int32_t             nRegions;
} TZDBNameInfo;
U_CDECL_END


class TZDBNameSearchHandler : public TextTrieMapSearchResultHandler {
public:
    TZDBNameSearchHandler(uint32_t types, const char* region);
    virtual ~TZDBNameSearchHandler();

    UBool handleMatch(int32_t matchLength, const CharacterNode *node, UErrorCode &status);
    TimeZoneNames::MatchInfoCollection* getMatches(int32_t& maxMatchLen);

private:
    uint32_t fTypes;
    int32_t fMaxMatchLen;
    TimeZoneNames::MatchInfoCollection* fResults;
    const char* fRegion;
};

TZDBNameSearchHandler::TZDBNameSearchHandler(uint32_t types, const char* region) 
: fTypes(types), fMaxMatchLen(0), fResults(NULL), fRegion(region) {
}

TZDBNameSearchHandler::~TZDBNameSearchHandler() {
    if (fResults != NULL) {
        delete fResults;
    }
}

UBool
TZDBNameSearchHandler::handleMatch(int32_t matchLength, const CharacterNode *node, UErrorCode &status) {
    if (U_FAILURE(status)) {
        return FALSE;
    }

    TZDBNameInfo *match = NULL;
    TZDBNameInfo *defaultRegionMatch = NULL;

    if (node->hasValues()) {
        int32_t valuesCount = node->countValues();
        for (int32_t i = 0; i < valuesCount; i++) {
            TZDBNameInfo *ninfo = (TZDBNameInfo *)node->getValue(i);
            if (ninfo == NULL) {
                continue;
            }
            if ((ninfo->type & fTypes) != 0) {
                // Some tz database abbreviations are ambiguous. For example,
                // CST means either Central Standard Time or China Standard Time.
                // Unlike CLDR time zone display names, this implementation
                // does not use unique names. And TimeZoneFormat does not expect
                // multiple results returned for the same time zone type.
                // For this reason, this implementation resolve one among same
                // zone type with a same name at this level.
                if (ninfo->parseRegions == NULL) {
                    // parseRegions == null means this is the default metazone
                    // mapping for the abbreviation.
                    if (defaultRegionMatch == NULL) {
                        match = defaultRegionMatch = ninfo;
                    }
                } else {
                    UBool matchRegion = FALSE;
                    // non-default metazone mapping for an abbreviation
                    // comes with applicable regions. For example, the default
                    // metazone mapping for "CST" is America_Central,
                    // but if region is one of CN/MO/TW, "CST" is parsed
                    // as metazone China (China Standard Time).
                    for (int32_t i = 0; i < ninfo->nRegions; i++) {
                        const char *region = ninfo->parseRegions[i];
                        if (uprv_strcmp(fRegion, region) == 0) {
                            match = ninfo;
                            matchRegion = TRUE;
                            break;
                        }
                    }
                    if (matchRegion) {
                        break;
                    }
                    if (match == NULL) {
                        match = ninfo;
                    }
                }
            }
        }

        if (match != NULL) {
            UTimeZoneNameType ntype = match->type;
            // Note: Workaround for duplicated standard/daylight names
            // The tz database contains a few zones sharing a
            // same name for both standard time and daylight saving
            // time. For example, Australia/Sydney observes DST,
            // but "EST" is used for both standard and daylight.
            // When both SHORT_STANDARD and SHORT_DAYLIGHT are included
            // in the find operation, we cannot tell which one was
            // actually matched.
            // TimeZoneFormat#parse returns a matched name type (standard
            // or daylight) and DateFormat implementation uses the info to
            // to adjust actual time. To avoid false type information,
            // this implementation replaces the name type with SHORT_GENERIC.
            if (match->ambiguousType
                    && (ntype == UTZNM_SHORT_STANDARD || ntype == UTZNM_SHORT_DAYLIGHT)
                    && (fTypes & UTZNM_SHORT_STANDARD) != 0
                    && (fTypes & UTZNM_SHORT_DAYLIGHT) != 0) {
                ntype = UTZNM_SHORT_GENERIC;
            }

            if (fResults == NULL) {
                fResults = new TimeZoneNames::MatchInfoCollection();
                if (fResults == NULL) {
                    status = U_MEMORY_ALLOCATION_ERROR;
                }
            }
            if (U_SUCCESS(status)) {
                U_ASSERT(fResults != NULL);
                U_ASSERT(match->mzID != NULL);
                fResults->addMetaZone(ntype, matchLength, UnicodeString(match->mzID, -1), status);
                if (U_SUCCESS(status) && matchLength > fMaxMatchLen) {
                    fMaxMatchLen = matchLength;
                }
            }
        }
    }
    return TRUE;
}

TimeZoneNames::MatchInfoCollection*
TZDBNameSearchHandler::getMatches(int32_t& maxMatchLen) {
    // give the ownership to the caller
    TimeZoneNames::MatchInfoCollection* results = fResults;
    maxMatchLen = fMaxMatchLen;

    // reset
    fResults = NULL;
    fMaxMatchLen = 0;
    return results;
}

U_CDECL_BEGIN
/**
 * Deleter for TZDBNames
 */
static void U_CALLCONV
deleteTZDBNames(void *obj) {
    if (obj != EMPTY) {
        delete (TZDBNames *)obj;
    }
}

static void U_CALLCONV initTZDBNamesMap(UErrorCode &status) {
    gTZDBNamesMap = uhash_open(uhash_hashUChars, uhash_compareUChars, NULL, &status);
    if (U_FAILURE(status)) {
        gTZDBNamesMap = NULL;
        return;
    }
    // no key deleters for tzdb name maps
    uhash_setValueDeleter(gTZDBNamesMap, deleteTZDBNames);
    ucln_i18n_registerCleanup(UCLN_I18N_TZDBTIMEZONENAMES, tzdbTimeZoneNames_cleanup);
}

/**
 * Deleter for TZDBNameInfo
 */
static void U_CALLCONV
deleteTZDBNameInfo(void *obj) {
    if (obj != NULL) {
        uprv_free(obj);
    }
}

static void U_CALLCONV prepareFind(UErrorCode &status) {
    if (U_FAILURE(status)) {
        return;
    }
    gTZDBNamesTrie = new TextTrieMap(TRUE, deleteTZDBNameInfo);
    if (gTZDBNamesTrie == NULL) {
        status = U_MEMORY_ALLOCATION_ERROR;
        return;
    }

    const UnicodeString *mzID;
    StringEnumeration *mzIDs = TimeZoneNamesImpl::_getAvailableMetaZoneIDs(status);
    if (U_SUCCESS(status)) {
        while ((mzID = mzIDs->snext(status)) && U_SUCCESS(status)) {
            const TZDBNames *names = TZDBTimeZoneNames::getMetaZoneNames(*mzID, status);
            if (names == NULL) {
                continue;
            }
            const UChar *std = names->getName(UTZNM_SHORT_STANDARD);
            const UChar *dst = names->getName(UTZNM_SHORT_DAYLIGHT);
            if (std == NULL && dst == NULL) {
                continue;
            }
            int32_t numRegions = 0;
            const char **parseRegions = names->getParseRegions(numRegions);

            // The tz database contains a few zones sharing a
            // same name for both standard time and daylight saving
            // time. For example, Australia/Sydney observes DST,
            // but "EST" is used for both standard and daylight.
            // we need to store the information for later processing.
            UBool ambiguousType = (std != NULL && dst != NULL && u_strcmp(std, dst) == 0);

            const UChar *uMzID = ZoneMeta::findMetaZoneID(*mzID);
            if (std != NULL) {
                TZDBNameInfo *stdInf = (TZDBNameInfo *)uprv_malloc(sizeof(TZDBNameInfo));
                if (stdInf == NULL) {
                    status = U_MEMORY_ALLOCATION_ERROR;
                    break;
                }
                stdInf->mzID = uMzID;
                stdInf->type = UTZNM_SHORT_STANDARD;
                stdInf->ambiguousType = ambiguousType;
                stdInf->parseRegions = parseRegions;
                stdInf->nRegions = numRegions;
                gTZDBNamesTrie->put(std, stdInf, status);
            }
            if (U_SUCCESS(status) && dst != NULL) {
                TZDBNameInfo *dstInf = (TZDBNameInfo *)uprv_malloc(sizeof(TZDBNameInfo));
                if (dstInf == NULL) {
                    status = U_MEMORY_ALLOCATION_ERROR;
                    break;
                }
                dstInf->mzID = uMzID;
                dstInf->type = UTZNM_SHORT_DAYLIGHT;
                dstInf->ambiguousType = ambiguousType;
                dstInf->parseRegions = parseRegions;
                dstInf->nRegions = numRegions;
                gTZDBNamesTrie->put(dst, dstInf, status);
            }
        }
    }
    delete mzIDs;

    if (U_FAILURE(status)) {
        delete gTZDBNamesTrie;
        gTZDBNamesTrie = NULL;
        return;
    }

    ucln_i18n_registerCleanup(UCLN_I18N_TZDBTIMEZONENAMES, tzdbTimeZoneNames_cleanup);
}

U_CDECL_END

TZDBTimeZoneNames::TZDBTimeZoneNames(const Locale& locale)
: fLocale(locale) {
    UBool useWorld = TRUE;
    const char* region = fLocale.getCountry();
    int32_t regionLen = uprv_strlen(region);
    if (regionLen == 0) {
        UErrorCode status = U_ZERO_ERROR;
        char loc[ULOC_FULLNAME_CAPACITY];
        uloc_addLikelySubtags(fLocale.getName(), loc, sizeof(loc), &status);
        regionLen = uloc_getCountry(loc, fRegion, sizeof(fRegion), &status);
        if (U_SUCCESS(status) && regionLen < (int32_t)sizeof(fRegion)) {
            useWorld = FALSE;
        }
    } else if (regionLen < (int32_t)sizeof(fRegion)) {
        uprv_strcpy(fRegion, region);
        useWorld = FALSE;
    }
    if (useWorld) {
        uprv_strcpy(fRegion, "001");
    }
}

TZDBTimeZoneNames::~TZDBTimeZoneNames() {
}

UBool
TZDBTimeZoneNames::operator==(const TimeZoneNames& other) const {
    if (this == &other) {
        return TRUE;
    }
    // No implementation for now
    return FALSE;
}

TimeZoneNames*
TZDBTimeZoneNames::clone() const {
    return new TZDBTimeZoneNames(fLocale);
}

StringEnumeration*
TZDBTimeZoneNames::getAvailableMetaZoneIDs(UErrorCode& status) const {
    return TimeZoneNamesImpl::_getAvailableMetaZoneIDs(status);
}

StringEnumeration*
TZDBTimeZoneNames::getAvailableMetaZoneIDs(const UnicodeString& tzID, UErrorCode& status) const {
    return TimeZoneNamesImpl::_getAvailableMetaZoneIDs(tzID, status);
}

UnicodeString&
TZDBTimeZoneNames::getMetaZoneID(const UnicodeString& tzID, UDate date, UnicodeString& mzID) const {
    return TimeZoneNamesImpl::_getMetaZoneID(tzID, date, mzID);
}

UnicodeString&
TZDBTimeZoneNames::getReferenceZoneID(const UnicodeString& mzID, const char* region, UnicodeString& tzID) const {
    return TimeZoneNamesImpl::_getReferenceZoneID(mzID, region, tzID);
}

UnicodeString&
TZDBTimeZoneNames::getMetaZoneDisplayName(const UnicodeString& mzID,
                                          UTimeZoneNameType type,
                                          UnicodeString& name) const {
    name.setToBogus();
    if (mzID.isEmpty()) {
        return name;
    }

    UErrorCode status = U_ZERO_ERROR;
    const TZDBNames *tzdbNames = TZDBTimeZoneNames::getMetaZoneNames(mzID, status);
    if (U_SUCCESS(status)) {
        const UChar *s = tzdbNames->getName(type);
        if (s != NULL) {
            name.setTo(TRUE, s, -1);
        }
    }

    return name;
}

UnicodeString&
TZDBTimeZoneNames::getTimeZoneDisplayName(const UnicodeString& /* tzID */, UTimeZoneNameType /* type */, UnicodeString& name) const {
    // No abbreviations associated a zone directly for now.
    name.setToBogus();
    return name;
}

TZDBTimeZoneNames::MatchInfoCollection*
TZDBTimeZoneNames::find(const UnicodeString& text, int32_t start, uint32_t types, UErrorCode& status) const {
    umtx_initOnce(gTZDBNamesTrieInitOnce, &prepareFind, status);
    if (U_FAILURE(status)) {
        return NULL;
    }

    TZDBNameSearchHandler handler(types, fRegion);
    gTZDBNamesTrie->search(text, start, (TextTrieMapSearchResultHandler *)&handler, status);
    if (U_FAILURE(status)) {
        return NULL;
    }
    int32_t maxLen = 0;
    return handler.getMatches(maxLen);
}

const TZDBNames*
TZDBTimeZoneNames::getMetaZoneNames(const UnicodeString& mzID, UErrorCode& status) {
    umtx_initOnce(gTZDBNamesMapInitOnce, &initTZDBNamesMap, status);
    if (U_FAILURE(status)) {
        return NULL;
    }

    TZDBNames* tzdbNames = NULL;

    UChar mzIDKey[ZID_KEY_MAX + 1];
    mzID.extract(mzIDKey, ZID_KEY_MAX + 1, status);
    U_ASSERT(status == U_ZERO_ERROR);   // already checked length above
    mzIDKey[mzID.length()] = 0;

    umtx_lock(&gTZDBNamesMapLock);
    {
        void *cacheVal = uhash_get(gTZDBNamesMap, mzIDKey);
        if (cacheVal == NULL) {
            UResourceBundle *zoneStringsRes = ures_openDirect(U_ICUDATA_ZONE, "tzdbNames", &status);
            zoneStringsRes = ures_getByKey(zoneStringsRes, gZoneStrings, zoneStringsRes, &status);
            if (U_SUCCESS(status)) {
                char key[ZID_KEY_MAX + 1];
                mergeTimeZoneKey(mzID, key);
                tzdbNames = TZDBNames::createInstance(zoneStringsRes, key);

                if (tzdbNames == NULL) {
                    cacheVal = (void *)EMPTY;
                } else {
                    cacheVal = tzdbNames;
                }
                // Use the persistent ID as the resource key, so we can
                // avoid duplications.
                const UChar* newKey = ZoneMeta::findMetaZoneID(mzID);
                if (newKey != NULL) {
                    uhash_put(gTZDBNamesMap, (void *)newKey, cacheVal, &status);
                    if (U_FAILURE(status)) {
                        if (tzdbNames != NULL) {
                            delete tzdbNames;
                            tzdbNames = NULL;
                        }
                    }
                } else {
                    // Should never happen with a valid input
                    if (tzdbNames != NULL) {
                        // It's not possible that we get a valid tzdbNames with unknown ID.
                        // But just in case..
                        delete tzdbNames;
                        tzdbNames = NULL;
                    }
                }
            }
            ures_close(zoneStringsRes);
        } else if (cacheVal != EMPTY) {
            tzdbNames = (TZDBNames *)cacheVal;
        }
    }
    umtx_unlock(&gTZDBNamesMapLock);

    return tzdbNames;
}

U_NAMESPACE_END


#endif /* #if !UCONFIG_NO_FORMATTING */

//eof