/* $Id: VirtualBoxTranslator.cpp 91393 2021-09-27 12:39:49Z vboxsync $ */
/** @file
 * VirtualBox Translator class.
 */

/*
 * Copyright (C) 2006-2020 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 */

#include <iprt/asm.h>
#include <iprt/ctype.h>
#include <iprt/err.h>
#include <iprt/locale.h>
#include <iprt/once.h>
#include <iprt/path.h>
#include <iprt/string.h>
#include <iprt/thread.h>
#include <iprt/strcache.h>

#include "Global.h"
#include "VirtualBoxBase.h"
#include "QMTranslator.h"
#include "VirtualBoxTranslator.h"

#define TRANSLATOR_CACHE_SIZE 32

/** Init once for the critical section. */
static RTONCE               g_Once = RTONCE_INITIALIZER;
RTCRITSECTRW                VirtualBoxTranslator::s_instanceRwLock;
VirtualBoxTranslator       *VirtualBoxTranslator::s_pInstance = NULL;
static RTTLS                g_idxTls = NIL_RTTLS;

typedef std::pair<const char *, const char *> LastTranslation;

/**
 * @callback_method_impl{FNRTONCE}
 */
static DECLCALLBACK(int32_t) initLock(void *pvUser)
{
    RT_NOREF(pvUser);
    return VirtualBoxTranslator::initCritSect();
}


/**
 * @callback_method_impl{FNRTTLSDTOR, Destroys the cache during thread termination.}
 */
static DECLCALLBACK(void) freeThreadCache(void *pvValue) RT_NOTHROW_DEF
{
    if (pvValue != NULL)
    {
        LastTranslation *pCache = (LastTranslation *)pvValue;
        delete pCache;
    }
}


VirtualBoxTranslator::VirtualBoxTranslator()
    : util::RWLockHandle(util::LOCKCLASS_TRANSLATOR)
    , m_cInstanceRefs(0)
    , m_pDefaultComponent(NULL)
    , m_strLanguage("C")
    , m_hStrCache(NIL_RTSTRCACHE)
{
    RTTlsAllocEx(&g_idxTls, &freeThreadCache);
    int rc = RTStrCacheCreate(&m_hStrCache, "API Translation");
    m_rcCache = rc;
    if (RT_FAILURE(rc))
        m_hStrCache = NIL_RTSTRCACHE; /* (loadLanguage will fail) */
}


VirtualBoxTranslator::~VirtualBoxTranslator()
{
    if (g_idxTls != NIL_RTTLS)
    {
        void *pvTlsValue = NULL;
        int rc = RTTlsGetEx(g_idxTls, &pvTlsValue);
        if (RT_SUCCESS(rc))
        {
            freeThreadCache(pvTlsValue);
            RTTlsSet(g_idxTls, NULL);
        }
        RTTlsFree(g_idxTls);
        g_idxTls = NIL_RTTLS;
    }

    m_pDefaultComponent = NULL;

    for (TranslatorList::iterator it = m_lTranslators.begin();
         it != m_lTranslators.end();
         ++it)
    {
        if (it->pTranslator != NULL)
            delete it->pTranslator;
        it->pTranslator = NULL;
    }
    if (m_hStrCache != NIL_RTSTRCACHE)
    {
        RTStrCacheDestroy(m_hStrCache);
        m_hStrCache = NIL_RTSTRCACHE;
        m_rcCache = VERR_WRONG_ORDER;
    }
}


/**
 * Get or create a translator instance (singelton), referenced.
 *
 * The main reference is held by the main VBox singelton objects (VirtualBox,
 * VirtualBoxClient) tying it's lifetime to theirs.
 */
/* static */
VirtualBoxTranslator *VirtualBoxTranslator::instance()
{
    int rc = RTOnce(&g_Once, initLock, NULL);
    if (RT_SUCCESS(rc))
    {
        RTCritSectRwEnterShared(&s_instanceRwLock);
        VirtualBoxTranslator *pInstance = s_pInstance;
        if (RT_LIKELY(pInstance != NULL))
        {
            uint32_t cRefs = ASMAtomicIncU32(&pInstance->m_cInstanceRefs);
            Assert(cRefs > 1); Assert(cRefs < _8K); RT_NOREF(cRefs);
            RTCritSectRwLeaveShared(&s_instanceRwLock);
            return pInstance;
        }

        /* Maybe create the instance: */
        RTCritSectRwLeaveShared(&s_instanceRwLock);
        RTCritSectRwEnterExcl(&s_instanceRwLock);
        pInstance = s_pInstance;
        if (pInstance == NULL)
            s_pInstance = pInstance = new VirtualBoxTranslator();
        ASMAtomicIncU32(&pInstance->m_cInstanceRefs);
        RTCritSectRwLeaveExcl(&s_instanceRwLock);
        return pInstance;
    }
    return NULL;
}


/* static */
VirtualBoxTranslator *VirtualBoxTranslator::tryInstance() RT_NOEXCEPT
{
    int rc = RTOnce(&g_Once, initLock, NULL);
    if (RT_SUCCESS(rc))
    {
        RTCritSectRwEnterShared(&s_instanceRwLock);
        VirtualBoxTranslator *pInstance = s_pInstance;
        if (RT_LIKELY(pInstance != NULL))
        {
            uint32_t cRefs = ASMAtomicIncU32(&pInstance->m_cInstanceRefs);
            Assert(cRefs > 1); Assert(cRefs < _8K); RT_NOREF(cRefs);
        }
        RTCritSectRwLeaveShared(&s_instanceRwLock);
        return pInstance;
    }
    return NULL;
}


/**
 * Release translator reference previous obtained via instance() or
 * tryinstance().
 */
void VirtualBoxTranslator::release()
{
    RTCritSectRwEnterShared(&s_instanceRwLock);
    uint32_t cRefs = ASMAtomicDecU32(&m_cInstanceRefs);
    Assert(cRefs < _8K);
    if (RT_LIKELY(cRefs > 0))
        RTCritSectRwLeaveShared(&s_instanceRwLock);
    else
    {
        /* Looks like we've got the last reference. Must switch to exclusive
           mode for safe cleanup. */
        ASMAtomicIncU32(&m_cInstanceRefs);
        RTCritSectRwLeaveShared(&s_instanceRwLock);
        RTCritSectRwEnterExcl(&s_instanceRwLock);
        cRefs = ASMAtomicDecU32(&m_cInstanceRefs);
        Assert(cRefs < _8K);
        if (cRefs == 0)
        {
            s_pInstance = NULL;
            delete this;
        }
        RTCritSectRwLeaveExcl(&s_instanceRwLock);
    }
}


HRESULT VirtualBoxTranslator::loadLanguage(ComPtr<IVirtualBox> aVirtualBox)
{
    AssertReturn(aVirtualBox, E_INVALIDARG);

    ComPtr<ISystemProperties> pSystemProperties;
    HRESULT hrc = aVirtualBox->COMGETTER(SystemProperties)(pSystemProperties.asOutParam());
    if (SUCCEEDED(hrc))
    {
        com::Bstr bstrLocale;
        hrc = pSystemProperties->COMGETTER(LanguageId)(bstrLocale.asOutParam());
        if (SUCCEEDED(hrc))
        {
            int vrc = i_loadLanguage(com::Utf8Str(bstrLocale).c_str());
            if (RT_FAILURE(vrc))
                hrc = Global::vboxStatusCodeToCOM(vrc);
        }
    }
    return hrc;
}


int VirtualBoxTranslator::i_loadLanguage(const char *pszLang)
{
    int  rc = VINF_SUCCESS;
    char szLocale[256];
    if (pszLang == NULL || *pszLang == '\0')
    {
        rc = RTLocaleQueryNormalizedBaseLocaleName(szLocale, sizeof(szLocale));
        if (RT_SUCCESS(rc))
            pszLang = szLocale;
    }
    else
    {
        /* check the pszLang looks like language code, i.e. {ll} or {ll}_{CC} */
        size_t cbLang = strlen(pszLang);
        if (   !(cbLang == 1 && pszLang[0] == 'C')
            && !(cbLang == 2 && RT_C_IS_LOWER(pszLang[0]) && RT_C_IS_LOWER(pszLang[1]))
            && !(cbLang == 5 && RTLOCALE_IS_LANGUAGE2_UNDERSCORE_COUNTRY2(pszLang)))
            rc = VERR_INVALID_PARAMETER;
    }
    if (RT_SUCCESS(rc))
    {
        AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);

        m_strLanguage = pszLang;

        for (TranslatorList::iterator it = m_lTranslators.begin();
             it != m_lTranslators.end();
             ++it)
        {
            /* ignore errors from particular translator allowing the use of others */
            i_loadLanguageForComponent(&(*it), pszLang);
        }
    }
    return rc;
}


int VirtualBoxTranslator::i_loadLanguageForComponent(TranslatorComponent *aComponent, const char *aLang)
{
    AssertReturn(aComponent, VERR_INVALID_PARAMETER);
    int rc;
    if (strcmp(aLang, "C") != 0)
    {
        /* Construct the base filename for the translations: */
        char szNlsPath[RTPATH_MAX];
        /* Try load language file on form 'VirtualBoxAPI_ll_CC.qm' if it exists
           where 'll_CC' could for example be 'en_US' or 'de_CH': */
        ssize_t cchOkay = RTStrPrintf2(szNlsPath, sizeof(szNlsPath), "%s_%s.qm",
                                       aComponent->strPath.c_str(), aLang);
        if (cchOkay > 0)
            rc = i_setLanguageFile(aComponent, szNlsPath);
        else
            rc = VERR_FILENAME_TOO_LONG;
        if (RT_FAILURE(rc))
        {
            /* No luck, drop the country part, i.e. 'VirtualBoxAPI_de.qm' or 'VirtualBoxAPI_en.qm': */
            const char *pszDash = strchr(aLang, '_');
            if (pszDash && pszDash != aLang)
            {
                cchOkay = RTStrPrintf2(szNlsPath, sizeof(szNlsPath), "%s_%.*s.qm",
                                       aComponent->strPath.c_str(), pszDash - aLang, aLang);
                if (cchOkay > 0)
                    rc = i_setLanguageFile(aComponent, szNlsPath);
            }
        }
    }
    else
    {
        /* No translator needed for 'C' */
        delete aComponent->pTranslator;
        aComponent->pTranslator = NULL;
        rc = VINF_SUCCESS;
    }
    return rc;
}


int VirtualBoxTranslator::i_setLanguageFile(TranslatorComponent *aComponent, const char *aFileName)
{
    AssertReturn(aComponent, VERR_INVALID_PARAMETER);

    int rc = m_rcCache;
    if (m_hStrCache != NIL_RTSTRCACHE)
    {
        QMTranslator *pNewTranslator;
        try { pNewTranslator = new QMTranslator(); }
        catch (std::bad_alloc &) { pNewTranslator = NULL; }
        if (pNewTranslator)
        {
            rc = pNewTranslator->load(aFileName, m_hStrCache);
            if (RT_SUCCESS(rc))
            {
                if (aComponent->pTranslator)
                    delete aComponent->pTranslator;
                aComponent->pTranslator = pNewTranslator;
            }
            else
                delete pNewTranslator;
        }
        else
            rc = VERR_NO_MEMORY;
    }
    else
        Assert(RT_FAILURE_NP(rc));
    return rc;
}


int VirtualBoxTranslator::registerTranslation(const char *aTranslationPath,
                                              bool aDefault,
                                              PTRCOMPONENT *aComponent)
{
    VirtualBoxTranslator *pCurrInstance = VirtualBoxTranslator::tryInstance();
    int rc = VERR_GENERAL_FAILURE;
    if (pCurrInstance != NULL)
    {
        rc = pCurrInstance->i_registerTranslation(aTranslationPath, aDefault, aComponent);
        pCurrInstance->release();
    }
    return rc;
}


int VirtualBoxTranslator::i_registerTranslation(const char *aTranslationPath,
                                                bool aDefault,
                                                PTRCOMPONENT *aComponent)
{
    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
    TranslatorComponent *pComponent;
    for (TranslatorList::iterator it = m_lTranslators.begin();
         it != m_lTranslators.end();
         ++it)
    {
        if (it->strPath == aTranslationPath)
        {
            pComponent = &(*it);
            if (aDefault)
                m_pDefaultComponent = pComponent;
            *aComponent = (PTRCOMPONENT)pComponent;
            return VINF_SUCCESS;
        }
    }

    try
    {
        m_lTranslators.push_back(TranslatorComponent());
        pComponent = &m_lTranslators.back();
    }
    catch(std::bad_alloc &)
    {
        return VERR_NO_MEMORY;
    }

    pComponent->strPath = aTranslationPath;
    if (aDefault)
        m_pDefaultComponent = pComponent;
    *aComponent = (PTRCOMPONENT)pComponent;
    /* ignore the error during loading because path
     * could contain no translation for current language */
    i_loadLanguageForComponent(pComponent, m_strLanguage.c_str());
    return VINF_SUCCESS;
}


int VirtualBoxTranslator::unregisterTranslation(PTRCOMPONENT aComponent)
{
    int rc;
    if (aComponent != NULL)
    {
        VirtualBoxTranslator *pCurrInstance = VirtualBoxTranslator::tryInstance();
        if (pCurrInstance != NULL)
        {
            rc = pCurrInstance->i_unregisterTranslation(aComponent);
            pCurrInstance->release();
        }
        else
            rc = VERR_GENERAL_FAILURE;
    }
    else
        rc = VWRN_NOT_FOUND;
    return rc;
}


int VirtualBoxTranslator::i_unregisterTranslation(PTRCOMPONENT aComponent)
{
    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);

    if (aComponent == m_pDefaultComponent)
        m_pDefaultComponent = NULL;

    for (TranslatorList::iterator it = m_lTranslators.begin();
         it != m_lTranslators.end();
         ++it)
    {
        if (&(*it) == aComponent)
        {
            delete aComponent->pTranslator;
            m_lTranslators.erase(it);
            return VINF_SUCCESS;
        }
    }

    return VERR_NOT_FOUND;
}


const char *VirtualBoxTranslator::translate(PTRCOMPONENT aComponent,
                                            const char *aContext,
                                            const char *aSourceText,
                                            const char *aComment,
                                            const int   aNum) RT_NOEXCEPT
{
    VirtualBoxTranslator *pCurrInstance = VirtualBoxTranslator::tryInstance();
    const char *pszTranslation = aSourceText;
    if (pCurrInstance != NULL)
    {
        pszTranslation = pCurrInstance->i_translate(aComponent, aContext, aSourceText, aComment, aNum);
        pCurrInstance->release();
    }
    return pszTranslation;
}


static LastTranslation *getTlsEntry() RT_NOEXCEPT
{
    if (RT_LIKELY(g_idxTls != NIL_RTTLS))
    {
        LastTranslation *pEntry = (LastTranslation *)RTTlsGet(g_idxTls);
        if (pEntry != NULL)
            return pEntry; /* likely */

        /* Create a new entry. */
        try
        {
            pEntry = new LastTranslation();
            pEntry->first = pEntry->second = "";
            int rc = RTTlsSet(g_idxTls, pEntry);
            if (RT_SUCCESS(rc))
                return pEntry;
            delete pEntry;
        }
        catch (std::bad_alloc &)
        {
        }
    }
    return NULL;
}


const char *VirtualBoxTranslator::i_translate(PTRCOMPONENT aComponent,
                                              const char *aContext,
                                              const char *aSourceText,
                                              const char *aComment,
                                              const int   aNum) RT_NOEXCEPT
{
    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);

    if (aComponent == NULL)
        aComponent = m_pDefaultComponent;

    if (   aComponent == NULL
        || aComponent->pTranslator == NULL)
        return aSourceText;

    const char *pszSafeSource  = NULL;
    const char *pszTranslation = aComponent->pTranslator->translate(aContext, aSourceText, &pszSafeSource, aComment, aNum);
    if (pszSafeSource)
    {
        LastTranslation *pEntry = getTlsEntry();
        if (pEntry)
        {
            pEntry->first = pszTranslation;
            pEntry->second = pszSafeSource;
        }
    }

    return pszTranslation;
}


const char *VirtualBoxTranslator::trSource(const char *aTranslation) RT_NOEXCEPT
{
    const char *pszSource = aTranslation;
    VirtualBoxTranslator *pCurInstance = VirtualBoxTranslator::tryInstance(); /* paranoia */
    if (pCurInstance != NULL)
    {
        LastTranslation *pEntry = getTlsEntry();
        if (   pEntry != NULL
            && (   pEntry->first == aTranslation
                || strcmp(pEntry->first, aTranslation) == 0) )
            pszSource = pEntry->second;
        pCurInstance->release();
    }
    return pszSource;
}


int32_t VirtualBoxTranslator::initCritSect()
{
    return RTCritSectRwInit(&s_instanceRwLock);
}
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