/*##############################################################################

    Copyright (C) 2011 HPCC Systems.

    All rights reserved. This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
############################################################################## */

#include "xslprocessor.ipp"
#include "jencrypt.hpp"
#include "jexcept.hpp"
#include "xalanc/XPath/XObjectFactory.hpp"
#include "xalanc/PlatformSupport/Writer.hpp"

/*
class StringBufferOStreamBuf : public std::basic_streambuf<char, std::char_traits<char> >
{
    StringBuffer & _inputbuffer;
    typedef std::char_traits<char> _Tr;
protected:
    virtual int overflow(int = _Tr::eof());
public:
    StringBufferOStreamBuf(StringBuffer &_str);
};

StringBufferOStreamBuf::StringBufferOStreamBuf(StringBuffer &_str) : _inputbuffer(_str)
{
}

int StringBufferOStreamBuf::overflow(int c)
{
     if(c == _Tr::eof()) return _Tr::not_eof(c);
     _inputbuffer.append((char) c);
     return c;
}

class StringBufferOStream : public std::basic_ostream<char, std::char_traits<char> >
{
     StringBufferOStreamBuf _streambuffer;
public:
     StringBufferOStream(StringBuffer &buf)
         : _streambuffer(buf),
          std::basic_ostream<char, std::char_traits<char> >(&_streambuffer)
     { clear(); }
};
*/

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

XALAN_USING_XALAN(Writer)
XALAN_USING_XALAN(XalanOutputStream)
XALAN_USING_XALAN(XalanDOMChar)

class ISocketOutputStream : public IInterface
{
public:
    virtual Writer* getWriter() = 0;
};

//XALAN_CPP_NAMESPACE_BEGIN

class SocketOutputStream : public CInterface, public ISocketOutputStream, public Writer
{
private:
    ISocket *m_socket;

public:
    IMPLEMENT_IINTERFACE;

    SocketOutputStream(ISocket *s);
    ~SocketOutputStream() { close(); }

    virtual Writer* getWriter() { return this; }

    // Close the stream
    virtual void close();

    // Flush the stream
    virtual void flush();

    // Get the stream associated with the writer...
    virtual XalanOutputStream* getStream();

    // Get the stream associated with the writer...
    virtual const XalanOutputStream* getStream() const;

    // Writes a string
    virtual void write(const char* s, size_t theOffset = 0, size_t theLength = ~0u);

    // Writes a string
    virtual void write(const XalanDOMChar* s, XalanDOMString::size_type theOffset=0,
        XalanDOMString::size_type   theLength = XalanDOMString::npos);

    // Writes a character
    virtual void write(XalanDOMChar c);

    // Writes a string
    virtual void write(const XalanDOMString& s, XalanDOMString::size_type   theOffset = 0,
            XalanDOMString::size_type   theLength = XalanDOMString::npos);
};

SocketOutputStream::SocketOutputStream(ISocket* s)
{
    m_socket = s;
}

void SocketOutputStream::close()
{
    //fprintf(stderr,"close()\n");
    //m_socket->shutdown();
    //m_socket->close();
}

void SocketOutputStream::flush()
{
    //fprintf(stderr,"flush()\n");
}

XalanOutputStream* SocketOutputStream::getStream()
{
    fprintf(stderr, "Unsupported getStream()!");
    return NULL;
}

const XalanOutputStream* SocketOutputStream::getStream() const
{
    fprintf(stderr, "Unsupported getStream()!");
    return NULL;
}

void SocketOutputStream::write(const char* s, size_t offset, size_t length)
{
    //wprintf(stderr,TEXT("write(char*='%s',offset=%d,length=%d)\n"),s,offset,length);
    m_socket->write(s + offset, length);
}

//XalanDOMChar: utf-8 or wchar_t
void SocketOutputStream::write(const XalanDOMChar* s, XalanDOMString::size_type offset,
        XalanDOMString::size_type length)
{
    //printf(stderr,"write(DOMChar='%s',offset=%d,length=%d)\n",s,offset,length);
    m_socket->write((const char* )(s+offset), length * sizeof(XalanDOMChar));
}

void SocketOutputStream::write(XalanDOMChar c)
{
    //printf(stderr, "write(%c)", c);
    m_socket->write((const char*)&c, sizeof(XalanDOMChar));
}

void SocketOutputStream::write(const XalanDOMString& s, XalanDOMString::size_type offset,
        XalanDOMString::size_type length)
{
    //printf(stderr,"write(DOMString='%s',offset=%d,length=%s", s.c_str(), offset, length);
    m_socket->write((const char*)(s.c_str()+offset), length*sizeof(XalanDOMChar));
}

extern ISocketOutputStream* createSocketOutputStream(ISocket* s)
{
    return new SocketOutputStream(s);
}

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

class XalanStringBufferOutputHandler
{
    StringBuffer & _inputbuffer;
public:
    XalanStringBufferOutputHandler(StringBuffer &_str) : _inputbuffer(_str)
    {
    }

    static unsigned long callback(const char *data, unsigned long len, void *ctx)
    {
        XalanStringBufferOutputHandler *self = (XalanStringBufferOutputHandler *) ctx;
        self->_inputbuffer.append(len, data);
        return len;
    }
};


//----------------------------------------------------------------------------
//                            CExternalFunction
//----------------------------------------------------------------------------

XObjectPtr CExternalFunction::execute( XPathExecutionContext&   executionContext,
                                    XalanNode*              /* context */,
                                    const XObjectPtr        arg1,
                                    const Locator*          /* locator */) const
{
    assert(arg1.null() == false);
    const XalanDOMString& arg = arg1->str();

    //convert XalanDOMString (implemented as unsigned short*) into StringBuffer
    StringBuffer sbInput;
    sbInput.ensureCapacity(arg.length()+1);

    size32_t len = arg.length();
    for (int i=0; i < len; i++)
        sbInput.append( (char) arg[i]);

    StringBuffer sbOutput;

    try
    {
        (*m_userFunction)(sbOutput, sbInput.str(), m_pTransform);
    }
    catch (IException* e)
    {
        StringBuffer msg;
        e->errorMessage(msg);
        e->Release();
    }
    catch (...)
    {
    }

    XalanDOMString xdsOutput( sbOutput.str() );
    return executionContext.getXObjectFactory().createString( xdsOutput );
}

//----------------------------------------------------------------------------
//                            CXslProcessor
//----------------------------------------------------------------------------

extern IXslProcessor* getXslProcessor()
{
    static CXslProcessor s_pXslProcessor;
    return LINK(&s_pXslProcessor);
}

// Should be called only once per-process
class XslProcessorInitializer
{
public:
    XslProcessorInitializer()
    {
        // Call the static initializer for Xerces.
        XMLPlatformUtils::Initialize();
        // Initialize Xalan.
        XalanTransformer::initialize();
    }
    ~XslProcessorInitializer()
    {
        // Terminate Xalan.
        XalanTransformer::terminate();
        // Call the static terminator for Xerces.
        XMLPlatformUtils::Terminate();
    }
};

CXslProcessor::CXslProcessor()
{
    static XslProcessorInitializer initializer;
    m_cachetimeout = XSLT_DEFAULT_CACHETIMEOUT;
}

// Should be called only once per-process
CXslProcessor::~CXslProcessor()
{
}

IXslTransform *CXslProcessor::createXslTransform()
{
    return new CXslTransform(inch.get());
}

int CXslProcessor::execute(IXslTransform *pITransform)
{
    return ((CXslTransform*)pITransform)->transform();
}

void CXslProcessor::setCacheTimeout(int timeout)
{
    m_cachetimeout = timeout;

    IXslCache* xslcache = getXslCache();
    if(xslcache)
        xslcache->setCacheTimeout(timeout);
}

int CXslProcessor::getCacheTimeout()
{
    return m_cachetimeout;
}

//----------------------------------------------------------------------------
//                            CXslTransform
//----------------------------------------------------------------------------
/*static*/ const char* CXslTransform::SEISINT_NAMESPACE = "http://seisint.com";

CXslTransform::CXslTransform(IIncludeHandler* handler) : m_XalanTransformer()
{
    m_ParsedSource = 0;
    m_resultTarget = 0;
    m_ostrstream = 0;
    m_sourceResolver = NULL;
    m_pUserData = NULL;

#ifdef _WIN32
    m_normalizeLinefeed = true; //default for Xalan
#endif

    if (handler)
        setIncludeHandler(handler);

    //set an external function to handle non-fatal XSL messages
    m_fnMessage.setown(createExternalFunction("message", message));
    setExternalFunction(SEISINT_NAMESPACE, m_fnMessage.get(), true);
}

CXslTransform::~CXslTransform()
{
    setExternalFunction(SEISINT_NAMESPACE, m_fnMessage.get(), false);

    if(m_sourceResolver != NULL)
        delete m_sourceResolver;

    if (m_xslsource)
        m_xslsource->clearIncludeHandler();

    if(m_ParsedSource)
    {
        m_XalanTransformer.destroyParsedSource(m_ParsedSource);
        m_ParsedSource = NULL;
    }

    closeResultTarget();
}

bool CXslTransform::checkSanity()
{
    return (m_xslsource && m_ParsedSource);
}

int CXslTransform::transform(StringBuffer &target)
{
    if(!m_ParsedSource)
        throw MakeStringException(1, "[XML source not set]");
    else if(!m_xslsource)
        throw MakeStringException(2, "[XSL stylesheet not set]");


    XalanCompiledStylesheet* pCompiledStylesheet = NULL;
    pCompiledStylesheet = m_xslsource->getStylesheet();

    if (!pCompiledStylesheet)
    {
        DBGLOG("[failed to compile XSLT stylesheet]");
        throw MakeStringException(2, "[failed to compile XSLT stylesheet]");
    }

    int rc=0;
    m_sMessages.clear();
    try
    {
        XalanStringBufferOutputHandler output(target);
        rc = m_XalanTransformer.transform(*m_ParsedSource, pCompiledStylesheet,
            (void*)&output, (XalanOutputHandlerType)output.callback, (XalanFlushHandlerType)0);
    }
    catch(...)
    {
        StringBuffer estr("[Exception running XSLT stylesheet]");
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }

    if (rc < 0)
    {
        StringBuffer estr;
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }

    return rc;
}

int CXslTransform::transform()
{
    if(!m_ParsedSource)
        throw MakeStringException(1, "[XML source not set for XSLT[");
    else if(!m_xslsource)
        throw MakeStringException(2, "[XSL stylesheet not set]");
    else if(!m_resultTarget)
        throw MakeStringException(2, "[XSLT target file/buffer not set]");

    XalanCompiledStylesheet* pCompiledStylesheet = NULL;
    pCompiledStylesheet = m_xslsource->getStylesheet();

    if (!pCompiledStylesheet)
    {
        DBGLOG("[failed to compile XSLT stylesheet]");
        throw MakeStringException(2, "[failed to compile XSLT stylesheet]");
    }

    int rc=0;
    m_sMessages.clear();
    try
    {
        rc = m_XalanTransformer.transform(*m_ParsedSource, pCompiledStylesheet, *m_resultTarget);
    }
    catch(...)
    {
        StringBuffer estr("[Exception running XSLT stylesheet]");
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }
    if (rc < 0)
    {
        StringBuffer estr;
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }

    return rc;
}

int CXslTransform::transform(ISocket* targetSocket)
{
    if(!m_ParsedSource)
        throw MakeStringException(1, "[XML source not set for XSLT[");
    else if(!m_xslsource)
        throw MakeStringException(2, "[XSL stylesheet not set]");

    XalanCompiledStylesheet* pCompiledStylesheet = NULL;
    pCompiledStylesheet = m_xslsource->getStylesheet();

    if (!pCompiledStylesheet)
    {
        DBGLOG("[failed to compile XSLT stylesheet]");
        throw MakeStringException(2, "[failed to compile XSLT stylesheet]");
    }

    int rc=0;
    m_sMessages.clear();
    try
    {
        m_resultTarget = new XSLTResultTarget();
        Owned<ISocketOutputStream> stream = createSocketOutputStream(targetSocket);
        m_resultTarget->setCharacterStream(stream->getWriter());
        rc = m_XalanTransformer.transform(*m_ParsedSource, pCompiledStylesheet, *m_resultTarget);
    }
    catch(...)
    {
        StringBuffer estr("[Exception running XSLT stylesheet]");
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }
    if (rc < 0)
    {
        StringBuffer estr;
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }

    return rc;
}


int CXslTransform::setXmlSource(const char *pszFileName)
{
    if(m_ParsedSource != NULL)
    {
        m_XalanTransformer.destroyParsedSource(m_ParsedSource);
        m_ParsedSource = NULL;
    }

    int theResult = 0;

    try
    {
        std::ifstream theXMLStream(pszFileName);
        const XSLTInputSource xmlinput(&theXMLStream);
        theResult = m_XalanTransformer.parseSource(xmlinput, (const XalanParsedSource*&)m_ParsedSource);
    }
    catch(...)
    {
        m_ParsedSource = NULL;
        StringBuffer estr("[Exception compiling xml]");
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }

    if (!m_ParsedSource)
    {
        StringBuffer estr("[failed to compile xml]");
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }

    return theResult;
}

int CXslTransform::setXmlSource(const char *pszBuffer, unsigned int nSize)
{
    if(m_ParsedSource != NULL)
    {
        m_XalanTransformer.destroyParsedSource(m_ParsedSource);
        m_ParsedSource = NULL;
    }

    int theResult = 0;
    try
    {
        //std::istringstream theXMLStream(pszBuffer, nSize);
        std::istringstream theXMLStream(pszBuffer);
        const XSLTInputSource xmlinput(&theXMLStream);
        theResult = m_XalanTransformer.parseSource(xmlinput, (const XalanParsedSource*&)m_ParsedSource);
    }
    catch(...)
    {
        m_ParsedSource = NULL;
        StringBuffer estr("[Exception compiling xml]");
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }

    if (!m_ParsedSource)
    {
        StringBuffer estr("[failed to compile xml]");
        estr.appendf("[%s]", m_XalanTransformer.getLastError());
        DBGLOG("%s", estr.str());
        throw MakeStringException(2, "%s", estr.str());
    }

    return theResult;
}

int CXslTransform::loadXslFromFile(const char *pszFileName, const char *cacheId)
{
    m_xslsource.setown(new CXslSource(pszFileName, m_sourceResolver?m_sourceResolver->getIncludeHandler():NULL, cacheId));

    return 0;
}

int CXslTransform::setXslSource(const char *pszBuffer, unsigned int nSize, const char *cacheId, const char *rootpath)
{
    assertex(cacheId && *cacheId);
    m_xslsource.setown(new CXslSource(pszBuffer, nSize, m_sourceResolver?m_sourceResolver->getIncludeHandler():NULL, cacheId, rootpath));

    return 0;
}

int CXslTransform::setXslNoCache(const char *pszBuffer, unsigned int nSize, const char *rootpath)
{
    m_xslsource.setown(new CXslSource(pszBuffer, nSize, m_sourceResolver?m_sourceResolver->getIncludeHandler():NULL, NULL, rootpath));

    return 0;
}

int CXslTransform::setResultTarget(const char *pszFileName)
{
    closeResultTarget();

    try
    {
        m_resultTargetFile.clear().append(pszFileName);
        m_resultTarget = new XSLTResultTarget(XalanDOMString(pszFileName));
    }
    catch(...)
    {
        throw MakeStringException(1, "Exception opening file %s", pszFileName);
    }
    return 0;
}

int CXslTransform::setResultTarget(char *pszBuffer, unsigned int nSize)
{
    closeResultTarget();

    // Our output target that uses an ostrstream that will use the buffer

    try
    {
        //m_ostrstream = new std::ostringstream(pszBuffer, nSize);
        m_ostrstream = new std::ostringstream(pszBuffer);
        m_resultTarget = new XSLTResultTarget(m_ostrstream);
    }
    catch(...)
    {
        throw MakeStringException(1, "Exception in setting character buffer as XSLT result target.");
    }
    return 0;
}

int CXslTransform::closeResultTarget()
{
    if (m_resultTarget)
    {
        delete m_resultTarget;
        m_resultTarget = 0;
    }

    if(m_ostrstream)
    {
        delete m_ostrstream;
        m_ostrstream = 0;
    }

    return 0;
}

int CXslTransform::setParameter(const char *pszName, const char *pszExpression)
{
    m_XalanTransformer.setStylesheetParam(XalanDOMString(pszName), XalanDOMString(pszExpression));
    return 0;
}

int CXslTransform::setStringParameter(const char *pszName, const char *pszString)
{
    m_XalanTransformer.setStylesheetParam(XalanDOMString(pszName), XalanDOMString(StringBuffer("'").append(pszString).append("'").str()));
    return 0;
}

int CXslTransform::setIncludeHandler(IIncludeHandler* handler)
{
    if(handler == NULL)
    {
        throw MakeStringException(-1, "From CXslTransform::setIncludeHandler: a NULL handler is passed in");
    }

    if(m_sourceResolver == NULL)
    {
        m_sourceResolver = new MemSourceResolver();
    }

    m_sourceResolver->setHandler(handler);
    m_XalanTransformer.setEntityResolver(m_sourceResolver);

    if(m_xslsource.get() != NULL)
    {
        m_xslsource->setIncludeHandler(handler);
    }

    return 0;
}


int CXslTransform::setExternalFunction(const char* pszNameSpace, IXslFunction* pXslFunction, bool set)
{
    CXslFunction* pFn = (CXslFunction*) pXslFunction;

    if (pFn == NULL || pFn->get() == NULL)
        throw MakeStringException(-1, "Null pointer violation in CXslTransform::setExternalFunction.");

    XalanDOMString nameSpace(pszNameSpace);
    XalanDOMString functionName(pFn->getName());
    bool bAssigned = pFn->isAssigned();

    if (set && !bAssigned)
        m_XalanTransformer.installExternalFunction(nameSpace, functionName, *pFn->get());
    else
    {
        if (!set && bAssigned)
            m_XalanTransformer.uninstallExternalFunction(nameSpace, functionName);
        else
            throw MakeStringException(-1, "XSLT external function assignment error!");
    }

    pFn->setAssigned(set);
    return 0;
}

/*static*/
void CXslTransform::message(StringBuffer& out, const char* in, IXslTransform* pTransform)
{
    CXslTransform* pTrans = dynamic_cast<CXslTransform*>(pTransform);
    pTrans->m_sMessages.append(in).append('\n');
}