/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * $Id: ReaderMgr.hpp 568078 2007-08-21 11:43:25Z amassari $
 */

#if !defined(READERMGR_HPP)
#define READERMGR_HPP

#include <xercesc/internal/XMLReader.hpp>
#include <xercesc/util/PlatformUtils.hpp>
#include <xercesc/util/RefStackOf.hpp>
#include <xercesc/sax/Locator.hpp>
#include <xercesc/framework/XMLBuffer.hpp>

XERCES_CPP_NAMESPACE_BEGIN

class XMLEntityDecl;
class XMLEntityHandler;
class XMLDocumentHandler;
class XMLScanner;


// ---------------------------------------------------------------------------
//  This class is used by the scanner. The scanner must deal with expansion
//  of entities, some of which are totally different files (external parsed
//  entities.) It does so by pushing readers onto a stack. The top reader is
//  the one it wants to read out of, but that one must be popped when it is
//  empty. To keep that logic from being all over the place, the scanner
//  talks to the reader manager, which handles the stack and popping off
//  used up readers.
// ---------------------------------------------------------------------------
class XMLPARSER_EXPORT ReaderMgr :   public XMemory 
                                   , public Locator
{
public :
    // -----------------------------------------------------------------------
    //  Class specific types
    // -----------------------------------------------------------------------
    struct LastExtEntityInfo : public XMemory
    {
        const   XMLCh*          systemId;
        const   XMLCh*          publicId;
                XMLSSize_t      lineNumber;
                XMLSSize_t      colNumber;
    };


    // -----------------------------------------------------------------------
    //  Constructors and Destructor
    // -----------------------------------------------------------------------
    ReaderMgr(MemoryManager* const manager = XMLPlatformUtils::fgMemoryManager);
    ~ReaderMgr();


    // -----------------------------------------------------------------------
    //  Convenience scanning methods
    //
    //  This are all convenience methods that work in terms of the core
    //  character spooling methods.
    // -----------------------------------------------------------------------
    bool atEOF() const;
    bool getName(XMLBuffer& toFill);
    bool getQName(XMLBuffer& toFill, int* colonPosition);
    bool getNameToken(XMLBuffer& toFill);
    XMLCh getNextChar();
    bool getNextCharIfNot(const XMLCh chNotToGet, XMLCh& chGotten);
    void movePlainContentChars(XMLBuffer &dest);
    void getSpaces(XMLBuffer& toFill);
    void getUpToCharOrWS(XMLBuffer& toFill, const XMLCh toCheck);
    bool isEmpty() const;
    bool lookingAtChar(const XMLCh toCheck);
    bool lookingAtSpace();
    XMLCh peekNextChar();
    bool skipIfQuote(XMLCh& chGotten);
    void skipPastChar(const XMLCh toSkip);
    bool skipPastSpaces(bool inDecl = false);
    void skipToChar(const XMLCh toSkipTo);
    bool skippedChar(const XMLCh toSkip);
    bool skippedSpace();
    bool skippedString(const XMLCh* const toSkip);
    void skipQuotedString(const XMLCh quoteCh);
    XMLCh skipUntilIn(const XMLCh* const listToSkip);
    XMLCh skipUntilInOrWS(const XMLCh* const listToSkip);
    bool peekString(const XMLCh* const toPeek);


    // -----------------------------------------------------------------------
    //  Control methods
    // -----------------------------------------------------------------------
    void cleanStackBackTo(const unsigned int readerNum);
    XMLReader* createReader
    (
        const   InputSource&        src
        , const bool                xmlDecl
        , const XMLReader::RefFrom  refFrom
        , const XMLReader::Types    type
        , const XMLReader::Sources  source
        , const bool                calcSrsOfs = true
    );
    XMLReader* createReader
    (
        const   XMLCh* const        sysId
        , const XMLCh* const        pubId
        , const bool                xmlDecl
        , const XMLReader::RefFrom  refFrom
        , const XMLReader::Types    type
        , const XMLReader::Sources  source
        ,       InputSource*&       srcToFill
        , const bool                calcSrcOfs = true
        , const bool                disableDefaultEntityResolution = false
    );
    XMLReader* createReader
    (
        const   XMLCh* const        baseURI
        , const XMLCh* const        sysId
        , const XMLCh* const        pubId
        , const bool                xmlDecl
        , const XMLReader::RefFrom  refFrom
        , const XMLReader::Types    type
        , const XMLReader::Sources  source
        ,       InputSource*&       srcToFill
        , const bool                calcSrcOfs = true
        , const bool                disableDefaultEntityResolution = false
    );
    XMLReader* createIntEntReader
    (
        const   XMLCh* const        sysId
        , const XMLReader::RefFrom  refFrom
        , const XMLReader::Types    type
        , const XMLCh* const        dataBuf
        , const unsigned int        dataLen
        , const bool                copyBuf
        , const bool                calcSrcOfs = true
    );
    bool isScanningPERefOutOfLiteral() const;
    bool pushReader
    (
                XMLReader* const        reader
        ,       XMLEntityDecl* const    entity
    );
    void reset();


    // -----------------------------------------------------------------------
    //  Getter methods
    // -----------------------------------------------------------------------
    const XMLCh* getCurrentEncodingStr() const;
    const XMLEntityDecl* getCurrentEntity() const;
    XMLEntityDecl* getCurrentEntity();
    const XMLReader* getCurrentReader() const;
    XMLReader* getCurrentReader();
    unsigned int getCurrentReaderNum() const;
    unsigned int getReaderDepth() const;
    void getLastExtEntityInfo(LastExtEntityInfo& lastInfo) const;
    unsigned int getSrcOffset() const;
    bool getThrowEOE() const;


    // -----------------------------------------------------------------------
    //  Setter methods
    // -----------------------------------------------------------------------
    void setEntityHandler(XMLEntityHandler* const newHandler);
    void setThrowEOE(const bool newValue);
    void setXMLVersion(const XMLReader::XMLVersion version);
    void setStandardUriConformant(const bool newValue);

    // -----------------------------------------------------------------------
    //  Implement the SAX Locator interface
    // -----------------------------------------------------------------------
    virtual const XMLCh* getPublicId() const;
    virtual const XMLCh* getSystemId() const;
    virtual XMLSSize_t getLineNumber() const;
    virtual XMLSSize_t getColumnNumber() const;


private :
    // -----------------------------------------------------------------------
    //  Private helper methods
    // -----------------------------------------------------------------------
    const XMLReader* getLastExtEntity(const XMLEntityDecl*& itsEntity) const;
    bool popReader();

    // -----------------------------------------------------------------------
    //  Unimplemented constructors and operators
    // -----------------------------------------------------------------------
    ReaderMgr(const ReaderMgr&);
    ReaderMgr& operator=(const ReaderMgr&);

    // -----------------------------------------------------------------------
    //  Private data members
    //
    //  fCurEntity
    //      This is the current top of stack entity. We pull it off the stack
    //      and store it here for efficiency.
    //
    //  fCurReader
    //      This is the current top of stack reader. We pull it off the
    //      stack and store it here for efficiency.
    //
    //  fEntityHandler
    //      This is the installed entity handler. Its installed via the
    //      scanner but he passes it on to us since we need it the most, in
    //      process of creating external entity readers.
    //
    //  fEntityStack
    //      We need to keep up with which of the pushed readers are pushed
    //      entity values that are being spooled. This is done to avoid the
    //      problem of recursive definitions. This stack consists of refs to
    //      EntityDecl objects for the pushed entities.
    //
    //  fNextReaderNum
    //      This is the reader serial number value. Each new reader that is
    //      created from this reader is given a successive number. This lets
    //      us catch things like partial markup errors and such.
    //
    //  fReaderStack
    //      This is the stack of reader references. We own all the readers
    //      and destroy them when they are used up.
    //
    //  fThrowEOE
    //      This flag controls whether we throw an exception when we hit an
    //      end of entity. The scanner doesn't really need to know about ends
    //      of entities in the int/ext subsets, so it will turn this flag off
    //      until it gets into the content usually.
    //
    //  fXMLVersion
    //      Enum to indicate if each Reader should be created as XML 1.1 or
    //      XML 1.0 conformant
    //
    //  fStandardUriConformant
    //      This flag controls whether we force conformant URI
    // -----------------------------------------------------------------------
    XMLEntityDecl*              fCurEntity;
    XMLReader*                  fCurReader;
    XMLEntityHandler*           fEntityHandler;
    RefStackOf<XMLEntityDecl>*  fEntityStack;
    unsigned int                fNextReaderNum;
    RefStackOf<XMLReader>*      fReaderStack;
    bool                        fThrowEOE;
    XMLReader::XMLVersion       fXMLVersion;
    bool                        fStandardUriConformant;
    MemoryManager*              fMemoryManager;
};



// ---------------------------------------------------------------------------
//  ReaderMgr: Inlined methods
//
//  NOTE: We cannot put these in alphabetical and type order as we usually
//  do because some of the compilers we have to support are too stupid to
//  understand out of order inlines!
// ---------------------------------------------------------------------------
inline unsigned int ReaderMgr::getCurrentReaderNum() const
{
    return fCurReader->getReaderNum();
}

inline const XMLReader* ReaderMgr::getCurrentReader() const
{
    return fCurReader;
}

inline XMLReader* ReaderMgr::getCurrentReader()
{
    return fCurReader;
}

inline bool ReaderMgr::getName(XMLBuffer& toFill)
{
    toFill.reset();
    return fCurReader->getName(toFill, false);
}

inline bool ReaderMgr::getQName(XMLBuffer& toFill, int *colonPosition)
{
    toFill.reset();
    return fCurReader->getQName(toFill, colonPosition);
}

inline bool ReaderMgr::getNameToken(XMLBuffer& toFill)
{
    toFill.reset();
    return fCurReader->getName(toFill, true);
}

inline bool ReaderMgr::getNextCharIfNot(const XMLCh chNotToGet, XMLCh& chGotten)
{
    return fCurReader->getNextCharIfNot(chNotToGet, chGotten);
}

inline void ReaderMgr::movePlainContentChars(XMLBuffer &dest)
{
    fCurReader->movePlainContentChars(dest);
}

inline bool ReaderMgr::getThrowEOE() const
{
    return fThrowEOE;
}

inline unsigned int ReaderMgr::getSrcOffset() const
{
    return fCurReader? fCurReader->getSrcOffset() : 0;
}

inline bool ReaderMgr::lookingAtChar(const XMLCh chToCheck)
{
    return (chToCheck == peekNextChar());
}

inline bool ReaderMgr::lookingAtSpace()
{
    XMLCh c = peekNextChar();
    return fCurReader->isWhitespace(c);
}

inline void ReaderMgr::setThrowEOE(const bool newValue)
{
    fThrowEOE = newValue;
}

inline void ReaderMgr::setStandardUriConformant(const bool newValue)
{
    fStandardUriConformant = newValue;
}

inline bool ReaderMgr::skippedString(const XMLCh* const toSkip)
{
    return fCurReader->skippedString(toSkip);
}

inline void ReaderMgr::skipToChar(const XMLCh toSkipTo)
{
	XMLCh nextCh = 0;
    do
    {
        // Get chars until we find the one to skip
        nextCh = getNextChar();
	} 
    // Break out at end of input or the char to skip
	while((nextCh != toSkipTo) && nextCh!=0);
}

inline void ReaderMgr::skipPastChar(const XMLCh toSkipPast)
{
	XMLCh nextCh = 0;
    do
    {
        // Get chars until we find the one to skip
        nextCh = getNextChar();
	} 
	while((nextCh != toSkipPast) && nextCh!=0);
}

inline bool ReaderMgr::peekString(const XMLCh* const toPeek)
{
    return fCurReader->peekString(toPeek);
}

inline void ReaderMgr::setEntityHandler(XMLEntityHandler* const newHandler)
{
    fEntityHandler = newHandler;
}

inline void ReaderMgr::setXMLVersion(const XMLReader::XMLVersion version)
{
    fXMLVersion = version;
    fCurReader->setXMLVersion(version);
}

//
//  This is a simple class to temporarily change the 'throw at end of entity'
//  flag of the reader manager. There are some places where we need to
//  turn this on and off on a scoped basis.
//
class XMLPARSER_EXPORT ThrowEOEJanitor
{
public :
    // -----------------------------------------------------------------------
    //  Constructors and destructor
    // -----------------------------------------------------------------------
    ThrowEOEJanitor(ReaderMgr* mgrTarget, const bool newValue) :

        fOld(mgrTarget->getThrowEOE())
        , fMgr(mgrTarget)
    {
        mgrTarget->setThrowEOE(newValue);
    }

    ~ThrowEOEJanitor()
    {
        fMgr->setThrowEOE(fOld);
    };

private :
    // -----------------------------------------------------------------------
    //  Unimplemented constructors and operators
    // -----------------------------------------------------------------------    
    ThrowEOEJanitor(const ThrowEOEJanitor&);
    ThrowEOEJanitor& operator=(const ThrowEOEJanitor&);

    // -----------------------------------------------------------------------
    //  Private data members
    //
    //  fOld
    //      The previous value of the flag, which we replaced during ctor,
    //      and will replace during dtor.
    //
    //  fMgr
    //      A pointer to the reader manager we are going to set/reset the
    //      flag on.
    // -----------------------------------------------------------------------
    bool        fOld;
    ReaderMgr*  fMgr;
};

XERCES_CPP_NAMESPACE_END

#endif