/**************************************************************
 * 
 * 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
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 *************************************************************/



#ifndef ADC_TKPCHARS_HXX
#define ADC_TKPCHARS_HXX

// USED SERVICES
	// BASE CLASSES
	// COMPONENTS
	// PARAMETRS
#include <adc_cl.hxx>
#include <stack>



/**	@descr

	dpSource:

	1||||||||||||||||||||||a||||||||||||b|||c||||||||||||||||||||...


	1 := first character of Sourcecode.
	a := nLastTokenStart, there starts the last cut token.
	b := nLastCut, there is a '\0'-char which marks the end of
		 the last cut token. The original character at b is stored
		 in cCharAtLastCut and will replace the '\0'-char, when the
		 next token is cut.
	c := The current cursor position.


	@needs 	cosv.lib

	@use    This class can be used by any parser to get the chars of a
			text one by one and separate them to tokens.
**/

class CharacterSource
{
	public:
		// LIFECYCLE
						CharacterSource();
						~CharacterSource();

		// OPERATIONS
		/** Loads the complete contents of in_rSource into the classes private memory.
			If in_rSource is a file, it has to be open of course.
            After loading the text, the CurChar() is set on the begin of the text.
		**/
		void			LoadText(
							csv::bstream &		io_rSource);

        void            InsertTextAtCurPos(
                            const char *        i_sText2Insert );

		///	@return CurChar() after moving forward one char.
            char            MoveOn();
		/** @return
			The token which starts at the char which was CurChar(), when
			CutToken() was called the last time - or at the beginning of the text.
			The token ends by the CurChar() being replaced by a '\0'.

			Value is valid until the next call of CutToken() or ~CharacterSource().
		**/
		const char *	CutToken();

		// INQUIRY
        char            CurChar() const;
		/// @return The result of the last CutToken(). Or NULL, if there was none yet.
		const char *	CurToken() const;

	// INQUIRY
		/// @return true, if
		bool			IsFinished() const;

	private:
        struct S_SourceState
        {
    		DYN char *		dpSource;
		    intt			nSourceSize;

		    intt			nCurPos;
		    intt			nLastCut;
		    intt			nLastTokenStart;
		    char 			cCharAtLastCut;

                            S_SourceState(
    		                    DYN char *		dpSource,
		                        intt			nSourceSize,
		                        intt			nCurPos,
		                        intt			nLastCut,
		                        intt			nLastTokenStart,
		                        char 			cCharAtLastCut );
        };

        void            BeginSource();
		intt			CurPos() const;
        char            MoveOn_OverStack();

        // DATA
        std::stack< S_SourceState >
                        aSourcesStack;

		DYN char *		dpSource;
		intt			nSourceSize;

		intt			nCurPos;
		intt			nLastCut;
		intt			nLastTokenStart;
		char 			cCharAtLastCut;
};


inline char
CharacterSource::MoveOn()
	{
if (DEBUG_ShowText())
{
		Cerr() << char(dpSource[nCurPos+1]) << Flush();
}
        if ( nCurPos < nSourceSize-1 )
    		return dpSource[++nCurPos];
        else if ( aSourcesStack.size() > 0 )
            return MoveOn_OverStack();
        else
            return dpSource[nCurPos = nSourceSize];
	}
inline char
CharacterSource::CurChar() const
	{ return nCurPos != nLastCut ? dpSource[nCurPos] : cCharAtLastCut; }
inline const char *
CharacterSource::CurToken() const
	{ return &dpSource[nLastTokenStart]; }
inline bool
CharacterSource::IsFinished() const
	{ return nCurPos >= nSourceSize; }
inline intt
CharacterSource::CurPos() const
	{ return nCurPos; }




#endif