/*------------------------------------------------------------------------------
* Copyright (C) 2003-2006 Ben van Klinken and the CLucene Team
* 
* Distributable under the terms of either the Apache License (Version 2.0) or 
* the GNU Lesser General Public License, as specified in the COPYING file.
------------------------------------------------------------------------------*/
#include "CLucene/StdHeader.h"
#include "TermVector.h"
#include "CLucene/util/Misc.h"

CL_NS_USE(util)
CL_NS_DEF(index)

const char* TermVectorsWriter::LUCENE_TVX_EXTENSION = ".tvx";
const char* TermVectorsWriter::LUCENE_TVD_EXTENSION = ".tvd";
const char* TermVectorsWriter::LUCENE_TVF_EXTENSION = ".tvf";

 TermVectorsWriter::TermVectorsWriter(CL_NS(store)::Directory* directory, 
    const char* segment,FieldInfos* fieldInfos)
 {
    // Open files for TermVector storage
	char fbuf[CL_MAX_NAME];
	strcpy(fbuf,segment);
	char* fpbuf=fbuf+strlen(fbuf);

	strcpy(fpbuf,LUCENE_TVX_EXTENSION);
    tvx = directory->createOutput(fbuf);
    tvx->writeInt(FORMAT_VERSION);

	strcpy(fpbuf,LUCENE_TVD_EXTENSION);
    tvd = directory->createOutput(fbuf);
    tvd->writeInt(FORMAT_VERSION);
	
	strcpy(fpbuf,LUCENE_TVF_EXTENSION);
    tvf = directory->createOutput(fbuf);
    tvf->writeInt(FORMAT_VERSION);

    this->fieldInfos = fieldInfos;

	currentField = NULL;
	currentDocPointer = -1;
  }

  TermVectorsWriter::~TermVectorsWriter(){
      if ( tvx != NULL ){
          tvx->close();
        _CLDELETE(tvx);
      }
      if ( tvd != NULL ){
          tvd->close();
        _CLDELETE(tvd);
      }
      if ( tvf != NULL ){
          tvf->close();
        _CLDELETE(tvf);
      }
  }


  void TermVectorsWriter::openDocument() {
    closeDocument();

    currentDocPointer = tvd->getFilePointer();
  }


  void TermVectorsWriter::closeDocument(){
    if (isDocumentOpen()) {
      closeField();
      writeDoc();
      fields.clear();
      currentDocPointer = -1;
    }
  }


  bool TermVectorsWriter::isDocumentOpen() const{
    return currentDocPointer != -1;
  }


  void TermVectorsWriter::openField(int32_t fieldNumber, bool storePositionWithTermVector, bool storeOffsetWithTermVector){
	if (!isDocumentOpen())
		_CLTHROWA(CL_ERR_InvalidState,"Cannot open field when no document is open.");

    closeField();
    currentField = _CLNEW TVField(fieldNumber, storePositionWithTermVector, storeOffsetWithTermVector);
  }
  void TermVectorsWriter::openField(const TCHAR* field) {
    FieldInfo* fieldInfo = fieldInfos->fieldInfo(field);
    openField(fieldInfo->number, fieldInfo->storePositionWithTermVector, fieldInfo->storeOffsetWithTermVector);
  }

  void TermVectorsWriter::closeField(){
    if (isFieldOpen()) {
      /* DEBUG */
      //System.out.println("closeField()");
      /* DEBUG */

      // save field and terms
      writeField();
      fields.push_back(currentField);
      terms.clear();
      currentField = NULL;
    }
  }

  bool TermVectorsWriter::isFieldOpen() const{
    return currentField != NULL;
  }

  void TermVectorsWriter::addTerm(const TCHAR* termText, int32_t freq, 
	  Array<int32_t>* positions, Array<TermVectorOffsetInfo>* offsets) {
    if (!isDocumentOpen()) 
		_CLTHROWA(CL_ERR_InvalidState,"Cannot add terms when document is not open");
    if (!isFieldOpen())
		_CLTHROWA(CL_ERR_InvalidState,"Cannot add terms when field is not open");

    addTermInternal(termText, freq, positions, offsets);
  }

  void TermVectorsWriter::addTermInternal(const TCHAR* termText, int32_t freq,
	  Array<int32_t>* positions, Array<TermVectorOffsetInfo>* offsets) {
    TVTerm* term = _CLNEW TVTerm();
    term->setTermText(termText);
    term->freq = freq;
    term->positions = positions;
    term->offsets = offsets;
    terms.push_back(term);
  }

  void TermVectorsWriter::addAllDocVectors(Array<TermFreqVector*>& vectors){
	openDocument();

	for (int32_t i = 0; i < vectors.length; ++i) {
		bool storePositionWithTermVector = false;
		bool storeOffsetWithTermVector = false;

		if ( vectors[i]->__asTermPositionVector() != NULL ) {
			TermPositionVector* tpVector = vectors[i]->__asTermPositionVector();

			if (tpVector->size() > 0 && tpVector->getTermPositions(0) != NULL)
				storePositionWithTermVector = true;
			if (tpVector->size() > 0 && tpVector->getOffsets(0) != NULL)
				storeOffsetWithTermVector = true;

			FieldInfo* fieldInfo = fieldInfos->fieldInfo(tpVector->getField());
			openField(fieldInfo->number, storePositionWithTermVector, storeOffsetWithTermVector);

			for (int32_t j = 0; j < tpVector->size(); ++j)
				addTermInternal(tpVector->getTerms()[j], 
					(*tpVector->getTermFrequencies())[j], 
					tpVector->getTermPositions(j),
					tpVector->getOffsets(j));

			closeField();

		} else {
			TermFreqVector* tfVector = vectors[i];

			FieldInfo* fieldInfo = fieldInfos->fieldInfo(tfVector->getField());
			openField(fieldInfo->number, storePositionWithTermVector, storeOffsetWithTermVector);

			for (int32_t j = 0; j < tfVector->size(); ++j)
				addTermInternal(tfVector->getTerms()[j], 
					(*tfVector->getTermFrequencies())[j], NULL, NULL);

			closeField();
		}
	}

    closeDocument();
  }


  void TermVectorsWriter::close() {
    try {
      closeDocument();

      // make an effort to close all streams we can but remember and re-throw
      // the first exception encountered in this process
	#define _DOTVWCLOSE(x) if (x != NULL){ \
		try { \
		  x->close(); _CLDELETE(x) \
        } catch (CLuceneError& e) { \
          if ( e.number() != CL_ERR_IO ) throw e; \
		  if (ikeep==0)ikeep=e.number(); \
          if (keep[0]==0) strcpy(keep,e.what()); \
		} catch (...) { \
			if (keep[0]==0) strcpy(keep,"Unknown error while closing " #x); \
		} \
	  }
	}_CLFINALLY( \
    char keep[200]; \
	  int32_t ikeep=0;
	  keep[0]=0; \
	  _DOTVWCLOSE(tvx); \
	  _DOTVWCLOSE(tvd); \
	  _DOTVWCLOSE(tvf); \
		if (keep[0] != 0 ) { \
			_CLTHROWA(ikeep,keep); \
		}
	);
  }

  

  void TermVectorsWriter::writeField()  {
    // remember where this field is written
    currentField->tvfPointer = tvf->getFilePointer();
    //System.out.println("Field Pointer: " + currentField.tvfPointer);
    int32_t size = terms.size();

    tvf->writeVInt(size);

    bool storePositions = currentField->storePositions;
    bool storeOffsets = currentField->storeOffsets;
    uint8_t bits = 0x0;
    if (storePositions) 
      bits |= STORE_POSITIONS_WITH_TERMVECTOR;
    if (storeOffsets) 
      bits |= STORE_OFFSET_WITH_TERMVECTOR;
    tvf->writeByte(bits);

    const TCHAR* lastTermText = LUCENE_BLANK_STRING;
	int32_t lastTermTextLen = 0;

    for (int32_t i = 0; i < size; ++i) {
      TVTerm* term = terms[i];
	  int32_t start = CL_NS(util)::Misc::stringDifference(lastTermText, lastTermTextLen, 
		  term->getTermText(),term->getTermTextLen());
      int32_t length = term->getTermTextLen() - start;
      tvf->writeVInt(start);			  // write shared prefix length
      tvf->writeVInt(length);			  // write delta length
      tvf->writeChars(term->getTermText(), start, length);  // write delta chars
      tvf->writeVInt(term->freq);

      lastTermText = term->getTermText();
	  lastTermTextLen = term->getTermTextLen();

	  if(storePositions){
        if(term->positions == NULL)
			_CLTHROWA(CL_ERR_IllegalState, "Trying to write positions that are NULL!");
        
        // use delta encoding for positions
        int32_t position = 0;
        for (int32_t j = 0; j < term->freq; ++j){
          tvf->writeVInt((*term->positions)[j] - position);
          position = (*term->positions)[j];
        }
      }
      
      if(storeOffsets){
        if(term->offsets == NULL)
          _CLTHROWA(CL_ERR_IllegalState, "Trying to write offsets that are NULL!");
        
        // use delta encoding for offsets
        int32_t position = 0;
        for (int32_t j = 0; j < term->freq; ++j) {
          tvf->writeVInt((*term->offsets)[j].getStartOffset() - position);
          tvf->writeVInt((*term->offsets)[j].getEndOffset() - (*term->offsets)[j].getStartOffset()); //Save the diff between the two.
          position = (*term->offsets)[j].getEndOffset();
        }
      }
    }
  }




  void TermVectorsWriter::writeDoc()  {
    if (isFieldOpen()) 
		_CLTHROWA(CL_ERR_InvalidState,"Field is still open while writing document");

	// write document index record
    tvx->writeLong(currentDocPointer);

    // write document data record
    int32_t size = fields.size();

    // write the number of fields
    tvd->writeVInt(size);

    // write field numbers
	for (int32_t j = 0; j < size; ++j) {
	  tvd->writeVInt(fields[j]->number);
	}

    // write field pointers
    int64_t lastFieldPointer = 0;
	for (int32_t i = 0; i < size; ++i) {
	  TVField* field = (TVField*) fields[i];
	  tvd->writeVLong(field->tvfPointer - lastFieldPointer);

	  lastFieldPointer = field->tvfPointer;
	}
  }


  const TCHAR* TermVectorsWriter::TVTerm::getTermText() const{
      return termText;
  }
    size_t TermVectorsWriter::TVTerm::getTermTextLen(){ 
		if (termTextLen==-1)
			termTextLen = _tcslen(termText);
		return termTextLen; 
	}
	void TermVectorsWriter::TVTerm::setTermText(const TCHAR* val){ 
        _CLDELETE_CARRAY(termText);
		termText = STRDUP_TtoT(val);
		termTextLen = -1;

	}
	TermVectorsWriter::TVTerm::TVTerm(): 
		freq(0),
		positions(NULL),
		offsets(NULL)
	{
        termText=NULL;  
        termTextLen=-1;
    }
    TermVectorsWriter::TVTerm::~TVTerm(){ 
        _CLDELETE_CARRAY(termText)
    }

CL_NS_END
