#include "CLucene/StdHeader.h"
#include "Reader.h"

using namespace lucene::store;

namespace lucene{namespace util{

	FileReader::FileReader(const char_t* fname):
		stream( new FSInputStream(fname) )
	{
	    cachepos = cache+FILEREADER_CACHE-1;
	}
	FileReader::~FileReader(){
		close();
	}
	void FileReader::close(){
		if ( stream != NULL){
			stream->close();
			delete stream;
			stream = NULL;
		}
	}
	int_t FileReader::read(char_t* buf, const int_t start, const int_t length){
		int_t av = available();
		if ( av > 0 ){
			if ( av < length ){
				av--;
				stream->readChars(buf,start,av);
				return av;
			}else{
				stream->readChars(buf,start,length);
				return length;
			}
		}else
			return 0;
	}
	int_t FileReader::read(char_t* buf){
		return read(buf,0,stringLength(buf));
	}
	int_t FileReader::available(){
		return stream->Length() - stream->getFilePointer();
	}
	uchar_t FileReader::readChar(){
		#ifdef UTF8
		#if 0
		char_t buf[6];
		int len=0;
		uchar_t ret;
		int avail = available();
		avail = (avail>=6 ? 6 : avail);
		if ( read(buf,0,avail) == avail ) {
			ret = lc_utf8_get_char(buf, &len);
			if (len==-1) return 0;
			stream->seek(stream->getFilePointer()-avail+len);
			//printf("FileReader read %d\n", ret);fflush(NULL);
			return ret;
		}
		else
			return 0;
		#endif
		
		//if you are within 6 of the end of the cache reread cache and set pointer to start of cache
		if (cachepos - cache >= FILEREADER_CACHE - 6)
		{
			int avail = available();
			avail = (avail>=FILEREADER_CACHE ? FILEREADER_CACHE : avail);
			if ( read(cache,0,avail) != avail )
			{
				throw "warning : FileReader::readChar : Failed to read into cache.";
				return '\0';
			}
			cachepos = cache;
			stream->seek(stream->getFilePointer()-avail);
			//printf("FileReader reloaded cache %s\n", cache);fflush(NULL);
		}
		int len=0;
		//get the char at current cachepos and set stream
		uchar_t ret = lc_utf8_get_char(cachepos, &len);
		if (len==-1)
		{
			throw "warning : FileReader::readChar : Read bad UTF-8 char.";
			return '\0';
		}
		stream->seek(stream->getFilePointer()+len);
		cachepos += len;
		//printf("FileReader read %d\n", ret);fflush(NULL);
		return ret;
		
		#else
		char_t buf[2];
		if ( read(buf,0,1) == 1 )
			return buf[0];
		else
			return 0;
		#endif
	}
	uchar_t FileReader::peek(){
		if ( available() == 0 )
			return 0;
		#ifdef UTF8
		char_t buf[6];
		int len=0;
		uchar_t ret;
		int avail = (available()>=6 ? 6 : available());
		if ( read(buf,0,avail) == avail ) {
			ret = lc_utf8_get_char(buf, &len);
			if (len==-1) return 0;
			stream->seek(stream->getFilePointer()-avail);
			//printf("FileReader peeked %d\n", ret);fflush(NULL);
			return ret;
		}
		else
			return 0;
		#else
		uchar_t ret = readChar();
		stream->seek(stream->getFilePointer()-1);
		return ret;
		#endif
	}
	int_t FileReader::position(){
		return stream->getFilePointer();
	}
	void FileReader::seek(int_t position){
		stream->seek(position);
		cachepos = cache+FILEREADER_CACHE-1;
	}




	StringReader::StringReader ( const char_t* value ):
		data(value),
		delVal(false)
	{
		pt = 0;
		len = stringLength(value);
		
	}
	StringReader::StringReader ( const char_t* value, const int length, const bool deletevalue ):
		data(value),
		len(length),
		delVal(deletevalue)
	{
		pt = 0;
	}
	StringReader::~StringReader(){
		close();
	}

	int_t StringReader::available(){
		return len-pt;
	}
	int_t StringReader::read ( char_t* buf ){
		return read(buf,0,stringLength(buf));
	}
	int_t StringReader::read ( char_t* buf, const int_t start, const int_t length ){
		if ( pt >= len )
			return -1;
		int_t rd = 0;
		while ( pt < len && rd < length ){
			buf[start+rd] = data[pt];
			rd ++;
			pt ++;
		}
		return rd;
	}
	uchar_t StringReader::readChar(){
		if ( pt>=len )
		{
			if (pt==len)
				return 0;
			printf("StringReader throwing EOF %d/%d\n", pt, len);fflush(NULL);
			throw "String reader EOF";
		}
		#ifdef UTF8
		int length;
		//printf("StringReader reading from %d/%d)\n", pt, len);fflush(NULL);
		uchar_t ret = lc_utf8_get_char(data+pt, &length);
		//printf("StringReader read %d from %s(%d)\n", ret, data+pt, length);fflush(NULL);
		pt+=length;
		#else
		char_t ret = data[pt];
		pt++;
		#endif
		return ret;
	}
	
	uchar_t StringReader::peek(){
		if ( pt>=len )
		{
			if (pt==len)
				return 0;
			printf("StringReader throwing EOF %d/%d\n", pt, len);fflush(NULL);
			throw "String reader EOF";
		}
		#ifdef UTF8
		int length=0;
		uchar_t ret = lc_utf8_get_char(data+pt, &length);
		//printf("StringReader peeked %d\n", ret);fflush(NULL);
		return ret;
		#else
		return data[pt];
		#endif
	}
	void StringReader::close(){
		if ( delVal )
			delete[] data;
	}
	int_t StringReader::position(){
		return pt;
	}
	void StringReader::seek(int_t position){
		pt=position;
	}

}}