#include <common/windows.hpp>
#include <common/stdio.hpp>
#include <common/stdlib.hpp>
#include <common/finddata.hpp>
#include <yproxy/pdecode.hpp>
#include <yproxy/crc.hpp>
#include <io.h>

PureDecoder::PureDecoder()
: mErrors(0), mErrParts(0), mErrFiles(0), mDisplay(true), myBegin(0), myEnd(0), mAdResCrc(0), mAdResLen(0)
{
  ::memset(mAttName,0,sizeof(mAttName));
	::memset(mAtText,0,sizeof(mAtText));
}

char *PureDecoder::ad_fgetscr(char * buffer, int maxlen, FILE * fp)
{
	char * cp;
	char * dp;

	cp=fgets(buffer,maxlen,fp);
	if(cp==NULL)return(NULL);
	dp=strrchr(buffer,'\n');   // Eliminate CRLF
	if (dp) *dp=0;
	dp=strrchr(buffer,'\r');
	if (dp) *dp=0;
	return(cp);
}

unsigned long PureDecoder::hex_to_ulong(char * text)
{
	unsigned long res;
	unsigned char c;

	if (text==NULL) return(-1);
	res=0;

  while(true)
	{
	  c=*text; text++;
	  if ((c>='0')&(c<='9'))
	  {
		  res=(res<<4)+((long)(c-48) & 0x0F);
			continue;
	  }
	  if ((c>='A')&(c<='F'))
	  {
		  res=(res<<4)+((long)(c-55) & 0x0F);
			continue;
    }
	  if ((c>='a')&(c<='f'))
	  {
		  res=(res<<4)+((long)(c-87) & 0x0F);
			continue;
	  }
		break;
	}
	return(res);
}

int PureDecoder::yDecode(FILE * fOut, FILE * fIn, long y_line, long y_size,int y_part)
{
	unsigned char srcbuf[4100];
	unsigned char desbuf[4100];
	unsigned char * srcp;
	unsigned char * desp;
	int deslen;
	int srclen;
	unsigned char c;
	int id;
	char * cp;
	long decolen;
	unsigned long crc32;
	char name[260];
	int esize;
	unsigned char * partbuf;
	unsigned char * partptr;
	long partsize;
	long partfree;
	long wlen;
	long flen;

	if(mDisplay)
	{
	  display("yDecoder started...\r\n");
	}
	CRC crc;

	decolen=0;
	deslen=0;
	desp=desbuf;

	if(y_part)  // This is a multipart message !
	{
		cp=ad_fgetscr((char*) srcbuf,4097,fIn);  // fgets especially with ad_length
		if (cp==NULL)
		{
			error("Unexpected eof in yEncoded file\r\n");
			mErrors++;
			return(1);
		}
		if(mDisplay)
		{
		  String str;
			::sprintf(str,"=ypart-line:  %s\r\n",srcbuf);
			display(str);
		}
		if (strncmp((char*) srcbuf,"=ypart ",7))
		{
			error("Missing =ypart line in yEncoded multipart message\r\n");
			mErrors++;
			return(2);
		}
		cp=strstr((char*)srcbuf,"end=");
		if (cp==NULL)
		{
			error("Missing end= in yEncoded multipart message\r\n");
			mErrors++;
			return(2);
		}
		myEnd=atol(cp+4);
		cp=strstr((char*)srcbuf,"begin=");
		if (cp==NULL)
		{
			error("Missing begin= in yEncoded multipart message\r\n");
			mErrors++;
			return(2);
		}
		myBegin=atol(cp+6);
		if(mDisplay)
		{
		  String str;
			::sprintf(str,"part-begin: %ld\r\n",myBegin);
			display(str);
      sprintf(str,"part-end  : %ld\r\n",myEnd);
			display(str);
		}
		partbuf=(unsigned char*)malloc(myEnd-myBegin+10);  // Allocate a buffer for the part
		partptr=partbuf;
		partsize=myEnd-myBegin+1;
		partfree=partsize;
	}

loop:

	cp=ad_fgetscr((char*) srcbuf,4097,fIn);  // fgets especially with ad_length
	if(cp==NULL)
	{
		error("Unexpected eof in yEncoded file\r\n");
		mErrors++;
		return(1);
	}
	if (strncmp((char*) srcbuf,"=yend ",6)==0)
	{
		if(mDisplay)
		{
		  String str;
		  sprintf(str,"Endline (%d bytes): %s\r\n",decolen,srcbuf);
			display(str);
		}
		goto end_of_file;
	}
	if (strncmp((char*) srcbuf,"=ybegin ",8)==0)
	{
		error("Unexpected =ybegin in yEncoded file\r\n");
		mErrors++;
		return(1);
	}
	srclen=strlen((char*)srcbuf);
	if (srclen<y_line)
	{
		if(mDisplay)display("Last line.\r\n");
	}
	srcp=srcbuf;

loop2:
	c=*srcp; srcp++;
	if(c==0)
	{
		goto loop;  // End of line reached
	}
	if(c=='=')  // The escape character comes in
	{
		c=*srcp; srcp++;
		if(c==0)return(2); // Last char cannot be escape char !
		c=(unsigned char)(c-64);
	}
	c=(unsigned char)(c-42);  // Subtract the secret number
	*desp=c;
	desp++;
	deslen++;
	decolen++;

//	crc.crcAdd(c);
	crc.crcAdd(c);

	if (deslen>=4096)
	{
		if (y_part)  // MultiPart --> to the partbuffer !
		{
		  if (deslen>partfree)
			{
				error("Partial message corrupt: longer than (end-begin)!\r\n");
				mErrors++;
			  return(11);
			}
			memcpy(partptr,desbuf,deslen);
			partptr=partptr+deslen;
			partfree=partfree-deslen;
		}
		else    // Single part --> directly to target file
		{
			id=fwrite(desbuf,deslen,1,fOut);
			if (id != 1)
			{
			  String strError;
				::sprintf(strError,"Error in writing decoded file (code=%d)\r\n",errno);
				error(strError);
				mErrors++;
				return(3);
				}
		}
		deslen=0;
		desp=desbuf;
	}
	goto loop2;

end_of_file:

	if (deslen>0)  // Empty the last buffer
	{
		if (y_part)
    {
			if (deslen>partfree)
			{
				error("Partial message corrupt: longer than (end-begin)!\r\n");
				mErrors++;
				return(11);
			}
			memcpy(partptr,desbuf,deslen);
			//partptr=partptr+deslen;
			//partfree=partfree-deslen;
		}
		else    // Single part --> directly to target file
		{
			id=fwrite(desbuf,deslen,1,fOut);
			if (id != 1)
			{
			  String strError;
				::sprintf(strError,"Error in writing decoded file (code=%d)\r\n",errno);
				error(strError);
				mErrors++;
				return(3);
			}
		}
	}
	cp=strstr((char*) srcbuf,"size=");  // Compare the decoded size to the =yend size
	if (cp)
	{
		esize=atoi(cp+5);
		if (esize != decolen)
		{
			sprintf(name,"%s(size=%ld)",mAttName,decolen);
			strcpy(mAttName,name);
			String strError;
			::sprintf(strError,"Corrupt yEnc binary - endsize mismatch (%s%s)\r\n",mAttName,mAtText);
			error(strError);
			mErrors++;
			mErrFiles++;
			return(0);
		}  
	}
	// Check the srcbuf for the CRC
	if (y_part==0)
	{
		cp=strstr((char*)srcbuf,"crc32=");
		if (cp)
		{
			crc32=hex_to_ulong((char*)(cp+6));
			mAdResCrc=crc.getVal() ^ 0xFFFFFFFFl;

		  if (mDisplay)
			{
			  String str;
			  sprintf(str,"Included CRC: $%08lx - calculated CRC: $%08lx\r\n",crc32,mAdResCrc);
				display(str);
			}
		}
	}
	else
	{
		cp=strstr((char*)srcbuf,"pcrc32=");
		if (cp)
		{
			crc32=hex_to_ulong((char*)(cp+7));
			mAdResCrc=crc.getVal() ^ 0xFFFFFFFFl;

			if (mDisplay)
			{
			  String str;
			  sprintf(str,"Included CRC: $%08lx - calculated CRC: $%08lx\r\n",crc32,mAdResCrc);
				display(str);
			}
		}
	}

	if (cp!=NULL)
	{
		if (crc32 != mAdResCrc)
		{
			sprintf(name,"%s(crc=%08lx)",mAttName,mAdResCrc);
			strcpy(mAttName,name);
			String strError;
			::sprintf(strError,"Corrupt yEnc binary - CRC mismatch (%s%s)\r\n",mAttName,mAtText);
			error(strError);
			mErrors++;
			mErrFiles++;
			return(0);
		}
	}

	if (y_part==0)  // Single message
	{
		if ((y_part==0) & (decolen != y_size))
		{
			// eprint("Y-Decoder: Size mismatch - file corrupt.\r\n");

			sprintf(name,"%s(len=%ld)",mAttName,decolen);
			strcpy(mAttName,name);

			String strError;
			::sprintf(strError,"Corrupt yEnc binary - size mismatch (%s%s)\r\n",mAttName,mAtText);
			error(strError);
			mErrors++;
			mErrFiles++;
			return(0);
		}
		mAdResLen=decolen;
		mAdResCrc=crc.getVal() ^ 0xFFFFFFFFl;
		if(mDisplay)
		{
		  String str;
		  sprintf(str,"yDecoder: Job done. %ld bytes written. CRC: $%08lx \r\n",decolen,mAdResCrc);
			display(str);
		}
		return(0);
	}
	if ((y_part>0) & (decolen != (myEnd-myBegin+1)))
	{
		error("yDecoder: Part size mismatch - file corrupt.\r\n");
		mErrors++;
		mErrParts++;
		return(6);
	}
	id=fseek(fOut,myBegin-1,0);
	if(id)
	{
	  String strError;
		::sprintf(strError,"Cannot write a part (fseek failed) [reason:%d]\r\n",errno);
		error(strError);
		mErrors++;
		return(12);
	}
	flen=decolen;
	partptr=partbuf;
	if (mDisplay)
	{
	  String str;
	  sprintf(str,"Write part to target file (start: %ld, size: %ld)\r\n",myBegin-1,flen);
		display(str);
	}
	while (flen>0)
	{
		wlen=flen;
		if (wlen>8192) wlen=8192;
		id=fwrite(partptr,wlen,1,fOut);
		if (id != 1)
		{
			String strError;
			::sprintf(strError,"Cannot write a part (fwrite failed) [reason:%d]\r\n",errno);
			error(strError);
			mErrors++;
			return(12);
		}
		partptr=partptr+wlen;
		flen=flen-wlen;
	}
	free(partbuf);
	return(0);
}

int PureDecoder::AddPart(char * srcname,long y_begin, long y_end)
{
	FILE * fSrc;
	FILE * fDes;
	char desname[260];
	char line[1024];
	long a,e;
	int copyrest;
	char * cp;
	int resparts;
	long flen;

	if (mDisplay)
	{
	  String str;
	  sprintf("AddPart (%s) [%ld - %ld]\r\n",srcname,y_begin,y_end);
		display(str);
	}
	copyrest=0;
	resparts=0;
	sprintf(desname,"%s.des",srcname);
	fSrc=fopen(srcname,"rb");
	if (fSrc==NULL)
	{
	  String strError;
		::sprintf(strError,"AddPart:  Part Info File not found (%s)\r\n",srcname);
		error(strError);
		mErrors++;
		return(-1);
	}
	flen=filelength(fileno(fSrc));
	if (flen==0)  // Already complete
	{
		return(-9);
	}
	fDes=fopen(desname,"wb");
	if(fDes==NULL)
	{
	  String strError;
		::sprintf(strError,"AddPart: Cannot create temporary part file (%s) [reason: %d]\r\n",desname,errno);
		error(strError);
		fclose(fSrc);
		mErrors++;
		return(-2);
	}
loop:
	cp=fgets(line,1000,fSrc);
	if (cp==NULL) goto eof1;
	cp=strrchr(line,'\n');
	if (cp) *cp=0;
	cp=strrchr(line,'\r');
	if (cp) *cp=0;

	// print("%s\r\n",line);

	if (copyrest)  // Analysis done - copy rest & done.
	{
		fprintf(fDes,"%s\r\n",line);
		resparts++;
		goto loop;
	}

	a=atol(line);
	if (a==0)
	{
	  String strError;
		::sprintf(strError,"Corrupt part-info file (%s)\r\n",line);
		error(strError);
		mErrors++;
		fclose(fSrc); fclose(fDes); return(-3);
		}
	cp=strchr(line,',');
	if (cp==NULL)
	{
		  String strError;
			::sprintf(strError,"Corrupt part-info file (%s)\r\n",line);
			error(strError);
		mErrors++;
		fclose(fSrc); fclose(fDes); return(-4);
	}
	e=atol(cp+1);
	//	print("a:%6d, e:%6d\r\n",a,e);

// ----- Case Analysis -----
//	.............[yb--------ye]      (The new, incoming block)
//	1...a****e                       (The old, missing block)
//	2...a********-----e              (***) Newly written missing block
//	3...a********--------------****e
//	.............[yb--------ye]
//	4............a-----e
// 5............a------------e
//	6............a-------------****e
//	.............[yb--------ye]
//	7............................a***e
//	.............[yb--------ye]
//	8................a----e
//	9................a---------****e




	if (a<y_begin)  // A previous section was missed
	{
		if (e<y_begin) // A previous section was missed entirely
		{
			// Case-1
			fprintf(fDes,"%ld,%ld\r\n",a,e);  // --> Keep that entry
			resparts++;
			goto loop;
		}
		if (e<=y_end)  // Rduce the old section
		{
			// Case-2
			fprintf(fDes,"%ld,%ld\r\n",a,y_begin-1);  // --> Reduce that entry
			resparts++;
			goto loop;
		}
		// The new section is splitting the old missing section
			// Case-3
			fprintf(fDes,"%ld,%ld\r\n",a,y_begin-1);  // --> First part
			fprintf(fDes,"%ld,%ld\r\n",y_end+1,e);  // --> First part
			resparts++; resparts++;
			goto loop;
	}

	if (a==y_begin)  // New part matches this segment
	{
		if (e<y_end)   // Just a smaller section was missed
		{
			// case 4
		  goto loop;  // Skip this and analyse next
		}
		if (e==y_end)  // This missing section was exactly -> remove it & done.
		{
			// case 5
			copyrest=1; goto loop;
		}
		if (e>y_end)  // The first part was found
		{
			// case-6
			fprintf(fDes,"%ld,%ld\r\n",y_end+1,e);  // Write the rest
			resparts++;
			copyrest=1; goto loop;
		}
	}

	if (a>y_begin)
	{
		if (a>y_end)  // the found section completely in front of this one.
		{
			// Case-7
			fprintf(fDes,"%ld,%ld\r\n",a,e);  // Rewrite it & copy the rest
			resparts++;
			copyrest=1; goto loop;
		}
		if (e<=y_end) // The section was completely found
		{
			// Case-8
			goto loop;  // Analyse the rest
		}
		// The first part of the missing section was found
			// case-9
			fprintf(fDes,"%ld,%ld\r\n",y_end+1,e);  // Reduce it & copy the rest
			resparts++;
			copyrest=1; goto loop;
	}

eof1:
	fclose(fSrc); fclose(fDes);
	remove(srcname);

	rename(desname,srcname);

	return(resparts);
}

// virtuals

void PureDecoder::error(const String &error)
{
  ::OutputDebugString(error.str());
}

void PureDecoder::display(const String &string)
{
  ::OutputDebugString(string.str());
}