/*
June 14, 1999

Recover text articles from cyclic buffers
Articles start with  "\0Path:"
and end with "\r\n.\r\n"

Tested with INND 2.2 under AIX 4.2

rifkin@uconn.edu
*/
/*
(1) Pull 16 bytes at a time
(2) Last 7 bytes must be \000\000\000Path
(3) When found, print "\nPath";
(4) print subsequent bytes until \r\n.\r\n found
*/

#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define INFILE     1
#define FILEPREFIX 2
#define HEADER     3
#define STRING     4

/*  String buffer size  */
#define NBUFF 512

#define MAX_ART_SIZE 2200000


#define WRITEMSG printf ("File %s line %i\n", __FILE__, __LINE__); \
	fflush(stdout);

#define WRITEVAR(VAR_NAME,VAR_TYPE) \
      { \
      printf ("FILE %s LINE %i :", __FILE__, __LINE__); \
      printf ("%s = ", #VAR_NAME); \
      printf (#VAR_TYPE, (VAR_NAME) ); \
      printf ("\n"); \
      }

#define WRITETXT(TEXT)  \
	printf ("FILE %s LINE %i \"%s\"\n", __FILE__, __LINE__, TEXT); \
	fflush(stdout);

#if 0
#define WRITEMSG
#define WRITEVAR(X,Y)
#endif


int WriteArticle (char *, int, char *, char *, char *, int);


char ArtHead[7] = {0, 0, 0, 'P', 'a', 't', 'h'};
char ArtTail[5] = {'\r', '\n', '.', '\r', '\n'};
int  LenTail    = 5;

int main (int argc, char *argv[])
	{
	FILE *Infile;
	int   NumTailCharFound;
	bool  ReadingArticle = false;
	char  buffer[32];
	char *obuffer = NULL;
	char *header  = NULL;
	char *string  = NULL;
	int   osize = MAX_ART_SIZE;
	int   opos  = 0;
	int   i;
	int   nchar;
	int   fileno = 0;
	int   artno  = 0;
	
	/*  Check number of args  */
	if (argc<3)
		{
		printf ("Usage: pullart <cycbuff> <fileprefix> [<header> <string>]\n");
		printf ("  Read cycbuffer <cycbuff> and print all articles whose\n");
		printf ("   article header <header> contains <string>.\n");
		printf ("  Articles are written to files name <fileprefix>.nnnnnn\n");
		printf ("   where nnnnnn is numbered sequentially from 0.\n");
		printf ("  If <header> and <string> not specified, all articles\n");
		printf ("   are written.\n");
		printf (" Examples:\n");
		printf ("  pullart /news3/cycbuff.3 alt.rec  Newsgroup: alt.rec\n");
		printf ("  pullart /news3/cycbuff.3  all\n");
		printf ("  pullart firstbuff  article Subject bluejay\n");
		return 0;
		}

	/*  Allocate output buffer  */
	obuffer = (char *) calloc (osize+1, sizeof(char));
	if (obuffer==NULL)
		{
		printf ("Cannot allocate obuffer[]\n");
		return 1;
		}


	/*  Open input file  */
	Infile = fopen (argv[INFILE], "rb");
	if (Infile==NULL)
		{
		printf ("Cannot open input file.\n");
		return 1;
		}


if (argc>=4) header = argv[HEADER];
if (argc>=5) string = argv[STRING];
if (*header=='\0') header=NULL;
if (*string=='\0') string=NULL;

/*test*/
printf ("filename <%s>\n", argv[INFILE]);
printf ("fileprefix <%s>\n", argv[FILEPREFIX]);
printf ("header <%s>\n", header);
printf ("string <%s>\n", string);


	/*  Skip first 0x38000 16byte buffers  */
	i = fseek (Infile, 0x38000L, SEEK_SET);

	/*  Read following 16 byte buffers  */
	ReadingArticle = false;
	NumTailCharFound = 0;
	nchar=0;
	artno=0;
	while ( 0!=fread(buffer, 16, 1, Infile) )
		{

		nchar+=16;

		/*  Found start of article, start writing to obuffer  */
		if (0==memcmp(buffer+9, ArtHead, 7))
			{
			ReadingArticle = true;
			memcpy (obuffer, "Path", 4);
			opos = 4;
			continue;
			}

		/*  Currnetly reading article  */
		if (ReadingArticle)
			{
			for (i=0; i<16; i++)
				{

				/*  Article too big, drop it and move on  */
				if (opos>=osize)
					{
					printf 
						("article number %i bigger than buffer size %i.\n", 
						artno+1, osize);
					artno++;
					ReadingArticle=false;
					break;
					}

				/*  Add current character to output buffer, but remove \r  */
				if ('\r' != buffer[i])
					obuffer[opos++] = buffer[i];

				/*  Check for article ending sequence  */
				if (buffer[i]==ArtTail[NumTailCharFound])
					{
					NumTailCharFound++;
					}
				else
					NumTailCharFound=0;

				/*  End found, write article, reset for next  */
				if (NumTailCharFound==LenTail)
					{
					ReadingArticle = false;
					NumTailCharFound = 0;

					/*  Add trailing \0 to buffer  */
					obuffer[opos+1] = '\0';

					fileno += WriteArticle 
						(obuffer, opos, argv[FILEPREFIX], 
						header, string, fileno);
					artno++;
					break;
					}
				}
			
			}

		}

	close (Infile);

	return 0;
	}



/*
Writes article stored in buff[] if it has a
"Newsgroups:" header line which contains *newsgroup
Write to a file named  fileprefix.fileno
*/
int
WriteArticle 
(char *buff, int n, char *fileprefix, char *headerin, char *string, int fileno)
	{
	char *begptr;
	char *endptr;
	char *newsptr;
	char savechar;
	char header[NBUFF];
	char filename[NBUFF];
	FILE *outfile;


	/*  Prevent buffer overflow due to fileprefix too long  */
	if (strlen(fileprefix)>384)
		{
		printf 
		("program error: cannot have file prefix greater then 384 characters\n");
		exit(1);
		}

	/*  
	Is header here?  Search if header string requested, leave if not found  
	*/
	if (headerin!=NULL)
		{
		/*  Find \nHEADER  */
                strlcpy(header, "\n", sizeof(header));
                strlcat(header, headerin, sizeof(header));

		begptr = strstr (buff, header);
		
		/*  return if Header name not found  */
		if (begptr==NULL)
			{
			return 0;
			}

		/*  
		Header found. What about string?
		Search if string requested, leave if not found  
		*/
		if (string!=NULL)
			{
			/*  Find end of header line  */
			begptr++;
			endptr = strchr (begptr, '\n');

			/*  Something is wrong, end of header not found, do not write
			 *  article  
			*/
			if (endptr==NULL)
				return 0;

			/*  Temporarily make string end a null char  */
			savechar = *endptr;
			*endptr = '\0';
			newsptr = strstr (begptr, string);

			/*  Requested newsgroup not found  */
			if (newsptr==NULL)
				return 0;

			/*  Restore character at end of header string  */
			*endptr = savechar;
			}
			/*  No string specified  */

		}
	/*  No header specified  */

	/*  Open file, write buffer, close file  */
	snprintf (filename, sizeof(filename), "%s.%06i", fileprefix, fileno);

	outfile = fopen (filename, "wt");
	if (outfile==NULL) {
		printf ("Cannot open file name %s\n", filename);
		exit(1);
		}

	while (n--)
		fprintf (outfile, "%c", *buff++);

	close (outfile);

	/*  Return number of files written  */
	return 1;
	}