/* 
 * Copyright 2016 - Eduardo Chappa
 * Last Modified: August 11, 2016
 */
/* ========================================================================
 * Copyright 1988-2006 University of Washington
 *
 * Licensed 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
 *
 * 
 * ========================================================================
 */

/*
 * Program:	Newsrc manipulation routines
 *
 * Author:	Mark Crispin
 *		Networks and Distributed Computing
 *		Computing & Communications
 *		University of Washington
 *		Administration Building, AG-44
 *		Seattle, WA  98195
 *		Internet: MRC@CAC.Washington.EDU
 *
 * Date:	12 September 1994
 * Last Edited:	30 August 2006
 */


#include <ctype.h>
#include <stdio.h>
#include "c-client.h"
#include "newsrc.h"

#ifndef OLDFILESUFFIX
#define OLDFILESUFFIX ".old"
#endif

/* Error message
 * Accepts: message format
 *	    additional message string
 *	    message level
 * Returns: NIL, always
 */

long newsrc_error (char *fmt,char *text,long errflg)
{
  char tmp[MAILTMPLEN];
  sprintf (tmp,fmt,text);
  MM_LOG (tmp,errflg);
  return NIL;
}


/* Write error message
 * Accepts: newsrc name
 *	    file designator
 *	    file designator
 * Returns: NIL, always
 */

long newsrc_write_error (char *name,FILE *f1,FILE *f2)
{
  if (f1) fclose (f1);		/* close file designators */
  if (f2) fclose (f2);
  return newsrc_error ("Error writing to %.80s",name,ERROR);
}


/* Create newsrc file in local form
 * Accepts: MAIL stream
 *	    notification flag
 * Returns: file designator of newsrc
 */

FILE *newsrc_create (MAILSTREAM *stream,int notify)
{
  char *newsrc = (char *) mail_parameters (stream,GET_NEWSRC,stream);
  FILE *f = fopen (newsrc,"wb");
  if (!f) newsrc_error ("Unable to create news state %.80s",newsrc,ERROR);
  else if (notify) newsrc_error ("Creating news state %.80s",newsrc,WARN);
  return f;
}

/* Write new state in newsrc
 * Accepts: file designator of newsrc
 *	    group
 *	    new subscription status character
 *	    newline convention
 * Returns: T if successful, NIL otherwise
 */

long newsrc_newstate (FILE *f,char *group,char state,char *nl)
{
  long ret = (f && (fputs (group,f) != EOF) && ((putc (state,f)) != EOF) &&
	      ((putc (' ',f)) != EOF) && (fputs (nl,f) != EOF)) ? LONGT : NIL;
  if (fclose (f) == EOF) ret = NIL;
  return ret;
}


/* Write messages in newsrc
 * Accepts: file designator of newsrc
 *	    MAIL stream
 *	    message number/newsgroup message map
 *	    newline convention
 * Returns: T if successful, NIL otherwise
 */

long newsrc_newmessages (FILE *f,MAILSTREAM *stream,char *nl)
{
  unsigned long i,j,k;
  char tmp[MAILTMPLEN];
  MESSAGECACHE *elt;
  int c = ' ';
  if (stream->nmsgs) {		/* have any messages? */
    for (i = 1,j = k = (mail_elt (stream,i)->private.uid > 1) ? 1 : 0;
	 i <= stream->nmsgs; ++i) {
				/* deleted message? */
      if ((elt = mail_elt (stream,i))->deleted) {
	k = elt->private.uid;	/* this is the top of the current range */
	if (!j) j = k;		/* if no range in progress, start one */
      }
      else if (j) {		/* unread message, ending a range */
				/* calculate end of range */
	if ((k = elt->private.uid - 1) != 0L) {
				/* dump range */
	  if(j == k) sprintf (tmp, "%c%ld",c,j);
	  else sprintf (tmp, "%c%ld-%ld",c,j,k);
	  if (fputs (tmp,f) == EOF) return NIL;
	  c = ',';		/* need a comma after the first time */
	}
	j = 0;			/* no more range in progress */
      }
    }
    if (j) {			/* dump trailing range */
      if(j == k) sprintf (tmp, "%c%ld",c,j);
      else sprintf (tmp,"%c%ld-%ld",c,j,k);
      if (fputs (tmp,f) == EOF) return NIL;
    }
  }
				/* write trailing newline, return */
  return (fputs (nl,f) == EOF) ? NIL : LONGT;
}

/* List subscribed newsgroups
 * Accepts: MAIL stream
 *	    prefix to append name
 * 	    pattern to search
 */

void newsrc_lsub (MAILSTREAM *stream,char *pattern)
{
  char *s,*t,*lcl,name[MAILTMPLEN];
  int c = ' ';
  int showuppers = pattern[strlen (pattern) - 1] == '%';
  FILE *f = fopen ((char *) mail_parameters (stream,GET_NEWSRC,stream),"rb");
  if (f) {			/* got file? */
				/* remote name? */
    if (*(lcl = strcpy (name,pattern)) == '{') lcl = strchr (lcl,'}') + 1;
    if (*lcl == '#') lcl += 6;	/* namespace format name? */
    while (c != EOF) {		/* yes, read newsrc */
      for (s = lcl; (s < (name + MAILTMPLEN - 1)) && ((c = getc (f)) != EOF) &&
	   (c != ':') && (c != '!') && (c != '\015') && (c != '\012');
	   *s++ = c);
      if (c == ':') {		/* found a subscribed newsgroup? */
	*s = '\0';		/* yes, tie off name */
				/* report if match */
	if (pmatch_full (name,pattern,'.')) mm_lsub (stream,'.',name,NIL);
	else while (showuppers && (t = strrchr (lcl,'.'))) {
	  *t = '\0';		/* tie off the name */
	  if (pmatch_full (name,pattern,'.'))
	    mm_lsub (stream,'.',name,LATT_NOSELECT);
	}
      }
      while ((c != '\015') && (c != '\012') && (c != EOF)) c = getc (f);
    }
    fclose (f);
  }
}

/* Update subscription status of newsrc
 * Accepts: MAIL stream
 * 	    group
 *	    new subscription status character
 * Returns: T if successful, NIL otherwise
 */

long newsrc_update (MAILSTREAM *stream,char *group,char state)
{
  char tmp[MAILTMPLEN];
  char *newsrc = (char *) mail_parameters (stream,GET_NEWSRC,stream);
  long ret = NIL;
  FILE *f = fopen (newsrc,"r+b");
  if (f) {			/* update existing file */
    int c = 0;
    char *s,nl[3];
    long pos = 0;
    nl[0] = nl[1] = nl[2]='\0';	/* no newline known yet */
    do {			/* read newsrc */
      for (s = tmp; (s < (tmp + MAILTMPLEN - 1)) && ((c = getc (f)) != EOF) &&
	   (c != ':') && (c != '!') && (c != '\015') && (c != '\012');
	   *s++ = c) pos = ftell (f);
      *s = '\0';		/* tie off name */
				/* found the newsgroup? */
      if (((c == ':') || (c == '!')) && !strcmp (tmp,group)) {
	if (c == state) {	/* already at that state? */
	  if (c == ':') newsrc_error("Already subscribed to %.80s",group,WARN);
	  ret = LONGT;		/* noop the update */
	}
				/* write the character */
	else if (!fseek (f,pos,0)) ret = ((putc (state,f)) == EOF) ? NIL:LONGT;
	if (fclose (f) == EOF) ret = NIL;
	f = NIL;		/* done with file */
	break;
      }
				/* gobble remainder of this line */
      while ((c != '\015') && (c != '\012') && (c != EOF)) c = getc (f);
				/* need to know about newlines and found it? */
      if (!nl[0] && ((c == '\015') || (c == '\012')) && ((nl[0]=c) == '\015')){
				/* sniff and see if an LF */
	if ((c = getc (f)) == '\012') nl[1] = c;
	else ungetc (c,f);	/* nope, push it back */
      }
    } while (c != EOF);

    if (f) {			/* still haven't written it yet? */
      if (nl[0]) {		/* know its newline convention? */
	fseek (f,0L,2);		/* yes, seek to end of file */
	ret = newsrc_newstate (f,group,state,nl);
      }
      else {			/* can't find a newline convention */
	fclose (f);		/* punt the file */
				/* can't win if read something */
	if (pos) newsrc_error ("Unknown newline convention in %.80s",
			       newsrc,ERROR);
				/* file must have been empty, rewrite it */
	else ret = newsrc_newstate(newsrc_create(stream,NIL),group,state,"\n");
      }
    }
  }
				/* create new file */
  else ret = newsrc_newstate (newsrc_create (stream,T),group,state,"\n");
  return ret;			/* return with update status */
}

/* Update newsgroup status in stream
 * Accepts: newsgroup name
 *	    MAIL stream
 * Returns: number of recent messages
 */

long newsrc_read (char *group,MAILSTREAM *stream)
{
  int c = 0;
  char *s,tmp[MAILTMPLEN];
  unsigned long i,j;
  MESSAGECACHE *elt;
  unsigned long m = 1,recent = 0,unseen = 0;
  FILE *f = fopen ((char *) mail_parameters (stream,GET_NEWSRC,stream),"rb");
  if (f) do {			/* read newsrc */
    for (s = tmp; (s < (tmp + MAILTMPLEN - 1)) && ((c = getc (f)) != EOF) &&
	 (c != ':') && (c != '!') && (c != '\015') && (c != '\012'); *s++ = c);
    *s = '\0';			/* tie off name */
    if ((c==':') || (c=='!')) {	/* found newsgroup? */
      if (strcmp (tmp,group))	/* group name match? */
	while ((c != '\015') && (c != '\012') && (c != EOF)) c = getc (f);
      else {			/* yes, skip leading whitespace */
	while ((c = getc (f)) == ' ');
				/* only if unprocessed messages */
	if (stream->nmsgs) while (f && (m <= stream->nmsgs)) {
				/* collect a number */
	  if (isdigit (c)) {	/* better have a number */
	    for (i = 0,j = 0; isdigit (c); c = getc (f)) i = i*10 + (c-'0');
	    if (c == '-') for (c = getc (f); isdigit (c); c = getc (f))
	      j = j*10 +(c-'0');/* collect second value if range */
	    if (!unseen && (mail_elt (stream,m)->private.uid < i)) unseen = m;
				/* skip messages before first value */
	    while ((m <= stream->nmsgs) &&
		   ((elt = mail_elt (stream,m))->private.uid < i) && m++)
	      elt->valid = T;
				/* do all messages in range */
	    while ((m <= stream->nmsgs) && (elt = mail_elt (stream,m)) &&
		   (j ? ((elt->private.uid >= i) && (elt->private.uid <= j)) :
		    (elt->private.uid == i)) && m++)
	      elt->valid = elt->deleted = T;
	  }

	  switch (c) {		/* what is the delimiter? */
	  case ',':		/* more to come */
	    c = getc (f);	/* get first character of number */
	    break;
	  default:		/* bogus character */
	    sprintf (tmp,"Bogus character 0x%x in news state",(unsigned int)c);
	    MM_LOG (tmp,ERROR);
	  case EOF: case '\015': case '\012':
	    fclose (f);		/* all done - close the file */
	    f = NIL;
	    break;
	  }
	}
	else {			/* empty newsgroup */
	  while ((c != '\015') && (c != '\012') && (c != EOF)) c = getc (f);
	  fclose (f);		/* all done - close the file */
	  f = NIL;
	}
      }
    }
  } while (f && (c != EOF));	/* until file closed or EOF */
  if (f) {			/* still have file open? */
    sprintf (tmp,"No state for newsgroup %.80s found, reading as new",group);
    MM_LOG (tmp,WARN);
    fclose (f);			/* close the file */
  }
  if (m <= stream->nmsgs) {	/* any messages beyond newsrc range? */
    if (!unseen) unseen = m;	/* then this must be the first unseen one */
    do {
      elt = mail_elt (stream,m++);
      elt->valid = elt->recent = T;
      ++recent;			/* count another recent message */
    }
    while (m <= stream->nmsgs);
  }
  if (unseen) {			/* report first unseen message */
    sprintf (tmp,"[UNSEEN] %lu is first unseen message in %.80s",unseen,group);
    MM_NOTIFY (stream,tmp,(long) NIL);
  }
  return recent;
}

/* Update newsgroup entry in newsrc
 * Accepts: newsgroup name
 *	    MAIL stream
 * Returns: T if successful, NIL otherwise
 */

long newsrc_write (char *group,MAILSTREAM *stream)
{
  long ret = NIL;
  int c = 0,d = EOF;
  char *newsrc = (char *) mail_parameters (stream,GET_NEWSRC,stream);
  char *s,tmp[MAILTMPLEN],backup[MAILTMPLEN],nl[3];
  FILE *f,*bf;
  nl[0] = nl[1] = nl[2] = '\0';	/* no newline known yet */
  if ((f = fopen (newsrc,"rb")) != NULL) {/* have existing newsrc file? */
    if (!(bf = fopen ((strcat (strcpy (backup,newsrc),OLDFILESUFFIX)),"wb"))) {
      fclose (f);		/* punt input file */
      return newsrc_error("Can't create backup news state %.80s",backup,ERROR);
    }
				/* copy to backup file */
    while ((c = getc (f)) != EOF) {
				/* need to know about newlines and found it? */
      if (!nl[0] && ((c == '\015') || (c == '\012')) && ((nl[0]=c) == '\015')){
				/* sniff and see if an LF */
	if ((c = getc (f)) == '\012') nl[1] = c;
	ungetc (c,f);		/* push it back */
      }
				/* write to backup file */
      if ((d = putc (c,bf)) == EOF) {
	fclose (f);		/* punt input file */
	fclose (bf);		/* and backup too  */
	return newsrc_error ("Error writing backup news state %.80s",
			     newsrc,ERROR);
      }
    }
    fclose (f);			/* close existing file */
    if (fclose (bf) == EOF)	/* and backup file */
      return newsrc_error ("Error closing backup news state %.80s",
			   newsrc,ERROR);
    if (d == EOF) {		/* open for write if empty file */
      if ((f = newsrc_create (stream,NIL)) != NULL) bf = NIL;
      else return NIL;
    }
    else if (!nl[0])		/* make sure newlines valid */
      return newsrc_error ("Unknown newline convention in %.80s",newsrc,ERROR);
				/* now read backup file */
    else if (!(bf = fopen (backup,"rb")))
      return newsrc_error ("Error reading backup news state %.80s",
			   backup,ERROR);
				/* open newsrc for writing */
    else if (!(f = fopen (newsrc,"wb"))) {
      fclose (bf);		/* punt backup */
      return newsrc_error ("Can't rewrite news state %.80s",newsrc,ERROR);
    }
  }
  else {			/* create new newsrc file */
    if ((f = newsrc_create (stream,T)) != NULL) bf = NIL;
    else return NIL;		/* can't create newsrc */
  }
  
  while (bf) {			/* read newsrc */
    for (s = tmp; (s < (tmp + MAILTMPLEN - 1)) && ((c = getc (bf)) != EOF) &&
	 (c != ':') && (c != '!') && (c != '\015') && (c != '\012'); *s++ = c);
    *s = '\0';			/* tie off name */
				/* saw correct end of group delimiter? */
    if (tmp[0] && ((c == ':') || (c == '!'))) {
				/* yes, write newsgroup name and delimiter */
      if ((tmp[0] && (fputs (tmp,f) == EOF)) || ((putc (c,f)) == EOF))
	return newsrc_write_error (newsrc,bf,f);
      if (!strcmp (tmp,group)) {/* found correct group? */
				/* yes, write new status */
	if (!newsrc_newmessages (f,stream,nl[0] ? nl : "\n"))
	  return newsrc_write_error (newsrc,bf,f);
				/* skip past old data */
	while (((c = getc (bf)) != EOF) && (c != '\015') && (c != '\012'));
				/* skip past newline */
	while ((c == '\015') || (c == '\012')) c = getc (bf);
	while (c != EOF) {	/* copy remainder of file */
	  if (putc (c,f) == EOF) return newsrc_write_error (newsrc,bf,f);
	  c = getc (bf);	/* get next character */
	}
				/* done with file */
	if (fclose (f) == EOF) return newsrc_write_error (newsrc,bf,NIL);
	f = NIL;
      }
				/* copy remainder of line */
      else while (((c = getc (bf)) != EOF) && (c != '\015') && (c != '\012'))
	if (putc (c,f) == EOF) return newsrc_write_error (newsrc,bf,f);
      if (c == '\015') {	/* write CR if seen */
	if (putc (c,f) == EOF) return newsrc_write_error (newsrc,bf,f);
				/* sniff to see if LF */
	if (((c = getc (bf)) != EOF) && (c != '\012')) ungetc (c,bf);
      }
				/* write LF if seen */
      if ((c == '\012') && (putc (c,f) == EOF))
	return newsrc_write_error (newsrc,bf,f);
    }
    if (c == EOF) {		/* hit end of file? */
      fclose (bf);		/* yup, close the file */
      bf = NIL;
    }
  }
  if (f) {			/* still have newsrc file open? */
    ret = ((fputs (group,f) != EOF) && ((putc (':',f)) != EOF) &&
	   newsrc_newmessages (f,stream,nl[0] ? nl : "\n")) ? LONGT : NIL;
    if (fclose (f) == EOF) ret = newsrc_write_error (newsrc,NIL,NIL);
  }
  else ret = LONGT;
  return ret;
}

/* Get newsgroup state as text stream
 * Accepts: MAIL stream
 *	    newsgroup name
 * Returns: string containing newsgroup state, or NIL if not found
 */

char *newsrc_state (MAILSTREAM *stream,char *group)
{
  int c = 0;
  char *s,tmp[MAILTMPLEN];
  long pos;
  size_t size;
  FILE *f = fopen ((char *) mail_parameters (stream,GET_NEWSRC,stream),"rb");
  if (f) do {			/* read newsrc */
    for (s = tmp; (s < (tmp + MAILTMPLEN - 1)) && ((c = getc (f)) != EOF) &&
	 (c != ':') && (c != '!') && (c != '\015') && (c != '\012'); *s++ = c);
    *s = '\0';			/* tie off name */
    if ((c==':') || (c=='!')) {	/* found newsgroup? */
      if (strcmp (tmp,group))	/* group name match? */
	while ((c != '\015') && (c != '\012') && (c != EOF)) c = getc (f);
      else {			/* yes, skip leading whitespace */
	do pos = ftell (f);
	while ((c = getc (f)) == ' ');
				/* count characters in state */
	for (size = 0; (c != '\015') && (c != '\012') && (c != EOF); size++)
	  c = getc (f);
				/* now copy it */
	s = (char *) fs_get (size + 1);
	if(fseek (f,pos,SEEK_SET) < 0
	   || fread (s,(size_t) 1,size,f) != size)
	  fatal("error on fseek() or fread() in newsrc module.");
	s[size] = '\0';		/* tie off string */
	fclose (f);		/* all done - close the file */
	return s;
      }
    }
  } while (f && (c != EOF));	/* until file closed or EOF */
  sprintf (tmp,"No state for newsgroup %.80s found",group);
  MM_LOG (tmp,WARN);
  if (f) fclose (f);		/* close the file */
  return NIL;			/* not found return */
}

/* Check UID in newsgroup state
 * Accepts: newsgroup state string
 *	    uid
 *	    returned recent count
 *	    returned unseen count
 */

void newsrc_check_uid (unsigned char *state,unsigned long uid,
		       unsigned long *recent,unsigned long *unseen)
{
  unsigned long i,j;
  while (*state) {		/* until run out of state string */
				/* collect a number */
    for (i = 0; isdigit (*state); i = i*10 + (*state++ - '0'));
    if (*state != '-') j = i;	/* coerce single mesage into range */
    else {			/* have a range */
      for (j = 0; isdigit (*++state); j = j*10 + (*state - '0'));
      if (!j) j = i;		/* guard against -0 */
      if (j < i) return;	/* bogon if end less than start */
    }
    if (*state == ',') state++;	/* skip past comma */
    else if (*state) return;	/* otherwise it's a bogon */
    if (uid <= j) {		/* covered by upper bound? */
      if (uid < i) ++*unseen;	/* unseen if not covered by lower bound */
      return;			/* don't need to look further */
    }
  }
  ++*unseen;			/* not found in any range, message is unseen */
  ++*recent;			/* and recent */
}