/*
 * ftpparse.c, ftpparse.h: library for parsing FTP LIST responses
 * 20001223
 *
 * D. J. Bernstein, djb@cr.yp.to
 * http://cr.yp.to/ftpparse.html
 *
 * Commercial use is fine, if you let me know what programs you're using
 * this in.
 *
 * Currently covered formats:
 *   EPLF
 *   UNIX ls, with or without gid
 *   Microsoft FTP Service
 *   Windows NT FTP Server
 *   VMS
 *   WFTPD
 *   NetPresenz (Mac)
 *   NetWare
 *   MSDOS
 *
 * Definitely not covered: 
 * Long VMS filenames, with information split across two lines.
 * NCSA Telnet FTP server. Has LIST = NLST (and bad NLST for directories).
 *
 * ftpparse(&fp, &file_size, &file_mtime, buf, len) tries to parse one
 * line of LIST output.
 *
 * The line is an array of len characters stored in buf.
 * It should not include the terminating CR LF; so buf[len] is typically CR.
 * 
 * If ftpparse() can't find a filename, it returns 0.
 * 
 * If ftpparse() can find a filename, it fills in fp and returns 1.
 * fp is a struct ftpparse, defined below.
 * The name is an array of fp.namelen characters stored in fp.name;
 * fp.name points somewhere within buf.
 */

#include "afddefs.h"
#include <stdio.h>
#include <stdlib.h>                /* strtoll()                          */
#include <time.h>                  /* gmtime()                           */ 
#include "ftpparse.h"


/* Local global variables. */
static int                        flagneedbase;
static time_t                     base; /* time() value on this OS at the beginning of 1970 TAI */
static long                       now; /* current time */
static int                        flagneedcurrentyear;
static long                       currentyear; /* approximation to current year */


/* Local function prototypes. */
static int                        getmonth(char *, int);
static long                       getlong(char *buf, int len),
                                  guesstai(long month, long),
                                  totai(long, long, long);
static void                       initbase(void),
                                  initnow(void);

/*############################## ftpparse() #############################*/
int
ftpparse(struct ftpparse *fp,
         off_t           *file_size,
         int             *exact_size,
         time_t          *file_mtime,
         int             *exact_date,
         char            *buf,
         int             len)
{
   int   i,
         j,
         state;
   long  year,
         month,
         mday,
         hour,
         minute;
   off_t size = 0;
   char  tmp_char;

   flagneedbase = 1;
   flagneedcurrentyear = 1;
   fp->name = 0;
   fp->namelen = 0;
   fp->flagtrycwd = 0;
   fp->flagtryretr = 0;
   fp->sizetype = FTPPARSE_SIZE_UNKNOWN;
   *file_size = 0;
   fp->mtimetype = FTPPARSE_MTIME_UNKNOWN;
   *file_mtime = 0;
   fp->idtype = FTPPARSE_ID_UNKNOWN;
   fp->id = 0;
   fp->idlen = 0;
   *exact_size = NO;
   *exact_date = NO;

   if (len < 2) /* an empty name in EPLF, with no info, could be 2 chars */
   {
      return(0);
   }

   switch(*buf)
   {
      /* see http://pobox.com/~djb/proto/eplf.txt */
      /* "+i8388621.29609,m824255902,/,\tdev" */
      /* "+i8388621.44468,m839956783,r,s10376,\tRFCEPLF" */
      case '+':
         i = 1;
         for (j = 1; j < len; ++j)
         {
            if (buf[j] == 9)
            {
               fp->name = buf + j + 1;
               fp->namelen = len - j - 1;
               return(1);
            }
            if (buf[j] == ',')
            {
               switch(buf[i])
               {
                  case '/':
                     fp->flagtrycwd = 1;
                     break;
                  case 'r':
                     fp->flagtryretr = 1;
                     break;
                  case 's':
                     fp->sizetype = FTPPARSE_SIZE_BINARY;
                     tmp_char = *(buf + i + 1 + (j - i - 1));
                     *(buf + i + 1 + (j - i - 1)) = '\0';
                     *file_size = (off_t)str2offt((buf + i + 1), NULL, 10);
                     *(buf + i + 1 + (j - i - 1)) = tmp_char;
                     *exact_size = YES;
                     break;
                  case 'm':
                     fp->mtimetype = FTPPARSE_MTIME_LOCAL;
                     initbase();
                     *file_mtime = base + getlong(buf + i + 1, j - i - 1);
                     *exact_date = YES;
                     break;
                  case 'i':
                     fp->idtype = FTPPARSE_ID_FULL;
                     fp->id = buf + i + 1;
                     fp->idlen = j - i - 1;
               }
               i = j + 1;
            }
         }
         return(0);
    
      /* UNIX-style listing, without inum and without blocks */
      /* "-rw-r--r--   1 root     other        531 Jan 29 03:26 README" */
      /* "dr-xr-xr-x   2 root     other        512 Apr  8  1994 etc" */
      /* "dr-xr-xr-x   2 root     512 Apr  8  1994 etc" */
      /* "lrwxrwxrwx   1 root     other          7 Jan 25 00:17 bin -> usr/bin" */
      /* Also produced by Microsoft's FTP servers for Windows: */
      /* "----------   1 owner    group         1803128 Jul 10 10:18 ls-lR.Z" */
      /* "d---------   1 owner    group               0 May  9 19:45 Softlib" */
      /* Also WFTPD for MSDOS: */
      /* "-rwxrwxrwx   1 noone    nogroup      322 Aug 19  1996 message.ftp" */
      /* Also NetWare: */
      /* "d [R----F--] supervisor            512       Jan 16 18:53    login" */
      /* "- [R----F--] rhesus             214059       Oct 20 15:27    cx.exe" */
      /* Also NetPresenz for the Mac: */
      /* "-------r--         326  1391972  1392298 Nov 22  1995 MegaPhone.sit" */
      /* "drwxrwxr-x               folder        2 May 10  1996 network" */
      case 'b':
      case 'c':
      case 'd':
      case 'l':
      case 'p':
      case 's':
      case '-':
 
        if (*buf == 'd')
        {
           fp->flagtrycwd = 1;
        }
        if (*buf == '-')
        {
           fp->flagtryretr = 1;
        }
        if (*buf == 'l')
        {
           fp->flagtrycwd = fp->flagtryretr = 1;
        }

        state = 1;
        i = 0;
        for (j = 1; j < len; ++j)
        {
           if ((buf[j] == ' ') && (buf[j - 1] != ' '))
           {
              switch(state)
              {
                case 1: /* skipping perm */
                   state = 2;
                   break;
                case 2: /* skipping nlink */
                   state = 3;
                   if ((j - i == 6) && (buf[i] == 'f')) /* for NetPresenz */
                   {
                      state = 4;
                   }
                   break;
                case 3: /* skipping uid */
                   state = 4;
                   break;
                case 4: /* getting tentative size */
                   tmp_char = *(buf + i + (j - i));
                   *(buf + i + (j - i)) = '\0';
                   size = (off_t)str2offt((buf + i), NULL, 10);
                   *(buf + i + (j - i)) = tmp_char;
                   state = 5;
                   break;
                case 5: /* searching for month, otherwise getting tentative size */
                   month = getmonth(buf + i, j - i);
                   if (month >= 0)
                   {
                      state = 6;
                   }
                   else
                   {
                      tmp_char = *(buf + i + (j - i));
                      *(buf + i + (j - i)) = '\0';
                      size = (off_t)str2offt((buf + i), NULL, 10);
                      *(buf + i + (j - i)) = tmp_char;
                   }
                   break;
                case 6: /* have size and month */
                   mday = getlong(buf + i, j - i);
                   state = 7;
                   break;
                case 7: /* have size, month, mday */
                   if ((j - i == 4) && (buf[i + 1] == ':'))
                   {
                      hour = getlong(buf + i, 1);
                      minute = getlong(buf + i + 2, 2);
                      fp->mtimetype = FTPPARSE_MTIME_REMOTEMINUTE;
                      initbase();
                      *file_mtime = base + guesstai(month, mday) + hour * 3600 + minute * 60;
                   }
                   else if ((j - i == 5) && (buf[i + 2] == ':'))
                        {
                           hour = getlong(buf + i, 2);
                           minute = getlong(buf + i + 3, 2);
                           fp->mtimetype = FTPPARSE_MTIME_REMOTEMINUTE;
                           initbase();
                           *file_mtime = base + guesstai(month, mday) + hour * 3600 + minute * 60;
                        }
                   else if (j - i >= 4)
                        {
                           year = getlong(buf + i, j - i);
                           fp->mtimetype = FTPPARSE_MTIME_REMOTEDAY;
                           initbase();
                           *file_mtime = base + totai(year, month, mday);
                        }
                        else
                        {
                           return(0);
                        }
                   fp->name = buf + j + 1;
                   fp->namelen = len - j - 1;
                   state = 8;
                   break;
                case 8: /* twiddling thumbs */
                   break;
              }
              i = j + 1;
              while ((i < len) && (buf[i] == ' '))
              {
                 ++i;
              }
           }
        }

        if (state != 8)
        {
           return(0);
        }

        *file_size = size;
        fp->sizetype = FTPPARSE_SIZE_BINARY;
        *exact_size = YES;

        if (*buf == 'l')
        {
           for (i = 0; i + 3 < fp->namelen; ++i)
           {
              if (fp->name[i] == ' ')
              {
                 if (fp->name[i + 1] == '-')
                 {
                    if (fp->name[i + 2] == '>')
                    {
                       if (fp->name[i + 3] == ' ')
                       {
                          fp->namelen = i;
                          break;
                       }
                    }
                 }
              }
           }
        }
 
        /* eliminate extra NetWare spaces */
        if ((buf[1] == ' ') || (buf[1] == '['))
        {
           if (fp->namelen > 3)
           {
              if (fp->name[0] == ' ')
              {
                 if (fp->name[1] == ' ')
                 {
                    if (fp->name[2] == ' ')
                    {
                       fp->name += 3;
                       fp->namelen -= 3;
                    }
                 }
              }
           }
        }
 
        return(1);
   }

   /* MultiNet (some spaces removed from examples) */
   /* "00README.TXT;1      2 30-DEC-1996 17:44 [SYSTEM] (RWED,RWED,RE,RE)" */
   /* "CORE.DIR;1          1  8-SEP-1996 16:09 [SYSTEM] (RWE,RWE,RE,RE)" */
   /* and non-MutliNet VMS: */
   /* "CII-MANUAL.TEX;1  213/216  29-JAN-1996 03:33:12  [ANONYMOU,ANONYMOUS]   (RWED,RWED,,)" */
   for (i = 0 ;i < len; ++i)
   {
      if (buf[i] == ';')
      {
         break;
      }
   }
   if (i < len)
   {
      fp->name = buf;
      fp->namelen = i;
      if (i > 4)
      {
         if (buf[i - 4] == '.')
         {
            if (buf[i - 3] == 'D')
            {
               if (buf[i - 2] == 'I')
               {
                 if (buf[i - 1] == 'R')
                 {
                    fp->namelen -= 4;
                    fp->flagtrycwd = 1;
                 }
               }
            }
         }
      }
      if (!fp->flagtrycwd)
      {
         fp->flagtryretr = 1;
      }
      while (buf[i] != ' ')
      {
         if (++i == len)
         {
            return(0);
         }
      }
      while (buf[i] == ' ')
      {
         if (++i == len)
         {
            return(0);
         }
      }
      while (buf[i] != ' ')
      {
         if (++i == len)
         {
            return(0);
         }
      }
      while (buf[i] == ' ')
      {
         if (++i == len)
         {
            return(0);
         }
      }
      j = i;
      while (buf[j] != '-')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      mday = getlong(buf + i, j - i);
      while (buf[j] == '-')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      i = j;
      while (buf[j] != '-')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      month = getmonth(buf + i, j - i);
      if (month < 0)
      {
         return(0);
      }
      while (buf[j] == '-')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      i = j;
      while (buf[j] != ' ')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      year = getlong(buf + i, j - i);
      while (buf[j] == ' ')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      i = j;
      while (buf[j] != ':')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      hour = getlong(buf + i, j - i);
      while (buf[j] == ':')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      i = j;
      while ((buf[j] != ':') && (buf[j] != ' '))
      {
         if (++j == len)
         {
            return(0);
         }
      }
      minute = getlong(buf + i, j - i);

      fp->mtimetype = FTPPARSE_MTIME_REMOTEMINUTE;
      initbase();
      *file_mtime = base + totai(year, month, mday) + hour * 3600 + minute * 60;

      return(1);
   }

   /* MSDOS format */
   /* 04-27-00  09:09PM       <DIR>          licensed */
   /* 07-18-00  10:16AM       <DIR>          pub */
   /* 04-14-00  03:47PM                  589 readme.htm */
   if ((*buf >= '0') && (*buf <= '9'))
   {
      i = 0;
      j = 0;
      while (buf[j] != '-')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      month = getlong(buf + i, j - i) - 1;
      while (buf[j] == '-')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      i = j;
      while (buf[j] != '-')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      mday = getlong(buf + i, j - i);
      while (buf[j] == '-')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      i = j;
      while (buf[j] != ' ')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      year = getlong(buf + i, j - i);
      if (year < 50)
      {
         year += 2000;
      }
      if (year < 1000)
      {
         year += 1900;
      }
      while (buf[j] == ' ')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      i = j;
      while (buf[j] != ':')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      hour = getlong(buf + i, j - i);
      while (buf[j] == ':')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      i = j;
      while ((buf[j] != 'A') && (buf[j] != 'P'))
      {
         if (++j == len)
         {
            return(0);
         }
      }
      minute = getlong(buf + i, j - i);
      if (hour == 12)
      {
         hour = 0;
      }
      if (buf[j] == 'A')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      if (buf[j] == 'P')
      {
         hour += 12;
         if (++j == len)
         {
            return(0);
         }
      }
      if (buf[j] == 'M')
      {
         if (++j == len)
         {
            return(0);
         }
      }

      while (buf[j] == ' ')
      {
         if (++j == len)
         {
            return(0);
         }
      }
      if (buf[j] == '<')
      {
         fp->flagtrycwd = 1;
         while (buf[j] != ' ')
         {
            if (++j == len)
            {
               return(0);
            }
         }
      }
      else
      {
         i = j;
         while (buf[j] != ' ')
         {
            if (++j == len)
            {
               return(0);
            }
         }
         tmp_char = *(buf + i + (j - i));
         *(buf + i + (j - i)) = '\0';
         *file_size = (off_t)str2offt((buf + i), NULL, 10);
         *(buf + i + (j - i)) = tmp_char;
         fp->sizetype = FTPPARSE_SIZE_BINARY;
         fp->flagtryretr = 1;
         *exact_size = YES;
      }
      while (buf[j] == ' ')
      {
         if (++j == len)
         {
            return(0);
         }
      }

      fp->name = buf + j;
      fp->namelen = len - j;

      fp->mtimetype = FTPPARSE_MTIME_REMOTEMINUTE;
      initbase();
      *file_mtime = base + totai(year, month, mday) + hour * 3600 + minute * 60;

      return(1);
   }

   /* Some useless lines, safely ignored: */
   /* "Total of 11 Files, 10966 Blocks." (VMS) */
   /* "total 14786" (UNIX) */
   /* "DISK$ANONFTP:[ANONYMOUS]" (VMS) */
   /* "Directory DISK$PCSA:[ANONYM]" (VMS) */

   return(0);
}


/*------------------------------- totai() -------------------------------*/
static long
totai(long year, long month, long mday)
{
   long result;

   if (month >= 2)
   {
      month -= 2;
   }
   else
   {
      month += 10;
      --year;
   }
   result = (mday - 1) * 10 + 5 + 306 * month;
   result /= 10;
   if (result == 365)
   {
      year -= 3;
      result = 1460;
   }
   else
   {
      result += 365 * (year % 4);
   }
   year /= 4;
   result += 1461 * (year % 25);
   year /= 25;
   if (result == 36524)
   {
      year -= 3;
      result = 146096;
   }
   else
   {
      result += 36524 * (year % 4);
   }
   year /= 4;
   result += 146097 * (year - 5);
   result += 11017;

   return(result * 86400);
}


/*----------------------------- initbase() ------------------------------*/
static void
initbase(void)
{
   struct tm *t;

   if (!flagneedbase)
   {
      return;
   }

   base = 0;
   t = gmtime(&base);
   base = -(totai(t->tm_year + 1900, t->tm_mon, t->tm_mday) + t->tm_hour * 3600 + t->tm_min * 60 + t->tm_sec);

   /* assumes the right time_t, counting seconds. */
   /* base may be slightly off if time_t counts non-leap seconds. */
   flagneedbase = 0;

   return;
}

/*------------------------------ initnow() ------------------------------*/
static void
initnow(void)
{
   long day,
        year;

   initbase();
   now = time((time_t *) 0) - base;

   if (flagneedcurrentyear)
   {
      day = now / 86400;
      if ((now % 86400) < 0)
      {
         --day;
      }
      day -= 11017;
      year = 5 + day / 146097;
      day = day % 146097;
      if (day < 0)
      {
         day += 146097;
         --year;
      }
      year *= 4;
      if (day == 146096)
      {
         year += 3;
         day = 36524;
      }
      else
      {
         year += day / 36524;
         day %= 36524;
      }
      year *= 25;
      year += day / 1461;
      day %= 1461;
      year *= 4;
      if (day == 1460)
      {
         year += 3;
         day = 365;
      }
      else
      {
         year += day / 365;
         day %= 365;
      }
      day *= 10;
      if ((day + 5) / 306 >= 10)
      {
         ++year;
      }
      currentyear = year;
      flagneedcurrentyear = 0;
   }

   return;
}


/*------------------------------ guesstai() -----------------------------*/
/* UNIX ls does not show the year for dates in the last six months.      */
/* So we have to guess the year.                                         */
/* Apparently NetWare uses ``twelve months'' instead of ``six months'';  */
/* ugh.                                                                  */
/* Some versions of ls also fail to show the year for future dates.      */
static long
guesstai(long month, long mday)
{
   long year,
        t;

   initnow();
   for (year = currentyear - 1; year < currentyear + 100; ++year)
   {
      t = totai(year, month, mday);
      if (now - t < 350 * 86400)
      {
         return(t);
      }
   }

   return(0);
}


/*------------------------------ getmonth() -----------------------------*/
static int
getmonth(char *buf, int len)
{
   int ret;

   if (len == 3)
   {
      if (((buf[0] == 'J') || (buf[0] == 'j')) &&
          ((buf[1] == 'a') || (buf[1] == 'A')) &&
          ((buf[2] == 'n') || (buf[2] == 'N')))
      {
         ret = 0;
      }
      else if (((buf[0] == 'F') || (buf[0] == 'f')) &&
               ((buf[1] == 'e') || (buf[1] == 'E')) &&
               ((buf[2] == 'b') || (buf[2] == 'B')))
           {
              ret = 1;
           }
      else if (((buf[0] == 'M') || (buf[0] == 'm')) &&
               ((buf[1] == 'a') || (buf[1] == 'A')) &&
               ((buf[2] == 'r') || (buf[2] == 'R')))
           {
              ret = 2;
           }
      else if (((buf[0] == 'A') || (buf[0] == 'a')) &&
               ((buf[1] == 'p') || (buf[1] == 'P')) &&
               ((buf[2] == 'r') || (buf[2] == 'R')))
           {
              ret = 3;
           }
      else if (((buf[0] == 'M') || (buf[0] == 'm')) &&
               ((buf[1] == 'a') || (buf[1] == 'A')) &&
               ((buf[2] == 'y') || (buf[2] == 'Y')))
           {
              ret = 4;
           }
      else if (((buf[0] == 'J') || (buf[0] == 'j')) &&
               ((buf[1] == 'u') || (buf[1] == 'U')) &&
               ((buf[2] == 'n') || (buf[2] == 'N')))
           {
              ret = 5;
           }
      else if (((buf[0] == 'J') || (buf[0] == 'j')) &&
               ((buf[1] == 'u') || (buf[1] == 'U')) &&
               ((buf[2] == 'l') || (buf[2] == 'L')))
           {
              ret = 6;
           }
      else if (((buf[0] == 'A') || (buf[0] == 'a')) &&
               ((buf[1] == 'u') || (buf[1] == 'U')) &&
               ((buf[2] == 'g') || (buf[2] == 'G')))
           {
              ret = 7;
           }
      else if (((buf[0] == 'S') || (buf[0] == 's')) &&
               ((buf[1] == 'e') || (buf[1] == 'E')) &&
               ((buf[2] == 'p') || (buf[2] == 'P')))
           {
              ret = 8;
           }
      else if (((buf[0] == 'O') || (buf[0] == 'o')) &&
               ((buf[1] == 'c') || (buf[1] == 'C')) &&
               ((buf[2] == 't') || (buf[2] == 'T')))
           {
              ret = 9;
           }
      else if (((buf[0] == 'N') || (buf[0] == 'n')) &&
               ((buf[1] == 'o') || (buf[1] == 'O')) &&
               ((buf[2] == 'v') || (buf[2] == 'V')))
           {
              ret = 10;
           }
      else if (((buf[0] == 'D') || (buf[0] == 'd')) &&
               ((buf[1] == 'e') || (buf[1] == 'E')) &&
               ((buf[2] == 'c') || (buf[2] == 'C')))
           {
              ret = 11;
           }
           else
           {
              ret = -1;
           }
   }
   else
   {
      ret = -1;
   }

   return(ret);
}


/*------------------------------ getlong() ------------------------------*/
static long
getlong(char *buf, int len)
{
   long u = 0;

   while (len-- > 0)
   {
      u = u * 10 + (*buf++ - '0');
   }

   return(u);
}