/* listfile.c -- display a long listing of a file
   Copyright (C) 1991-2023 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
/* config.h must be included first. */
#include <config.h>

/* system headers. */
#include <alloca.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h> /* for readlink() */

/* gnulib headers. */
#include "areadlink.h"
#include "error.h"
#include "filemode.h"
#include "human.h"
#include "mbswidth.h"
#include "idcache.h"
#include "pathmax.h"
#include "stat-size.h"

/* find headers. */
#include "system.h"
#include "die.h"
#include "listfile.h"

/* Since major is a function on SVR4, we can't use `ifndef major'.  */
#ifdef MAJOR_IN_MKDEV
# include <sys/mkdev.h>
#else
# ifdef MAJOR_IN_SYSMACROS
#  include <sys/sysmacros.h>
# else
#  ifndef major                    /* Might be defined in sys/types.h.  */
#   define major(dev)  (((dev) >> 8) & 0xff)
#   define minor(dev)  ((dev) & 0xff)
#  endif
# endif
#endif


static bool print_name (register const char *p, FILE *stream, int literal_control_chars);

/* We have some minimum field sizes, though we try to widen these fields on systems
 * where we discover examples where the field width we started with is not enough. */
static int inode_number_width = 9;
static int block_size_width = 6;
static int nlink_width = 3;
static int owner_width = 8;
static int group_width = 8;
/* We don't print st_author even if the system has it. */
static int major_device_number_width = 3;
static int minor_device_number_width = 3;
static int file_size_width = 8;

static bool print_num(FILE *stream, unsigned long num, int *width)
{
  const int chars_out = fprintf (stream, "%*lu", *width, num);
  if (chars_out >= 0)
    {
      if (*width < chars_out)
        *width = chars_out;
      return true;
    }
  return false;
}


/* NAME is the name to print.
   RELNAME is the path to access it from the current directory.
   STATP is the results of stat or lstat on it.
   Use CURRENT_TIME to decide whether to print yyyy or hh:mm.
   Use OUTPUT_BLOCK_SIZE to determine how to print file block counts
   and sizes.
   STREAM is the stdio stream to print on.  */

void
list_file (const char *name,
           int dir_fd,
           const char *relname,
           const struct stat *statp,
           time_t current_time,
           int output_block_size,
           int literal_control_chars,
           FILE *stream)
{
  char modebuf[12];
  struct tm const *when_local;
  char const *user_name;
  char const *group_name;
  char hbuf[LONGEST_HUMAN_READABLE + 1];
  bool output_good = true;
  int chars_out;
  int failed_at = 000;

#if HAVE_ST_DM_MODE
  /* Cray DMF: look at the file's migrated, not real, status */
  strmode (statp->st_dm_mode, modebuf);
#else
  strmode (statp->st_mode, modebuf);
#endif

  chars_out = fprintf (stream, "%*s", inode_number_width,
                       human_readable ((uintmax_t) statp->st_ino, hbuf,
                                       human_ceiling,
                                       1u, 1u));
  if (chars_out < 0)
    {
      output_good = false;
      failed_at = 100;
    }
  else if (chars_out > inode_number_width)
    {
      inode_number_width = chars_out;
    }
  if (output_good)
    {
      if (EOF == putc(' ', stream))
        {
          output_good = false;
          failed_at = 150;
        }
      chars_out = fprintf (stream, "%*s",
                           block_size_width,
                           human_readable ((uintmax_t) ST_NBLOCKS (*statp), hbuf,
                                           human_ceiling,
                                           ST_NBLOCKSIZE, output_block_size));
      if (chars_out < 0)
        {
          output_good = false;
          failed_at = 200;
        }
      else
        {
          if (chars_out > block_size_width)
            block_size_width = chars_out;
        }
    }

  if (output_good)
    {
      if (EOF == putc(' ', stream))
        {
          output_good = false;
          failed_at = 250;
        }
    }
  if (output_good)
    {
      /* modebuf includes the space between the mode and the number of links,
         as the POSIX "optional alternate access method flag".  */
      if (fputs (modebuf, stream) < 0)
        {
          output_good = false;
          failed_at = 275;
        }
    }
  if (output_good)
    {
      /* This format used to end in a space, but the output of "ls"
         has only one space between the link count and the owner name,
         so we removed the trailing space.  Happily this also makes it
         easier to update nlink_width. */
      chars_out =  fprintf (stream, "%*lu",
			    nlink_width, (unsigned long) statp->st_nlink);
      if (chars_out < 0)
        {
          output_good = false;
          failed_at = 300;
        }
      else
	{
	  if (chars_out > nlink_width)
	    nlink_width = chars_out;
	}
    }

  if (output_good)
    {
      if (EOF == putc(' ', stream))
        {
          output_good = false;
          failed_at = 250;
        }
      user_name = getuser (statp->st_uid);
      if (user_name)
        {
          int len = mbswidth (user_name, 0);
          if (len > owner_width)
            owner_width = len;
          output_good = (fprintf (stream, "%-*s ", owner_width, user_name) >= 0);
          if (!output_good)
            failed_at = 400;
        }
      else
        {
          chars_out = fprintf (stream, "%-8lu ", (unsigned long) statp->st_uid);
          if (chars_out > owner_width)
            owner_width = chars_out;
          output_good = (chars_out > 0);
          if (!output_good)
            failed_at = 450;
        }
    }

  if (output_good)
    {
      group_name = getgroup (statp->st_gid);
      if (group_name)
        {
          int len = mbswidth (group_name, 0);
          if (len > group_width)
            group_width = len;
          output_good = (fprintf (stream, "%-*s ", group_width, group_name) >= 0);
          if (!output_good)
            failed_at = 500;
        }
      else
        {
          chars_out = fprintf (stream, "%-*lu",
                               group_width, (unsigned long) statp->st_gid);
          if (chars_out > group_width)
            group_width = chars_out;
          output_good = (chars_out >= 0);
          if (output_good)
            {
              if (EOF == putc(' ', stream))
                {
                  output_good = false;
                  failed_at = 525;
                }
            }
          else
            {
              if (!output_good)
                failed_at = 550;
            }
        }
    }

  if (output_good)
    {
      if (S_ISCHR (statp->st_mode) || S_ISBLK (statp->st_mode))
        {
#ifdef HAVE_STRUCT_STAT_ST_RDEV
          if (!print_num (stream,
                          (unsigned long) major (statp->st_rdev),
                          &major_device_number_width))
            {
              output_good = false;
              failed_at = 600;
            }
          if (output_good)
            {
              if (fprintf (stream, ", ") < 0)
                {
                  output_good = false;
                  failed_at = 625;
                }
            }
          if (output_good)
            {
              if (!print_num (stream,
                              (unsigned long) minor (statp->st_rdev),
                              &minor_device_number_width))
                {
                  output_good = false;
                  failed_at = 650;
                }
            }
#else
          if (fprintf (stream, "%*s  %*s",
                       major_device_number_width,
                       minor_device_number_width) < 0)
            {
              output_good = false;
              failed_at = 700;
            }
#endif
        }
      else
        {
          const int blocksize = output_block_size < 0 ? output_block_size : 1;
          chars_out = fprintf (stream, "%*s",
                               file_size_width,
                               human_readable ((uintmax_t) statp->st_size, hbuf,
                                               human_ceiling,
                                               1, blocksize));
          if (chars_out < 0)
            {
              output_good = false;
              failed_at = 800;
            }
          else
            {
              if (chars_out > file_size_width)
                {
                  file_size_width = chars_out;
                }
            }
        }
    }

  if (output_good)
    {
      if (EOF == putc(' ', stream))
        {
          output_good = false;
          failed_at = 850;
        }
    }

  if (output_good)
    {
      if ((when_local = localtime (&statp->st_mtime)))
        {
          char init_bigbuf[256];
          char *buf = init_bigbuf;
          size_t bufsize = sizeof init_bigbuf;

          /* Use strftime rather than ctime, because the former can produce
             locale-dependent names for the month (%b).

             Output the year if the file is fairly old or in the future.
             POSIX says the cutoff is 6 months old;
             approximate this by 6*30 days.
             Allow a 1 hour slop factor for what is considered "the future",
             to allow for NFS server/client clock disagreement.  */
          char const *fmt =
            ((current_time - 6 * 30 * 24 * 60 * 60 <= statp->st_mtime
              && statp->st_mtime <= current_time + 60 * 60)
             ? "%b %e %H:%M"
             : "%b %e  %Y");

          while (!strftime (buf, bufsize, fmt, when_local))
            buf = alloca (bufsize *= 2);

          if (fprintf (stream, "%s ", buf) < 0)
            {
              output_good = false;
              failed_at = 900;
            }
        }
      else
        {
          /* The time cannot be represented as a local time;
             print it as a huge integer number of seconds.  */
          int width = 12;

          if (statp->st_mtime < 0)
            {
              char const *num = human_readable (- (uintmax_t) statp->st_mtime,
                                                hbuf, human_ceiling, 1, 1);
              int sign_width = width - strlen (num);
              if (fprintf (stream, "%*s%s ",
                           sign_width < 0 ? 0 : sign_width, "-", num) < 0)
                {
                  output_good = false;
                  failed_at = 1000;
                }
            }
          else
            {
              if (fprintf (stream, "%*s ", width,
                           human_readable ((uintmax_t) statp->st_mtime, hbuf,
                                           human_ceiling,
                                           1, 1)) < 0)
                {
                  output_good = false;
                  failed_at = 1100;
                }
            }
        }
    }

  if (output_good)
    {
      output_good = print_name (name, stream, literal_control_chars);
      if (!output_good)
        {
          failed_at = 1200;
        }
    }

  if (output_good)
    {
      if (S_ISLNK (statp->st_mode))
        {
          char *linkname = areadlinkat (dir_fd, relname);
          if (linkname)
            {
              if (fputs (" -> ", stream) < 0)
                {
                  output_good = false;
                  failed_at = 1300;
                }
              if (output_good)
                {
                  output_good = print_name (linkname, stream, literal_control_chars);
                  if (!output_good)
                    {
                      failed_at = 1350;
                    }
                }
            }
          else
            {
              /* POSIX requires in the case of find that if we issue a
               * diagnostic we should have a nonzero status.  However,
               * this function doesn't have a way of telling the caller to
               * do that.  However, since this function is only used when
               * processing "-ls", we're already using an extension.
               */
              error (0, errno, "%s", name);
            }
          free (linkname);
        }
      if (output_good)
        {
          if (EOF == putc ('\n', stream))
            {
              output_good = false;
              if (!output_good)
                {
                  failed_at = 1400;
                }
            }
        }
    }
  if (!output_good)
    {
      die (EXIT_FAILURE, errno, _("Failed to write output (at stage %d)"), failed_at);
    }
}


static bool
print_name_without_quoting (const char *p, FILE *stream)
{
  return (fprintf (stream, "%s", p) >= 0);
}


static bool
print_name_with_quoting (register const char *p, FILE *stream)
{
  register unsigned char c;

  while ((c = *p++) != '\0')
    {
      int fprintf_result = -1;
      switch (c)
        {
        case '\\':
          fprintf_result = fprintf (stream, "\\\\");
          break;

        case '\n':
          fprintf_result = fprintf (stream, "\\n");
          break;

        case '\b':
          fprintf_result = fprintf (stream, "\\b");
          break;

        case '\r':
          fprintf_result = fprintf (stream, "\\r");
          break;

        case '\t':
          fprintf_result = fprintf (stream, "\\t");
          break;

        case '\f':
          fprintf_result = fprintf (stream, "\\f");
          break;

        case ' ':
          fprintf_result = fprintf (stream, "\\ ");
          break;

        case '"':
          fprintf_result = fprintf (stream, "\\\"");
          break;

        default:
          if (c > 040 && c < 0177)
            {
              if (EOF == putc (c, stream))
                return false;
              fprintf_result = 1; /* otherwise it's used uninitialized. */
            }
          else
            {
              fprintf_result = fprintf (stream, "\\%03o", (unsigned int) c);
            }
        }
      if (fprintf_result < 0)
        return false;
    }
  return true;
}

static bool print_name (register const char *p, FILE *stream, int literal_control_chars)
{
  if (literal_control_chars)
    return print_name_without_quoting (p, stream);
  else
    return print_name_with_quoting (p, stream);
}