/*
 * Copyright notice from original mutt:
 * Copyright (C) 1996-2000 Michael R. Elkins <me@mutt.org>
 *
 * This file is part of mutt-ng, see http://www.muttng.org/.
 * It's licensed under the GNU General Public License,
 * please see the file GPL in the top level source directory.
 */

/* 
 * rfc1524 defines a format for the Multimedia Mail Configuration, which
 * is the standard mailcap file format under Unix which specifies what 
 * external programs should be used to view/compose/edit multimedia files
 * based on content type.
 *
 * This file contains various functions for implementing a fair subset of 
 * rfc1524.
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include "mutt.h"
#include "ascii.h"
#include "rfc1524.h"
#include "attach.h"

#include "lib/mem.h"
#include "lib/intl.h"
#include "lib/str.h"
#include "lib/debug.h"

#include <string.h>
#include <stdlib.h>
#include <ctype.h>

#include <sys/stat.h>
#include <sys/wait.h>
#include <errno.h>
#include <unistd.h>

/* The command semantics include the following:
 * %s is the filename that contains the mail body data
 * %t is the content type, like text/plain
 * %{parameter} is replaced by the parameter value from the content-type field
 * \% is %
 * Unsupported rfc1524 parameters: these would probably require some doing
 * by mutt, and can probably just be done by piping the message to metamail
 * %n is the integer number of sub-parts in the multipart
 * %F is "content-type filename" repeated for each sub-part
 *
 * In addition, this function returns a 0 if the command works on a file,
 * and 1 if the command works on a pipe.
 */
int rfc1524_expand_command (BODY * a, char *filename, char *_type,
                            char *command, int clen)
{
  int x = 0, y = 0;
  int needspipe = TRUE;
  char buf[LONG_STRING];
  char type[LONG_STRING];

  strfcpy (type, _type, sizeof (type));

  if (option (OPTMAILCAPSANITIZE))
    mutt_sanitize_filename (type, 0);

  while (command[x] && x < clen && y < sizeof (buf)) {
    if (command[x] == '\\') {
      x++;
      buf[y++] = command[x++];
    }
    else if (command[x] == '%') {
      x++;
      if (command[x] == '{') {
        char param[STRING];
        char pvalue[STRING];
        char *_pvalue;
        int z = 0;

        x++;
        while (command[x] && command[x] != '}' && z < sizeof (param))
          param[z++] = command[x++];
        param[z] = '\0';

        _pvalue = mutt_get_parameter (param, a->parameter);
        strfcpy (pvalue, NONULL (_pvalue), sizeof (pvalue));
        if (option (OPTMAILCAPSANITIZE))
          mutt_sanitize_filename (pvalue, 0);

        y += mutt_quote_filename (buf + y, sizeof (buf) - y, pvalue);
      }
      else if (command[x] == 's' && filename != NULL) {
        y += mutt_quote_filename (buf + y, sizeof (buf) - y, filename);
        needspipe = FALSE;
      }
      else if (command[x] == 't') {
        y += mutt_quote_filename (buf + y, sizeof (buf) - y, type);
      }
      x++;
    }
    else
      buf[y++] = command[x++];
  }
  buf[y] = '\0';
  strfcpy (command, buf, clen);

  return needspipe;
}

/* NUL terminates a rfc 1524 field,
 * returns start of next field or NULL */
static char *get_field (char *s)
{
  char *ch;

  if (!s)
    return NULL;

  while ((ch = strpbrk (s, ";\\")) != NULL) {
    if (*ch == '\\') {
      s = ch + 1;
      if (*s)
        s++;
    }
    else {
      *ch++ = 0;
      SKIPWS (ch);
      break;
    }
  }
  str_skip_trailws (s);
  return ch;
}

static int get_field_text (char *field, char **entry,
                           char *type, char *filename, int line)
{
  field = str_skip_initws (field);
  if (*field == '=') {
    if (entry) {
      field++;
      field = str_skip_initws (field);
      str_replace (entry, field);
    }
    return 1;
  }
  else {
    mutt_error (_("Improperly formated entry for type %s in \"%s\" line %d"),
                type, filename, line);
    return 0;
  }
}

static int rfc1524_mailcap_parse (BODY * a,
                                  char *filename,
                                  char *type, rfc1524_entry * entry, int opt)
{
  FILE *fp;
  char *buf = NULL;
  size_t buflen;
  char *ch;
  char *field;
  int found = FALSE;
  int copiousoutput;
  int composecommand;
  int editcommand;
  int printcommand;
  int btlen;
  int line = 0;

  /* rfc1524 mailcap file is of the format:
   * base/type; command; extradefs
   * type can be * for matching all
   * base with no /type is an implicit wild
   * command contains a %s for the filename to pass, default to pipe on stdin
   * extradefs are of the form:
   *  def1="definition"; def2="define \;";
   * line wraps with a \ at the end of the line
   * # for comments
   */

  /* find length of basetype */
  if ((ch = strchr (type, '/')) == NULL)
    return FALSE;
  btlen = ch - type;

  if ((fp = fopen (filename, "r")) != NULL) {
    while (!found && (buf = mutt_read_line (buf, &buflen, fp, &line)) != NULL) {
      /* ignore comments */
      if (*buf == '#')
        continue;
      debug_print (2, ("mailcap entry: %s\n", buf));

      /* check type */
      ch = get_field (buf);
      if (ascii_strcasecmp (buf, type) && (ascii_strncasecmp (buf, type, btlen) || (buf[btlen] != 0 &&  /* implicit wild */
                                                                                    str_cmp (buf + btlen, "/*"))))  /* wildsubtype */
        continue;

      /* next field is the viewcommand */
      field = ch;
      ch = get_field (ch);
      if (entry)
        entry->command = str_dup (field);

      /* parse the optional fields */
      found = TRUE;
      copiousoutput = FALSE;
      composecommand = FALSE;
      editcommand = FALSE;
      printcommand = FALSE;

      while (ch) {
        field = ch;
        ch = get_field (ch);
        debug_print (2, ("field: %s\n", field));

        if (!ascii_strcasecmp (field, "needsterminal")) {
          if (entry)
            entry->needsterminal = TRUE;
        }
        else if (!ascii_strcasecmp (field, "copiousoutput")) {
          copiousoutput = TRUE;
          if (entry)
            entry->copiousoutput = TRUE;
        }
        else if (!ascii_strncasecmp (field, "composetyped", 12)) {
          /* this compare most occur before compose to match correctly */
          if (get_field_text
              (field + 12, entry ? &entry->composetypecommand : NULL, type,
               filename, line))
            composecommand = TRUE;
        }
        else if (!ascii_strncasecmp (field, "compose", 7)) {
          if (get_field_text
              (field + 7, entry ? &entry->composecommand : NULL, type,
               filename, line))
            composecommand = TRUE;
        }
        else if (!ascii_strncasecmp (field, "print", 5)) {
          if (get_field_text (field + 5, entry ? &entry->printcommand : NULL,
                              type, filename, line))
            printcommand = TRUE;
        }
        else if (!ascii_strncasecmp (field, "edit", 4)) {
          if (get_field_text (field + 4, entry ? &entry->editcommand : NULL,
                              type, filename, line))
            editcommand = TRUE;
        }
        else if (!ascii_strncasecmp (field, "nametemplate", 12)) {
          get_field_text (field + 12, entry ? &entry->nametemplate : NULL,
                          type, filename, line);
        }
        else if (!ascii_strncasecmp (field, "x-convert", 9)) {
          get_field_text (field + 9, entry ? &entry->convert : NULL,
                          type, filename, line);
        }
        else if (!ascii_strncasecmp (field, "test", 4)) {
          /* 
           * This routine executes the given test command to determine
           * if this is the right entry.
           */
          char *test_command = NULL;
          size_t len;

          if (get_field_text (field + 4, &test_command, type, filename, line)
              && test_command) {
            len = str_len (test_command) + STRING;
            mem_realloc (&test_command, len);
            rfc1524_expand_command (a, a->filename, type, test_command, len);
            if (mutt_system (test_command)) {
              /* a non-zero exit code means test failed */
              found = FALSE;
            }
            mem_free (&test_command);
          }
        }
      }                         /* while (ch) */

      if (opt == M_AUTOVIEW) {
        if (!copiousoutput)
          found = FALSE;
      }
      else if (opt == M_COMPOSE) {
        if (!composecommand)
          found = FALSE;
      }
      else if (opt == M_EDIT) {
        if (!editcommand)
          found = FALSE;
      }
      else if (opt == M_PRINT) {
        if (!printcommand)
          found = FALSE;
      }

      if (!found) {
        /* reset */
        if (entry) {
          mem_free (&entry->command);
          mem_free (&entry->composecommand);
          mem_free (&entry->composetypecommand);
          mem_free (&entry->editcommand);
          mem_free (&entry->printcommand);
          mem_free (&entry->nametemplate);
          mem_free (&entry->convert);
          entry->needsterminal = 0;
          entry->copiousoutput = 0;
        }
      }
    }                           /* while (!found && (buf = mutt_read_line ())) */
    fclose (fp);
  }                             /* if ((fp = fopen ())) */
  mem_free (&buf);
  return found;
}

rfc1524_entry *rfc1524_new_entry (void)
{
  return (rfc1524_entry *) mem_calloc (1, sizeof (rfc1524_entry));
}

void rfc1524_free_entry (rfc1524_entry ** entry)
{
  rfc1524_entry *p = *entry;

  mem_free (&p->command);
  mem_free (&p->testcommand);
  mem_free (&p->composecommand);
  mem_free (&p->composetypecommand);
  mem_free (&p->editcommand);
  mem_free (&p->printcommand);
  mem_free (&p->nametemplate);
  mem_free (entry);
}

/*
 * rfc1524_mailcap_lookup attempts to find the given type in the
 * list of mailcap files.  On success, this returns the entry information
 * in *entry, and returns 1.  On failure (not found), returns 0.
 * If entry == NULL just return 1 if the given type is found.
 */
int rfc1524_mailcap_lookup (BODY * a, char *type, rfc1524_entry * entry,
                            int opt)
{
  char path[_POSIX_PATH_MAX];
  int x;
  int found = FALSE;
  char *curr = MailcapPath;

  /* rfc1524 specifies that a path of mailcap files should be searched.
   * joy.  They say 
   * $HOME/.mailcap:/etc/mailcap:/usr/etc/mailcap:/usr/local/etc/mailcap, etc
   * and overriden by the MAILCAPS environment variable, and, just to be nice, 
   * we'll make it specifiable in .muttrc
   */
  if (!curr || !*curr) {
    mutt_error _("No mailcap path specified");

    return 0;
  }

  mutt_check_lookup_list (a, type, SHORT_STRING);

  while (!found && *curr) {
    x = 0;
    while (*curr && *curr != ':' && x < sizeof (path) - 1) {
      path[x++] = *curr;
      curr++;
    }
    if (*curr)
      curr++;

    if (!x)
      continue;

    path[x] = '\0';
    mutt_expand_path (path, sizeof (path));

    debug_print (2, ("Checking mailcap file: %s\n", path));
    found = rfc1524_mailcap_parse (a, path, type, entry, opt);
  }

  if (entry && !found)
    mutt_error (_("mailcap entry for type %s not found"), type);

  return found;
}


/* This routine will create a _temporary_ filename matching the
 * name template given if this needs to be done.
 * 
 * Please note that only the last path element of the
 * template and/or the old file name will be used for the
 * comparison and the temporary file name.
 * 
 * Returns 0 if oldfile is fine as is.
 * Returns 1 if newfile specified
 */

static void strnfcpy (char *d, char *s, size_t siz, size_t len)
{
  if (len > siz)
    len = siz - 1;
  strfcpy (d, s, len);
}

int rfc1524_expand_filename (char *nametemplate,
                             char *oldfile, char *newfile, size_t nflen)
{
  int i, j, k, ps, r;
  char *s;
  short lmatch = 0, rmatch = 0;
  char left[_POSIX_PATH_MAX];
  char right[_POSIX_PATH_MAX];

  newfile[0] = 0;

  /* first, ignore leading path components.
   */

  if (nametemplate && (s = strrchr (nametemplate, '/')))
    nametemplate = s + 1;

  if (oldfile && (s = strrchr (oldfile, '/')))
    oldfile = s + 1;

  if (!nametemplate) {
    if (oldfile)
      strfcpy (newfile, oldfile, nflen);
  }
  else if (!oldfile) {
    mutt_expand_fmt (newfile, nflen, nametemplate, "mutt");
  }
  else {                        /* oldfile && nametemplate */


    /* first, compare everything left from the "%s" 
     * (if there is one).
     */

    lmatch = 1;
    ps = 0;
    for (i = 0; nametemplate[i]; i++) {
      if (nametemplate[i] == '%' && nametemplate[i + 1] == 's') {
        ps = 1;
        break;
      }

      /* note that the following will _not_ read beyond oldfile's end. */

      if (lmatch && nametemplate[i] != oldfile[i])
        lmatch = 0;
    }

    if (ps) {

      /* If we had a "%s", check the rest. */

      /* now, for the right part: compare everything right from 
       * the "%s" to the final part of oldfile.
       * 
       * The logic here is as follows:
       * 
       * - We start reading from the end.
       * - There must be a match _right_ from the "%s",
       *   thus the i + 2.  
       * - If there was a left hand match, this stuff
       *   must not be counted again.  That's done by the
       *   condition (j >= (lmatch ? i : 0)).
       */

      rmatch = 1;

      for (r = 0, j = str_len (oldfile) - 1, k =
           str_len (nametemplate) - 1;
           j >= (lmatch ? i : 0) && k >= i + 2; j--, k--) {
        if (nametemplate[k] != oldfile[j]) {
          rmatch = 0;
          break;
        }
      }

      /* Now, check if we had a full match. */

      if (k >= i + 2)
        rmatch = 0;

      if (lmatch)
        *left = 0;
      else
        strnfcpy (left, nametemplate, sizeof (left), i);

      if (rmatch)
        *right = 0;
      else
        strfcpy (right, nametemplate + i + 2, sizeof (right));

      snprintf (newfile, nflen, "%s%s%s", left, oldfile, right);
    }
    else {
      /* no "%s" in the name template. */
      strfcpy (newfile, nametemplate, nflen);
    }
  }

  mutt_adv_mktemp (NULL, newfile, nflen);

  if (rmatch && lmatch)
    return 0;
  else
    return 1;

}

/* If rfc1524_expand_command() is used on a recv'd message, then
 * the filename doesn't exist yet, but if its used while sending a message,
 * then we need to rename the existing file.
 *
 * This function returns 0 on successful move, 1 on old file doesn't exist,
 * 2 on new file already exists, and 3 on other failure.
 */

/* note on access(2) use: No dangling symlink problems here due to
 * safe_fopen().
 */

int _mutt_rename_file (char *oldfile, char *newfile, int overwrite)
{
  FILE *ofp, *nfp;

  if (access (oldfile, F_OK) != 0)
    return 1;
  if (!overwrite && access (newfile, F_OK) == 0)
    return 2;
  if ((ofp = fopen (oldfile, "r")) == NULL)
    return 3;
  if ((nfp = safe_fopen (newfile, "w")) == NULL) {
    fclose (ofp);
    return 3;
  }
  mutt_copy_stream (ofp, nfp);
  fclose (nfp);
  fclose (ofp);
  mutt_unlink (oldfile);
  return 0;
}

int mutt_rename_file (char *oldfile, char *newfile)
{
  return _mutt_rename_file (oldfile, newfile, 0);
}