/*

 * utils.c      -- Various utility functions

 *

 * Copyright (C) 2005-2014 Mikael Berthe <mikael@lilotux.net>

 * Some of the ut_* functions are derived from Cabber debug/log code.

 * from_iso8601() comes from the Pidgin (libpurple) project.

 *

 * 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 2 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 <http://www.gnu.org/licenses/>.

 */

#include <config.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <stdarg.h>

#include <errno.h>

#ifdef HAVE_LIBIDN

#include <idna.h>

#include <stringprep.h>

static char idnprep[1024];

#endif

#include <glib.h>

#include <glib/gprintf.h>

/* For Cygwin (thanks go to Yitzchak Scott-Thoennes) */

#ifdef __CYGWIN__

#  define timezonevar

   extern long timezone;

#endif

#include <time.h>

#include <unistd.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <ctype.h>

#include "utils.h"

#include "logprint.h"

#include "settings.h"

#include "main.h"

#include "screen.h"

static int DebugEnabled;

static char *FName;

//  jidtodisp(jid)

// Strips the resource part from the jid

// The caller should g_free the result after use.

char *jidtodisp(const char *fjid)

{

  char *ptr;

  char *alias;

  if (!fjid) {

    scr_LogPrint(LPRINT_LOGNORM, "** jidtodisp: NULL JID, "

                                 "this is probably a bug, please report!");

    return NULL;

  }

  alias = g_strdup(fjid);

  if ((ptr = strchr(alias, JID_RESOURCE_SEPARATOR)) != NULL) {

    *ptr = 0;

  }

  return alias;

}

// The caller must free the string after use.

char *jid_get_username(const char *fjid)

{

  char *ptr;

  char *username;

  username = g_strdup(fjid);

  if ((ptr = strchr(username, JID_DOMAIN_SEPARATOR)) != NULL) {

    *ptr = 0;

  }

  return username;

}

// The caller must free the string after use.

char *get_servername(const char *username, const char *servername)

{

  char *ptr;

  char *server;

  if (!username) {

    return NULL;

  }

  if ((ptr = strchr(username, JID_DOMAIN_SEPARATOR)) != NULL) {

    server = g_strdup(ptr+1);

    return server;

  }

  return g_strdup(servername);

}

// The caller must free the string after use.

char *compose_jid(const char *username, const char *servername,

                  const char *resource)

{

  char *fjid;

  if (!strchr(username, JID_DOMAIN_SEPARATOR)) {

    fjid = g_strdup_printf("%s%c%s%c%s", username,

                           JID_DOMAIN_SEPARATOR, servername,

                           JID_RESOURCE_SEPARATOR, resource);

  } else {

    fjid = g_strdup_printf("%s%c%s", username,

                           JID_RESOURCE_SEPARATOR, resource);

  }

  return fjid;

}

gboolean jid_equal(const char *jid1, const char *jid2)

{

  char *a,*b;

  int ret;

  if (!jid1 && !jid2)

    return TRUE;

  if (!jid1 || !jid2)

    return FALSE;

  a = jidtodisp(jid1);

  b = jidtodisp(jid2);

  ret = strcasecmp(a, b);

  g_free(a);

  g_free(b);

  return (ret == 0) ? TRUE : FALSE;

}

//  expand_filename(filename)

// Expand "~/" with the $HOME env. variable in a file name.

// The caller must free the string after use.

char *expand_filename(const char *fname)

{

  if (!fname)

    return NULL;

  if (!strncmp(fname, "~/", 2)) {

    char *homedir = getenv("HOME");

    if (homedir)

      return g_strdup_printf("%s%s", homedir, fname+1);

  }

  return g_strdup(fname);

}

#ifndef LOUDMOUTH_USES_SHA256

//  fingerprint_to_hex(fprstr, hex, fpr_len)

// Convert the binary fingerprint fprstr (which is fpr_len bytes long)

// to a NULL-terminated hexadecimal string hex.

// The destination array hex should have been preallocated by the caller,

// and should be big enough (i.e. >= 3*fpr_len bytes).

void fingerprint_to_hex(const char *fprstr, char *hex, size_t fpr_len)

{

  unsigned int i;

  const unsigned char *fpr = (const unsigned char *)fprstr;

  char *p;

  hex[0] = 0;

  if (!fpr || fpr_len < 16) return;

  for (p = hex, i = 0; i < fpr_len - 1; i++, p+=3)

    g_snprintf(p, 4, "%02X:", fpr[i]);

  g_snprintf(p, 3, "%02X", fpr[i]);

}

//  hex_to_fingerprint(hex, fpr, fpr_len)

// Convert the hexadecimal fingerprint hex to a byte array fpr[].

// The fpr array should have been preallocated  with a size >= fpr_len.

gboolean hex_to_fingerprint(const char *hex, char *fpr, size_t fpr_len)

{

  unsigned int i;

  const char *p;

  if (fpr_len < 16) return FALSE;

  fpr[0] = 0;

  if (strlen(hex) != fpr_len*3 - 1)

    return FALSE;

  for (i = 0, p = hex; i < fpr_len && *p && *(p+1); i++, p += 3) {

    // Check we have two hex digits followed by a colon (or end of string)

    if (!isxdigit(*p) || !isxdigit(*(p+1)))

      return FALSE;

    if (*(p+2) && (*(p+2) != ':'))

      return FALSE;

    fpr[i] = (char)g_ascii_strtoull(p, NULL, 16);

  }

  return TRUE;

}

#endif

static gboolean tracelog_create(void)

{

  FILE *fp;

  struct stat buf;

  int err;

  char *v;

  fp = fopen(FName, "a");

  if (!fp) {

    scr_LogPrint(LPRINT_NORMAL, "ERROR: Cannot open tracelog file: %s",

                 strerror(errno));

    return FALSE;

  }

  err = fstat(fileno(fp), &buf);

  if (err || buf.st_uid != geteuid()) {

    fclose(fp);

    if (err)

      scr_LogPrint(LPRINT_NORMAL, "ERROR: cannot stat the tracelog file: %s",

                   strerror(errno));

    else

      scr_LogPrint(LPRINT_NORMAL, "ERROR: tracelog file does not belong to you!");

    return FALSE;

  }

  if (fchmod(fileno(fp), S_IRUSR|S_IWUSR)) {

    scr_LogPrint(LPRINT_NORMAL, "WARNING: Cannot set tracelog file permissions: %s",

                 strerror(errno));

  }

  v = mcabber_version();

  fprintf(fp, "New trace log started.  MCabber version %s\n"

              "----------------------\n", v);

  g_free(v);

  fclose(fp);

  return TRUE;

}

// The caller must free the string after use.

static gchar *tracelog_level_guard(const gchar *key, const gchar *new_value)

{

  int new_level = 0;

  if (new_value)

    new_level = atoi(new_value);

  if (DebugEnabled < 1 && new_level > 0 && FName && !tracelog_create())

    DebugEnabled = 0;

  else

    DebugEnabled = new_level;

  return g_strdup(new_value);

}

// The caller must free the string after use.

static gchar *tracelog_file_guard(const gchar *key, const gchar *new_value)

{

  gchar *new_fname = NULL;

  if (new_value)

    new_fname = expand_filename(new_value);

  if (g_strcmp0(FName, new_fname)) {

    g_free(FName);

    FName = new_fname;

    if (DebugEnabled > 0 && !tracelog_create()) {

      g_free(FName);

      FName = NULL;

    }

  } else

    g_free(new_fname);

  return g_strdup(new_value);

}

//  ut_init_debug()

// Install option guards before initial config file parsing.

void ut_init_debug(void)

{

  DebugEnabled = 0;

  FName        = NULL;

  settings_set_guard("tracelog_level", tracelog_level_guard);

  settings_set_guard("tracelog_file",  tracelog_file_guard);

}

void ut_write_log(unsigned int flag, const char *data)

{

  if (!DebugEnabled || !FName) return;

  if (((DebugEnabled >= 2) && (flag & (LPRINT_LOG|LPRINT_DEBUG))) ||

      ((DebugEnabled == 1) && (flag & LPRINT_LOG))) {

    FILE *fp = fopen(FName, "a+");

    if (!fp) {

      scr_LogPrint(LPRINT_NORMAL, "ERROR: Cannot open tracelog file: %s.",

                   strerror(errno));

      return;

    }

    // Check file permissions again (it could be a new file)

    fchmod(fileno(fp), S_IRUSR|S_IWUSR);

    if (fputs(data, fp) == EOF)

      scr_LogPrint(LPRINT_NORMAL, "ERROR: Cannot write to tracelog file.");

    fclose(fp);

  }

}

//  checkset_perm(name, setmode)

// Check the permissions of the "name" file/dir

// If setmode is true, correct the permissions if they are wrong

// Return values: -1 == bad file/dir, 0 == success, 1 == cannot correct

int checkset_perm(const char *name, unsigned int setmode)

{

  int fd;

  struct stat buf;

  if (!name) return -1;

#ifdef __CYGWIN__

  // Permission checking isn't efficient on Cygwin

  return 0;

#endif

  fd = stat(name, &buf);

  if (fd == -1) return -1;

  if (buf.st_uid != geteuid()) {

    scr_LogPrint(LPRINT_LOGNORM, "Wrong file owner [%s]", name);

    return 1;

  }

  if (buf.st_mode & (S_IRGRP | S_IWGRP | S_IXGRP) ||

      buf.st_mode & (S_IROTH | S_IWOTH | S_IXOTH)) {

    if (setmode) {

      mode_t newmode = 0;

      scr_LogPrint(LPRINT_LOGNORM, "Bad permissions [%s]", name);

      if (S_ISDIR(buf.st_mode))

        newmode |= S_IXUSR;

      newmode |= S_IRUSR | S_IWUSR;

      if (chmod(name, newmode)) {

        scr_LogPrint(LPRINT_LOGNORM, "WARNING: Failed to correct permissions!");

        return 1;

      }

      scr_LogPrint(LPRINT_LOGNORM, "Permissions have been corrected");

    } else {

      scr_LogPrint(LPRINT_LOGNORM, "WARNING: Bad permissions [%s]", name);

      return 1;

    }

  }

  return 0;

}

const char *ut_get_tmpdir(void)

{

  static const char *tmpdir;

  const char *tmpvars[] = { "MCABBERTMPDIR", "TMP", "TMPDIR", "TEMP" };

  unsigned int i;

  if (tmpdir)

    return tmpdir;

  for (i = 0; i < (sizeof(tmpvars) / sizeof(const char *)); i++) {

    tmpdir = getenv(tmpvars[i]);

    if (tmpdir && tmpdir[0] && tmpdir[0] == '/' && tmpdir[1]) {

      // Looks ok.

      return tmpdir;

    }

  }

  // Default temporary directory

  tmpdir = "/tmp";

  return tmpdir;

}

//  to_iso8601(dststr, timestamp)

// Convert timestamp to iso8601 format, and store it in dststr.