/*
 * function.C: Miscellaneous functions.
 * Rights to this code are documented in doc/pod/license.pod.
 *
 * Copyright © 2005-2007 Atheme Project (http://www.atheme.org)           
 */

static char const rcsid[] = "$Id: function.C,v 1.4 2007/08/28 17:08:12 pippijn Exp $";

#include "atheme.h"
#include <ermyth/crypto.h>
#include <account/mychan.h>
#include <account/chanacs.h>
#include <account/myuser.h>
#include <common/random.h>

char ch[27] = "abcdefghijklmnopqrstuvwxyz";

/* This function uses allocates memory.
 * You MUST free the result when you are done with it!
 */
char *
gen_pw (int sz)
{
  int i;
  char *buf = alloc<char> (sz + 1); 	/* padding */

  for (i = 0; i < sz; i++)
    {
      buf[i] = ch[gen_rand32 () % 26];
    }

  buf[sz] = 0;

  return buf;
}

#ifdef HAVE_GETTIMEOFDAY
/* starts a timer */
void
s_time (struct timeval *sttime)
{
  gettimeofday (sttime, NULL);
}
#endif

#ifdef HAVE_GETTIMEOFDAY
/* ends a timer */
void
e_time (struct timeval sttime, struct timeval *ttime)
{
  struct timeval now;

  gettimeofday (&now, NULL);
  timersub (&now, &sttime, ttime);
}
#endif

#ifdef HAVE_GETTIMEOFDAY
/* translates microseconds into miliseconds */
int
tv2ms (struct timeval *tv)
{
  return (tv->tv_sec * 1000) + (int) (tv->tv_usec / 1000);
}
#endif

/* replaces tabs with a single ASCII 32 */
void
tb2sp (char *line)
{
  char *c;

  while ((c = strchr (line, '\t')))
    *c = ' ';
}

/* replace all occurances of 'oldstr' with 'newstr' */
char *
replace (char *s, int size, char const * const oldstr, char const * const newstr)
{
  char *ptr = s;
  int left = strlen (s);
  int avail = size - (left + 1);
  int oldstrlen = strlen (oldstr);
  int newstrlen = strlen (newstr);
  int diff = newstrlen - oldstrlen;

  while (left >= oldstrlen)
    {
      if (strncmp (ptr, oldstr, oldstrlen))
	{
	  left--;
	  ptr++;
	  continue;
	}

      if (diff > avail)
	break;

      if (diff != 0)
	memmove (ptr + oldstrlen + diff, ptr + oldstrlen, left + 1);

      memcpy (ptr, newstr, newstrlen);
      ptr += newstrlen;
      left -= oldstrlen;
    }

  return s;
}

/* reverse of atoi() */
char *
itoa (int num)
{
  static char ret[32];
  sprintf (ret, "%d", num);
  return ret;
}

/* return the time elapsed since an event */
char *
time_ago (time_t event)
{
  static char ret[128];
  int years, weeks, days, hours, minutes, seconds;

  event = NOW - event;
  years = weeks = days = hours = minutes = seconds = 0;

  while (event >= 60 * 60 * 24 * 365)
    {
      event -= 60 * 60 * 24 * 365;
      years++;
    }
  while (event >= 60 * 60 * 24 * 7)
    {
      event -= 60 * 60 * 24 * 7;
      weeks++;
    }
  while (event >= 60 * 60 * 24)
    {
      event -= 60 * 60 * 24;
      days++;
    }
  while (event >= 60 * 60)
    {
      event -= 60 * 60;
      hours++;
    }
  while (event >= 60)
    {
      event -= 60;
      minutes++;
    }

  seconds = event;

  if (years)
    snprintf (ret, sizeof (ret), "%d year%s, %d week%s, %d day%s, %02d:%02d:%02d", years, years == 1 ? "" : "s", weeks, weeks == 1 ? "" : "s", days, days == 1 ? "" : "s", hours, minutes, seconds);
  else if (weeks)
    snprintf (ret, sizeof (ret), "%d week%s, %d day%s, %02d:%02d:%02d", weeks, weeks == 1 ? "" : "s", days, days == 1 ? "" : "s", hours, minutes, seconds);
  else if (days)
    snprintf (ret, sizeof (ret), "%d day%s, %02d:%02d:%02d", days, days == 1 ? "" : "s", hours, minutes, seconds);
  else if (hours)
    snprintf (ret, sizeof (ret), "%d hour%s, %d minute%s, %d second%s", hours, hours == 1 ? "" : "s", minutes, minutes == 1 ? "" : "s", seconds, seconds == 1 ? "" : "s");
  else if (minutes)
    snprintf (ret, sizeof (ret), "%d minute%s, %d second%s", minutes, minutes == 1 ? "" : "s", seconds, seconds == 1 ? "" : "s");
  else
    snprintf (ret, sizeof (ret), "%d second%s", seconds, seconds == 1 ? "" : "s");

  return ret;
}

char *
timediff (time_t seconds)
{
  static char buf[BUFSIZE];
  long unsigned days, hours, minutes;

  days = seconds / 86400;
  seconds %= 86400;
  hours = seconds / 3600;
  hours %= 3600;
  minutes = seconds / 60;
  minutes %= 60;
  seconds %= 60;

  snprintf (buf, sizeof (buf), "%lu day%s, %lu:%02lu:%02lu", days, (days == 1) ? "" : "s", hours, minutes, (long unsigned) seconds);

  return buf;
}

/* generate a random number, for use as a key */
unsigned long
makekey (void)
{
  unsigned long k;

  k = gen_rand32 () & 0x7FFFFFFF;

  /* shorten or pad it to 9 digits */
  if (k > 1000000000)
    k = k - 1000000000;
  if (k < 100000000)
    k = k + 100000000;

  return k;
}

bool
is_internal_client (user_t *u)
{
  return (u && (!u->server || u->server == me.me));
}

int
validemail (char *email)
{
  int i, valid = 1, chars = 0;

  /* sane length */
  if (strlen (email) >= EMAILLEN)
    valid = 0;

  /* make sure it has @ and . */
  if (!strchr (email, '@') || !strchr (email, '.'))
    valid = 0;

  /* check for other bad things */
  if (strchr (email, '\'') || strchr (email, ' ') || strchr (email, ',') || strchr (email, '$') || strchr (email, '/') || strchr (email, ';') || strchr (email, '<') || strchr (email, '>') || strchr (email, '&') || strchr (email, '"'))
    valid = 0;

  /* make sure there are at least 6 characters besides the above
   * mentioned @ and .
   */
  for (i = strlen (email) - 1; i > 0; i--)
    if (!(email[i] == '@' || email[i] == '.'))
      chars++;

  if (chars < 6)
    valid = 0;

  return valid;
}

bool
validhostmask (char *host)
{
  char *p, *q;

  if (strchr (host, ' '))
    return false;

  /* make sure it has ! and @ in that order and only once */
  p = strchr (host, '!');
  q = strchr (host, '@');
  if (p == NULL || q == NULL || p > q || strchr (p + 1, '!') || strchr (q + 1, '@'))
    return false;

  /* XXX this NICKLEN is too long */
  if (strlen (host) > NICKLEN + USERLEN + HOSTLEN + 1)
    return false;

  if (host[0] == ',' || host[0] == '-' || host[0] == '#' || host[0] == '@' || host[0] == '!')
    return false;

  return true;
}

/* send the specified type of email.
 *
 * u is whoever caused this to be called, the corresponding service
 *   in case of xmlrpc
 * type is EMAIL_*, see include/tools.h
 * mu is the recipient user
 * param depends on type, also see include/tools.h
 */
int
sendemail (user_t *u, int type, myuser_t *mu, char const * const param)
{
  char *email, *date = NULL;
  char cmdbuf[512], timebuf[256], to[128], from[128], subject[128];
  FILE *out;
  time_t t;
  struct tm tm;
  int pipfds[2];
  pid_t pid;
  int status;
  int rc;
  static time_t period_start = 0, lastwallops = 0;
  static unsigned emailcount = 0;

  if (u == NULL || mu == NULL)
    return 0;

  if (me.mta == NULL)
    {
      if (type != EMAIL_MEMO && !is_internal_client (u))
	notice (opersvs.me ? opersvs.nick : me.name, u->nick, "Sending email is administratively disabled.");
      return 0;
    }

  if (type == EMAIL_SETEMAIL)
    {
      /* special case for e-mail change */
      metadata *md = mu->find_metadata ("private:verify:emailchg:newemail");

      if (md && md->value)
	email = md->value;
      else			/* should NEVER happen */
	{
	  slog (LG_ERROR, "sendemail(): got email change request, but newemail unset!");
	  return 0;
	}
    }
  else
    email = mu->email;

  if (NOW - period_start > me.emailtime)
    {
      emailcount = 0;
      period_start = NOW;
    }
  emailcount++;
  if (emailcount > me.emaillimit)
    {
      if (NOW - lastwallops > 60)
	{
	  wallops (_("Rejecting email for %s[%s@%s] due to too high load (type %d to %s <%s>)"), u->nick, u->user, u->vhost, type, mu->name, email);
	  slog (LG_ERROR, "sendemail(): rejecting email for %s[%s@%s] (%s) due to too high load (type %d to %s <%s>)", u->nick, u->user, u->vhost, u->ip[0] ? u->ip : u->host, type, mu->name, email);
	  lastwallops = NOW;
	}
      return 0;
    }

  slog (LG_INFO, "sendemail(): email for %s[%s@%s] (%s) type %d to %s <%s>", u->nick, u->user, u->vhost, u->ip[0] ? u->ip : u->host, type, mu->name, email);

  /* set up the email headers */
  time (&t);
  tm = *gmtime (&t);
  strftime (timebuf, sizeof (timebuf) - 1, "%a, %d %b %Y %H:%M:%S +0000", &tm);

  date = timebuf;

  snprintf (from, sizeof from, "%s automailer <noreply.%s>", me.netname, me.adminemail);
  snprintf (to, sizeof to, "%s <%s>", mu->name, email);

  strlcpy (subject, me.netname, sizeof subject);
  strlcat (subject, " ", sizeof subject);
  if (type == EMAIL_REGISTER)
    if (nicksvs.no_nick_ownership)
      strlcat (subject, "Account Registration", sizeof subject);
    else
      strlcat (subject, "Nickname Registration", sizeof subject);
  else if (type == EMAIL_SENDPASS || type == EMAIL_SETPASS)
    strlcat (subject, "Password Retrieval", sizeof subject);
  else if (type == EMAIL_SETEMAIL)
    strlcat (subject, "Change Email Confirmation", sizeof subject);
  else if (type == EMAIL_MEMO)
    strlcat (subject, "New memo", sizeof subject);

  /* now set up the email */
  sprintf (cmdbuf, "%s %s", me.mta, email);
  if (pipe (pipfds) < 0)
    return 0;
  switch (pid = fork ())
    {
    case -1:
      return 0;
    case 0:
      close (pipfds[1]);
      dup2 (pipfds[0], 0);
      switch (fork ())
	{
	  /* fork again to avoid zombies -- jilles */
	case -1:
	  _exit (255);
	case 0:
	  execl ("/bin/sh", "sh", "-c", cmdbuf, NULL);
	  _exit (255);
	default:
	  _exit (0);
	}
    }
  close (pipfds[0]);
  waitpid (pid, &status, 0);
  out = fdopen (pipfds[1], "w");

  fprintf (out, "From: %s\n", from);
  fprintf (out, "To: %s\n", to);
  fprintf (out, "Subject: %s\n", subject);
  fprintf (out, "Date: %s\n\n", date);

  fprintf (out, "%s,\n\n", mu->name);

  if (type == EMAIL_REGISTER)
    {
      fprintf (out, "In order to complete your registration, you must send the following\ncommand on IRC:\n");
      fprintf (out, "/MSG %s VERIFY REGISTER %s %s\n\n", nicksvs.nick, mu->name, param);
      fprintf (out, "Thank you for registering your %s on the %s IRC " "network!\n\n", (nicksvs.no_nick_ownership ? "account" : "nickname"), me.netname);
    }
  else if (type == EMAIL_SENDPASS)
    {
      fprintf (out, "Someone has requested the password for %s be sent to the\n" "corresponding email address. If you did not request this action\n" "please let us know.\n\n", mu->name);
      fprintf (out, "The password for %s is %s. Please write this down for " "future reference.\n\n", mu->name, param);
    }
  else if (type == EMAIL_SETEMAIL)
    {
      fprintf (out, "In order to complete your email change, you must send\n" "the following command on IRC:\n");
      fprintf (out, "/MSG %s VERIFY EMAILCHG %s %s\n\n", nicksvs.nick, mu->name, param);
    }
  else if (type == EMAIL_MEMO)
    {
      if (u->myuser != NULL)
	fprintf (out, "You have a new memo from %s.\n\n", u->myuser->name);
      else
	/* shouldn't happen */
	fprintf (out, "You have a new memo from %s (unregistered?).\n\n", u->nick);
      fprintf (out, "%s\n\n", param);
    }
  else if (type == EMAIL_SETPASS)
    {
      fprintf (out, "In order to set a new password, you must send\n" "the following command on IRC:\n");
      fprintf (out, "/MSG %s SETPASS %s %s <password>\nwhere <password> is your desired new password.\n\n", nicksvs.nick, mu->name, param);
    }

  fprintf (out, "Thank you for your interest in the %s IRC network.\n", me.netname);
  if (u->server != me.me)
    fprintf (out, "\nThis email was sent due to a command from %s[%s@%s]\nat %s.\n", u->nick, u->user, u->vhost, date);
  fprintf (out, "If this message is spam, please contact %s\nwith a full copy.\n", me.adminemail);
  fprintf (out, ".\n");
  rc = 1;
  if (ferror (out))
    rc = 0;
  if (fclose (out) < 0)
    rc = 0;
  if (rc == 0)
    slog (LG_ERROR, "sendemail(): mta failure");
  return rc;
}

/* various access level checkers */
bool
myuser_t::is_founder (mychan_t *mc) const
{
  if (chanacs_find (mc, this, CA_FOUNDER))
    return true;

  return false;
}

bool
myuser_t::should_owner (mychan_t *mc) const
{
  if (MC_NOOP & mc->flags)
    return false;

  if (MU_NOOP & flags)
    return false;

  if (is_founder (mc))
    return true;

  return false;
}

bool
myuser_t::should_protect (mychan_t *mc) const
{
  if (MC_NOOP & mc->flags)
    return false;

  if (MU_NOOP & flags)
    return false;

  if (chanacs_find (mc, this, CA_SET))
    return true;

  return false;
}

bool
is_ircop (user_t *user)
{
  if (UF_IRCOP & user->flags)
    return true;

  return false;
}

bool
is_admin (user_t *user)
{
  if (UF_ADMIN & user->flags)
    return true;

  return false;
}

void
myuser_t::set_password (char const * const newpassword)
{
  if (newpassword == NULL)
    return;

  /* if we can, try to crypt it */
  if (crypto::handler::loaded)
    {
      flags |= MU_CRYPTPASS;
      strlcpy (pass, crypter->crypt (newpassword, crypto::gen_salt ()), NICKLEN);
    }
  else
    {
      flags &= ~MU_CRYPTPASS;	/* just in case */
      strlcpy (pass, newpassword, NICKLEN);
    }
}

bool
myuser_t::verify_password (char const * const password) const
{
  if (password == NULL)
    return false;

  if (flags & MU_CRYPTPASS)
    if (crypto::handler::loaded)
      return crypto::verify_password (password, pass);
    else
      {				/* not good! */
	slog (LG_ERROR, "check_password(): can't check crypted password -- no crypto module!");
	return false;
      }
  else
    return (strcmp (pass, password) == 0);
}

char const *
sbytes (float x)
{
  if (x > 1073741824.0)
    return "GB";

  else if (x > 1048576.0)
    return "MB";

  else if (x > 1024.0)
    return "KB";

  return "B";
}

float
bytes (float x)
{
  if (x > 1073741824.0)
    return (x / 1073741824.0);

  if (x > 1048576.0)
    return (x / 1048576.0);

  if (x > 1024.0)
    return (x / 1024.0);

  return x;
}