/* tinyproxy - A fast light-weight HTTP proxy
 * Copyright (C) 1998 Steven Young <sdyoung@miranda.org>
 * Copyright (C) 1999 Robert James Kaes <rjkaes@users.sourceforge.net>
 *
 * 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/* Logs the various messages which tinyproxy produces to either a log file
 * or the syslog daemon. Not much to it...
 */

#include "main.h"

#include "heap.h"
#include "log.h"
#include "utils.h"
#include "vector.h"

static const char *syslog_level[] = {
  NULL,
  NULL,
  "CRITICAL",
  "ERROR",
  "WARNING",
  "NOTICE",
  "INFO",
  "DEBUG",
  "CONNECT"
};

#define TIME_LENGTH 16
#define STRING_LENGTH 800

/*
 * Global file descriptor for the log file
 */
int log_file_fd = -1;

/*
 * Store the log level setting.
 */
static int log_level = LOG_INFO;

/*
 * Hold a listing of log messages which need to be sent once the log
 * file has been established.
 * The key is the actual messages (already filled in full), and the value
 * is the log level.
 */
static vector_t log_message_storage;

/*
 * Open the log file and store the file descriptor in a global location.
 */
int
open_log_file (const char *log_file_name)
{
  log_file_fd = create_file_safely (log_file_name, FALSE);
  return log_file_fd;
}

/*
 * Close the log file
 */
void
close_log_file (void)
{
  close (log_file_fd);
}

/*
 * Truncate log file to a zero length.
 */
void
truncate_log_file (void)
{
  lseek (log_file_fd, 0, SEEK_SET);
  ftruncate (log_file_fd, 0);
}

/*
 * Set the log level for writing to the log file.
 */
void
set_log_level (int level)
{
  log_level = level;
}

/*
 * This routine logs messages to either the log file or the syslog function.
 */
void
log_message (int level, const char *fmt, ...)
{
  va_list args;
  time_t nowtime;

  char time_string[TIME_LENGTH];
  char str[STRING_LENGTH];

#ifdef NDEBUG
  /*
   * Figure out if we should write the message or not.
   */
  if (log_level == LOG_CONN)
    {
      if (level == LOG_INFO)
        return;
    }
  else if (log_level == LOG_INFO)
    {
      if (level > LOG_INFO && level != LOG_CONN)
        return;
    }
  else if (level > log_level)
    return;
#endif

#ifdef HAVE_SYSLOG_H
  if (config.syslog && level == LOG_CONN)
    level = LOG_INFO;
#endif

  va_start (args, fmt);

  /*
   * If the config file hasn't been processed, then we need to store
   * the messages for later processing.
   */
  if (!processed_config_file)
    {
      char *entry_buffer;

      if (!log_message_storage)
        {
          log_message_storage = vector_create ();
          if (!log_message_storage)
            goto out;
        }

      vsnprintf (str, STRING_LENGTH, fmt, args);

      entry_buffer = safemalloc (strlen (str) + 6);
      if (!entry_buffer)
        goto out;

      sprintf (entry_buffer, "%d %s", level, str);
      vector_append (log_message_storage, entry_buffer,
                     strlen (entry_buffer) + 1);

      safefree (entry_buffer);
      goto out;
    }
#ifdef HAVE_SYSLOG_H
  if (config.syslog)
    {
#  ifdef HAVE_VSYSLOG_H
      vsyslog (level, fmt, args);
#  else
      vsnprintf (str, STRING_LENGTH, fmt, args);
      syslog (level, "%s", str);
#  endif
    }
  else
    {
#endif
      nowtime = time (NULL);
      /* Format is month day hour:minute:second (24 time) */
      strftime (time_string, TIME_LENGTH, "%b %d %H:%M:%S",
                localtime (&nowtime));

      snprintf (str, STRING_LENGTH, "%-9s %s [%ld]: ",
                syslog_level[level], time_string, (long int) getpid ());

      assert (log_file_fd >= 0);

      write (log_file_fd, str, strlen (str));
      vsnprintf (str, STRING_LENGTH, fmt, args);
      write (log_file_fd, str, strlen (str));
      write (log_file_fd, "\n", 1);
      fsync (log_file_fd);

#ifdef HAVE_SYSLOG_H
    }
#endif

out:
  va_end (args);
}

/*
 * This needs to send any stored log messages.
 */
void
send_stored_logs (void)
{
  char *string;
  char *ptr;

  int level;

  size_t i;

  for (i = 0; i != vector_length (log_message_storage); ++i)
    {
      string = vector_getentry (log_message_storage, i, NULL);

      ptr = strchr (string, ' ') + 1;
      level = atoi (string);

#ifdef NDEBUG
      if (log_level == LOG_CONN && level == LOG_INFO)
        continue;
      else if (log_level == LOG_INFO)
        {
          if (level > LOG_INFO && level != LOG_CONN)
            continue;
        }
      else if (level > log_level)
        continue;
#endif

      log_message (level, ptr);
    }

  vector_delete (log_message_storage);
  log_message_storage = NULL;
}