/* $Id: log.c,v 1.31 2005-08-15 03:54:31 rjkaes Exp $
 *
 * Logs the various messages which tinyproxy produces to either a log file or
 * the syslog daemon. Not much to it...
 *
 * Copyright (C) 1998  Steven Young
 * 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, 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.
 */

#include "tinyproxy.h"

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

static 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, 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;

        int 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;
}