/****************************************************************************
 * drivers/syslog/vsyslog.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdio.h>
#include <syslog.h>
#include <errno.h>

#include <nuttx/arch.h>
#include <nuttx/init.h>
#include <nuttx/clock.h>
#include <nuttx/streams.h>

#include "syslog.h"

/****************************************************************************
 * Private Data
 ****************************************************************************/

#if defined(CONFIG_SYSLOG_COLOR_OUTPUT)
static FAR const char * const g_priority_color[] =
  {
    "\e[31;1;5m", /* LOG_EMERG, Red, Bold, Blinking */
    "\e[31;1m",   /* LOG_ALERT, Red, Bold */
    "\e[31;1m",   /* LOG_CRIT, Red, Bold */
    "\e[31m",     /* LOG_ERR, Red */
    "\e[33m",     /* LOG_WARNING, Yellow */
    "\e[1m",      /* LOG_NOTICE, Bold */
    "",           /* LOG_INFO, Normal */
    "\e[2m",      /* LOG_DEBUG, Dim */
  };
#endif

#if defined(CONFIG_SYSLOG_PRIORITY)
static FAR const char * const g_priority_str[] =
  {
    "EMERG", "ALERT", "CRIT", "ERROR",
    "WARN", "NOTICE", "INFO", "DEBUG"
  };
#endif

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: nx_vsyslog
 *
 * Description:
 *   nx_vsyslog() handles the system logging system calls. It is functionally
 *   equivalent to vsyslog() except that (1) the per-process priority
 *   filtering has already been performed and the va_list parameter is
 *   passed by reference.  That is because the va_list is a structure in
 *   some compilers and passing of structures in the NuttX sycalls does
 *   not work.
 *
 ****************************************************************************/

int nx_vsyslog(int priority, FAR const IPTR char *fmt, FAR va_list *ap)
{
  struct lib_syslogstream_s stream;
  int ret = 0;
#if CONFIG_TASK_NAME_SIZE > 0 && defined(CONFIG_SYSLOG_PROCESS_NAME)
  struct tcb_s *tcb;
#endif
#ifdef CONFIG_SYSLOG_TIMESTAMP
  struct timespec ts;
#if defined(CONFIG_SYSLOG_TIMESTAMP_FORMATTED)
  int d_ret;
  struct tm tm;
  char date_buf[CONFIG_SYSLOG_TIMESTAMP_BUFFER];
#endif
#endif

  /* Wrap the low-level output in a stream object and let lib_vsprintf
   * do the work.
   */

  lib_syslogstream_open(&stream);

#ifdef CONFIG_SYSLOG_TIMESTAMP
  ts.tv_sec = 0;
  ts.tv_nsec = 0;

#if defined(CONFIG_SYSLOG_TIMESTAMP_FORMATTED)
  memset(&tm, 0, sizeof(tm));
#endif

  /* Get the current time.  Since debug output may be generated very early
   * in the start-up sequence, hardware timer support may not yet be
   * available.
   */

  if (OSINIT_HW_READY())
    {
#if defined(CONFIG_SYSLOG_TIMESTAMP_REALTIME)
      /* Use CLOCK_REALTIME if so configured */

      clock_gettime(CLOCK_REALTIME, &ts);

#else
      /* Prefer monotonic when enabled, as it can be synchronized to
       * RTC with clock_resynchronize.
       */

      clock_gettime(CLOCK_MONOTONIC, &ts);
#endif

      /* Prepend the message with the current time, if available */

#if defined(CONFIG_SYSLOG_TIMESTAMP_FORMATTED)
#if defined(CONFIG_SYSLOG_TIMESTAMP_LOCALTIME)
      localtime_r(&ts.tv_sec, &tm);
#else
      gmtime_r(&ts.tv_sec, &tm);
#endif
#endif
    }

#if defined(CONFIG_SYSLOG_COLOR_OUTPUT)
  /* Reset the terminal style. */

  ret = lib_sprintf(&stream.public, "\e[0m");
#endif

#if defined(CONFIG_SYSLOG_TIMESTAMP_FORMATTED)
  d_ret = strftime(date_buf, CONFIG_SYSLOG_TIMESTAMP_BUFFER,
                   CONFIG_SYSLOG_TIMESTAMP_FORMAT, &tm);

  if (d_ret > 0)
    {
#if defined(CONFIG_SYSLOG_TIMESTAMP_FORMAT_MICROSECOND)
      ret += lib_sprintf(&stream.public, "[%s.%06ld] ",
                         date_buf, ts.tv_nsec / NSEC_PER_USEC);
#else
      ret += lib_sprintf(&stream.public, "[%s] ", date_buf);
#endif
    }
#else
  ret += lib_sprintf(&stream.public, "[%5jd.%06ld] ",
                     (uintmax_t)ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC);
#endif
#endif

#if defined(CONFIG_SMP)
  ret += lib_sprintf(&stream.public, "[CPU%d] ", up_cpu_index());
#endif

#if defined(CONFIG_SYSLOG_PROCESSID)
  /* Prepend the Thread ID */

  ret += lib_sprintf(&stream.public, "[%2d] ", gettid());
#endif

#if defined(CONFIG_SYSLOG_COLOR_OUTPUT)
  /* Set the terminal style according to message priority. */

  ret += lib_sprintf(&stream.public, "%s", g_priority_color[priority]);
#endif

#if defined(CONFIG_SYSLOG_PRIORITY)
  /* Prepend the message priority. */

  ret += lib_sprintf(&stream.public, "[%6s] ", g_priority_str[priority]);
#endif

#if defined(CONFIG_SYSLOG_PREFIX)
  /* Prepend the prefix, if available */

  ret += lib_sprintf(&stream.public, "[%s] ", CONFIG_SYSLOG_PREFIX_STRING);
#endif

#if CONFIG_TASK_NAME_SIZE > 0 && defined(CONFIG_SYSLOG_PROCESS_NAME)
  /* Prepend the thread name */

  tcb = nxsched_get_tcb(gettid());
  ret += lib_sprintf(&stream.public, "%s: ",
                     tcb != NULL ? tcb->name : "(null)");
#endif

  /* Generate the output */

  ret += lib_vsprintf(&stream.public, fmt, *ap);

  if (stream.last_ch != '\n')
    {
      lib_stream_putc(&stream.public, '\n');
    }

#if defined(CONFIG_SYSLOG_COLOR_OUTPUT)
  /* Reset the terminal style back to normal. */

  ret += lib_stream_puts(&stream.public, "\e[0m", sizeof("\e[0m"));
#endif

  /* Flush and destroy the syslog stream buffer */

  lib_syslogstream_close(&stream);
  return ret;
}