/* Pinos
 * Copyright (C) 2015 Wim Taymans <wim.taymans@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

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

#include <spa/ringbuffer.h>

#include <pinos/client/log.h>

#define DEFAULT_LOG_LEVEL SPA_LOG_LEVEL_ERROR

SpaLogLevel pinos_log_level = DEFAULT_LOG_LEVEL;

#define TRACE_BUFFER (16*1024)

typedef struct {
  SpaLog log;
  SpaRingbuffer  trace_rb;
  uint8_t        trace_data[TRACE_BUFFER];
  SpaSource     *source;
} DebugLog;

static void
do_logv (SpaLog        *log,
         SpaLogLevel    level,
         const char    *file,
         int            line,
         const char    *func,
         const char    *fmt,
         va_list        args)
{
  DebugLog *l = SPA_CONTAINER_OF (log, DebugLog, log);
  char text[1024], location[1024];
  static const char *levels[] = { "-", "E", "W", "I", "D", "T", };
  int size;

  vsnprintf (text, sizeof(text), fmt, args);
  size = snprintf (location, sizeof(location), "[%s][%s:%i %s()] %s\n",
      levels[level], strrchr (file, '/')+1, line, func, text);

  if (SPA_UNLIKELY (level == SPA_LOG_LEVEL_TRACE && l->source)) {
    uint32_t index;
    uint64_t count = 1;

    spa_ringbuffer_get_write_index (&l->trace_rb, &index);
    spa_ringbuffer_write_data (&l->trace_rb, l->trace_data,
                                index & l->trace_rb.mask,
                                location, size);
    spa_ringbuffer_write_update (&l->trace_rb, index + size);

    write (l->source->fd, &count, sizeof(uint64_t));
  } else
    fputs (location, stderr);
}

static void
do_log (SpaLog        *log,
        SpaLogLevel    level,
        const char    *file,
        int            line,
        const char    *func,
        const char    *fmt, ...)
{
  va_list args;
  va_start (args, fmt);
  do_logv (log, level, file, line, func, fmt, args);
  va_end (args);
}

static DebugLog log = {
  { sizeof (SpaLog),
    NULL,
    DEFAULT_LOG_LEVEL,
    do_log,
    do_logv,
  },
  {  0, 0, TRACE_BUFFER, TRACE_BUFFER - 1 },
};

SpaLog *
pinos_log_get (void)
{
  return &log.log;
}

void
pinos_log_set_level (SpaLogLevel level)
{
  pinos_log_level = level;
  log.log.level = level;
}

static void
on_trace_event (SpaSource *source)
{
  int32_t avail;
  uint32_t index;
  uint64_t count;

  if (read (source->fd, &count, sizeof (uint64_t)) != sizeof (uint64_t))
    fprintf (stderr, "failed to read event fd: %s", strerror (errno));

  while ((avail = spa_ringbuffer_get_read_index (&log.trace_rb, &index)) > 0) {
    uint32_t offset, first, written;

    if (avail > log.trace_rb.size) {
      index += avail - log.trace_rb.size;
      avail = log.trace_rb.size;
    }
    offset = index & log.trace_rb.mask;
    first = SPA_MIN (avail, log.trace_rb.size - offset);

    written = fprintf (stderr, "%*s", first, log.trace_data + offset);
    if (SPA_UNLIKELY (avail > first)) {
      written += fprintf (stderr, "%*s", avail - first, log.trace_data + first);
    }
    spa_ringbuffer_read_update (&log.trace_rb, index + written);
  }
}

void
pinos_log_set_trace_event (SpaSource *source)
{
  log.source = source;
  log.source->func = on_trace_event;
  log.source->data = &log;
}

void
pinos_log_log (SpaLogLevel  level,
               const char  *file,
               int          line,
               const char  *func,
               const char  *fmt, ...)
{
  if (SPA_UNLIKELY (pinos_log_level_enabled (level))) {
    va_list args;
    va_start (args, fmt);
    do_logv (&log.log, level, file, line, func, fmt, args);
    va_end (args);
  }
}

void
pinos_log_logv (SpaLogLevel  level,
                const char  *file,
                int          line,
                const char  *func,
                const char  *fmt,
                va_list      args)
{
  if (SPA_UNLIKELY (pinos_log_level_enabled (level))) {
    do_logv (&log.log, level, file, line, func, fmt, args);
  }
}