/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set et sw=2 ts=2: */
/***************************************************************************
 *            debug.c
 *
 *  Thu Nov  1 13:38:47 CET 2012
 *  Copyright 2012 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of Debug Module.
 *
 *  Debug Module 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.
 *
 *  Debug Module 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 Debug Module; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
#include "debug.h"

#include <stdio.h>
#include <stdarg.h>
#include <time.h>
#include <string.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#ifdef WITH_DBG_MUTEX
#include <pthread.h>
#endif

#ifdef WITH_DBG_FILTER
#include "debug_filter.h"
#endif

#ifdef WITH_DBG_SYSLOG
#include "debug_syslog.h"
#endif

struct dbg_config_t {
  unsigned int flags;
#ifdef WITH_DBG_MUTEX
  pthread_mutex_t mutex;
#endif
  int fd;
  int file_fd;
#ifdef WITH_DBG_SYSLOG
  const char* syslog_host;
  int syslog_port;
#endif
};// dbg_config;// = { .flags = DBG_FLAG_DEFAULT, .fd = -1, .file_fd = -1 }; 
static struct dbg_config_t dbg_config;

static void dbg_mutex_init()
{
#ifdef WITH_DBG_MUTEX
  if(dbg_config.flags & DBG_FLAG_USE_MUTEX) {
    pthread_mutex_init(&dbg_config.mutex, NULL);
  }
#endif
}

static void dbg_mutex_lock()
{
#ifdef WITH_DBG_MUTEX
  if(dbg_config.flags & DBG_FLAG_USE_MUTEX) {
    pthread_mutex_lock(&dbg_config.mutex);
  }
#endif
}

static void dbg_mutex_unlock()
{
#ifdef WITH_DBG_MUTEX
  if(dbg_config.flags & DBG_FLAG_USE_MUTEX) {
    pthread_mutex_unlock(&dbg_config.mutex);
  }
#endif
}

static void dbg_mutex_close()
{
#ifdef WITH_DBG_MUTEX
  if(dbg_config.flags & DBG_FLAG_USE_MUTEX) {
    // Make sure we don't destroy the mutex while another thread is using it.
    dbg_mutex_lock();
    dbg_mutex_unlock();
    pthread_mutex_destroy(&dbg_config.mutex);
  }
#endif
}

dbg_status_t dbg_init(unsigned int flags, ...)
{
  dbg_status_t status = DBG_STATUS_OK;

  dbg_config.flags = flags;

  dbg_config.flags = DBG_FLAG_DEFAULT;
  dbg_config.fd = -1;
  dbg_config.file_fd = -1;

  int end = 0;

  va_list vl;
  va_start(vl, flags);
  while(!end) {
    int option = va_arg(vl, int);
    switch(option) {
    case DBG_OPTION_END:
      end = 1;
      break;
    case DBG_OPTION_FD:
      dbg_config.fd = va_arg(vl, int);
      break;
    case DBG_OPTION_FILENAME:
      if(dbg_config.flags & DBG_FLAG_OUTPUT_TO_FILE) {
        const char *filename = (const char*)va_arg(vl, char*);
        dbg_config.file_fd = open(filename, O_CREAT | O_RDWR, 0777);
      }
      break;
#ifdef WITH_DBG_SYSLOG
    case DBG_OPTION_SYSLOG_PORT:
      dbg_config.syslog_port = va_arg(vl, int);
      break;
    case DBG_OPTION_SYSLOG_HOST:
      dbg_config.syslog_host = (const char*)va_arg(vl, char*);
      break;
#endif
#ifdef WITH_DBG_FILTER
    case DBG_OPTION_FILTER:
      dbg_filter_parse((const char*)va_arg(vl, char*));
      break;
#endif
    default:
      status = DBG_STATUS_UNKNOWN_OPTION;
      printf("option: %x\n", option);
      goto err;
    }
  }

  dbg_mutex_init();

#ifdef WITH_DBG_SYSLOG
  if(dbg_config.flags & DBG_FLAG_OUTPUT_TO_SYSLOG) {
    dbg_syslog_init(dbg_config.syslog_host, dbg_config.syslog_port);
  }
#endif

 err:
  va_end(vl);

  return status;
}

void dbg_close()
{
  if(dbg_config.flags & DBG_FLAG_OUTPUT_TO_FILE) {
    if(dbg_config.file_fd != -1) close(dbg_config.file_fd);
  }

#ifdef WITH_DBG_SYSLOG
  dbg_syslog_close();
#endif

  dbg_mutex_close();
}

const char * const debug_class_str[] =
  { "fixme", "err", "warn", "info", "debug" };

/*
static unsigned int gettid()
{
  return (unsigned int)pthread_self();
}
*/

static int dbg_create_header(char *hdr, size_t size)
{
  time_t rawtime = time(NULL);
  struct tm t;
  localtime_r(&rawtime, &t);

  return snprintf(hdr, size,
                  "%d-%02d-%02d %02d:%02d:%02d",
                  t.tm_year + 1900,
                  t.tm_mon + 1,
                  t.tm_mday,
                  t.tm_hour,
                  t.tm_min,
                  t.tm_sec);
}

static int dbg_output_fd(int fd, const char *msg)
{
  if(fd == -1) return 1;

  char hdr[32];
  dbg_create_header(hdr, sizeof(hdr));

  int s = -1;
  s = write(fd, hdr, strlen(hdr));
  s = write(fd, " ", 1);
  s = write(fd, msg, strlen(msg));
  if(msg[strlen(msg) - 1] != '\n') {
    s = write(fd, "\n", 1);
  }
  return 0;
}

int __debug(const char *func, const int line,
            const enum __debug_class cl,
            const char *ch, const char *fmt, ...)
{
  int result = 0;
  int sz;

  dbg_mutex_lock();

#ifdef WITH_DBG_FILTER
  if(!dbg_filter_enabled(cl, ch)) goto done;
#endif

  //
  // Generate message
  //

  char buf[1024];

  sz = snprintf(buf, sizeof(buf),
                "%s:%s:%s:%d ",
                debug_class_str[(unsigned)cl], ch, func, line);
  va_list va;
  va_start(va, fmt);
  sz += vsnprintf(buf + sz, sizeof(buf) - sz, fmt, va);
  va_end(va);

  //
  // Send message to output
  //

  if(dbg_config.flags & DBG_FLAG_OUTPUT_TO_STDOUT) {
    dbg_output_fd(STDOUT_FILENO, buf);
  }

  if(dbg_config.flags & DBG_FLAG_OUTPUT_TO_STDERR) {
    dbg_output_fd(STDERR_FILENO, buf);
  }

  if(dbg_config.flags & DBG_FLAG_OUTPUT_TO_FD) {
    dbg_output_fd(dbg_config.fd, buf);
  }

  if(dbg_config.flags & DBG_FLAG_OUTPUT_TO_FILE) {
    dbg_output_fd(dbg_config.file_fd, buf);
  }

  if(dbg_config.flags & DBG_FLAG_OUTPUT_TO_SYSLOG) {
    dbg_syslog_output(buf);
  }

// done:
  dbg_mutex_unlock();

  return result;
}