/* -*- 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

struct {
  unsigned int flags;
#ifdef WITH_DBG_MUTEX
  pthread_mutex_t mutex;
#endif
  int fd;
  int file_fd;
} dbg_config = { .flags = DBG_FLAG_DEFAULT, .fd = -1, .file_fd = -1 }; 

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;

  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;
    default:
      status = DBG_STATUS_UNKNOWN_OPTION;
      printf("option: %x\n", option);
      goto err;
    }
  }

  dbg_mutex_init();

 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);
  }

  dbg_mutex_close();
}

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

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));
  write(fd, hdr, strlen(hdr));
  write(fd, " ", 1);
  write(fd, msg, strlen(msg));
  if(msg[strlen(msg) - 1] != '\n') 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;

  dbg_mutex_lock();

  //
  // Generate message
  //

  char buf[1024];

  int 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);
  }

 done:
  dbg_mutex_unlock();

  return result;
}

#if 0

#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
//#include <pthread.h>
#include <string>
#include <time.h>

//#include "mutex.h"

//static Mutex mutex;

static unsigned int gettid()
{
  return 0;//(unsigned int)pthread_self();
}

static FILE *logfp = stderr;

#define NELEM(x)	(sizeof(x)/sizeof((x)[0]))
struct __debug_channel
{
	char name[32];
	unsigned flags;
};

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

#define __DEBUG_CHANNEL_MAX 256

static struct __debug_channel debug_channel[__DEBUG_CHANNEL_MAX];
static unsigned n_debug_channel = 0;
static unsigned debug_flags = (1 << __class_err) | (1 << __class_fixme);

static int __debug_enabled(const enum __debug_class cl, const char *ch)
{
	unsigned i;
	for(i = 0; i < n_debug_channel; i++) {
		if(!strcmp(ch, debug_channel[i].name)) {
			return (debug_channel[i].flags & (1 << cl)) != 0;
		}
	}
	return debug_flags & (1 << cl);
}

int __debug(const char *func, const int line,
            const enum __debug_class cl,
            const char *ch, const char *fmt, ...)
{
  time_t rawtime = time(NULL);
  struct tm *t = localtime(&rawtime);

  //  MutexAutolock m(mutex);
	int ret = 0;
	if(__debug_enabled(cl, ch)) {
		if((unsigned)cl < NELEM(debug_class_str))
			ret += fprintf(logfp, "%d-%02d-%02d %02d:%02d:%02d %u %s:%s:%s:%d ",
                     t->tm_year + 1900,
                     t->tm_mon + 1,
                     t->tm_mday,
                     t->tm_hour,
                     t->tm_min,
                     t->tm_sec,
                     gettid(),
                     debug_class_str[(unsigned)cl], ch, func, line);
		if(fmt) {
			va_list va;
			va_start(va, fmt);
			ret += vfprintf(logfp, fmt, va);
			va_end(va);
		}
	}
	if(ret){
		fflush(logfp);
  }
	return ret;
}

void debug_init(FILE *fp)
{
  //  mutex.name = "debug";
  //  MutexAutolock m(mutex);
  logfp = fp;
}

/*
 * fmt := [set[,set]*]*
 * set := [+-]channel
 *     |  class[+-]channel
 *     |  [+-]all
 */
void debug_parse(const char *fmt)
{
  //  MutexAutolock m(mutex);
	char *s;
	char *next;
	char *opt;

	if(!(s = strdup(fmt))) return;

	for(opt = s; opt; opt = next) {
		int set = 0;
		int clr = 0;
		unsigned i;
		if((next = strchr(opt, ','))) *next++ = '\0';
		char *p = opt + strcspn(opt, "+-");
		if(!*p) p = opt;	// All chars -> a channel name
		if(p > opt) {
			// we have a class
			for(i = 0; i < NELEM(debug_class_str); i++) {
				int n = strlen(debug_class_str[i]);
				if(n != (p - opt)) continue;
				if(!memcmp(opt, debug_class_str[i], n)) {
					// Found the class
					if(*p == '+')
						set = 1 << i;
					else
						clr = 1 << i;
					break;
				}
			}
			if(i == NELEM(debug_class_str)) continue;
		} else {
			if(*p == '-')
				clr = ~0;
			else
				set = ~0;
		}
		if(*p == '+' || *p == '-') p++;
		if(!*p) continue;
		if(!strcmp("all", p)) {
			debug_flags = (debug_flags & ~clr) | set;
		} else {
			if(strlen(p) >= sizeof(debug_channel[0].name)) continue;
			for(i = 0; i < n_debug_channel; i++) {
				if(!strcmp(p, debug_channel[i].name)) {
					debug_channel[i].flags = (debug_channel[i].flags & ~clr) | set;
					break;
				}
			}
			if(i == n_debug_channel && n_debug_channel < __DEBUG_CHANNEL_MAX) {
				strcpy(debug_channel[i].name, p);
				debug_channel[i].flags = (debug_flags & ~clr) | set;
				n_debug_channel++;
			}
		}
	}
	free(s);
}


#endif