/*
 * Copyright (c) 2011 Collabora Ltd.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *     * Redistributions of source code must retain the above
 *       copyright notice, this list of conditions and the
 *       following disclaimer.
 *     * Redistributions in binary form must reproduce the
 *       above copyright notice, this list of conditions and
 *       the following disclaimer in the documentation and/or
 *       other materials provided with the distribution.
 *     * The names of contributors to this software may not be
 *       used to endorse or promote products derived from this
 *       software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 *
 * CONTRIBUTORS
 *  Stef Walter <stef@memberwebs.com>
 */

#include "config.h"

#include "debug.h"

#include <pthread.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

struct DebugKey {
	const char *name;
	int value;
};

static struct DebugKey debug_keys[] = {
	{ "lib", DEBUG_LIB },
	{ "conf", DEBUG_CONF },
	{ "uri", DEBUG_URI },
	{ "proxy", DEBUG_PROXY },
	{ 0, }
};

pthread_mutex_t debug_mutex = PTHREAD_MUTEX_INITIALIZER;

/* global variable exported in debug.h */
int debug_current_flags = ~0;

static int
parse_environ_flags (void)
{
	const char *env;
	int result = 0;
	const char *p;
	const char *q;
	int i;

	env = getenv ("P11_KIT_DEBUG");
	if (!env)
		return 0;

	if (strcmp (env, "all") == 0) {
		for (i = 0; debug_keys[i].name; i++)
			result |= debug_keys[i].value;

	} else if (strcmp (env, "help") == 0) {
		fprintf (stderr, "Supported debug values:");
		for (i = 0; debug_keys[i].name; i++)
			fprintf (stderr, " %s", debug_keys[i].name);
		fprintf (stderr, "\n");

	} else {
		p = env;
		while (*p) {
			q = strpbrk (p, ":;, \t");
			if (!q)
				q = p + strlen (p);

			for (i = 0; debug_keys[i].name; i++) {
				if (q - p == strlen (debug_keys[i].name) &&
				    strncmp (debug_keys[i].name, p, q - p) == 0)
					result |= debug_keys[i].value;
			}

			p = q;
			if (*p)
				p++;
		}
	}

	return result;
}

void
debug_message (int flag, const char *format, ...)
{
	static int initialized_flags = 0;
	char buffer[512];
	va_list args;

	pthread_mutex_lock (&debug_mutex);

	/*
	 * This is not thread-safe, but it's not really the end of the
	 * world if it happens more than once.
	 */
	if (!initialized_flags) {
		initialized_flags = 1;
		debug_current_flags = parse_environ_flags ();
	}

	if (flag & debug_current_flags) {
		va_start (args, format);
		vsnprintf (buffer, sizeof (buffer), format, args);
		buffer[sizeof (buffer) -1] = 0;
		va_end (args);
		fprintf (stderr, "(p11-kit:%d) %s\n", getpid(), buffer);
	}

	pthread_mutex_unlock (&debug_mutex);
}