/*
 * trace.h -- non-fatal message logs
 *
 * Copyright (c) 2020-2023 David Demelier <markand@malikania.fr>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef MLK_CORE_TRACE_H
#define MLK_CORE_TRACE_H

/**
 * \file mlk/core/trace.h
 * \brief Non-fatal message logs
 *
 * This module provides a simple way to log messages from the API or user code,
 * mostly when non-fatal errors happened.
 *
 * The default implementation uses printf with a timestamp in the form hh:mm::s
 * to the standard output, it can be disabled using your own
 * ::mlk_trace_handler or setting it to NULL.
 *
 * Example of lines generated by default:
 *
 * ```
 * 10:20:30: hello world
 * 20:50:00: goodbye world
 * ```
 */

#include <stdarg.h>

/**
 * Maximum trace line
 */
#define MLK_TRACE_LINE_MAX (128)

/**
 * Default trace handler implementation
 *
 * Can be set to NULL to disable logging.
 *
 * \param line the line to print
 */
extern void (*mlk_trace_handler)(const char *line);

#if defined(__cplusplus)
extern "C" {
#endif

/**
 * Write a trace log using a [printf] format style.
 *
 * [printf]: https://en.cppreference.com/w/c/io/fprintf
 *
 * \pre fmt != NULL
 * \param fmt the printf format string
 */
void
mlk_tracef(const char *fmt, ...);

/**
 * Similar to ::mlk_tracef but using a `va_list` instead.
 *
 * \pre fmt != NULL
 * \param fmt the printf format string
 * \param ap the variadic handle
 */
void
mlk_traceva(const char *fmt, va_list ap);

#if defined(__cplusplus)
}
#endif

#endif /* !MLK_CORE_TRACE_H */