/* SPDX-License-Identifier: GPL-3.0-or-later
 * Copyright © 2016-2018 The TokTok team.
 * Copyright © 2013 Tox project.
 */

/*
 * Logger abstraction backed by callbacks for writing.
 */
#ifndef C_TOXCORE_TOXCORE_LOGGER_H
#define C_TOXCORE_TOXCORE_LOGGER_H

#include <stdint.h>

#include "ccompat.h"

#ifndef MIN_LOGGER_LEVEL
#define MIN_LOGGER_LEVEL LOGGER_LEVEL_INFO
#endif

// NOTE: Don't forget to update build system files after modifying the enum.
typedef enum Logger_Level {
    LOGGER_LEVEL_TRACE,
    LOGGER_LEVEL_DEBUG,
    LOGGER_LEVEL_INFO,
    LOGGER_LEVEL_WARNING,
    LOGGER_LEVEL_ERROR,
} Logger_Level;

typedef struct Logger Logger;

typedef void logger_cb(void *context, Logger_Level level, const char *file, int line,
                       const char *func, const char *message, void *userdata);

/**
 * Creates a new logger with logging disabled (callback is NULL) by default.
 */
Logger *logger_new(void);

/**
 * Frees all resources associated with the logger.
 */
void logger_kill(Logger *log);

/**
 * Sets the logger callback. Disables logging if set to NULL.
 * The context parameter is passed to the callback as first argument.
 */
void logger_callback_log(Logger *log, logger_cb *function, void *context, void *userdata);

/**
 * Main write function. If logging is disabled, this does nothing.
 *
 * If the logger is NULL, this writes to stderr. This behaviour should not be
 * used in production code, but can be useful for temporarily debugging a
 * function that does not have a logger available. It's essentially
 * fprintf(stderr, ...), but with timestamps and source location. Toxcore must
 * be built with -DUSE_STDERR_LOGGER for this to work. It will cause an
 * assertion failure otherwise.
 */
void logger_write(
    const Logger *log, Logger_Level level, const char *file, int line, const char *func,
    const char *format, ...) GNU_PRINTF(6, 7);


#define LOGGER_WRITE(log, level, ...) \
    do { \
        if (level >= MIN_LOGGER_LEVEL) { \
            logger_write(log, level, __FILE__, __LINE__, __func__, __VA_ARGS__); \
        } \
    } while (0)

/* To log with an logger */
#define LOGGER_TRACE(log, ...)   LOGGER_WRITE(log, LOGGER_LEVEL_TRACE  , __VA_ARGS__)
#define LOGGER_DEBUG(log, ...)   LOGGER_WRITE(log, LOGGER_LEVEL_DEBUG  , __VA_ARGS__)
#define LOGGER_INFO(log, ...)    LOGGER_WRITE(log, LOGGER_LEVEL_INFO   , __VA_ARGS__)
#define LOGGER_WARNING(log, ...) LOGGER_WRITE(log, LOGGER_LEVEL_WARNING, __VA_ARGS__)
#define LOGGER_ERROR(log, ...)   LOGGER_WRITE(log, LOGGER_LEVEL_ERROR  , __VA_ARGS__)

#define LOGGER_FATAL(log, ...) \
    do { \
        LOGGER_ERROR(log, __VA_ARGS__); \
        abort(); \
    } while(0)

#define LOGGER_ASSERT(log, cond, ...) \
    do { \
        if (!(cond)) { \
            LOGGER_ERROR(log, "Assertion failed"); \
            LOGGER_FATAL(log, __VA_ARGS__); \
        } \
    } while(0)

#endif // C_TOXCORE_TOXCORE_LOGGER_H
