#ifndef LOG_H
#define LOG_H

/** @file log.h
 *
 * Local logging functions
 */
#include "error.h"

/**
 * Log level definitions
 *
 * XXX: these names conflict with <syslog.h>
 */
enum log_level {
    LOG_DEBUG,
    LOG_INFO,
    LOG_WARN,
    LOG_ERROR,
    LOG_FATAL,
};

/**
 * List of log_level values as strings, NULL-terminated
 */
extern const char *log_level_names[];

/**
 * The default log level
 */
#define LOG_LEVEL_DEFAULT LOG_INFO

/**
 * Maximum length of a log message, including terminating NUL
 */
#define LOG_MSG_MAX 1024

/**
 * Log output function, for displaying a line of text, without any trailing newline.
 */
typedef void (*log_output_func) (const char *line, void *arg);

/**
 * Set the current log level to filter out messages below the given level
 */
void set_log_level (enum log_level level);

/**
 * Set the current log output function, replacing any default or previous value.
 *
 * Pass in func as NULL to revert to the default handler.
 */
void log_set_func (log_output_func func, void *arg);

/**
 * Log a message with the given level
 */
void log_msg (enum log_level level, const char *func, const char *format, ...)
    __attribute__ ((format (printf, 3, 4)));

/**
 * Shorthand for log_msg
 */
#define log_debug(...) log_msg(LOG_DEBUG, __func__, __VA_ARGS__)
#define log_info(...)  log_msg(LOG_INFO,  __func__, __VA_ARGS__)
#define log_warn(...)  log_msg(LOG_WARN,  __func__, __VA_ARGS__)
#define log_error(...) log_msg(LOG_ERROR, __func__, __VA_ARGS__)
#define log_fatal(...) log_msg(LOG_FATAL, __func__, __VA_ARGS__)

/**
 * Log a message with the given level, appending the formatted error code name
 */
void _log_err_code (enum log_level level, err_t err, const char *func, const char *format, ...)
    __attribute__ ((format (printf, 4, 5)));

/**
 * Log a message with the given level, appending the formatted error message
 */
void _log_err (enum log_level level, const error_t *err, const char *func, const char *format, ...)
    __attribute__ ((format (printf, 4, 5)));

/**
 * Log using errno.
 */
void _log_perr (enum log_level level, const char *func, const char *format, ...)
    __attribute__ ((format (printf, 3, 4)));

/**
 * Shorthand for _log_*
 *
 * XXX: kill log_err_info, add log_err_code
 */
#define log_err(err_code, ...) _log_err_code(LOG_ERROR, err_code, __func__, __VA_ARGS__)
#define log_err_info(err_info, ...) _log_err(LOG_ERROR, err_info, __func__, __VA_ARGS__)
#define log_perr(...) _log_perr(LOG_ERROR, __func__, __VA_ARGS__)

#define log_warn_err_code(err_code, ...) _log_err_code(LOG_WARN, err_code, __func__, __VA_ARGS__)
#define log_warn_err(err_info, ...) _log_err(LOG_WARN, err_info, __func__, __VA_ARGS__)

/**
 * log_fatal + exit failure
 */
#define FATAL(...) do { log_fatal(__VA_ARGS__); abort(); } while (0)

/**
 * log_err + exit failure
 */
#define FATAL_ERR(err_code, ...) do { _log_err_code(LOG_FATAL, err_code, __func__, __VA_ARGS__); abort(); } while (0)

/**
 * log_err_info + exit failure
 */
#define FATAL_ERROR(err_info, ...) do { _log_err(LOG_FATAL, err_info, __func__, __VA_ARGS__); abort(); } while (0)

/**
 * log_perr + exit failure
 */
#define FATAL_PERROR(...) do { _log_perr(LOG_FATAL, __func__, __VA_ARGS__); abort(); } while (0)

#endif /* LOG_H */