# -*- coding: utf-8 -*-

import sys, syslog, datetime

EMERG                = int(syslog.LOG_EMERG)
ALERT                = int(syslog.LOG_ALERT)
CRIT                 = int(syslog.LOG_CRIT)
ERR                  = int(syslog.LOG_ERR)
WARNING              = int(syslog.LOG_WARNING)
NOTICE               = int(syslog.LOG_NOTICE)
INFO                 = int(syslog.LOG_INFO)
DEBUG                = int(syslog.LOG_DEBUG)
DEVEL                = int(syslog.LOG_DEBUG + 1)
OFF                  = DEVEL + 1

_log_level           = NOTICE
_last_tstamp         = datetime.datetime.now()
_first_tstamp        = _last_tstamp

def _log_level_name_by_value():
    if _log_level_name_by_value.map is None:
        _log_level_name_by_value.map = {
            EMERG: "EMERG",
            ALERT: "ALERT",
            CRIT: "CRIT",
            ERR: "ERR",
            WARNING: "WARNING",
            NOTICE: "NOTICE",
            INFO: "INFO",
            DEBUG: "DEBUG",
            DEVEL: "DEVEL",
            OFF: "OFF"
        }
    return _log_level_name_by_value.map
_log_level_name_by_value.map: dict[int, str]|None = None

def _log_level_value_by_name():
    if _log_level_value_by_name.map is None:
        _log_level_value_by_name.map = {}
        for value, name in _log_level_name_by_value().items():
            _log_level_value_by_name.map[name] = value
            _log_level_value_by_name.map[name.lower()] = value
    return _log_level_value_by_name.map
_log_level_value_by_name.map: dict[str, int]|None = None

def get_log_level_name(level: int) -> str:
    return _log_level_name_by_value()[level]

def parse_log_level(level: str|int) -> int:
    try:
        ret = int(level)
        if ret >= 0 and ret <= DEVEL:
            return ret
    except ValueError:
       return _log_level_value_by_name()[level]
    raise Exception("Invalid log level ", level)

def set_log_level(level: int|None=None) -> int:
    global _log_level
    ret = _log_level
    if level is not None:
        _log_level = parse_log_level(level)
    return ret

def set_log_flags(*args, **kwargs):
    pass

def log(prio: int, *args, **kwargs):
    global _log_level
    if prio > _log_level:
        return
    print(*args, file = sys.stderr)

def log_time_diff(prio: int, *args, **kwargs):
    global _last_tstamp
    now = datetime.datetime.now()
    log(prio, now - _last_tstamp, now - _first_tstamp, *args)
    _last_tstamp = now