import datetime
import sys
import syslog

# fmt: disable # don't conflate
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
# fmt: enable

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  # type: ignore

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  # type: ignore

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: str | 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