"""
DDNS Service - Dynamic DNS update service.

A daemon that accepts HTTP(S) requests to dynamically update DNS entries.
Includes CLI administration tools for user and hostname management.
"""

import datetime

__version__ = "1.0.0"
__author__ = "Thomas Oettli <spacefreak@noop.ch>"

# DynDNS-compatible response statuses
STATUS_GOOD = "good"
STATUS_NOCHG = "nochg"
STATUS_BADAUTH = "badauth"
STATUS_NOHOST = "nohost"
STATUS_DNSERR = "dnserr"
STATUS_ABUSE = "abuse"
STATUS_BADIP = "badip"

__all__ = [
    "app",
    "cleanup",
    "cli",
    "config",
    "datetime_str",
    "dns",
    "email",
    "logging",
    "main",
    "models",
    "ratelimit",
    "server",
    "STATUS_GOOD",
    "STATUS_NOCHG",
    "STATUS_BADAUTH",
    "STATUS_NOHOST",
    "STATUS_DNSERR",
    "STATUS_ABUSE",
    "STATUS_BADIP",
]

DATETIME_FORMAT = "%Y-%m-%d %H:%M:%S %Z"

# Datetime convention:
# All datetime objects in this codebase are naive UTC to match database storage.
# - utc_now(): returns naive UTC datetime
# - datetime_str(): converts naive UTC to display string (adds tzinfo for formatting)
# - Database stores/returns naive datetimes (always UTC by convention)


def datetime_str(dt, utc=False):
    """
    Convert datetime to display string.

    Assumes naive datetimes are UTC per codebase convention.

    Args:
        dt: Datetime object (naive UTC or timezone-aware).
        utc: If True, display in UTC; otherwise convert to local timezone.

    Returns:
        Formatted datetime string, or "Never" if dt is not a datetime.
    """
    if not isinstance(dt, datetime.datetime):
        return "Never"

    aware_dt = dt.replace(tzinfo=datetime.UTC) if not dt.tzinfo else dt

    if utc:
        return aware_dt.strftime(DATETIME_FORMAT)
    else:
        return aware_dt.astimezone().strftime(DATETIME_FORMAT)


def utc_now():
    """
    Get current time as naive UTC datetime.

    Returns naive datetime to match database storage behavior.
    All naive datetimes in this codebase are assumed to be UTC.
    """
    return datetime.datetime.now(datetime.UTC).replace(tzinfo=None)