Files
BanGUI/backend/app/utils/time_utils.py
Lukas ac2028e1c2 Fix: Consolidate divergent _since_unix implementations (T-09)
Consolidate the two divergent implementations of _since_unix from ban_service.py
and history_service.py into a single shared utility function in time_utils.py.

Changes:
- Move _since_unix to app/utils/time_utils.py with consistent time.time() approach
- Move TIME_RANGE_SLACK_SECONDS constant to app/utils/constants.py
- Update ban_service.py to import since_unix from time_utils
- Update history_service.py to import since_unix from time_utils
- Both services now use the same window boundary calculation with 60-second slack
- Add comprehensive tests for the shared since_unix function
- Document timestamp handling rationale in Backend-Development.md

This ensures dashboard and history queries return consistent row counts for the
same time range by using the same timestamp calculation and slack window across
all services.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-04-25 18:44:59 +02:00

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"""Timezone-aware datetime helpers.
All datetimes in BanGUI are stored and transmitted in UTC.
Conversion to the user's display timezone happens only at the presentation
layer (frontend). These utilities provide a consistent, safe foundation
for working with time throughout the backend.
"""
import datetime
import time
def utc_now() -> datetime.datetime:
"""Return the current UTC time as a timezone-aware :class:`datetime.datetime`.
Returns:
Current UTC datetime with ``tzinfo=datetime.UTC``.
"""
return datetime.datetime.now(datetime.UTC)
def utc_from_timestamp(ts: float) -> datetime.datetime:
"""Convert a POSIX timestamp to a timezone-aware UTC datetime.
Args:
ts: POSIX timestamp (seconds since Unix epoch).
Returns:
Timezone-aware UTC :class:`datetime.datetime`.
"""
return datetime.datetime.fromtimestamp(ts, tz=datetime.UTC)
def add_minutes(dt: datetime.datetime, minutes: int) -> datetime.datetime:
"""Return a new datetime that is *minutes* ahead of *dt*.
Args:
dt: The source datetime (must be timezone-aware).
minutes: Number of minutes to add. May be negative.
Returns:
A new timezone-aware :class:`datetime.datetime`.
"""
return dt + datetime.timedelta(minutes=minutes)
def is_expired(expires_at: datetime.datetime) -> bool:
"""Return ``True`` if *expires_at* is in the past relative to UTC now.
Args:
expires_at: The expiry timestamp to check (must be timezone-aware).
Returns:
``True`` when the timestamp is past, ``False`` otherwise.
"""
return utc_now() >= expires_at
def hours_ago(hours: int) -> datetime.datetime:
"""Return a timezone-aware UTC datetime *hours* before now.
Args:
hours: Number of hours to subtract from the current time.
Returns:
Timezone-aware UTC :class:`datetime.datetime`.
"""
return utc_now() - datetime.timedelta(hours=hours)
def since_unix(range_: str) -> int:
"""Return the Unix timestamp for the start of a time-range window.
Uses :func:`time.time` (always UTC epoch seconds on all platforms) to be
consistent with how fail2ban stores ``timeofban`` values in its SQLite
database. fail2ban records :func:`time.time()` values directly, so using
a timezone-aware :func:`datetime.datetime.now`\\ ``(UTC).timestamp()``
would theoretically produce the same result but using :func:`time.time`
avoids any timezone-aware datetime pitfalls on misconfigured systems.
A 60-second slack window is applied to accommodate clock drift and
test seeding delays. This ensures consistent query windows across services
(e.g., dashboard vs. history).
Args:
range_: One of the supported time-range presets (e.g., ``"24h"``).
Returns:
Unix timestamp (seconds since epoch) representing the start of the
time window: *now range_ slack*.
"""
from app.models.ban import TIME_RANGE_SECONDS # noqa: F401
from app.utils.constants import TIME_RANGE_SLACK_SECONDS
seconds: int = TIME_RANGE_SECONDS[range_]
return int(time.time()) - seconds - TIME_RANGE_SLACK_SECONDS