hermes-agent/agent/battery.py
Brooklyn Nicholson 625687f334 feat(status-bar): add /battery toggle for a color-coded battery read-out
Add an opt-in battery indicator to the CLI and TUI status bars, shown as
the first element and colour-coded by charge (green/yellow/orange/red, or
green while charging). Off by default and a no-op on machines without a
battery.

- agent/battery.py: shared psutil-backed reader with a short TTL cache,
  category bucketing, and a compact 🔋/ label. Fails open to
  "unavailable" everywhere.
- CLI: /battery [on|off|status] toggle persisted to display.battery,
  rendered first in every status-bar width tier.
- TUI: /battery slash command, config sync, a system.battery RPC polled
  while enabled, and a pinned first segment in StatusRule.
2026-07-21 13:54:11 -05:00

131 lines
3.8 KiB
Python

"""System-battery read-out for the CLI/TUI status bar.
Reads the host battery through ``psutil`` (already a Hermes dependency) and
exposes a compact, colour-coded label. Everything degrades to "unavailable"
when there is no battery (desktops, servers, VMs) or when the read fails, so
callers can render the result unconditionally and simply show nothing.
The status bar repaints often (every keystroke and on a ~1s idle refresh), so
:func:`read_battery` memoises the last reading for a few seconds instead of
hitting ``psutil`` on every frame.
"""
from __future__ import annotations
import time
from dataclasses import dataclass
from typing import Optional
@dataclass(frozen=True)
class BatteryStatus:
"""A single battery reading.
``available`` is False on machines without a battery (or when the read
failed). ``percent`` is clamped to 0-100. ``plugged`` is True when on AC
power, False on battery, and None when the platform can't tell.
"""
available: bool
percent: Optional[int] = None
plugged: Optional[bool] = None
@property
def charging(self) -> bool:
return bool(self.plugged)
UNAVAILABLE = BatteryStatus(available=False)
# Colour buckets, mirroring the status-bar context styles but inverted (a full
# battery is "good", an empty one is "critical").
CATEGORY_GOOD = "good"
CATEGORY_WARN = "warn"
CATEGORY_BAD = "bad"
CATEGORY_CRITICAL = "critical"
CATEGORY_DIM = "dim"
_CACHE_TTL_SECONDS = 8.0
_cache: Optional[tuple[float, BatteryStatus]] = None
def _read_battery_uncached() -> BatteryStatus:
try:
import psutil
except Exception:
return UNAVAILABLE
# ``sensors_battery`` is missing on some platforms/builds of psutil.
reader = getattr(psutil, "sensors_battery", None)
if reader is None:
return UNAVAILABLE
try:
batt = reader()
except Exception:
return UNAVAILABLE
if batt is None:
return UNAVAILABLE
percent: Optional[int] = None
raw_percent = getattr(batt, "percent", None)
if raw_percent is not None:
try:
percent = max(0, min(100, int(round(float(raw_percent)))))
except (TypeError, ValueError):
percent = None
plugged = getattr(batt, "power_plugged", None)
if plugged is not None:
plugged = bool(plugged)
return BatteryStatus(available=True, percent=percent, plugged=plugged)
def read_battery(use_cache: bool = True) -> BatteryStatus:
"""Return the current battery status (cached for a few seconds)."""
global _cache
if use_cache and _cache is not None:
ts, cached = _cache
if time.monotonic() - ts < _CACHE_TTL_SECONDS:
return cached
status = _read_battery_uncached()
_cache = (time.monotonic(), status)
return status
def clear_cache() -> None:
"""Drop the memoised reading (used by tests)."""
global _cache
_cache = None
def battery_category(status: BatteryStatus) -> str:
"""Bucket a reading into a colour category: good/warn/bad/critical/dim."""
if not status.available or status.percent is None:
return CATEGORY_DIM
# On AC power the level isn't a concern — always read as healthy.
if status.charging:
return CATEGORY_GOOD
pct = status.percent
if pct <= 10:
return CATEGORY_CRITICAL
if pct <= 20:
return CATEGORY_BAD
if pct <= 50:
return CATEGORY_WARN
return CATEGORY_GOOD
def battery_glyph(status: BatteryStatus) -> str:
"""Return the leading glyph: a bolt while charging, else a battery."""
return "\u26a1" if status.charging else "\U0001f50b" # ⚡ / 🔋
def format_battery(status: BatteryStatus) -> str:
"""Return a compact label like ``🔋 82%`` / ``⚡ 82%`` (empty if N/A)."""
if not status.available or status.percent is None:
return ""
return f"{battery_glyph(status)} {status.percent}%"