50 lines
1.8 KiB
Python
50 lines
1.8 KiB
Python
"""Low-frequency read-only observation emits transitions, never frame writes."""
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import json
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from pigway_frame_flow.storage.database import encode
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class DeviceObserver:
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def __init__(self, service):
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self.service = service
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def tick(self):
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for id, driver in self.service.registry.drivers.items():
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try:
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device = driver.device()
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except Exception:
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# Cloud query failure is not evidence that the physical device is offline.
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continue
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low = (
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device.power.battery_percent is not None
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and device.power.battery_percent <= 20
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)
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state = {"status": device.status, "low_battery": low}
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key = "device-observation:" + id
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row = self.service.db.one(
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"SELECT payload FROM app_config WHERE key=?", (key,)
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)
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previous = json.loads(row["payload"]) if row else None
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if previous == state:
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continue
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if previous:
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if previous["status"] != state["status"] and state["status"] in (
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"online",
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"offline",
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):
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self.service.db.event(
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"device." + state["status"], {"device_id": id}
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)
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if low and not previous["low_battery"]:
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self.service.db.event(
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"device.low_battery",
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{
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"device_id": id,
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"battery_percent": device.power.battery_percent,
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},
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)
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self.service.db.execute(
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"INSERT OR REPLACE INTO app_config VALUES(?,?)", (key, encode(state))
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)
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