from dataclasses import dataclass

from edge.tracking import Track
from edge.geometry import track_displacement


@dataclass
class ImmobilityConfig:
    motion_thr: float = 0.02
    immobile_s: float = 120.0
    zone_immobile_s: float = 30.0


class ImmobilityWatchdog:
    def __init__(self, cfg: ImmobilityConfig):
        self.cfg = cfg
        self._still_since: dict[int, float] = {}
        self._fired: set[int] = set()

    def forget(self, track_id: int) -> None:
        self._still_since.pop(track_id, None)
        self._fired.discard(track_id)

    def update(self, track: Track, now: float, in_danger_zone: bool = False) -> tuple[bool, dict]:
        tid = track.track_id
        window = self.cfg.zone_immobile_s if in_danger_zone else self.cfg.immobile_s
        if track_displacement(track) >= self.cfg.motion_thr:
            self._still_since.pop(tid, None)
            self._fired.discard(tid)
            return False, {}
        if tid not in self._still_since:
            if len(track.frames) >= 2:
                self._still_since[tid] = track.frames[-2].t
            else:
                self._still_since[tid] = now
        start = self._still_since[tid]
        if now - start >= window and tid not in self._fired:
            self._fired.add(tid)
            return True, {"immobility_s": round(now - start, 1)}
        return False, {}