from dataclasses import dataclass

from edge.tracking import Track
from edge.geometry import normalize


@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 _displacement(self, track: Track) -> float:
        if len(track.frames) < 2:
            return 1.0
        a, b = track.frames[-2], track.frames[-1]
        h = b.bbox.height or 1.0
        d = sum(((p.x - q.x) ** 2 + (p.y - q.y) ** 2) ** 0.5
                for p, q in zip(a.keypoints, b.keypoints)) / len(b.keypoints)
        return normalize(d, h)

    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 self._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, {}