"""Gesture event state machine."""

from __future__ import annotations

from dataclasses import dataclass

from .events import GestureEvent
from .recognizer import GestureObservation


@dataclass
class GestureStateMachine:
    confidence_threshold: float = 0.72
    cooldown_ms: int = 450
    mode: str = "single"

    def __post_init__(self) -> None:
        self._last_emit_by_gesture: dict[str, int] = {}
        self._seq = 0

    def accept(self, observation: GestureObservation) -> GestureEvent | None:
        if observation.confidence < self.confidence_threshold:
            return None

        timestamp_ms = observation.timestamp_ms
        if timestamp_ms is None:
            from .events import now_ms

            timestamp_ms = now_ms()

        last_emit_at = self._last_emit_by_gesture.get(observation.gesture)
        if last_emit_at is not None and timestamp_ms - last_emit_at < self.cooldown_ms:
            return None

        self._seq += 1
        self._last_emit_by_gesture[observation.gesture] = timestamp_ms
        return GestureEvent(
            gesture=observation.gesture,
            confidence=round(max(0.0, min(1.0, observation.confidence)), 4),
            intensity=round(max(0.0, min(1.0, observation.intensity)), 4),
            timestamp_ms=timestamp_ms,
            seq=self._seq,
            mode=self.mode,
            input_mode=self.mode,
            camera_id=observation.camera_id,
        )