from datetime import datetime, timedelta
from typing import Optional
from sqlalchemy.ext.asyncio import AsyncSession

from app.models import Vehicle, Position, Event
from app.config import settings


async def detect_events(
    db: AsyncSession,
    vehicle: Vehicle,
    current: Position,
    previous: Optional[Position]
) -> list[Event]:
    """Обнаружение событий на основе новой позиции"""
    events = []

    # Check for overspeed
    if current.speed > settings.overspeed_limit:
        event = Event(
            vehicle_id=vehicle.id,
            timestamp=current.timestamp,
            type="OVERSPEED",
            payload={
                "speed": current.speed,
                "limit": settings.overspeed_limit,
                "lat": current.lat,
                "lon": current.lon
            }
        )
        db.add(event)
        await db.commit()
        await db.refresh(event)
        events.append(event)

    # Check for long stop (if speed is 0 and was 0 for a while)
    if previous and current.speed < 2 and previous.speed < 2:
        time_diff = current.timestamp - previous.timestamp
        if time_diff >= timedelta(minutes=settings.long_stop_minutes):
            event = Event(
                vehicle_id=vehicle.id,
                timestamp=current.timestamp,
                type="LONG_STOP",
                payload={
                    "duration_minutes": time_diff.total_seconds() / 60,
                    "lat": current.lat,
                    "lon": current.lon
                }
            )
            db.add(event)
            await db.commit()
            await db.refresh(event)
            events.append(event)

    return events