"""Celery tasks for POI distance calculation."""
import asyncio
import logging
from typing import Any

from celery import Task
from celery_app import app
from database import engine
from models.listing import ListingType
from repositories.listing_repository import ListingRepository
from repositories.poi_repository import POIRepository
from services.poi_distance_calculator import calculate_poi_distances

logger = logging.getLogger(__name__)

celery_logger = logging.getLogger("celery.task")
if not celery_logger.handlers:
    handler = logging.StreamHandler()
    handler.setFormatter(logging.Formatter(
        "%(asctime)s [%(levelname)s] %(name)s: %(message)s"
    ))
    celery_logger.addHandler(handler)
    celery_logger.setLevel(logging.INFO)


@app.task(
    bind=True,
    autoretry_for=(Exception,),
    max_retries=3,
    retry_backoff=True,
    retry_backoff_max=300,
)
def calculate_poi_distances_task(
    self: Task,
    poi_id: int,
    travel_modes: list[str],
    listing_type: str,
    listing_ids: list[int] | None = None,
) -> dict[str, Any]:
    """Background task to calculate distances from listings to a POI.

    Args:
        poi_id: ID of the PointOfInterest.
        travel_modes: List of travel modes (WALK, BICYCLE, TRANSIT).
        listing_type: "BUY" or "RENT".
        listing_ids: Optional subset of listing IDs.
    """
    celery_logger.info(
        f"Starting POI distance calculation: poi_id={poi_id}, "
        f"modes={travel_modes}, type={listing_type}"
    )

    self.update_state(state="PROGRESS", meta={
        "phase": "starting",
        "progress": 0,
        "message": "Starting distance calculation...",
    })

    listing_repo = ListingRepository(engine)
    poi_repo = POIRepository(engine)

    poi = poi_repo.get_poi_by_id(poi_id)
    if poi is None:
        celery_logger.error(f"POI {poi_id} not found")
        return {"error": f"POI {poi_id} not found", "distances_computed": 0}

    lt = ListingType(listing_type)

    def on_progress(completed: int, total: int, message: str) -> None:
        progress = round(completed / total, 2) if total > 0 else 0
        self.update_state(state="PROGRESS", meta={
            "phase": "computing",
            "progress": progress,
            "processed": completed,
            "total": total,
            "message": message,
        })

    try:
        total = asyncio.run(
            calculate_poi_distances(
                listing_repo=listing_repo,
                poi_repo=poi_repo,
                poi=poi,
                travel_modes=travel_modes,
                listing_type=lt,
                listing_ids=listing_ids,
                on_progress=on_progress,
            )
        )
    except Exception:
        celery_logger.exception(
            f"POI distance calculation failed: poi_id={poi_id}"
        )
        raise  # Let Celery's autoretry handle it

    celery_logger.info(f"POI distance calculation complete: {total} distances computed")

    return {
        "phase": "completed",
        "progress": 1,
        "distances_computed": total,
        "message": f"Computed {total} distances for POI '{poi.name}'",
    }