"""Weather data router -- primary + secondary locations and hourly forecast."""

from __future__ import annotations

import asyncio
import logging
from typing import Any, Dict, List

from fastapi import APIRouter

from server.cache import cache
from server.config import get_settings
from server.services.weather_service import fetch_hourly_forecast, fetch_weather

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api", tags=["weather"])

CACHE_KEY = "weather"


@router.get("/weather")
async def get_weather() -> Dict[str, Any]:
    """Return weather for both configured locations plus an hourly forecast."""

    # --- cache hit? -----------------------------------------------------------
    cached = await cache.get(CACHE_KEY)
    if cached is not None:
        logger.debug("[WEATHER] Cache hit (key=%s)", CACHE_KEY)
        return cached

    # --- cache miss -- fetch all three in parallel ----------------------------
    cfg = get_settings()
    logger.info("[WEATHER] Cache miss — fetching '%s' + '%s'",
                cfg.weather_location, cfg.weather_location_secondary)

    results = await asyncio.gather(
        _safe_fetch_weather(cfg.weather_location),
        _safe_fetch_weather(cfg.weather_location_secondary),
        _safe_fetch_hourly(cfg.weather_location),
        return_exceptions=False,
    )

    primary_data = results[0]
    secondary_data = results[1]
    hourly_data = results[2]

    # Log result summary
    _log_weather_result("primary", cfg.weather_location, primary_data)
    _log_weather_result("secondary", cfg.weather_location_secondary, secondary_data)
    logger.info("[WEATHER] Hourly: %d slots", len(hourly_data))

    payload: Dict[str, Any] = {
        "primary": primary_data,
        "secondary": secondary_data,
        "hourly": hourly_data,
    }

    await cache.set(CACHE_KEY, payload, cfg.weather_cache_ttl)
    logger.debug("[WEATHER] Cached for %ds", cfg.weather_cache_ttl)
    return payload


# -- internal helpers ---------------------------------------------------------

def _log_weather_result(label: str, location: str, data: Dict[str, Any]) -> None:
    """Log a concise summary of a weather result."""
    if data.get("error"):
        logger.error("[WEATHER] %s (%s): ERROR — %s", label, location,
                     data.get("message", data.get("error")))
    else:
        logger.info("[WEATHER] %s (%s): %d°C, %s",
                    label, data.get("location", location),
                    data.get("temp", 0), data.get("description", "?"))


async def _safe_fetch_weather(location: str) -> Dict[str, Any]:
    """Fetch weather for *location*, returning an error stub on failure."""
    try:
        return await fetch_weather(location)
    except Exception as exc:
        logger.exception("[WEATHER] Unhandled error fetching '%s'", location)
        return {"error": True, "message": str(exc), "location": location}


async def _safe_fetch_hourly(location: str) -> List[Dict[str, Any]]:
    """Fetch hourly forecast for *location*, returning ``[]`` on failure."""
    try:
        return await fetch_hourly_forecast(location)
    except Exception as exc:
        logger.exception("[WEATHER] Unhandled error fetching hourly for '%s'", location)
        return []