from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from datetime import datetime, timedelta
import urllib.request
import urllib.parse
import urllib.error
import json

from app.database import get_db
from app.models.settings import Settings
from app.config import settings as app_settings
from app.routers.auth import get_current_session

router = APIRouter()

_cache: dict = {}


@router.get("/weather")
async def get_weather(
    db: AsyncSession = Depends(get_db),
    current_user: Settings = Depends(get_current_session)
):
    # Check cache
    now = datetime.now()
    if _cache.get("expires_at") and now < _cache["expires_at"]:
        return _cache["data"]

    # Get city from settings
    result = await db.execute(select(Settings))
    settings_row = result.scalar_one_or_none()
    city = settings_row.weather_city if settings_row else None
    if not city:
        raise HTTPException(status_code=400, detail="No weather city configured")

    api_key = app_settings.OPENWEATHERMAP_API_KEY
    if not api_key:
        raise HTTPException(status_code=500, detail="Weather API key not configured")

    try:
        # Current weather
        current_url = f"https://api.openweathermap.org/data/2.5/weather?q={urllib.parse.quote(city)}&units=metric&appid={api_key}"
        with urllib.request.urlopen(current_url, timeout=10) as resp:
            current_data = json.loads(resp.read().decode())

        # Forecast for rain probability
        forecast_url = f"https://api.openweathermap.org/data/2.5/forecast?q={urllib.parse.quote(city)}&units=metric&cnt=8&appid={api_key}"
        with urllib.request.urlopen(forecast_url, timeout=10) as resp:
            forecast_data = json.loads(resp.read().decode())

        rain_chance = 0
        for item in forecast_data.get("list", []):
            pop = item.get("pop", 0)
            if pop > rain_chance:
                rain_chance = pop

        weather_result = {
            "temp": round(current_data["main"]["temp"]),
            "temp_min": round(current_data["main"]["temp_min"]),
            "temp_max": round(current_data["main"]["temp_max"]),
            "description": current_data["weather"][0]["description"],
            "rain_chance": round(rain_chance * 100),
            "sunrise": current_data["sys"]["sunrise"],
            "sunset": current_data["sys"]["sunset"],
            "city": current_data["name"],
        }

        # Cache for 1 hour
        _cache["data"] = weather_result
        _cache["expires_at"] = now + timedelta(hours=1)

        return weather_result

    except urllib.error.URLError as e:
        raise HTTPException(status_code=502, detail=f"Weather service unavailable: {str(e)}")
    except (KeyError, json.JSONDecodeError) as e:
        raise HTTPException(status_code=502, detail=f"Invalid weather data: {str(e)}")