"""Weather service for fetching forecasts from VisualCrossing API."""

from typing import Optional
from urllib.parse import quote

from app.models.weather import WeatherForecast
from app.utils.http_client import HttpClient
from app.utils.logging_config import get_logger


class WeatherServiceError(Exception):
    """Raised when the weather service encounters an error."""

    pass


class WeatherService:
    """Client for the VisualCrossing Weather API."""

    BASE_URL = "https://weather.visualcrossing.com/VisualCrossingWebServices/rest/services/timeline"

    def __init__(
        self,
        api_key: str,
        http_client: Optional[HttpClient] = None,
    ) -> None:
        """Initialize the weather service.

        Args:
            api_key: VisualCrossing API key.
            http_client: Optional HTTP client instance. Creates one if not provided.
        """
        if not api_key:
            raise WeatherServiceError("VisualCrossing API key is required")

        self.api_key = api_key
        self.http_client = http_client or HttpClient()
        self.logger = get_logger(__name__)

    def get_forecast(
        self,
        location: str,
        hours_ahead: int = 24,
        unit_group: str = "us",
    ) -> WeatherForecast:
        """Fetch weather forecast for a location.

        Args:
            location: Location string (e.g., "viola,tn" or ZIP code).
            hours_ahead: Number of hours of forecast to retrieve.
            unit_group: Unit system ("us" for imperial, "metric" for metric).

        Returns:
            WeatherForecast with hourly data and any active alerts.

        Raises:
            WeatherServiceError: If the API request fails.
        """
        self.logger.info(
            "fetching_forecast",
            location=location,
            hours_ahead=hours_ahead,
        )

        # Build API URL
        encoded_location = quote(location, safe="")
        url = f"{self.BASE_URL}/{encoded_location}"

        params = {
            "unitGroup": unit_group,
            "include": "days,hours,alerts,current,events",
            "key": self.api_key,
            "contentType": "json",
        }

        response = self.http_client.get(url, params=params)

        if not response.success:
            self.logger.error(
                "forecast_fetch_failed",
                status_code=response.status_code,
                error=response.text,
            )
            raise WeatherServiceError(
                f"Failed to fetch forecast: {response.status_code} - {response.text}"
            )

        if response.json_data is None:
            self.logger.error("forecast_invalid_json", response_text=response.text[:200])
            raise WeatherServiceError("Invalid JSON response from weather API")

        forecast = WeatherForecast.from_api_data(response.json_data, hours_ahead)

        self.logger.info(
            "forecast_fetched",
            location=forecast.resolved_address,
            hourly_count=len(forecast.hourly_forecasts),
            alert_count=len(forecast.alerts),
        )

        return forecast