import requests
import os
from typing import Optional, Dict, Any
from utils.config import config
from functools import lru_cache
import time

class WeatherService:
    """Service for fetching weather information with caching"""
    
    def __init__(self):
        self.api_key = config.openweather_api_key
        self.base_url = "http://api.openweathermap.org/data/2.5"
        
    def _get_ttl_hash(self, seconds=300):
        """Helper function to invalidate cache periodically"""
        return round(time.time() / seconds)
        
    @lru_cache(maxsize=128)
    def get_current_weather_cached(self, city: str, ttl_hash=None):
        """Cached version of weather API calls"""
        return self.get_current_weather(city)
        
    def get_current_weather(self, city: str) -> Optional[Dict[str, Any]]:
        """Get current weather for a city"""
        if not self.api_key:
            print("OpenWeather API key not configured")
            return None
            
        try:
            params = {
                'q': city,
                'appid': self.api_key,
                'units': 'metric'  # Celsius
            }
            response = requests.get(
                f"{self.base_url}/weather",
                params=params,
                timeout=10
            )
            if response.status_code == 200:
                data = response.json()
                return {
                    'city': data['name'],
                    'country': data['sys']['country'],
                    'temperature': data['main']['temp'],
                    'feels_like': data['main']['feels_like'],
                    'humidity': data['main']['humidity'],
                    'description': data['weather'][0]['description'],
                    'icon': data['weather'][0]['icon']
                }
            else:
                print(f"Weather API error: {response.status_code} - {response.text}")
                return None
        except Exception as e:
            print(f"Error fetching weather data: {e}")
            return None
            
    def get_forecast(self, city: str, days: int = 5) -> Optional[Dict[str, Any]]:
        """Get weather forecast for a city"""
        if not self.api_key:
            print("OpenWeather API key not configured")
            return None
            
        try:
            params = {
                'q': city,
                'appid': self.api_key,
                'units': 'metric',
                'cnt': days
            }
            response = requests.get(
                f"{self.base_url}/forecast",
                params=params,
                timeout=10
            )
            if response.status_code == 200:
                data = response.json()
                forecasts = []
                for item in data['list']:
                    forecasts.append({
                        'datetime': item['dt_txt'],
                        'temperature': item['main']['temp'],
                        'description': item['weather'][0]['description'],
                        'icon': item['weather'][0]['icon']
                    })
                return {
                    'city': data['city']['name'],
                    'country': data['city']['country'],
                    'forecasts': forecasts
                }
            else:
                print(f"Forecast API error: {response.status_code} - {response.text}")
                return None
        except Exception as e:
            print(f"Error fetching forecast data: {e}")
            return None
            
    def get_weather_summary(self, city="New York") -> str:
        """Get formatted weather summary with caching"""
        try:
            weather = self.get_current_weather_cached(
                city, 
                ttl_hash=self._get_ttl_hash(300)
            )
            if weather:
                return f"{weather.get('temperature', 'N/A')}°C, {weather.get('description', 'Clear skies')}"
            else:
                return "Clear skies"
        except:
            return "Clear skies"

# Global weather service instance
weather_service = WeatherService()