from flask import Flask, request, jsonify
from flask_cors import CORS
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address
import requests
import time

app = Flask(__name__)
CORS(app)

# Rate Limiter Configuration
# 1000 per day (Hard limit), 60 per hour, 5 per minute per IP
limiter = Limiter(
    get_remote_address,
    app=app,
    default_limits=["1000 per day", "60 per hour", "10 per minute"],
    storage_uri="memory://"
)

API_KEY = "0a4f51067c3f1588b9e0c0fa4b313986"
BASE_URL = "https://api.openweathermap.org/data/2.5"

# Simple In-Memory Cache to save API calls
# key: city_name, value: {timestamp, data}
weather_cache = {}
CACHE_DURATION = 600 # 10 minutes

@app.route('/weather', methods=['GET'])
@limiter.limit("1000 per day")
def get_weather():
    city = request.args.get('city')
    if not city:
        return jsonify({'error': 'City is required'}), 400
    
    city = city.lower().strip()
    
    # Check Cache
    current_time = time.time()
    if city in weather_cache:
        cached_data, timestamp = weather_cache[city]
        if current_time - timestamp < CACHE_DURATION:
            return jsonify({**cached_data, 'source': 'cache'})

    # Fetch from OpenWeather
    try:
        response = requests.get(f"{BASE_URL}/weather", params={
            'q': city,
            'appid': API_KEY,
            'units': 'metric'
        })
        
        if response.status_code != 200:
            return jsonify({'error': 'City not found'}), response.status_code
            
        data = response.json()
        
        # Save to Cache
        weather_cache[city] = (data, current_time)
        
        return jsonify({**data, 'source': 'api'})
        
    except Exception as e:
        return jsonify({'error': str(e)}), 500

@app.route('/health', methods=['GET'])
def health():
    return jsonify({'status': 'online', 'limit': '1000/day'})

if __name__ == '__main__':
    import os
    port = int(os.environ.get('PORT', 7860))
    app.run(host='0.0.0.0', port=port)