"""
Geocoding Service - Uses Nominatim (OpenStreetMap) for free geocoding
"""
import httpx
from typing import Optional, Tuple
import asyncio


NOMINATIM_URL = "https://nominatim.openstreetmap.org/search"
USER_AGENT = "NUMIDIUM/1.0 (Intelligence System)"


async def geocode(location_name: str) -> Optional[Tuple[float, float]]:
    """
    Convert a location name to coordinates using Nominatim.
    Returns (latitude, longitude) or None if not found.
    
    Note: Nominatim has rate limits (1 request/second), so be careful with batch operations.
    """
    try:
        async with httpx.AsyncClient(timeout=10.0) as client:
            response = await client.get(
                NOMINATIM_URL,
                params={
                    "q": location_name,
                    "format": "json",
                    "limit": 1,
                    "addressdetails": 0
                },
                headers={
                    "User-Agent": USER_AGENT
                }
            )
            
            if response.status_code == 200:
                data = response.json()
                if data and len(data) > 0:
                    lat = float(data[0]["lat"])
                    lon = float(data[0]["lon"])
                    return (lat, lon)
            
            return None
            
    except Exception as e:
        print(f"Geocoding error for '{location_name}': {e}")
        return None


async def geocode_batch(location_names: list[str], delay: float = 1.0) -> dict[str, Tuple[float, float]]:
    """
    Geocode multiple locations with proper rate limiting.
    Returns a dict mapping location names to (lat, lon) tuples.
    """
    results = {}
    
    for name in location_names:
        coords = await geocode(name)
        if coords:
            results[name] = coords
        # Respect Nominatim rate limits
        await asyncio.sleep(delay)
    
    return results