from smolagents import Tool
from typing import Any, Optional

class SimpleTool(Tool):
    name = "calculate_journey_metrics"
    description = "Calculates journey metrics including distance and time."
    inputs = {"start_location":{"type":"string","description":"The starting point of the journey."},"destination_location":{"type":"string","description":"The endpoint of the journey."},"transportation_mode":{"type":"string","nullable":True,"description":"Mode of transport ('driving', 'walking', 'bicycling', or 'transit'). Defaults to 'driving'."}}
    output_type = "string"

    def forward(self, start_location: str, destination_location: str, transportation_mode: Optional[str] = None) -> str:
        """Calculates journey metrics including distance and time.

        Args:
            start_location: The starting point of the journey.
            destination_location: The endpoint of the journey.
            transportation_mode: Mode of transport ('driving', 'walking', 'bicycling', or 'transit'). 
                               Defaults to 'driving'.

        Returns:
            str: Journey distance and estimated time.
        """
        from geopy.geocoders import Nominatim
        from geopy.distance import geodesic

        try:
            # Initialize geocoder
            geolocator = Nominatim(user_agent="journey_metrics_calculator")

            # Get coordinates
            start = geolocator.geocode(start_location)
            end = geolocator.geocode(destination_location)

            if not start or not end:
                return "Could not find one or both locations"

            # Calculate distance
            distance_km = geodesic(
                (start.latitude, start.longitude),
                (end.latitude, end.longitude)
            ).kilometers

            # Define speeds (km/h)
            speeds = {
                'driving': 60,
                'walking': 5,
                'bicycling': 15,
                'transit': 30
            }

            # Get speed for mode
            speed = speeds.get(transportation_mode, speeds['driving'])

            # Calculate time
            hours = distance_km / speed

            # Format time string
            if hours < 1:
                time_str = f"{int(hours * 60)} minutes"
            elif hours < 24:
                hrs = int(hours)
                mins = int((hours - hrs) * 60)
                time_str = f"{hrs} hours and {mins} minutes"
            else:
                days = hours / 24
                time_str = f"{days:.1f} days"

            return (
                f"Journey metrics:\n"
                f"Distance: {distance_km:.1f} kilometers\n"
                f"Estimated time by {transportation_mode or 'driving'}: {time_str}"
            )

        except Exception as e:
            return f"Error calculating journey metrics: {str(e)}"