from tools_registry import tool
import urllib.request
import json

@tool()
def convert_currency(amount: float, from_currency: str, to_currency: str) -> str:
    """Converts currency using latest exchange rates.
    
    Parameters:
        - amount: Amount to convert
        - from_currency: Source currency code (e.g., USD)
        - to_currency: Target currency code (e.g., EUR)
    """
    try:
        url = f"https://open.er-api.com/v6/latest/{from_currency.upper()}"
        with urllib.request.urlopen(url) as response:
            data = json.loads(response.read())
            
        if "rates" not in data:
            return "Error: Could not fetch exchange rates"
            
        rate = data["rates"].get(to_currency.upper())
        if not rate:
            return f"Error: No rate found for {to_currency}"
            
        converted = amount * rate
        return f"{amount} {from_currency.upper()} = {converted:.2f} {to_currency.upper()}"
        
    except Exception as e:
        return f"Error converting currency: {str(e)}"