import os
from langchain.tools import tool

@tool
def get_price(symbol: str) -> str:
    """Return the current price for a given stock symbol.
    For demo purposes, this function returns a mocked value.
    In a real implementation you would query an API such as Yahoo Finance or Alpha Vantage.
    """
    # Mocked response – replace with real API call
    prices = {
        "AAPL": 150.12,
        "GOOG": 2750.45,
        "MSFT": 299.87,
        "TSLA": 720.33,
    }
    price = prices.get(symbol.upper(), None)
    if price is None:
        return f"Price for {symbol} not found."
    return f"The current price of {symbol.upper()} is ${price:.2f}."