app.py

# main.py
import gradio as gr
from fastapi import FastAPI, HTTPException

from models import CalculationRequest

# FastAPI setup
app = FastAPI()


@app.post("/calculate")
def calculate(request: CalculationRequest):
    operation = request.operation.value
    
    try:
        if operation == "add":
            answer = request.x + request.y
        elif operation == "subtract":
            answer = request.x - request.y
        elif operation == "multiply":
            answer = request.x * request.y
        else: # only option left is divide
            if request.y == 0:
                raise HTTPException(status_code=400, detail="Division by zero is not allowed")
            answer = request.x / request.y
        
        return {"result": answer}
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid input types")

# Gradio interface
def perform_calculation(operation, x, y):
    try:
        x = float(x)
        y = float(y)
    except ValueError:
        return "Error: Invalid input. Please enter numbers only."

    request = CalculationRequest(operation=operation, x=x, y=y)
    response = calculate(request)
    return f"Result: {response['result']}"

demo = gr.Interface(
    fn=perform_calculation,
    inputs=[
        gr.Dropdown(["add", "subtract", "multiply", "divide"], label="Operation"),
        gr.Textbox(label="First Number"),
        gr.Textbox(label="Second Number")
    ],
    outputs="text",
    title="Simple Calculator",
    description="Enter two numbers and select an operation to perform a calculation."
)

# Run the application
if __name__ == "__main__":
    demo.launch()