import gradio as gr
from fastapi import FastAPI, HTTPException
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse
from fastapi.middleware.wsgi import WSGIMiddleware

# FastAPI setup
app = FastAPI()

@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request, exc):
  return JSONResponse(
      status_code=400,
      content={"detail": "Invalid input. Please provide valid numbers."}
  )

@app.get("/")
async def root():
  return {"message": "Welcome to the Calculator API"}

@app.get("/add/{a}/{b}")
async def add(a: float, b: float):
  return {"result": a + b}

@app.get("/subtract/{a}/{b}")
async def subtract(a: float, b: float):
  return {"result": a - b}

@app.get("/multiply/{a}/{b}")
async def multiply(a: float, b: float):
  return {"result": a * b}

@app.get("/divide/{a}/{b}")
async def divide(a: float, b: float):
  if b == 0:
      raise HTTPException(status_code=400, detail="Cannot divide by zero")
  return {"result": a / b}

# Gradio interface
def calculate(operation, num1, num2):
  try:
      num1, num2 = float(num1), float(num2)
      if operation == "add":
          result = add(num1, num2)
      elif operation == "subtract":
          result = subtract(num1, num2)
      elif operation == "multiply":
          result = multiply(num1, num2)
      elif operation == "divide":
          result = divide(num1, num2)
      else:
          return "Invalid operation"
      return result["result"]
  except HTTPException as e:
      return f"Error: {e.detail}"
  except Exception as e:
      return f"Error: {str(e)}"

iface = gr.Interface(
  fn=calculate,
  inputs=[
      gr.Dropdown(["add", "subtract", "multiply", "divide"], label="Operation"),
      gr.Number(label="Number 1"),
      gr.Number(label="Number 2")
  ],
  outputs="text"
)

# Mount Gradio app to FastAPI
app = gr.mount_gradio_app(app, iface, path="/")

# For running locally
if __name__ == "__main__":
  import uvicorn
  uvicorn.run(app, host="0.0.0.0", port=7860)