from fastapi import status
from fastapi.responses import JSONResponse
from blackbox.blackbox import Blackbox


class Calculator(Blackbox):
    
    """This class just for example, it show how to implement Blackbox interface."""

    def valid(self, data: any) -> bool:
        return isinstance(data, dict) and "op" in data and "left" in data and "right" in data
    
    def processing(self, data: dict) -> any:
        if not self.valid(data):
            raise ValueError("Invalid data")
        a = data["left"]
        b = data["right"]
        op = data["op"]
        if op == "add":
            return a + b
        if op == "sub":
            return a - b
        if op == "mul":
            return a * b
        if op == "div":
            return a / b
        raise ValueError("Invalid operation")
    
    async def fast_api_handler(self, request) -> any:
        try:
            data = await request.json()
        except:
            return JSONResponse(content={"error": "json parse error"}, status_code=status.HTTP_400_BAD_REQUEST)
        try:
            result = self.processing(data)
        except ValueError as e:
            return JSONResponse(content={"error": str(e)}, status_code=status.HTTP_400_BAD_REQUEST)
        return JSONResponse(content={"result": result}, status_code=status.HTTP_200_OK)