from __future__ import annotations

from abc import ABC, abstractmethod
from dataclasses import dataclass
from datetime import datetime

from app.models import OrderSide


@dataclass(slots=True)
class Fill:
    symbol: str
    side: OrderSide
    qty: float
    price: float
    fee: float
    ts: datetime

    @property
    def notional(self) -> float:
        return self.qty * self.price


class Broker(ABC):
    """Executes market orders. Paper and live brokers share this interface."""

    @abstractmethod
    async def buy(self, symbol: str, qty: float, ref_price: float) -> Fill:
        raise NotImplementedError

    @abstractmethod
    async def sell(self, symbol: str, qty: float, ref_price: float) -> Fill:
        raise NotImplementedError

    async def close(self) -> None:
        return None