"""Minimal exchange gateway adapter stub.

Provides a toy FillEvent for deterministic replay demonstrations.
"""
from __future__ import annotations

import time
from deltatrace.core import FillEvent


class ExchangeGatewayAdapter:
    def __init__(self, venue: str = "TESTEX"):  # simple venue name
        self.venue = venue
        self._counter = 0

    def fill(self, order_id: str, size: int, price: float) -> FillEvent:
        self._counter += 1
        return FillEvent(
            fill_id=f"F-{self._counter}",
            order_id=order_id,
            price=price,
            size=size,
            timestamp=time.time(),
            venue=self.venue,
            related_delta=None,
        )