from __future__ import annotations

from collections.abc import AsyncIterator
from datetime import datetime
from typing import Protocol

from broker_sync.models import Account, Activity


class Provider(Protocol):
    """Broker connector surface.

    Each provider implementation is responsible for fetching raw broker
    data, turning it into canonical `Activity` rows (with `account_id`
    matching an `Account.id` from `accounts()`), and yielding them.

    GBP conversion is performed by the shared normaliser, not here —
    providers emit native currency and the caller converts.
    """

    name: str

    def accounts(self) -> list[Account]:
        ...

    def fetch(
        self,
        *,
        since: datetime | None = None,
        before: datetime | None = None,
    ) -> AsyncIterator[Activity]:
        ...