"""Venue adapter contracts for DITAv2."""

from __future__ import annotations

from dataclasses import dataclass, field
from datetime import datetime
from typing import Any, AsyncIterator, Dict, List, Optional, Protocol

from .contracts import (
    KernelCommandType,
    KernelIntent,
    KernelEventKind,
    TradeSide,
    VenueEvent,
    VenueEventStatus,
    VenueOrder,
    VenueOrderStatus,
)
from .exchange_event import ExchangeEvent


class VenueAdapter(Protocol):
    """Abstract venue adapter used by the kernel."""

    def submit(self, intent: KernelIntent) -> List[VenueEvent]:
        ...

    def cancel(self, order: VenueOrder, *, reason: str = "") -> List[VenueEvent]:
        ...

    def open_orders(self) -> List[VenueOrder]:
        ...

    def open_positions(self) -> List[Dict[str, Any]]:
        ...

    def reconcile(self) -> List[VenueEvent]:
        ...

    # ------------------------------------------------------------------
    # Phase 2 — stream seam (spec G3)
    # ------------------------------------------------------------------

    async def subscribe(self) -> AsyncIterator[ExchangeEvent]:
        """
        Yield ExchangeEvent instances in arrival order.  Implementations
        must handle reconnection, keepalive, and 24h rotation internally.
        The iterator never terminates normally — callers cancel it on
        shutdown.  Both the WS and poll-failover paths implement this
        interface so the kernel layer is source-agnostic.
        """
        ...  # pragma: no cover

    async def account_snapshot(self) -> ExchangeEvent:
        """
        Return a single ACCOUNT_UPDATE + POSITION_UPDATE merged event
        by calling the exchange REST API.  Used for gap-backfill on
        reconnect and as the poll-failover path.
        """
        ...  # pragma: no cover