"""Kernel 事件日志：一炁（EventStore）之上的 Kernel 写入接口。

- 落库走 ``DbEventStore``（run 内单调 sequence，DB 为事实源，SSE 断线重放依据）；
- 双发进程内 ``bus``（RunEventBus）供既有 ``/runs/{id}/stream`` SSE 实时转发。
  该双发是 M0 骨架的过渡接法，M2 重建 runs 路由时收敛为 EventStore 单通道。
"""

from __future__ import annotations

from typing import Any

from app.modules.runtime.events import Event, EventStore
from app.schemas.runtime import EventResponse
from app.services.event_bus import bus


class KernelEventLog:
    """Kernel 视角的事件写入与检索。"""

    def __init__(self, store: EventStore) -> None:
        self._store = store

    async def emit(
        self,
        *,
        type: str,  # noqa: A002 — 对齐事件字段名
        run_id: str,
        character_id: str,
        source: str = "kernel",
        payload: dict[str, Any] | None = None,
        visibility: str = "public",
        trace_id: str | None = None,
    ) -> Event:
        event = await self._store.append(
            Event(
                type=type,
                source=source,
                payload=payload or {},
                visibility=visibility,  # type: ignore[arg-type]
                run_id=run_id,
                character_id=character_id,
                trace_id=trace_id,
            )
        )
        bus.publish(run_id, _to_response(event))
        return event

    async def list_by_run(self, run_id: str) -> list[Event]:
        return await self._store.list_by_run(run_id)


def _to_response(event: Event) -> EventResponse:
    return EventResponse(
        event_id=event.id,
        run_id=event.run_id or "",
        character_id=event.character_id or "",
        type=event.type,
        sequence=event.sequence if event.sequence is not None else 0,
        visibility=event.visibility,
        payload=event.payload,
        created_at=event.created_at,
        trace_id=event.trace_id,
    )