"""极小硬核 Kernel：不变量裁决、命台并发控制、事件日志写入、Run 循环骨架。

不可插拔（lingtai-runtime.md §1）；插件与 Profile 见 ``app.runtime``。
"""

from __future__ import annotations

import asyncio

from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker

from app.kernel.eventlog import KernelEventLog
from app.kernel.loop import KernelRunLoop, OnRunFinal
from app.kernel.seat import SeatManager
from app.models.runtime import Run
from app.runtime.bus import WaterfallBus
from app.runtime.profile import resolve_profile
from app.shenshi_client.client import ShenshiClient

__all__ = ["Kernel", "KernelEventLog", "KernelRunLoop", "SeatManager"]


class Kernel:
    """门面：持有 Kernel 全部部件，供 lifespan 装配与 API 层调用。"""

    def __init__(
        self,
        *,
        shenshi: ShenshiClient,
        session_factory: async_sessionmaker[AsyncSession],
        event_log: KernelEventLog,
        bus: WaterfallBus | None = None,
        seats: SeatManager | None = None,
        timeout_seconds: float = 120.0,
    ) -> None:
        self._sessions = session_factory
        self.bus = bus or WaterfallBus()
        self.seats = seats or SeatManager()
        self.loop = KernelRunLoop(
            event_log=event_log,
            seats=self.seats,
            bus=self.bus,
            shenshi=shenshi,
            session_factory=session_factory,
            timeout_seconds=timeout_seconds,
        )
        self._tasks: set[asyncio.Task[None]] = set()

    async def start_foreground_run(
        self,
        *,
        character_id: str,
        prompt: str,
        owner_id: str = "",
        trace_id: str | None = None,
        system_contract: str | None = None,
        origin: str = "kernel",
        on_run_final: OnRunFinal | None = None,
        temperature: float | None = None,
        max_tokens: int | None = None,
    ) -> Run:
        """创建 Run 行（queued）并异步启动循环；前台席位在循环内排队获取。"""
        profile = resolve_profile()
        async with self._sessions() as session:
            run = Run(
                character_id=character_id,
                owner_id=owner_id,
                status="queued",
                kind="foreground",
                goal=prompt[:300] if prompt else None,
                origin=origin,
                model_hint=str(profile.params.get("slot", "chat")),
            )
            session.add(run)
            await session.commit()
            run_id = run.id
        self._spawn(
            run_id=run_id,
            character_id=character_id,
            owner_id=owner_id,
            prompt=prompt,
            trace_id=trace_id,
            seat_key=None,
            system_contract=system_contract,
            on_final=on_run_final,
            temperature=temperature,
            max_tokens=max_tokens,
        )
        async with self._sessions() as session:
            created = await session.get(Run, run_id)
            assert created is not None
            return created

    async def start_backstage_run(
        self,
        *,
        character_id: str | None,
        prompt: str,
        owner_id: str = "",
        on_task_final=None,
    ) -> Run:
        """天工阁受托任务 Run（kind=background_task）：不占前台席位、并行于前台。

        无身份写入路径：结果只回呈任务（on_task_final），不触发记忆候选与身份写入
        （息壤归真提取只挂在 canonize 链上，后台 Run 不归真）。
        """
        profile = resolve_profile()
        async with self._sessions() as session:
            run = Run(
                character_id=character_id,
                owner_id=owner_id,
                status="queued",
                kind="background_task",
                goal=prompt[:300] if prompt else None,
                origin="tiangong_task",
                model_hint=str(profile.params.get("slot", "chat")),
            )
            session.add(run)
            await session.commit()
            run_id = run.id
        self._spawn(
            run_id=run_id,
            character_id=character_id,
            owner_id=owner_id,
            prompt=prompt,
            trace_id=None,
            seat_key=None,
            system_contract=None,
            on_final=on_task_final,
            background=True,
        )
        async with self._sessions() as session:
            created = await session.get(Run, run_id)
            assert created is not None
            return created

    async def start_rehearsal_run(
        self, *, embryo_id: str, prompt: str, system_contract: str, owner_id: str = ""
    ) -> Run:
        """照心试演（幻境 Run）：无正式人物、不占人物命台、不产生人物经历。"""
        profile = resolve_profile()
        async with self._sessions() as session:
            run = Run(
                character_id=None,
                owner_id=owner_id,
                status="queued",
                kind="rehearsal",
                goal=prompt[:300] if prompt else None,
                origin="embryo_rehearse",
                model_hint=str(profile.params.get("slot", "chat")),
            )
            session.add(run)
            await session.commit()
            run_id = run.id
        self._spawn(
            run_id=run_id,
            character_id=None,
            owner_id=owner_id,
            prompt=prompt,
            trace_id=None,
            seat_key=f"embryo:{embryo_id}",
            system_contract=system_contract,
            on_final=None,
        )
        async with self._sessions() as session:
            created = await session.get(Run, run_id)
            assert created is not None
            return created

    @property
    def shenshi(self) -> ShenshiClient:
        """神识客户端（息壤提取等功能任务的受控取用点）。"""
        return self.loop._shenshi  # noqa: SLF001

    def _spawn(
        self,
        *,
        run_id: str,
        character_id: str | None,
        owner_id: str,
        prompt: str,
        trace_id: str | None,
        seat_key: str | None,
        system_contract: str | None,
        on_final: OnRunFinal | None,
        temperature: float | None = None,
        max_tokens: int | None = None,
        background: bool = False,
    ) -> None:
        task = asyncio.create_task(
            self.loop.execute(
                run_id=run_id,
                character_id=character_id,
                owner_id=owner_id,
                prompt=prompt,
                trace_id=trace_id,
                seat_key=seat_key,
                system_contract=system_contract,
                on_final=on_final,
                temperature=temperature,
                max_tokens=max_tokens,
                background=background,
            )
        )
        self._tasks.add(task)
        task.add_done_callback(self._tasks.discard)