"""T4.1 通用长任务 runner 单测（ARCH §7.4）。

直接 `await run_job(...)`（不起后台线程、不连真 DB），注入 fake session 工厂 + fake job
repo + fake work，断言：
- 成功路：set_running → work → complete(result) → commit；
- 失败路：work 抛 → 回滚 → 新 session 里 fail(error) → commit，且异常不冒泡。

独立 session 纪律 = `run_job` 自建 session（经 session_factory），与 `run_overdue_scan`
先例一致。这里的 fake session 工厂记录开了几次 session + 各次 commit。
"""

from __future__ import annotations

import uuid
from collections.abc import AsyncIterator
from contextlib import asynccontextmanager
from dataclasses import dataclass, field
from typing import Any

from sqlalchemy.ext.asyncio import AsyncSession
from ww_api.services.job_runner import run_job
from ww_core.domain.job_repo import (
    PROGRESS_COMPLETE,
    STATUS_DONE,
    STATUS_FAILED,
    STATUS_RUNNING,
    JobView,
)

JOB_ID = uuid.UUID("00000000-0000-0000-0000-0000000000aa")


class _FakeSession:
    """最小 fake：记录 commit 次数（提交边界断言）。"""

    def __init__(self) -> None:
        self.commits = 0

    async def commit(self) -> None:
        self.commits += 1


class _FakeSessionFactory:
    """独立 session 工厂替身：`()` → async-CM 产新 `_FakeSession`，记录开了几次。"""

    def __init__(self) -> None:
        self.sessions: list[_FakeSession] = []

    def __call__(self) -> Any:
        session = _FakeSession()
        self.sessions.append(session)

        @asynccontextmanager
        async def _cm() -> AsyncIterator[_FakeSession]:
            yield session

        return _cm()


@dataclass
class _FakeJobRepo:
    """内存 job repo：记录状态流转 + result/error（不触 DB）。"""

    status: str = "queued"
    progress: int = 0
    result: dict[str, Any] | None = None
    error: str | None = None
    calls: list[str] = field(default_factory=list)

    def _view(self, job_id: uuid.UUID) -> JobView:
        return JobView(
            id=job_id,
            kind="style_learn",
            status=self.status,
            progress=self.progress,
            result=self.result,
            error=self.error,
        )

    async def set_running(self, job_id: uuid.UUID) -> JobView:
        self.calls.append("set_running")
        self.status = STATUS_RUNNING
        return self._view(job_id)

    async def complete(self, job_id: uuid.UUID, result: dict[str, Any]) -> JobView:
        self.calls.append("complete")
        self.status = STATUS_DONE
        self.progress = PROGRESS_COMPLETE
        self.result = dict(result)
        return self._view(job_id)

    async def fail(self, job_id: uuid.UUID, error: str) -> JobView:
        self.calls.append("fail")
        self.status = STATUS_FAILED
        self.error = error
        return self._view(job_id)


# ---- success path ----


async def test_run_job_success_sets_done_and_commits() -> None:
    factory = _FakeSessionFactory()
    repo = _FakeJobRepo()
    received: list[AsyncSession] = []

    async def work(session: AsyncSession) -> dict[str, Any]:
        received.append(session)
        return {"version": 1, "dims_count": 16}

    await run_job(
        factory,
        JOB_ID,
        work,
        repo_factory=lambda _s: repo,
    )

    assert repo.calls == ["set_running", "complete"]
    assert repo.status == STATUS_DONE
    assert repo.progress == PROGRESS_COMPLETE
    assert repo.result == {"version": 1, "dims_count": 16}
    # 自建了一个独立 session 且提交了一次
    assert len(factory.sessions) == 1
    assert factory.sessions[0].commits == 1
    # work 拿到的就是 run_job 自建的 session
    assert len(received) == 1


# ---- failure path ----


async def test_run_job_failure_sets_failed_and_does_not_raise() -> None:
    factory = _FakeSessionFactory()
    repo = _FakeJobRepo()

    async def work(_session: AsyncSession) -> dict[str, Any]:
        raise RuntimeError("extraction blew up")

    # 异常被吞（后台任务边界），不冒泡
    await run_job(
        factory,
        JOB_ID,
        work,
        repo_factory=lambda _s: repo,
    )

    assert "complete" not in repo.calls
    assert "fail" in repo.calls
    assert repo.status == STATUS_FAILED
    assert repo.error == "extraction blew up"
    # 失败置态在一个**全新** session 里完成并 commit（原事务作废）
    assert len(factory.sessions) == 2
    assert factory.sessions[1].commits == 1