"""运行取消路径的错误码契约测试（不连数据库）。

`POST /api/v1/agent-runs/{run_id}/cancellations` 的语义来自 `docs/05-接口文档.md` §6.4：

- 运行不存在或不属于当前用户 → `404 RUN_NOT_FOUND`（不泄露运行是否存在）；
- 已成功、已失败或进入最终提交事务 → `409 RUN_NOT_CANCELLABLE`；
- **重复取消返回同一状态**：`cancel_requested` 与 `cancelled` 都必须幂等返回当前快照，
  不得把重复取消当成错误（`RUN_CANCELLED` 不是 HTTP 响应码，见下方幂等断言）；
- 取消成功后 `request_idempotency` 落 `failed + RUN_CANCELLED`。

测试手法与 `test_public_platform_service.py` 一致：替换权限闸门与事务服务，
直接驱动 `_cancel`，因此既不需要数据库，也不需要真实 repository。
"""

from datetime import UTC, datetime
from typing import Any

import pytest

from app.core.errors import RunNotCancellableError, RunNotFoundError

NOW = datetime.now(UTC).replace(tzinfo=None)


class FakeRun:
    def __init__(self, status: str) -> None:
        self.run_id = "run-1"
        self.user_id = 9001
        self.status = status
        self.cancel_requested_at: datetime | None = None
        self.session_id = "session-1"
        self.idempotency_id = 7


class FakeSession:
    """只记录 `execute` 的绑定参数，用来断言 `request_idempotency` 的落库取值。"""

    def __init__(self, run: FakeRun | None) -> None:
        self._run = run
        self.updates: list[dict[str, Any]] = []

    async def scalar(self, _query: Any) -> FakeRun | None:
        return self._run

    async def execute(self, statement: Any) -> None:
        self.updates.append(dict(statement.compile().params))


def service() -> Any:
    from app.service.public_platform_service import PublicPlatformService

    return PublicPlatformService.__new__(PublicPlatformService)


async def cancel(run: FakeRun | None) -> tuple[tuple[dict[str, Any], str], FakeSession]:
    session = FakeSession(run)
    result = await service()._cancel(session, "run-1", 9001, NOW)
    return result, session


def idempotency_writes(session: FakeSession) -> list[dict[str, Any]]:
    return [
        update for update in session.updates
        if update.get("status") == "failed" and "error_code" in update
    ]


async def test_missing_or_foreign_run_is_run_not_found() -> None:
    """越权与不存在必须返回同一码，否则可以据状态码探测运行是否存在。"""
    with pytest.raises(RunNotFoundError) as excinfo:
        await cancel(None)

    assert excinfo.value.code == "RUN_NOT_FOUND"
    assert excinfo.value.status_code == 404


@pytest.mark.parametrize("status", ["succeeded", "failed"])
async def test_terminal_run_is_not_cancellable(status: str) -> None:
    with pytest.raises(RunNotCancellableError) as excinfo:
        await cancel(FakeRun(status))

    assert excinfo.value.code == "RUN_NOT_CANCELLABLE"
    assert excinfo.value.status_code == 409


@pytest.mark.parametrize(
    ("status", "expected_status"),
    [("cancel_requested", "cancel_requested"), ("cancelled", "cancelled")],
)
async def test_repeated_cancel_is_idempotent_and_never_an_error(
    status: str, expected_status: str
) -> None:
    """重复取消必须返回同一状态，不得以 `409 RUN_CANCELLED` 之类的错误回应。"""
    run = FakeRun(status)
    run.cancel_requested_at = NOW

    (payload, session_id), session = await cancel(run)

    assert payload == {
        "run_id": "run-1",
        "status": expected_status,
        "cancel_requested_at": NOW.isoformat() + "Z",
    }
    assert session_id == "session-1"
    # 重复取消不改写幂等记录，也不产生新的状态迁移。
    assert idempotency_writes(session) == []


async def test_queued_run_is_marked_cancel_requested_and_terminates_original_request() -> None:
    run = FakeRun("queued")

    (payload, session_id), session = await cancel(run)

    assert run.status == "cancel_requested"
    assert run.cancel_requested_at == NOW
    assert payload["run_id"] == "run-1"
    assert payload["status"] == "cancel_requested"
    assert session_id == "session-1"
    # 文档 §6.4：原请求以 failed + RUN_CANCELLED 结束，不扩展状态枚举。
    writes = idempotency_writes(session)
    assert writes == [{"id_1": 7, "status": "failed", "error_code": "RUN_CANCELLED",
                       "updated_at": NOW}]


async def test_running_run_is_cancellable_too() -> None:
    run = FakeRun("running")

    (payload, _session_id), session = await cancel(run)

    assert payload["status"] == "cancel_requested"
    assert len(idempotency_writes(session)) == 1


async def test_cancelled_run_never_reports_run_cancelled_as_http_error() -> None:
    """`RUN_CANCELLED` 是 request_idempotency 的状态标识，不是客户端错误码。"""
    from app.core import errors

    assert not hasattr(errors, "RunCancelledError")
    run = FakeRun("cancelled")
    run.cancel_requested_at = NOW

    payload, _session_id = (await cancel(run))[0]

    assert payload["status"] == "cancelled"