"""知识库管理服务契约测试（Task 11）。

被测的是**接口层用例**：鉴权 → 开事务 → 复用入库链 → 提交；删除则是"标记 + 投递向量删除事件"。

全部用替身，**不连真库、不连 Milvus、不连 Redis**（本环境 Milvus/Redis 不可用，
上传与删除的向量落地由 Outbox Worker 负责，本层只保证事件被正确投出）。

固定口径（见 `app/service/knowledge_management_service.py` 的模块 docstring）：
- `created_by` 只来自认证上下文，方法不提供该参数；
- 删除是**标记** `status='expired'` + 投 `knowledge.vector_delete_requested`，不物理删除；
- 删不存在的 id 抛 404 语义异常，不静默成功。
"""

import base64
from datetime import UTC, datetime
from pathlib import Path
from typing import Any

import pytest

from app.api.controllers.knowledge_management import knowledge_management_service
from app.core.contracts import RequestContext
from app.core.errors import ForbiddenAgentError, GenericResourceNotFoundError, ValidationAgentError
from app.model.knowledge import KnowledgeMeta
from app.model.platform import DomainEventOutbox
from app.service.knowledge_management_service import (
    EXPIRED_STATUS,
    REQUIRED_PERMISSION,
    KnowledgeManagementService,
    decode_content,
)

PERMISSION = REQUIRED_PERMISSION


class _AsyncContext:
    def __init__(self, value: Any = None, error: BaseException | None = None) -> None:
        self._value = value
        self._error = error

    async def __aenter__(self) -> Any:
        return self._value

    async def __aexit__(self, *exc: object) -> bool:
        if self._error is not None:
            raise self._error
        return False


class FakeIngest:
    """`KnowledgeIngestService` 替身：记录调用参数，返回预设的 `knowledge_id` 列表。"""

    def __init__(self, ids: list[int] | None = None, error: BaseException | None = None) -> None:
        self._ids = ids if ids is not None else [11, 12]
        self._error = error
        self.calls: list[dict[str, Any]] = []

    async def ingest(self, **kwargs: Any) -> list[int]:
        self.calls.append(kwargs)
        if self._error is not None:
            raise self._error
        return list(self._ids)


def meta_row(
    knowledge_id: int = 7,
    *,
    status: str = "active",
    knowledge_type: str = "faq",
    storage_key: str | None = "kb/faq/abc-faq.md",
    content: str = "正文",
) -> KnowledgeMeta:
    now = datetime.now(UTC).replace(tzinfo=None)
    return KnowledgeMeta(
        id=knowledge_id,
        knowledge_type=knowledge_type,
        title="标题",
        source_file="faq.md",
        minio_path=storage_key,
        milvus_collection="fin_faq_collection",
        version="v1",
        content_text=content,
        tags={"chunk_index": 0},
        reviewer_id=9003,
        review_status="published",
        status=status,
        created_at=now,
        updated_at=now,
    )


class FakeSession:
    """替身 session：记录语句、`add()` 与**编译后的绑定参数**，并把 UPDATE 真的应用到内存行上。

    两点是刻意的：

    1. `session.execute(update(...).values(...))` 这类 SQLAlchemy 构造式语句的参数**不在**
       `execute(params=...)` 里，而是编译进语句本身（`compile().params`）。只记录 `params`
       会得到空 dict，让"UPDATE 到底改了什么"变成盲区；
    2. 把 UPDATE 落地到内存行：删除的验收点是"提交后这行确实是 `expired`"，
       只断言"发过一条 UPDATE"接不住"WHERE 条件写错、什么也没改"这类错误。
    """

    def __init__(self, rows: list[KnowledgeMeta] | None = None) -> None:
        self.rows = rows if rows is not None else []
        self.statements: list[tuple[str, dict[str, Any]]] = []
        self.added: list[Any] = []
        self.begin_calls = 0
        self.commits = 0

    def begin(self) -> _AsyncContext:
        self.begin_calls += 1
        return _AsyncContext()

    async def __aenter__(self) -> "FakeSession":
        return self

    async def __aexit__(self, *exc: object) -> bool:
        return False

    async def get(self, model: Any, ident: Any) -> Any:
        return next((row for row in self.rows if row.id == ident), None)

    async def scalars(self, statement: Any) -> Any:
        params = _bound_params(statement)
        self.statements.append((str(statement), params))

        class Rows:
            """最小 `ScalarResult` 替身：只提供服务实际用到的 `.all()`。"""

            def __init__(self, rows: list[KnowledgeMeta]) -> None:
                self._rows = rows

            def all(self) -> list[KnowledgeMeta]:
                return list(self._rows)

        return Rows(self.rows_for(statement, params))

    def rows_for(self, statement: Any, params: dict[str, Any]) -> list[KnowledgeMeta]:
        """按编译后的 WHERE 语义做**最小**过滤：目前只认"排除某个 status"这一个条件。

        为什么值得实现这一层：列表的验收点是"只返回未过期行"。如果替身把整表原样返回，
        `count` 就只能证明"计数=行数"，证明不了任何过滤；而真机 Milvus/Redis 不可用、
        这里也不连 MySQL，所以必须让替身在内存里执行这一条语义。
        """
        sql = str(statement)
        rows = list(self.rows)
        if "fin_knowledge_meta.status !=" in sql:
            excluded = next(
                (value for key, value in params.items() if key.startswith("status")), None
            )
            rows = [row for row in rows if row.status != excluded]
        type_key = next(
            (key for key in params if key.startswith("knowledge_type")), None
        )
        if type_key is not None:
            rows = [row for row in rows if row.knowledge_type == params[type_key]]
        return rows

    async def execute(self, statement: Any, params: Any = None) -> Any:
        values = dict(params or {}) or _bound_params(statement)
        self.statements.append((str(statement), values))
        if str(statement).upper().startswith("UPDATE"):
            for row in self.rows:
                for column, value in values.items():
                    if hasattr(row, column):
                        setattr(row, column, value)

        class Result:
            rowcount = len(values) and 1

        return Result()

    def add(self, value: Any) -> None:
        self.added.append(value)

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


def _bound_params(statement: Any) -> dict[str, Any]:
    """取 SQLAlchemy 构造式语句编译后的绑定参数（纯 SQL 字符串没有可编译对象）。"""
    compile_ = getattr(statement, "compile", None)
    if compile_ is None:
        return {}
    return dict(compile_().params)


class FakeStorage:
    def __init__(self, error: BaseException | None = None) -> None:
        self.archived: list[str] = []
        self._error = error

    async def archive(self, *, key: str) -> None:
        if self._error is not None:
            raise self._error
        self.archived.append(key)


def context(
    *, permissions: tuple[str, ...] = (PERMISSION,), user_id: str = "9003"
) -> RequestContext:
    return RequestContext(user_id=user_id, trace_id="trace-task11", permissions=permissions)


def build_service(
    *,
    rows: list[KnowledgeMeta] | None = None,
    ingest: FakeIngest | None = None,
    storage: FakeStorage | None = None,
) -> tuple[KnowledgeManagementService, FakeSession, FakeIngest, FakeStorage]:
    session = FakeSession(rows)
    fake_ingest = ingest or FakeIngest()
    fake_storage = storage or FakeStorage()
    service = KnowledgeManagementService(
        ingest_factory=lambda _session: fake_ingest,
        session_factory=lambda: session,
        storage=fake_storage,
        archive_on_delete=False,
    )
    return service, session, fake_ingest, fake_storage


def delete_events(session: FakeSession) -> list[Any]:
    return [
        event for event in session.added
        if isinstance(event, DomainEventOutbox)
        and event.event_type == "knowledge.vector_delete_requested"
    ]


# --- ① 上传 -----------------------------------------------------------------


async def test_upload_returns_knowledge_ids_and_takes_created_by_from_context() -> None:
    service, session, ingest, _ = build_service(ingest=FakeIngest([11, 12]))

    result = await service.upload(
        context(user_id="9003"),
        filename="faq.md",
        content=b"# \xe7\x94\xb3\xe8\xb4\xad",
        knowledge_type="faq",
    )

    assert result["knowledge_ids"] == [11, 12]
    assert result["chunk_count"] == 2
    assert result["created_by"] == "9003"
    assert ingest.calls[0]["created_by"] == 9003  # 取自 context.user_id，不是硬编码
    assert ingest.calls[0]["filename"] == "faq.md"
    assert ingest.calls[0]["content"] == b"# \xe7\x94\xb3\xe8\xb4\xad"
    assert session.begin_calls == 1  # 事务归本服务：提交由 session.begin() 的退出负责


async def test_upload_rejects_unknown_knowledge_type_without_touching_the_session() -> None:
    service, session, ingest, _ = build_service(
        ingest=FakeIngest(error=ValidationAgentError("knowledge_type 非法：secret"))
    )

    with pytest.raises(ValidationAgentError):
        await service.upload(
            context(), filename="a.txt", content=b"x", knowledge_type="secret"
        )

    assert session.begin_calls == 1
    assert session.added == []
    assert len(ingest.calls) == 1  # 校验发生在入库链里（白名单只有一份真相）


async def test_upload_requires_the_management_permission(monkeypatch: pytest.MonkeyPatch) -> None:
    """无权限时必须在开事务之前就被拦下：替身 session 一旦被使用就报错。"""
    service, _, _, _ = build_service()

    def explode() -> None:
        raise AssertionError("未授权请求不得打开数据库会话")

    service._session_factory = explode  # type: ignore[assignment]

    with pytest.raises(ForbiddenAgentError):
        await service.upload(context(permissions=()), filename="a.txt", content=b"x",
                             knowledge_type="faq")


async def test_upload_rejects_filename_with_path() -> None:
    service, _, _, _ = build_service()

    with pytest.raises(ValidationAgentError):
        await service.upload(context(), filename=r"C:\kb\faq.md", content=b"x",
                             knowledge_type="faq")


def test_decode_content_rejects_non_base64() -> None:
    """宽容解码会把 `!!!` 解成空字节 → "上传成功但内容为空"，必须失败关闭。"""
    with pytest.raises(ValidationAgentError):
        decode_content("!!!not base64!!!")

    assert decode_content(base64.b64encode("正文".encode()).decode()) == "正文".encode()


# --- ② 列表 -----------------------------------------------------------------


async def test_list_only_returns_rows_that_are_not_expired() -> None:
    rows = [meta_row(7, status="active"), meta_row(8, status=EXPIRED_STATUS)]
    service, session, _, _ = build_service(rows=rows)

    result = await service.list_documents(context(), limit=20, offset=0)

    assert [item["knowledge_id"] for item in result["items"]] == [7]
    assert result["count"] == 1
    # 过滤必须发生在 **SQL 侧**：断言编译后语句里的 WHERE 条件与绑定值。
    sql, params = session.statements[0]
    assert "fin_knowledge_meta.status !=" in sql
    assert EXPIRED_STATUS in params.values()


async def test_list_never_returns_the_full_content_text() -> None:
    service, _, _, _ = build_service(rows=[meta_row(7, content="正" * 500)])

    item = (await service.list_documents(context(), limit=20, offset=0))["items"][0]

    assert "content_text" not in item
    assert item["content_preview"] == "正" * 200
    assert item["content_length"] == 500
    assert item["created_by"] == 9003


async def test_list_rejects_unknown_knowledge_type_filter() -> None:
    service, session, _, _ = build_service(rows=[meta_row(7)])

    with pytest.raises(ValidationAgentError):
        await service.list_documents(context(), limit=20, offset=0, knowledge_type="secret")
    assert session.statements == []


# --- ③ 删除 -----------------------------------------------------------------


async def test_delete_marks_expired_and_enqueues_vector_delete_event() -> None:
    row = meta_row(7, status="active")
    service, session, _, _ = build_service(rows=[row])

    result = await service.delete_document(context(), 7)

    assert row.status == EXPIRED_STATUS  # UPDATE 真的落到该行上
    events = delete_events(session)
    assert len(events) == 1
    event = events[0]
    assert event.event_type == "knowledge.vector_delete_requested"
    assert event.aggregate_type == "knowledge_meta"
    assert event.aggregate_id == "7"
    assert event.trace_id == "trace-task11"
    assert event.status == "pending"
    assert event.retry_count == 0
    # payload 是 JSON 列口径：`knowledge_id` 必须是**字符串**（与投递侧同口径，
    # 消费侧 `_knowledge_id` 只接受纯数字字符串）。
    assert event.payload == {"knowledge_id": "7"}
    assert result == {"knowledge_id": 7, "status": EXPIRED_STATUS,
                      "vector_delete_event": "knowledge.vector_delete_requested"}


async def test_delete_unknown_id_raises_not_found_and_emits_no_event() -> None:
    service, session, _, _ = build_service(rows=[meta_row(7)])

    with pytest.raises(GenericResourceNotFoundError):
        await service.delete_document(context(), 999)

    assert delete_events(session) == []
    assert session.commits == 0


async def test_deleting_an_already_expired_row_is_also_not_found() -> None:
    """重复删除不得再投一次删除事件（否则向量删除会被反复排队）。"""
    service, session, _, _ = build_service(rows=[meta_row(7, status=EXPIRED_STATUS)])

    with pytest.raises(GenericResourceNotFoundError):
        await service.delete_document(context(), 7)

    assert delete_events(session) == []


async def test_archive_is_best_effort_and_does_not_roll_back_the_delete() -> None:
    """归档失败不得影响已提交的删除（否则会出现"库还是 active、文件已归档"的不一致）。"""
    row = meta_row(7)
    storage = FakeStorage(error=OSError("磁盘满"))
    service, session, _, _ = build_service(rows=[row], storage=storage)
    service._archive_on_delete = True

    await service.delete_document(context(), 7)

    assert row.status == EXPIRED_STATUS
    assert len(delete_events(session)) == 1


async def test_archive_key_comes_from_the_knowledge_row() -> None:
    row = meta_row(7, storage_key="kb/faq/deadbeef-faq.md")
    storage = FakeStorage()
    service, _, _, _ = build_service(rows=[row], storage=storage)
    service._archive_on_delete = True

    await service.delete_document(context(), 7)

    assert storage.archived == ["kb/faq/deadbeef-faq.md"]


# --- 装配与路由 -------------------------------------------------------------


async def test_service_factory_tolerates_a_cold_composition_root() -> None:
    """接口工厂应当可构造（Milvus/Redis 不可用不影响装配：这层不连它们）。"""
    service = knowledge_management_service()

    assert isinstance(service, KnowledgeManagementService)


def test_router_registers_the_three_required_paths() -> None:
    """老师 Phase 1 第 7 条点名的那三个端点必须在 `/api/v1` 下注册。"""
    from app.api.controllers.knowledge_management import router

    paths = {(route.path, method) for route in router.routes for method in route.methods}
    assert ("/api/v1/knowledge/upload", "POST") in paths
    assert ("/api/v1/knowledge/list", "GET") in paths
    assert ("/api/v1/knowledge/{knowledge_id}", "DELETE") in paths


def test_every_endpoint_depends_on_the_authentication_gate() -> None:
    """硬约束：三个端点都必须依赖 `build_request_context`，禁止匿名入口。"""
    from app.api.controllers.knowledge_management import router

    for route in router.routes:
        names = {
            getattr(dependency.call, "__name__", "")
            for dependency in route.dependant.dependencies
        }
        assert "build_request_context" in names, route.path


def test_management_permission_is_registered_in_the_rbac_seed() -> None:
    """权限码必须与 `tools/seed_test_rbac.py` 一致，否则"实现了却一直 403"。"""
    seed = Path("tools/seed_test_rbac.py").read_text(encoding="utf-8")

    assert f'"{PERMISSION}"' in seed