"""`ConversationService` 契约测试（全部替身，不连数据库）。

覆盖三条与安全/正确性直接相关的语义：
1. 消息列表必须按**当前用户**过滤（`user_id` 必须透传给 Repository，不能被绕过）；
2. 反馈的四种结局各自独立：权限不足 / 消息不存在 / 重复反馈 / 成功；
3. 成功路径在同一事务里既写反馈又写审计，且审计带 `trace_id`。
"""

from datetime import datetime
from typing import Any

import pytest

from app.core.contracts import RequestContext
from app.core.errors import (
    FeedbackAlreadyExistsError,
    ForbiddenAgentError,
    GenericResourceNotFoundError,
)
from app.service.conversation_service import ConversationService

CONTEXT = RequestContext(user_id="9001", trace_id="trace-42")
NOW = datetime(2026, 9, 10, 12, 0, 0)


class FakeRow:
    def __init__(self) -> None:
        self.id = 11
        self.role = "user"
        self.content = "稳健型"
        self.created_at = NOW


class FakeMessage:
    def __init__(self) -> None:
        self.session_id = "session-1"


class FakeSession:
    def __init__(self) -> None:
        self.added: list[Any] = []

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

    def begin(self) -> Any:
        return _AsyncContext()


class _AsyncContext:
    async def __aenter__(self) -> None:
        return None

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


class AllowingAuth:
    @staticmethod
    async def require(context: RequestContext, permission: str) -> None:
        del context, permission


class DenyingAuth:
    @staticmethod
    async def require(context: RequestContext, permission: str) -> None:
        del context, permission
        raise ForbiddenAgentError("缺少 conversation:feedback 权限")


def patch(
    monkeypatch: pytest.MonkeyPatch,
    *,
    rows: list[Any] | None = None,
    message: Any = "present",
    existing_feedback: Any = None,
    auth: type = AllowingAuth,
) -> dict[str, Any]:
    captured: dict[str, Any] = {}

    class FakeRepository:
        def __init__(self, _session: Any) -> None:
            pass

        async def messages(
            self, session_id: str, user_id: int, limit: int, before: int | None = None
        ) -> list[Any]:
            captured.update(session_id=session_id, user_id=user_id, limit=limit, before=before)
            return rows or []

        async def message(self, message_id: int, user_id: int) -> Any:
            captured.update(message_id=message_id, owner=user_id)
            return None if message == "missing" else FakeMessage()

        async def feedback(self, message_id: int, user_id: int) -> Any:
            del message_id, user_id
            return existing_feedback

    monkeypatch.setattr("app.service.conversation_service.ConversationRepository", FakeRepository)
    monkeypatch.setattr("app.service.conversation_service.AuthorizationService", auth)
    return captured


async def test_messages_are_scoped_to_current_user(monkeypatch: pytest.MonkeyPatch) -> None:
    captured = patch(monkeypatch, rows=[FakeRow()])

    result = await ConversationService(FakeSession()).messages("session-1", CONTEXT, 20)

    # user_id 必须透传：Repository 靠它做归属过滤，漏传就等于不限范围。
    assert captured["user_id"] == 9001
    assert captured["limit"] == 20
    assert captured["session_id"] == "session-1"
    # 不带游标时必须传 None，行为与加游标前一致（取最新一页）。
    assert captured["before"] is None
    assert result["data"] == [
        {"message_id": "11", "role": "user", "content": "稳健型",
         "created_at": NOW.isoformat() + "Z"}
    ]


async def test_messages_forward_cursor_to_repository(monkeypatch: pytest.MonkeyPatch) -> None:
    """合法游标必须真正作为分页边界透传，而不是被静默忽略。"""
    captured = patch(monkeypatch, rows=[FakeRow()])

    await ConversationService(FakeSession()).messages("session-1", CONTEXT, 20, before=42)

    assert captured["before"] == 42


async def test_feedback_requires_permission(monkeypatch: pytest.MonkeyPatch) -> None:
    patch(monkeypatch, auth=DenyingAuth)

    with pytest.raises(ForbiddenAgentError):
        await ConversationService(FakeSession()).feedback(11, CONTEXT, 1, None, None)


async def test_feedback_on_missing_message_is_not_found(monkeypatch: pytest.MonkeyPatch) -> None:
    patch(monkeypatch, message="missing")

    with pytest.raises(GenericResourceNotFoundError):
        await ConversationService(FakeSession()).feedback(11, CONTEXT, 1, None, None)


async def test_duplicate_feedback_conflicts(monkeypatch: pytest.MonkeyPatch) -> None:
    patch(monkeypatch, existing_feedback=object())

    with pytest.raises(FeedbackAlreadyExistsError):
        await ConversationService(FakeSession()).feedback(11, CONTEXT, 1, None, None)


async def test_feedback_writes_feedback_and_audit_with_trace_id(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    session = FakeSession()
    patch(monkeypatch)

    result = await ConversationService(session).feedback(11, CONTEXT, 1, "rating", "很有帮助")

    assert result["data"]["status"] == "open"
    kinds = [type(item).__name__ for item in session.added]
    assert kinds == ["ConversationFeedback", "InteractionAudit"]
    audit = session.added[1]
    assert audit.action_type == "conversation.feedback_created"
    assert audit.detail["trace_id"] == "trace-42"
    assert session.added[0].rating == 1