"""Unit tests for the search_regulations MCP tool function.

Mocks AgentConversationService so no real retrieval/LLM call happens —
verifies only the protocol-adapter contract: correct call shape in,
correct dict shape out.
"""

from __future__ import annotations

from dataclasses import dataclass
from unittest.mock import MagicMock, patch


@dataclass
class _FakeSource:
    """Minimal stand-in for a real Source dataclass (only __dict__ is used)."""

    doc_id: str
    doc_title: str
    score: float


@dataclass
class _FakeAnswerResult:
    """Minimal stand-in for AnswerResult — only .answer/.sources are read."""

    answer: str
    sources: list


def test_search_regulations_calls_agent_ask_without_session():
    """search_regulations must call ask() with no session_id (stateless search)."""
    from app.mcp.server import search_regulations

    fake_service = MagicMock()
    fake_service.ask.return_value = (
        None,
        _FakeAnswerResult(answer="国六排放标准要求...", sources=[_FakeSource("doc-1", "国六标准", 0.9)]),
    )

    with patch("app.mcp.server.get_agent_conversation_service", return_value=fake_service):
        search_regulations(query="国六排放标准最新要求", top_k=3)

    fake_service.ask.assert_called_once_with(query="国六排放标准最新要求", top_k=3)
    assert "session_id" not in fake_service.ask.call_args.kwargs


def test_search_regulations_shapes_response_dict():
    """The returned dict must expose 'answer' and 'sources' (list of plain dicts)."""
    from app.mcp.server import search_regulations

    fake_service = MagicMock()
    fake_service.ask.return_value = (
        None,
        _FakeAnswerResult(answer="答案文本", sources=[_FakeSource("doc-2", "国标GB1589", 0.8)]),
    )

    with patch("app.mcp.server.get_agent_conversation_service", return_value=fake_service):
        result = search_regulations(query="q")

    assert result == {
        "answer": "答案文本",
        "sources": [{"doc_id": "doc-2", "doc_title": "国标GB1589", "score": 0.8}],
    }


def test_search_regulations_default_top_k():
    """top_k defaults to 5 when the caller omits it."""
    from app.mcp.server import search_regulations

    fake_service = MagicMock()
    fake_service.ask.return_value = (None, _FakeAnswerResult(answer="a", sources=[]))

    with patch("app.mcp.server.get_agent_conversation_service", return_value=fake_service):
        search_regulations(query="q")

    assert fake_service.ask.call_args.kwargs["top_k"] == 5