import asyncio

from app.modules.chat.direct_service import CodeExplainChatService
from app.modules.chat.session_resolver import ChatSessionResolver
from app.modules.chat.task_store import TaskStore
from app.modules.agent.runtime.steps.explain.models import ExplainIntent, ExplainPack
from app.schemas.chat import ChatFileContext, ChatMessageRequest


class _FakeRetriever:
    def build_pack(self, rag_session_id: str, user_query: str, *, file_candidates: list[dict] | None = None) -> ExplainPack:
        return ExplainPack(
            intent=ExplainIntent(raw_query=user_query, normalized_query=user_query),
            missing=["code_excerpts"],
        )


class _FakeLlm:
    def __init__(self) -> None:
        self.calls = 0

    def generate(self, prompt_name: str, user_input: str, *, log_context: str | None = None) -> str:
        self.calls += 1
        return "should not be called"


class _FakeDialogs:
    def get(self, dialog_session_id: str):
        return None


def test_direct_service_skips_llm_when_evidence_is_insufficient() -> None:
    messages: list[tuple[str, str, str, str | None]] = []
    llm = _FakeLlm()
    task_store = TaskStore()
    service = CodeExplainChatService(
        retriever=_FakeRetriever(),
        llm=llm,
        session_resolver=ChatSessionResolver(_FakeDialogs(), lambda rag_session_id: rag_session_id == "rag-1"),
        task_store=task_store,
        message_sink=lambda dialog_session_id, role, content, task_id=None: messages.append((dialog_session_id, role, content, task_id)),
    )

    result = asyncio.run(
        service.handle_message(
            ChatMessageRequest(
                session_id="dialog-1",
                project_id="rag-1",
                message="Explain get_user",
                files=[ChatFileContext(path="app/api/users.py", content="", content_hash="x")],
            )
        )
    )

    task = task_store.get(result.task_id)
    assert task is not None
    assert task.answer is not None
    assert "Недостаточно опоры в коде" in task.answer
    assert result.status == "done"
    assert llm.calls == 0
    assert [item[1] for item in messages] == ["user", "assistant"]