from app.modules.agent.runtime.steps.explain.models import CodeLocation, LayeredRetrievalItem
from app.modules.agent.runtime.steps.explain.retriever_v2 import CodeExplainRetrieverV2


class _FakeGateway:
    def retrieve_layer(
        self,
        rag_session_id: str,
        query: str,
        layer: str,
        *,
        limit: int,
        path_prefixes: list[str] | None = None,
        exclude_tests: bool = True,
        prefer_non_tests: bool = False,
        include_spans: bool = False,
    ):
        if layer == "C3_ENTRYPOINTS":
            return __import__("types").SimpleNamespace(
                items=[
                    LayeredRetrievalItem(
                        source="app/api/users.py",
                        content="GET /users/{id}",
                        layer=layer,
                        title="GET /users/{id}",
                        metadata={"entry_type": "http", "handler_symbol_id": "handler-1"},
                        location=CodeLocation(path="app/api/users.py", start_line=10, end_line=10),
                    )
                ],
                missing=[],
            )
        if layer == "C1_SYMBOL_CATALOG":
            return __import__("types").SimpleNamespace(
                items=[
                    LayeredRetrievalItem(
                        source="app/api/users.py",
                        content="def get_user_handler",
                        layer=layer,
                        title="get_user_handler",
                        metadata={"symbol_id": "handler-1"},
                        location=CodeLocation(path="app/api/users.py", start_line=10, end_line=18),
                    )
                ],
                missing=[],
            )
        raise AssertionError(layer)

    def retrieve_lexical_code(
        self,
        rag_session_id: str,
        query: str,
        *,
        limit: int,
        path_prefixes: list[str] | None = None,
        exclude_tests: bool = True,
        include_spans: bool = False,
    ):
        return __import__("types").SimpleNamespace(items=[], missing=[])


class _FakeGraphRepository:
    def get_symbols_by_ids(self, rag_session_id: str, symbol_ids: list[str]):
        return [
            LayeredRetrievalItem(
                source="app/api/users.py",
                content="def get_user_handler",
                layer="C1_SYMBOL_CATALOG",
                title="get_user_handler",
                metadata={"symbol_id": "handler-1"},
                location=CodeLocation(path="app/api/users.py", start_line=10, end_line=18),
            )
        ]

    def get_out_edges(self, rag_session_id: str, src_symbol_ids: list[str], edge_types: list[str], limit_per_src: int):
        return []

    def resolve_symbol_by_ref(self, rag_session_id: str, dst_ref: str, package_hint: str | None = None):
        return None

    def get_chunks_by_symbol_ids(self, rag_session_id: str, symbol_ids: list[str], prefer_chunk_type: str = "symbol_block"):
        return [
            LayeredRetrievalItem(
                source="app/api/users.py",
                content="async def get_user_handler(user_id: str):\n    return await service.get_user(user_id)",
                layer="C0_SOURCE_CHUNKS",
                title="get_user_handler",
                metadata={"symbol_id": "handler-1"},
                location=CodeLocation(path="app/api/users.py", start_line=10, end_line=18),
            )
        ]


def test_retriever_v2_builds_pack_with_trace_and_excerpts() -> None:
    retriever = CodeExplainRetrieverV2(
        gateway=_FakeGateway(),
        graph_repository=_FakeGraphRepository(),
    )

    pack = retriever.build_pack("rag-1", "Explain endpoint get_user")

    assert len(pack.selected_entrypoints) == 1
    assert len(pack.seed_symbols) == 1
    assert len(pack.trace_paths) == 1
    assert len(pack.code_excerpts) == 1
    assert pack.code_excerpts[0].path == "app/api/users.py"