from repograg.answer import (
    AnswerGenerator,
    build_generator,
    extract_citations,
    validate_citations,
)
from repograg.retrieval import RetrievalResult


def make_result(file_path="src/elo.py", start=10, end=20, name="update_elo"):
    return RetrievalResult(
        chunk={
            "id": 1,
            "file_path": file_path,
            "start_line": start,
            "end_line": end,
            "name": name,
            "parent": "",
            "kind": "function",
            "language": "python",
            "text": "def update_elo(): ...",
            "header": f"# {file_path}:{start}-{end}",
            "calls": "[]",
        },
        score=1.0,
        sources=["bm25"],
    )


class StubResponse:
    def __init__(self, text):
        self.text = text


class StubClient:
    """Mimics google-genai's Client: returns queued responses in order."""

    def __init__(self, *texts):
        self._texts = list(texts)
        self.calls = 0
        self.last_kwargs = None

        outer = self

        class Models:
            def generate_content(self, **kwargs):
                outer.calls += 1
                outer.last_kwargs = kwargs
                return StubResponse(outer._texts.pop(0))

        self.models = Models()


def test_extract_citations():
    cits = extract_citations(
        "Ratings update in update_elo [src/elo.py:10-20], "
        "using expected_score [src/elo.py:3]."
    )
    assert len(cits) == 2
    assert cits[0].file_path == "src/elo.py"
    assert (cits[0].start_line, cits[0].end_line) == (10, 20)
    assert (cits[1].start_line, cits[1].end_line) == (3, 3)


def test_validate_citations_rejects_fabricated():
    results = [make_result()]
    cits = extract_citations(
        "Real [src/elo.py:12-15]. Fabricated file [src/fake.py:1-5]. "
        "Out of range [src/elo.py:100-110]."
    )
    valid = validate_citations(cits, results)
    assert len(valid) == 1
    assert valid[0].file_path == "src/elo.py"


def test_answer_with_valid_citations():
    gen = AnswerGenerator(client=StubClient(
        "update_elo mutates the ratings dict [src/elo.py:10-20]."
    ))
    ans = gen.answer("how do ratings update", [make_result()])
    assert ans.citations
    assert gen.client.calls == 1


def test_answer_retries_when_uncited():
    gen = AnswerGenerator(client=StubClient(
        "Ratings update in place.",  # no citations → retry
        "Ratings update in place [src/elo.py:10-20].",
    ))
    ans = gen.answer("how do ratings update", [make_result()])
    assert gen.client.calls == 2
    assert ans.citations
    assert "[src/elo.py:10-20]" in ans.text


def test_answer_handles_blocked_response():
    # google-genai returns text=None when the response is blocked/empty
    gen = AnswerGenerator(client=StubClient(None))
    ans = gen.answer("how do ratings update", [make_result()])
    assert ans.text == ""
    assert not ans.citations
    assert gen.client.calls == 1  # no retry on empty text


def test_conversation_roles_mapped_for_gemini():
    # the corrective retry sends the assistant turn back as role "model"
    stub = StubClient(
        "Uncited first answer.",
        "Cited [src/elo.py:10-20].",
    )
    AnswerGenerator(client=stub).answer("q", [make_result()])
    roles = [c["role"] for c in stub.last_kwargs["contents"]]
    assert roles == ["user", "model", "user"]


def test_build_generator_disabled_without_key(monkeypatch):
    monkeypatch.delenv("GEMINI_API_KEY", raising=False)
    monkeypatch.delenv("GOOGLE_API_KEY", raising=False)
    assert build_generator() is None