from unittest.mock import AsyncMock

import pytest
from fastapi.testclient import TestClient

from api.config import Settings
from api.main import app
from rag.retriever import RetrievedChunk


def _test_settings(tmp_path) -> Settings:
    return Settings(
        llm_provider="ollama",
        chroma_persist_directory=str(tmp_path / "chroma"),
        audit_db_path=str(tmp_path / "audit.db"),
        jobs_db_path=str(tmp_path / "jobs.db"),
        top_k_results=3,
    )


@pytest.fixture
def client(tmp_path, monkeypatch):
    settings = _test_settings(tmp_path)
    monkeypatch.setattr("api.main.get_settings", lambda: settings)
    monkeypatch.setattr("api.routes.query.get_settings", lambda: settings)
    with TestClient(app) as test_client:
        yield test_client


def test_ask_returns_grounded_answer_with_sources(client, monkeypatch):
    chunks = [
        RetrievedChunk(
            text="Audi has strategic EV expansion plans.",
            score=0.92,
            source="strategy.md",
            page=1,
            chunk_index=0,
        )
    ]
    monkeypatch.setattr("api.routes.query.create_embedding_function", lambda: object())
    monkeypatch.setattr("api.routes.query.get_vector_store", lambda **_: object())
    monkeypatch.setattr("api.routes.query.retrieve_chunks", lambda *_: chunks)
    monkeypatch.setattr("api.routes.query.answer_with_grounding", lambda *_: ("Audi is expanding EV investment.", 42))
    monkeypatch.setattr("api.routes.query.persist_query_audit", AsyncMock(return_value="evt-1"))

    response = client.post(
        "/query/ask",
        json={
            "question": "What is Audi doing in EV markets worldwide?",
            "collection_name": "default",
            "top_k": 3,
            "user_id": "tester",
        },
    )

    assert response.status_code == 200
    body = response.json()
    assert body["answer"] == "Audi is expanding EV investment."
    assert "query_id" in body
    assert body["question"].startswith("What is Audi")
    assert len(body["sources"]) == 1
    assert body["sources"][0]["document_name"] == "strategy.md"
    assert body["sources"][0]["page_number"] == 1
    assert body["tokens_used"] == 42
    assert "response_time_ms" in body
    assert "model_used" in body


def test_ask_respects_top_k_in_retrieve_call(client, monkeypatch):
    captured: dict[str, object] = {}

    def capture_retrieve(vs, question, k):
        captured["k"] = k
        return []

    monkeypatch.setattr("api.routes.query.create_embedding_function", lambda: object())
    monkeypatch.setattr("api.routes.query.get_vector_store", lambda **_: object())
    monkeypatch.setattr("api.routes.query.retrieve_chunks", capture_retrieve)
    monkeypatch.setattr("api.routes.query.answer_with_grounding", lambda *_: ("No match answer", 0))
    monkeypatch.setattr("api.routes.query.persist_query_audit", AsyncMock())

    response = client.post(
        "/query/ask",
        json={"question": "What is known about the topic here?", "collection_name": "default", "top_k": 7},
    )
    assert response.status_code == 200
    assert captured.get("k") == 7


def test_ask_returns_422_for_invalid_payload(client):
    response = client.post("/query/ask", json={"collection_name": "default"})
    assert response.status_code == 422


def test_ask_returns_422_for_short_question(client):
    response = client.post(
        "/query/ask",
        json={"question": "hi", "collection_name": "default"},
    )
    assert response.status_code == 422


def test_ask_returns_500_when_retrieval_fails(client, monkeypatch):
    monkeypatch.setattr("api.routes.query.create_embedding_function", lambda: object())
    monkeypatch.setattr("api.routes.query.get_vector_store", lambda **_: object())
    monkeypatch.setattr("api.routes.query.retrieve_chunks", lambda *_: (_ for _ in ()).throw(RuntimeError("retrieval failed")))

    response = client.post(
        "/query/ask",
        json={"question": "What happened in the documents?", "collection_name": "default"},
    )

    assert response.status_code == 500
    assert "retrieval failed" in response.json()["detail"]


def test_summarise_returns_500_when_audit_persist_fails(client, monkeypatch):
    chunks = [
        RetrievedChunk(
            text="Revenue and risks are discussed in the report.",
            score=0.88,
            source="report.txt",
            page=None,
            chunk_index=2,
        )
    ]
    monkeypatch.setattr("api.routes.query.create_embedding_function", lambda: object())
    monkeypatch.setattr("api.routes.query.get_vector_store", lambda **_: object())
    monkeypatch.setattr("api.routes.query.retrieve_chunks", lambda *_: chunks)
    monkeypatch.setattr("api.routes.query.summarise_with_grounding", lambda *_, **__: ("Summary output", 10))
    monkeypatch.setattr("api.routes.query.collection_document_count", lambda *_: 5)
    monkeypatch.setattr(
        "api.routes.query.persist_query_audit",
        AsyncMock(side_effect=RuntimeError("audit write failed")),
    )

    response = client.post(
        "/query/summarise",
        json={"collection_name": "default", "focus": "summarise risks", "user_id": "u1"},
    )

    assert response.status_code == 500
    assert "audit write failed" in response.json()["detail"]