"""Tests for EPUB search health and readiness routes."""

from __future__ import annotations

from typing import TYPE_CHECKING

from fastapi.testclient import TestClient
from sqlalchemy import create_engine

from python.ebook_search.api.main import create_app
from python.ebook_search.config import EbookSearchConfig, RerankConfig

HEALTH_MODULE = "python.ebook_search.api.routes.health"

if TYPE_CHECKING:
    from pytest_mock import MockerFixture


def fake_get_postgres_engine(**_kwargs):
    """Return an in-memory engine for route tests."""
    return create_engine("sqlite+pysqlite:///:memory:", future=True)


def patch_app_runtime(mocker: MockerFixture):
    mocker.patch("python.ebook_search.api.main.get_postgres_engine", side_effect=fake_get_postgres_engine)
    mocker.patch("python.ebook_search.api.main.ensure_bm25_corpus", side_effect=lambda _session, _config: None)


def patch_dependencies(mocker: MockerFixture, *, database=True, embedding=True, chat=True, bm25="ok"):
    mocker.patch(f"{HEALTH_MODULE}.check_database", side_effect=lambda _session: database)
    mocker.patch(f"{HEALTH_MODULE}.check_embedding_endpoint", side_effect=lambda _config: embedding)
    mocker.patch(f"{HEALTH_MODULE}.check_chat_endpoint", side_effect=lambda _config: chat)
    mocker.patch(f"{HEALTH_MODULE}.check_bm25_status", side_effect=lambda _config: bm25)


def build_client(mocker: MockerFixture, config=None):
    resolved = config or EbookSearchConfig(rerank=RerankConfig(enabled=False))
    mocker.patch("python.ebook_search.api.main.load_config", side_effect=lambda: resolved)
    patch_app_runtime(mocker)
    app = create_app()
    return TestClient(app)


def test_health_returns_ok(mocker: MockerFixture) -> None:
    with build_client(mocker) as client:
        response = client.get("/health")

    assert response.status_code == 200
    assert response.json() == {"status": "ok"}


def test_ready_all_dependencies_ok(mocker: MockerFixture) -> None:
    patch_dependencies(mocker)

    with build_client(mocker) as client:
        response = client.get("/ready")

    assert response.status_code == 200
    body = response.json()
    assert body["status"] == "ready"
    assert body["checks"] == {"database": "ok", "embedding": "ok", "chat": "ok", "bm25": "ok"}


def test_ready_embedding_down_is_degraded(mocker: MockerFixture) -> None:
    patch_dependencies(mocker, embedding=False)

    with build_client(mocker) as client:
        response = client.get("/ready")

    assert response.status_code == 200
    body = response.json()
    assert body["status"] == "degraded"
    assert body["checks"]["embedding"] == "fail"


def test_ready_chat_down_is_degraded(mocker: MockerFixture) -> None:
    patch_dependencies(mocker, chat=False)

    with build_client(mocker) as client:
        response = client.get("/ready")

    assert response.status_code == 200
    body = response.json()
    assert body["status"] == "degraded"
    assert body["checks"]["chat"] == "fail"


def test_ready_chat_disabled_when_answers_off(mocker: MockerFixture) -> None:
    patch_dependencies(mocker)
    config = EbookSearchConfig(rerank=RerankConfig(enabled=False), answer_enabled=False)

    with build_client(mocker, config) as client:
        response = client.get("/ready")

    assert response.status_code == 200
    body = response.json()
    assert body["status"] == "ready"
    assert body["checks"]["chat"] == "disabled"


def test_ready_database_down_is_unavailable(mocker: MockerFixture) -> None:
    patch_dependencies(mocker, database=False)

    with build_client(mocker) as client:
        response = client.get("/ready")

    assert response.status_code == 503
    body = response.json()
    assert body["status"] == "unavailable"
    assert body["checks"]["database"] == "fail"


def test_ready_bm25_missing_is_degraded(mocker: MockerFixture) -> None:
    patch_dependencies(mocker, bm25="missing")

    with build_client(mocker) as client:
        response = client.get("/ready")

    assert response.status_code == 200
    body = response.json()
    assert body["status"] == "degraded"
    assert body["checks"]["bm25"] == "missing"