"""Tests for the shallow readiness probe and its /ready/ view.

The probe never connects to a real DB here: ``_probe`` / ``is_ready`` are patched. What is pinned
is the TTL-cache bust behaviour and the view's status-code contract (200 ok / 503 unavailable).
"""

from unittest.mock import patch

from flask import Flask

from core.blueprints.base import base_api
from core.hardening import readiness


def test_ready_false_when_db_raises() -> None:
    """A failing probe makes the service report not-ready."""
    with patch.object(readiness, '_probe', side_effect=Exception('db down')):
        readiness._CACHE['at'] = 0.0  # bust cache
        assert readiness.is_ready() is False


def test_ready_true_when_probe_ok() -> None:
    """A clean probe makes the service report ready."""
    with patch.object(readiness, '_probe', return_value=None):
        readiness._CACHE['at'] = 0.0  # bust cache
        assert readiness.is_ready() is True


def test_is_ready_serves_cached_value_within_ttl() -> None:
    """Within the TTL, a second call returns the cached result without re-probing."""
    calls = {'n': 0}

    def probe() -> None:
        calls['n'] += 1

    with patch.object(readiness, '_probe', side_effect=probe):
        readiness._CACHE['at'] = 0.0  # bust so the first call probes and caches
        assert readiness.is_ready() is True
        assert calls['n'] == 1
        assert readiness.is_ready() is True  # within TTL: served from cache
        assert calls['n'] == 1  # _probe was not called again


def _client() -> Flask:
    app = Flask(__name__)
    app.register_blueprint(base_api)
    return app


def test_ready_view_returns_200_when_ready() -> None:
    """GET /ready/ returns 200 ok when the service is ready."""
    app = _client()
    with patch('core.blueprints.base.is_ready', return_value=True):
        resp = app.test_client().get('/ready/')
    assert resp.status_code == 200
    assert resp.get_json() == {'status': 'ok'}


def test_ready_view_returns_503_when_not_ready() -> None:
    """GET /ready/ returns 503 unavailable when the service is not ready."""
    app = _client()
    with patch('core.blueprints.base.is_ready', return_value=False):
        resp = app.test_client().get('/ready/')
    assert resp.status_code == 503
    assert resp.get_json() == {'status': 'unavailable'}