"""Tests for app.config.get_settings — env-var binding and cache isolation."""

from pathlib import Path

from app.config import Settings, get_settings


def test_get_settings_reads_env_vars(monkeypatch):
    """get_settings() must reflect env vars set before it is called."""
    # Clear any cached singleton from earlier tests / module imports.
    get_settings.cache_clear()

    monkeypatch.setenv("YUNKE_BASE_URL", "https://example.test/")
    monkeypatch.setenv("YUNKE_USERNAME", "tester")
    monkeypatch.setenv("YUNKE_PASSWORD", "shh")
    monkeypatch.setenv(
        "DB_URL",
        "mysql+asyncmy://u:p@db.example:3306/yunke_test",
    )
    monkeypatch.setenv("REDIS_URL", "redis://redis.example:6379/2")
    monkeypatch.setenv("MEDIA_DIR", "/tmp/yunke_media")
    monkeypatch.setenv("ENCRYPTION_KEY", "abc123")

    settings = get_settings()

    assert settings.yunke_base_url == "https://example.test/"
    assert settings.yunke_username == "tester"
    assert settings.yunke_password == "shh"
    assert settings.db_url == "mysql+asyncmy://u:p@db.example:3306/yunke_test"
    assert settings.redis_url == "redis://redis.example:6379/2"
    assert settings.media_dir == Path("/tmp/yunke_media")
    assert settings.encryption_key == "abc123"


def test_get_settings_is_cached(monkeypatch):
    """get_settings() returns the same instance until the cache is cleared."""
    get_settings.cache_clear()

    first = get_settings()
    second = get_settings()
    assert first is second

    # After clearing the cache, a new instance is built.
    get_settings.cache_clear()
    third = get_settings()
    assert third is not first


def test_get_settings_picks_up_changes_after_cache_clear(monkeypatch):
    """After cache_clear(), the next call re-reads the environment."""
    get_settings.cache_clear()
    monkeypatch.setenv("DB_URL", "sqlite+aiosqlite:///:memory:")
    initial = get_settings()
    assert initial.db_url == "sqlite+aiosqlite:///:memory:"

    monkeypatch.setenv("DB_URL", "mysql+asyncmy://other:3306/yunke")
    # Cached value must NOT change just because env changed.
    assert get_settings().db_url == "sqlite+aiosqlite:///:memory:"

    # After clearing, the new env var is picked up.
    get_settings.cache_clear()
    assert get_settings().db_url == "mysql+asyncmy://other:3306/yunke"


def test_settings_constructable_without_env():
    """Settings() can be built with defaults (no env required)."""
    s = Settings()
    assert isinstance(s.db_url, str)
    assert s.encryption_key == ""


def test_stealth_defaults_are_conservative():
    """The anti-risk-control settings declare conservative defaults.

    Asserted via Pydantic field-introspection rather than ``Settings()`` so it
    is immune to the test-env throttle-zeroing in conftest (which intentionally
    pins ``REQUEST_MIN_INTERVAL``/``REQUEST_JITTER`` to 0 for suite speed).
    Production deployments that don't set these env vars get the slow,
    jittered defaults declared here.
    """
    f = Settings.model_fields
    assert f["request_min_interval"].default == 2.0
    assert f["request_jitter"].default == 2.5
    assert f["max_requests_per_run"].default == 300
    assert f["risk_backoff_base"].default == 5.0
    assert f["risk_backoff_max"].default == 120.0
    assert f["risk_backoff_attempts"].default == 6