use super::*;
use tempfile::NamedTempFile;

const BLESSED_SERVER_TO_RCT_VIDEO_OFFSETS: &[(&str, i64)] = &[
    ("1280x720@20", 162_659),
    ("1280x720@30", 135_090),
    ("1920x1080@20", 160_045),
    ("1920x1080@30", 127_952),
];

/// Keeps `with_clean_offset_env` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn with_clean_offset_env(test: impl FnOnce()) {
    temp_env::with_vars(
        [
            ("LESAVKA_UPSTREAM_AUDIO_PLAYOUT_OFFSET_US", None::<&str>),
            ("LESAVKA_UPSTREAM_VIDEO_PLAYOUT_OFFSET_US", None::<&str>),
            (
                "LESAVKA_UPSTREAM_AUDIO_PLAYOUT_MODE_OFFSETS_US",
                None::<&str>,
            ),
            (
                "LESAVKA_UPSTREAM_VIDEO_PLAYOUT_MODE_OFFSETS_US",
                None::<&str>,
            ),
            ("UVC_MODE", None::<&str>),
            ("LESAVKA_UVC_MODE", None::<&str>),
            ("LESAVKA_UVC_WIDTH", None::<&str>),
            ("LESAVKA_UVC_HEIGHT", None::<&str>),
            ("LESAVKA_UVC_FPS", None::<&str>),
            ("LESAVKA_UVC_INTERVAL", None::<&str>),
            ("LESAVKA_CAM_WIDTH", None::<&str>),
            ("LESAVKA_CAM_HEIGHT", None::<&str>),
            ("LESAVKA_CAM_FPS", None::<&str>),
        ],
        test,
    );
}

#[test]
/// Keeps `blessed_server_to_rct_offsets_are_release_defaults` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn blessed_server_to_rct_offsets_are_release_defaults() {
    assert_eq!(
        FACTORY_MJPEG_VIDEO_OFFSET_US, FACTORY_MJPEG_VIDEO_OFFSET_1280X720_30_US,
        "720p30 is the blessed default profile until a new lab matrix replaces it"
    );
    assert_eq!(FACTORY_MJPEG_VIDEO_OFFSET_1280X720_20_US, 162_659);
    assert_eq!(FACTORY_MJPEG_VIDEO_OFFSET_1280X720_30_US, 135_090);
    assert_eq!(FACTORY_MJPEG_VIDEO_OFFSET_1920X1080_20_US, 160_045);
    assert_eq!(FACTORY_MJPEG_VIDEO_OFFSET_1920X1080_30_US, 127_952);
    assert_eq!(
        FACTORY_MJPEG_AUDIO_MODE_OFFSETS_US,
        "1280x720@20=0,1280x720@30=0,1920x1080@20=0,1920x1080@30=0"
    );
    assert_eq!(
        FACTORY_MJPEG_VIDEO_MODE_OFFSETS_US,
        "1280x720@20=162659,1280x720@30=135090,1920x1080@20=160045,1920x1080@30=127952"
    );
}

#[test]
/// Keeps `every_supported_uvc_mode_loads_tailored_factory_offset` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn every_supported_uvc_mode_loads_tailored_factory_offset() {
    for (mode, expected_offset_us) in BLESSED_SERVER_TO_RCT_VIDEO_OFFSETS {
        with_clean_offset_env(|| {
            temp_env::with_var("UVC_MODE", Some(*mode), || {
                let state = snapshot_from_env();
                assert_eq!(
                    state.factory_video_offset_us, *expected_offset_us,
                    "{mode} should use its baked server-to-RCT factory offset"
                );
                assert_eq!(
                    state.default_video_offset_us, *expected_offset_us,
                    "{mode} should default to its baked server-to-RCT offset"
                );
                assert_eq!(state.default_audio_offset_us, 0);
                assert_eq!(state.source, "factory");
                assert_eq!(state.confidence, FACTORY_CONFIDENCE);
            });
        });
    }
}

#[test]
fn default_snapshot_uses_factory_mjpeg_calibration() {
    with_clean_offset_env(|| {
        let state = snapshot_from_env();
        assert_eq!(state.default_audio_offset_us, 0);
        assert_eq!(state.active_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.source, "factory");
    });
}

#[test]
/// Keeps `default_snapshot_uses_uvc_mode_factory_calibration` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn default_snapshot_uses_uvc_mode_factory_calibration() {
    temp_env::with_vars(
        [
            ("LESAVKA_UPSTREAM_AUDIO_PLAYOUT_OFFSET_US", None::<&str>),
            ("LESAVKA_UPSTREAM_VIDEO_PLAYOUT_OFFSET_US", None::<&str>),
            (
                "LESAVKA_UPSTREAM_AUDIO_PLAYOUT_MODE_OFFSETS_US",
                None::<&str>,
            ),
            (
                "LESAVKA_UPSTREAM_VIDEO_PLAYOUT_MODE_OFFSETS_US",
                None::<&str>,
            ),
            ("LESAVKA_UVC_WIDTH", Some("1920")),
            ("LESAVKA_UVC_HEIGHT", Some("1080")),
            ("LESAVKA_UVC_FPS", Some("30")),
            ("LESAVKA_UVC_INTERVAL", None::<&str>),
        ],
        || {
            let state = snapshot_from_env();
            assert_eq!(
                state.default_video_offset_us,
                FACTORY_MJPEG_VIDEO_OFFSET_1920X1080_30_US
            );
            assert_eq!(
                state.factory_video_offset_us,
                FACTORY_MJPEG_VIDEO_OFFSET_1920X1080_30_US
            );
            assert_eq!(state.source, "factory");
        },
    );
}

#[test]
/// Keeps `mode_offset_map_overrides_stale_scalar_offset` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn mode_offset_map_overrides_stale_scalar_offset() {
    temp_env::with_vars(
        [
            ("LESAVKA_UPSTREAM_AUDIO_PLAYOUT_OFFSET_US", None::<&str>),
            ("LESAVKA_UPSTREAM_VIDEO_PLAYOUT_OFFSET_US", Some("170000")),
            (
                "LESAVKA_UPSTREAM_AUDIO_PLAYOUT_MODE_OFFSETS_US",
                None::<&str>,
            ),
            (
                "LESAVKA_UPSTREAM_VIDEO_PLAYOUT_MODE_OFFSETS_US",
                Some("1280x720@20=123456"),
            ),
            ("LESAVKA_UVC_WIDTH", Some("1280")),
            ("LESAVKA_UVC_HEIGHT", Some("720")),
            ("LESAVKA_UVC_FPS", Some("20")),
            ("LESAVKA_UVC_INTERVAL", None::<&str>),
        ],
        || {
            let state = snapshot_from_env();
            assert_eq!(state.default_video_offset_us, 123_456);
            assert_eq!(state.source, "env");
            assert_eq!(state.confidence, "configured");
        },
    );
}

#[test]
/// Keeps `stale_scalar_video_offset_falls_back_to_mode_factory` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn stale_scalar_video_offset_falls_back_to_mode_factory() {
    temp_env::with_vars(
        [
            ("LESAVKA_UPSTREAM_AUDIO_PLAYOUT_OFFSET_US", None::<&str>),
            ("LESAVKA_UPSTREAM_VIDEO_PLAYOUT_OFFSET_US", Some("170000")),
            (
                "LESAVKA_UPSTREAM_AUDIO_PLAYOUT_MODE_OFFSETS_US",
                None::<&str>,
            ),
            (
                "LESAVKA_UPSTREAM_VIDEO_PLAYOUT_MODE_OFFSETS_US",
                None::<&str>,
            ),
            ("LESAVKA_UVC_WIDTH", Some("1920")),
            ("LESAVKA_UVC_HEIGHT", Some("1080")),
            ("LESAVKA_UVC_FPS", Some("20")),
            ("LESAVKA_UVC_INTERVAL", None::<&str>),
        ],
        || {
            let state = snapshot_from_env();
            assert_eq!(
                state.default_video_offset_us,
                FACTORY_MJPEG_VIDEO_OFFSET_1920X1080_20_US
            );
            assert_eq!(state.source, "factory");
        },
    );
}

#[test]
/// Keeps `store_persists_manual_adjustments_and_updates_runtime` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn store_persists_manual_adjustments_and_updates_runtime() {
    let file = NamedTempFile::new().expect("temp calibration file");
    let path = file.path().to_string_lossy().to_string();
    temp_env::with_var("LESAVKA_CALIBRATION_PATH", Some(path.as_str()), || {
        let runtime = Arc::new(UpstreamMediaRuntime::new());
        let store = CalibrationStore::load(runtime.clone());
        let state = store
            .apply(CalibrationRequest {
                action: CalibrationAction::AdjustActive as i32,
                audio_delta_us: -5_000,
                video_delta_us: 0,
                observed_delivery_skew_ms: 0.0,
                observed_enqueue_skew_ms: 0.0,
                note: String::new(),
            })
            .expect("manual adjust applies");
        assert_eq!(state.active_audio_offset_us, -5_000);
        assert_eq!(
            runtime.playout_offsets(),
            (FACTORY_MJPEG_VIDEO_OFFSET_US, -5_000)
        );
        let raw = std::fs::read_to_string(file.path()).expect("persisted calibration");
        assert!(raw.contains("active_audio_offset_us=-5000"));
    });
}

#[test]
fn calibration_path_uses_default_for_blank_override() {
    temp_env::with_var("LESAVKA_CALIBRATION_PATH", Some(""), || {
        assert_eq!(
            calibration_path(),
            PathBuf::from("/var/lib/lesavka/calibration.toml")
        );
    });
}

#[test]
/// Keeps `snapshot_from_env_uses_configured_offsets_and_clamps_extremes` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn snapshot_from_env_uses_configured_offsets_and_clamps_extremes() {
    temp_env::with_vars(
        [
            ("LESAVKA_UPSTREAM_AUDIO_PLAYOUT_OFFSET_US", Some("-9999999")),
            ("LESAVKA_UPSTREAM_VIDEO_PLAYOUT_OFFSET_US", Some("12345")),
        ],
        || {
            let state = snapshot_from_env();
            assert_eq!(state.default_audio_offset_us, -OFFSET_LIMIT_US);
            assert_eq!(state.default_video_offset_us, 12_345);
            assert_eq!(state.source, "env");
            assert_eq!(state.confidence, "configured");
        },
    );
}

#[test]
/// Keeps `parse_snapshot_falls_back_for_missing_and_malformed_fields` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn parse_snapshot_falls_back_for_missing_and_malformed_fields() {
    temp_env::with_vars(
        [
            ("LESAVKA_UPSTREAM_AUDIO_PLAYOUT_OFFSET_US", None::<&str>),
            ("LESAVKA_UPSTREAM_VIDEO_PLAYOUT_OFFSET_US", None::<&str>),
        ],
        || {
            let state = parse_snapshot(
                r#"
                    profile="mjpeg"
                    default_audio_offset_us=bad
                    default_video_offset_us=2500
                    active_audio_offset_us=-1600000
                    source="saved"
                    detail="loaded \"quoted\" value"
                    "#,
            );
            assert_eq!(state.default_audio_offset_us, FACTORY_MJPEG_AUDIO_OFFSET_US);
            assert_eq!(state.default_video_offset_us, 2_500);
            assert_eq!(state.active_audio_offset_us, -OFFSET_LIMIT_US);
            assert_eq!(state.active_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
            assert_eq!(state.source, "saved");
            assert_eq!(state.confidence, FACTORY_CONFIDENCE);
        },
    );
}

#[test]
/// Keeps `load_migrates_untouched_legacy_factory_mjpeg_baseline` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn load_migrates_untouched_legacy_factory_mjpeg_baseline() {
    let file = NamedTempFile::new().expect("temp calibration file");
    std::fs::write(
        file.path(),
        r#"
            profile="mjpeg"
            default_audio_offset_us=-45000
            default_video_offset_us=0
            active_audio_offset_us=-45000
            active_video_offset_us=0
            source="env"
            confidence="configured"
            detail="loaded upstream A/V calibration defaults"
            "#,
    )
    .expect("legacy calibration seed");
    let path = file.path().to_string_lossy().to_string();
    temp_env::with_var("LESAVKA_CALIBRATION_PATH", Some(path.as_str()), || {
        let runtime = Arc::new(UpstreamMediaRuntime::new());
        let store = CalibrationStore::load(runtime.clone());
        let state = store.current();
        assert_eq!(state.active_audio_offset_us, 0);
        assert_eq!(state.default_audio_offset_us, 0);
        assert_eq!(state.active_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.default_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.source, "factory");
        assert_eq!(
            runtime.playout_offsets(),
            (FACTORY_MJPEG_VIDEO_OFFSET_US, 0)
        );
        assert!(state.detail.contains("migrated legacy MJPEG"));
    });
}

#[test]
/// Keeps `load_migrates_untouched_previous_factory_mjpeg_baseline` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn load_migrates_untouched_previous_factory_mjpeg_baseline() {
    let file = NamedTempFile::new().expect("temp calibration file");
    std::fs::write(
        file.path(),
        r#"
            profile="mjpeg"
            default_audio_offset_us=720000
            default_video_offset_us=0
            active_audio_offset_us=720000
            active_video_offset_us=0
            source="env"
            confidence="configured"
            detail="loaded upstream A/V calibration defaults"
            "#,
    )
    .expect("previous calibration seed");
    let path = file.path().to_string_lossy().to_string();
    temp_env::with_var("LESAVKA_CALIBRATION_PATH", Some(path.as_str()), || {
        let runtime = Arc::new(UpstreamMediaRuntime::new());
        let store = CalibrationStore::load(runtime.clone());
        let state = store.current();
        assert_eq!(state.active_audio_offset_us, 0);
        assert_eq!(state.default_audio_offset_us, 0);
        assert_eq!(state.active_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.default_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.source, "factory");
        assert_eq!(
            runtime.playout_offsets(),
            (FACTORY_MJPEG_VIDEO_OFFSET_US, 0)
        );
        assert!(state.detail.contains("to audio +0.0ms/video +135.1ms"));
    });
}

#[test]
/// Keeps `load_migrates_overshot_video_factory_mjpeg_baseline` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn load_migrates_overshot_video_factory_mjpeg_baseline() {
    let file = NamedTempFile::new().expect("temp calibration file");
    std::fs::write(
        file.path(),
        r#"
            profile="mjpeg"
            default_audio_offset_us=0
            default_video_offset_us=1090000
            active_audio_offset_us=0
            active_video_offset_us=1090000
            source="factory"
            confidence="factory"
            detail="loaded upstream A/V calibration defaults"
            "#,
    )
    .expect("overshot video calibration seed");
    let path = file.path().to_string_lossy().to_string();
    temp_env::with_var("LESAVKA_CALIBRATION_PATH", Some(path.as_str()), || {
        let runtime = Arc::new(UpstreamMediaRuntime::new());
        let store = CalibrationStore::load(runtime.clone());
        let state = store.current();
        assert_eq!(state.active_audio_offset_us, 0);
        assert_eq!(state.default_audio_offset_us, 0);
        assert_eq!(state.active_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.default_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.source, "factory");
        assert_eq!(
            runtime.playout_offsets(),
            (FACTORY_MJPEG_VIDEO_OFFSET_US, 0)
        );
        assert!(state.detail.contains("from audio +0.0ms/video +1090.0ms"));
    });
}

#[test]
/// Keeps `load_migrates_browser_video_factory_mjpeg_baseline` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn load_migrates_browser_video_factory_mjpeg_baseline() {
    let file = NamedTempFile::new().expect("temp calibration file");
    std::fs::write(
        file.path(),
        r#"
            profile="mjpeg"
            default_audio_offset_us=0
            default_video_offset_us=130000
            active_audio_offset_us=0
            active_video_offset_us=130000
            source="factory"
            confidence="factory"
            detail="loaded upstream A/V calibration defaults"
            "#,
    )
    .expect("browser video calibration seed");
    let path = file.path().to_string_lossy().to_string();
    temp_env::with_var("LESAVKA_CALIBRATION_PATH", Some(path.as_str()), || {
        let runtime = Arc::new(UpstreamMediaRuntime::new());
        let store = CalibrationStore::load(runtime.clone());
        let state = store.current();
        assert_eq!(state.active_audio_offset_us, 0);
        assert_eq!(state.default_audio_offset_us, 0);
        assert_eq!(state.active_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.default_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.source, "factory");
        assert_eq!(
            runtime.playout_offsets(),
            (FACTORY_MJPEG_VIDEO_OFFSET_US, 0)
        );
    });
}

#[test]
/// Keeps `load_migrates_delayed_video_factory_mjpeg_baseline` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn load_migrates_delayed_video_factory_mjpeg_baseline() {
    let file = NamedTempFile::new().expect("temp calibration file");
    std::fs::write(
        file.path(),
        r#"
            profile="mjpeg"
            default_audio_offset_us=0
            default_video_offset_us=350000
            active_audio_offset_us=0
            active_video_offset_us=350000
            source="factory"
            confidence="factory"
            detail="loaded upstream A/V calibration defaults"
            "#,
    )
    .expect("delayed video calibration seed");
    let path = file.path().to_string_lossy().to_string();
    temp_env::with_var("LESAVKA_CALIBRATION_PATH", Some(path.as_str()), || {
        let runtime = Arc::new(UpstreamMediaRuntime::new());
        let store = CalibrationStore::load(runtime.clone());
        let state = store.current();
        assert_eq!(state.active_audio_offset_us, 0);
        assert_eq!(state.default_audio_offset_us, 0);
        assert_eq!(state.active_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.default_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.source, "factory");
        assert_eq!(
            runtime.playout_offsets(),
            (FACTORY_MJPEG_VIDEO_OFFSET_US, 0)
        );
    });
}

#[test]
/// Keeps `load_migrates_early_zero_video_factory_mjpeg_baseline` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn load_migrates_early_zero_video_factory_mjpeg_baseline() {
    let file = NamedTempFile::new().expect("temp calibration file");
    std::fs::write(
        file.path(),
        r#"
            profile="mjpeg"
            default_audio_offset_us=0
            default_video_offset_us=0
            active_audio_offset_us=0
            active_video_offset_us=0
            source="factory"
            confidence="factory"
            detail="loaded upstream A/V calibration defaults"
            "#,
    )
    .expect("early zero calibration seed");
    let path = file.path().to_string_lossy().to_string();
    temp_env::with_var("LESAVKA_CALIBRATION_PATH", Some(path.as_str()), || {
        let runtime = Arc::new(UpstreamMediaRuntime::new());
        let store = CalibrationStore::load(runtime.clone());
        let state = store.current();
        assert_eq!(state.active_audio_offset_us, 0);
        assert_eq!(state.default_audio_offset_us, 0);
        assert_eq!(state.active_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.default_video_offset_us, FACTORY_MJPEG_VIDEO_OFFSET_US);
        assert_eq!(state.source, "factory");
        assert_eq!(
            runtime.playout_offsets(),
            (FACTORY_MJPEG_VIDEO_OFFSET_US, 0)
        );
    });
}

#[test]
/// Keeps `load_keeps_manual_legacy_sized_calibration` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn load_keeps_manual_legacy_sized_calibration() {
    let file = NamedTempFile::new().expect("temp calibration file");
    std::fs::write(
        file.path(),
        r#"
            profile="mjpeg"
            default_audio_offset_us=-45000
            default_video_offset_us=0
            active_audio_offset_us=-45000
            active_video_offset_us=0
            source="manual"
            confidence="manual"
            detail="operator-set"
            "#,
    )
    .expect("manual calibration seed");
    let path = file.path().to_string_lossy().to_string();
    temp_env::with_var("LESAVKA_CALIBRATION_PATH", Some(path.as_str()), || {
        let runtime = Arc::new(UpstreamMediaRuntime::new());
        let store = CalibrationStore::load(runtime.clone());
        let state = store.current();
        assert_eq!(state.active_audio_offset_us, -45_000);
        assert_eq!(state.active_video_offset_us, 0);
        assert_eq!(state.source, "manual");
        assert_eq!(runtime.playout_offsets(), (0, -45_000));
    });
}

#[test]
/// Keeps `store_applies_all_calibration_actions_and_persists_defaults` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn store_applies_all_calibration_actions_and_persists_defaults() {
    let dir = tempfile::tempdir().expect("calibration dir");
    let path = dir.path().join("calibration.toml");
    let path_string = path.to_string_lossy().to_string();
    temp_env::with_var(
        "LESAVKA_CALIBRATION_PATH",
        Some(path_string.as_str()),
        || {
            let runtime = Arc::new(UpstreamMediaRuntime::new());
            let store = CalibrationStore::load(runtime.clone());

            let blind = store
                .apply(CalibrationRequest {
                    action: CalibrationAction::BlindEstimate as i32,
                    audio_delta_us: 5_000,
                    video_delta_us: -2_000,
                    observed_delivery_skew_ms: 44.0,
                    observed_enqueue_skew_ms: 3.5,
                    note: String::new(),
                })
                .expect("blind estimate");
            assert_eq!(blind.source, "blind");
            assert!(blind.detail.contains("delivery skew 44.0ms"));
            assert_eq!(
                runtime.playout_offsets(),
                (FACTORY_MJPEG_VIDEO_OFFSET_US - 2_000, 5_000)
            );

            let manual = store
                .apply(CalibrationRequest {
                    action: CalibrationAction::AdjustActive as i32,
                    audio_delta_us: 1_999_999,
                    video_delta_us: 0,
                    observed_delivery_skew_ms: 0.0,
                    observed_enqueue_skew_ms: 0.0,
                    note: String::new(),
                })
                .expect("manual clamp");
            assert_eq!(manual.active_audio_offset_us, OFFSET_LIMIT_US);

            let saved = store
                .apply(CalibrationRequest {
                    action: CalibrationAction::SaveActiveAsDefault as i32,
                    ..CalibrationRequest::default()
                })
                .expect("save default");
            assert_eq!(saved.default_audio_offset_us, saved.active_audio_offset_us);
            assert_eq!(saved.confidence, "measured");

            let factory = store
                .apply(CalibrationRequest {
                    action: CalibrationAction::RestoreFactory as i32,
                    ..CalibrationRequest::default()
                })
                .expect("factory restore");
            assert_eq!(
                factory.active_audio_offset_us,
                FACTORY_MJPEG_AUDIO_OFFSET_US
            );
            assert_eq!(
                factory.active_video_offset_us,
                FACTORY_MJPEG_VIDEO_OFFSET_US
            );
            assert_eq!(factory.source, "factory");

            let restored = store
                .apply(CalibrationRequest {
                    action: CalibrationAction::RestoreDefault as i32,
                    ..CalibrationRequest::default()
                })
                .expect("default restore");
            assert_eq!(
                restored.active_audio_offset_us,
                restored.default_audio_offset_us
            );
            assert_eq!(
                store.current().active_audio_offset_us,
                restored.active_audio_offset_us
            );

            let no_op = store
                .apply(CalibrationRequest::default())
                .expect("unspecified action is ok");
            assert_eq!(
                no_op.active_audio_offset_us,
                restored.active_audio_offset_us
            );

            let raw = std::fs::read_to_string(&path).expect("persisted actions");
            assert!(raw.contains("confidence="));
            assert!(raw.contains("detail="));
            assert_eq!(escape_value("a\\b\"c"), "a\\\\b\\\"c");
        },
    );
}

#[test]
/// Keeps `transient_blind_estimate_updates_runtime_without_persisting_active_file_state` explicit because it sits on calibration state, where persisted and factory offsets must stay auditable.
/// Inputs are the typed parameters; output is the return value or side effect.
fn transient_blind_estimate_updates_runtime_without_persisting_active_file_state() {
    let dir = tempfile::tempdir().expect("calibration dir");
    let path = dir.path().join("calibration.toml");
    let path_string = path.to_string_lossy().to_string();
    temp_env::with_var(
        "LESAVKA_CALIBRATION_PATH",
        Some(path_string.as_str()),
        || {
            let runtime = Arc::new(UpstreamMediaRuntime::new());
            let store = CalibrationStore::load(runtime.clone());
            let before_raw = std::fs::read_to_string(&path).ok();

            let state = store.apply_transient_blind_estimate(
                0,
                -12_000,
                48.0,
                7.0,
                "runtime blind healer nudge",
            );

            assert_eq!(state.source, "blind");
            assert_eq!(state.confidence, "runtime-estimated");
            assert_eq!(
                runtime.playout_offsets(),
                (FACTORY_MJPEG_VIDEO_OFFSET_US - 12_000, 0)
            );
            assert_eq!(std::fs::read_to_string(&path).ok(), before_raw);
        },
    );
}