Ferrous-Solitaire/solitaire_engine/src/replay_overlay.rs

//! On-screen overlay shown while a recorded [`Replay`] plays back.
//!
//! The overlay is a thin top-of-window banner with three pieces of UI:
//!
//! - A "Replay" label on the left so the player knows the surface is
//!   under playback control rather than live input.
//! - A "Move N of M" progress indicator in the centre, recomputed every
//!   frame the cursor advances.
//! - A "Stop" button on the right that aborts playback and returns
//!   control to the player.
//!
//! When playback finishes ([`ReplayPlaybackState::Completed`]) the banner
//! label swaps to "Replay complete" and stays visible until the playback
//! core auto-clears the resource back to [`ReplayPlaybackState::Inactive`]
//! a few seconds later, at which point the overlay despawns.
//!
//! The overlay sits at z-layer [`Z_REPLAY_OVERLAY`] — above gameplay but
//! below every modal layer ([`Z_MODAL_SCRIM`] and up). That ordering lets
//! the player still open Settings, Pause, and Help during a replay; those
//! modals will render on top of the banner as expected.
//!
//! [`Replay`]: solitaire_data::Replay
//! [`Z_MODAL_SCRIM`]: crate::ui_theme::Z_MODAL_SCRIM

use bevy::prelude::*;

use crate::font_plugin::FontResource;
use crate::replay_playback::{stop_replay_playback, ReplayPlaybackState};
use crate::ui_modal::{spawn_modal_button, ButtonVariant};
use crate::ui_theme::{
    ACCENT_PRIMARY, BG_ELEVATED_HI, BORDER_SUBTLE, TEXT_PRIMARY, TYPE_BODY, TYPE_HEADLINE,
    VAL_SPACE_2, VAL_SPACE_4, Z_DROP_OVERLAY,
};

// ---------------------------------------------------------------------------
// Z-index — see `ui_theme::Z_MODAL_SCRIM` (200) for the next layer above.
// ---------------------------------------------------------------------------

/// `bevy::ui` `ZIndex` value for the replay overlay banner.
///
/// Numeric value is `Z_DROP_OVERLAY as i32 + 5 = 55`; chosen so the banner
/// sits clearly above the HUD top layer (`Z_HUD_TOP = 60` is intentionally
/// **below** modals, but the overlay needs to be above HUD readouts) yet
/// well below `Z_MODAL_SCRIM = 200` so Settings, Pause, and Help modals
/// continue to render on top of the overlay during a replay.
///
/// The `Z_DROP_OVERLAY + 5` formula in the spec is reproduced here as an
/// integer because `Z_DROP_OVERLAY` itself is a `f32` Sprite-space z used
/// for the drop-target overlay sprites — UI nodes use `i32` `ZIndex`, so
/// we materialise a separate constant rather than reuse the `f32` value.
pub const Z_REPLAY_OVERLAY: i32 = Z_DROP_OVERLAY as i32 + 5;

/// Total height of the banner in pixels. Thin enough to leave the
/// gameplay surface visible underneath, tall enough to comfortably fit
/// the headline-sized "Replay" label.
const BANNER_HEIGHT: f32 = 48.0;

/// Background colour alpha for the banner. `BG_ELEVATED_HI` at this alpha
/// reads as a clear "this is a UI strip" callout while still letting the
/// felt show through enough to anchor the banner to the play surface.
const BANNER_ALPHA: f32 = 0.92;

// ---------------------------------------------------------------------------
// Marker components
// ---------------------------------------------------------------------------

/// Marker on the banner's root `Node`. Used by the spawn / despawn /
/// progress-update systems to find the overlay.
#[derive(Component, Debug)]
pub struct ReplayOverlayRoot;

/// Marker on the left-hand banner label `Text`. Carries either "Replay"
/// (during playback) or "Replay complete" (once finished); the
/// completion-text-update system swaps the contents in place.
#[derive(Component, Debug)]
pub struct ReplayOverlayBannerText;

/// Marker on the centre progress `Text`. Updated every frame to reflect
/// the current `(cursor, total)` returned by
/// [`ReplayPlaybackState::progress`].
#[derive(Component, Debug)]
pub struct ReplayOverlayProgressText;

/// Marker on the right-hand "Stop" button. Click handler queries for this
/// and calls [`stop_replay_playback`] when an `Interaction::Pressed`
/// transition is seen.
#[derive(Component, Debug)]
pub struct ReplayStopButton;

/// Marker on the cyan "fill" of the bottom-edge scrub bar. The
/// `Node`'s `width` is rewritten every frame the cursor advances to
/// `cursor / total` of the bar's full width, so the player has a
/// continuous visual cue of how far through the replay they are.
///
/// Distinct from the simpler text-based `ReplayOverlayProgressText`
/// (which spells out "Move N of M"): the scrub fill gives immediate
/// at-a-glance positioning; the text gives the exact numbers. Both
/// surfaces stay together because they answer the same question for
/// players with different scanning preferences.
#[derive(Component, Debug)]
pub struct ReplayOverlayScrubFill;

// ---------------------------------------------------------------------------
// Plugin
// ---------------------------------------------------------------------------

/// Bevy plugin that registers every system needed to drive the replay
/// overlay's lifecycle.
///
/// The plugin is independent of [`crate::replay_playback::ReplayPlaybackPlugin`]
/// — it only reads the shared `ReplayPlaybackState` resource. Tests insert
/// the resource manually and exercise the overlay in isolation.
pub struct ReplayOverlayPlugin;

impl Plugin for ReplayOverlayPlugin {
    fn build(&self, app: &mut App) {
        // The systems are ordered so that, on a single frame:
        //   1. The state-watcher spawns or despawns the overlay if the
        //      `ReplayPlaybackState` resource changed.
        //   2. The completion-text update swaps the banner label when the
        //      state is `Completed`.
        //   3. The progress-text update writes the latest "Move N of M".
        //   4. The Stop-button click handler reads `Interaction::Pressed`
        //      and calls `stop_replay_playback` (which mutates the state).
        // Putting Stop last means a click in frame N is observed by
        // `react_to_state_change` in frame N+1, which then despawns the
        // overlay in response — a clean state-driven loop.
        app.add_systems(
            Update,
            (
                react_to_state_change,
                update_banner_label,
                update_progress_text,
                update_scrub_fill,
                handle_stop_button,
            )
                .chain(),
        );
    }
}

// ---------------------------------------------------------------------------
// Spawning
// ---------------------------------------------------------------------------

/// Reads [`ReplayPlaybackState`] every time the resource changes and either
/// spawns or despawns the overlay accordingly. Treats the resource as the
/// single source of truth — the spawn / despawn decision is derived from
/// `is_playing() || is_completed()` rather than tracking previous-state
/// transitions explicitly, which keeps the system stateless.
fn react_to_state_change(
    mut commands: Commands,
    state: Res<ReplayPlaybackState>,
    existing: Query<Entity, With<ReplayOverlayRoot>>,
    font_res: Option<Res<FontResource>>,
) {
    if !state.is_changed() {
        return;
    }

    let should_be_visible = state.is_playing() || state.is_completed();
    let already_spawned = existing.iter().next().is_some();

    if should_be_visible && !already_spawned {
        spawn_overlay(&mut commands, font_res.as_deref(), &state);
    } else if !should_be_visible && already_spawned {
        for entity in &existing {
            commands.entity(entity).despawn();
        }
    }
    // The `should_be_visible && already_spawned` branch is a no-op here —
    // the per-frame text update systems below repaint the banner label
    // and progress readout in place without a respawn.
}

/// Spawns the banner — a flex-row Node anchored to the top edge of the
/// window with three children: the "Replay" / "Replay complete" label,
/// the centred progress text, and the right-aligned Stop button.
fn spawn_overlay(
    commands: &mut Commands,
    font_res: Option<&FontResource>,
    state: &ReplayPlaybackState,
) {
    let font_handle = font_res.map(|f| f.0.clone()).unwrap_or_default();

    let banner_label = if state.is_completed() {
        "Replay complete"
    } else {
        "Replay"
    };
    let progress_label = format_progress(state);

    let banner_bg = Color::srgba(
        BG_ELEVATED_HI.to_srgba().red,
        BG_ELEVATED_HI.to_srgba().green,
        BG_ELEVATED_HI.to_srgba().blue,
        BANNER_ALPHA,
    );

    commands
        .spawn((
            ReplayOverlayRoot,
            Node {
                position_type: PositionType::Absolute,
                left: Val::Px(0.0),
                top: Val::Px(0.0),
                width: Val::Percent(100.0),
                height: Val::Px(BANNER_HEIGHT),
                // Column outer so the content row sits above the 1px
                // scrub bar at the bottom edge.
                flex_direction: FlexDirection::Column,
                ..default()
            },
            BackgroundColor(banner_bg),
            // Pin the banner to its z layer in both the local and the
            // global stacking context — `GlobalZIndex` matters because
            // the overlay is a top-level Node (no parent), and Bevy 0.18
            // has historically had subtle stacking-context drift here.
            ZIndex(Z_REPLAY_OVERLAY),
            GlobalZIndex(Z_REPLAY_OVERLAY),
        ))
        .with_children(|banner| {
            // Top row: the existing content (label / progress / Stop).
            banner
                .spawn(Node {
                    flex_grow: 1.0,
                    flex_direction: FlexDirection::Row,
                    align_items: AlignItems::Center,
                    justify_content: JustifyContent::SpaceBetween,
                    padding: UiRect::axes(VAL_SPACE_4, VAL_SPACE_2),
                    column_gap: VAL_SPACE_4,
                    ..default()
                })
                .with_children(|row| {
                    // Left: "Replay" label in the cyan primary accent
                    // (`ACCENT_PRIMARY`) so it reads unmistakably as a
                    // non-gameplay surface.
                    row.spawn((
                        ReplayOverlayBannerText,
                        Text::new(banner_label),
                        TextFont {
                            font: font_handle.clone(),
                            font_size: TYPE_HEADLINE,
                            ..default()
                        },
                        TextColor(ACCENT_PRIMARY),
                    ));

                    // Centre: progress readout — neutral primary text
                    // colour so the eye treats it as data, not a
                    // callout.
                    row.spawn((
                        ReplayOverlayProgressText,
                        Text::new(progress_label),
                        TextFont {
                            font: font_handle,
                            font_size: TYPE_BODY,
                            ..default()
                        },
                        TextColor(TEXT_PRIMARY),
                    ));

                    // Right: Stop button. Tertiary variant — the
                    // action is available but not the loudest element
                    // in the banner; the "Replay" cyan accent owns
                    // that slot. `spawn_modal_button` gives us hover /
                    // press paint and focus rings for free via the
                    // existing `UiModalPlugin` paint system.
                    row.spawn(Node {
                        flex_direction: FlexDirection::Row,
                        align_items: AlignItems::Center,
                        column_gap: VAL_SPACE_2,
                        ..default()
                    })
                    .with_children(|wrap| {
                        spawn_modal_button(
                            wrap,
                            ReplayStopButton,
                            "Stop",
                            None,
                            ButtonVariant::Tertiary,
                            font_res,
                        );
                    });
                });

            // Bottom edge: 1px-tall scrub bar. Track in `BORDER_SUBTLE`,
            // fill in `ACCENT_PRIMARY`. The fill width is rewritten by
            // [`update_scrub_fill`] every tick the cursor advances.
            // Initial fill width matches the spawn-time progress so the
            // first-frame paint already reflects state instead of
            // popping from 0 → cursor on the first tick.
            let initial_scrub_pct = scrub_pct(state);
            banner
                .spawn((
                    Node {
                        width: Val::Percent(100.0),
                        height: Val::Px(1.0),
                        ..default()
                    },
                    BackgroundColor(BORDER_SUBTLE),
                ))
                .with_children(|track| {
                    track.spawn((
                        ReplayOverlayScrubFill,
                        Node {
                            width: Val::Percent(initial_scrub_pct),
                            height: Val::Percent(100.0),
                            ..default()
                        },
                        BackgroundColor(ACCENT_PRIMARY),
                    ));
                });
        });
}

/// Pure helper — returns the scrub-fill width as a percentage of the
/// track for the given playback state. `Completed` reads as 100 %;
/// `Inactive` and `Playing` with no progress read as 0 %.
fn scrub_pct(state: &ReplayPlaybackState) -> f32 {
    if state.is_completed() {
        return 100.0;
    }
    match state.progress() {
        Some((_, 0)) | None => 0.0,
        Some((cursor, total)) => {
            let frac = (cursor as f32 / total as f32).clamp(0.0, 1.0);
            frac * 100.0
        }
    }
}

// ---------------------------------------------------------------------------
// Per-frame text updates
// ---------------------------------------------------------------------------

/// Overwrites the banner label whenever the resource changes — covers the
/// `Playing → Completed` transition by swapping "Replay" for
/// "Replay complete" in place without despawning the overlay.
fn update_banner_label(
    state: Res<ReplayPlaybackState>,
    mut q: Query<&mut Text, With<ReplayOverlayBannerText>>,
) {
    if !state.is_changed() {
        return;
    }
    let label = if state.is_completed() {
        "Replay complete"
    } else if state.is_playing() {
        "Replay"
    } else {
        return;
    };
    for mut text in &mut q {
        **text = label.to_string();
    }
}

/// Repaints the "Move N of M" centre readout every frame the cursor moves.
/// Cheap — early-exits if the resource has not changed since the last
/// frame so idle replays don't churn the text mesh.
fn update_progress_text(
    state: Res<ReplayPlaybackState>,
    mut q: Query<&mut Text, With<ReplayOverlayProgressText>>,
) {
    if !state.is_changed() {
        return;
    }
    let label = format_progress(&state);
    for mut text in &mut q {
        **text = label.clone();
    }
}

/// Repaints the bottom-edge cyan scrub fill to mirror cursor progress.
/// Same change-detection guard as the text updaters — the overlay
/// already early-exits when nothing moved, so an idle replay leaves the
/// scrub bar's `Node` untouched.
fn update_scrub_fill(
    state: Res<ReplayPlaybackState>,
    mut q: Query<&mut Node, With<ReplayOverlayScrubFill>>,
) {
    if !state.is_changed() {
        return;
    }
    let pct = scrub_pct(&state);
    for mut node in &mut q {
        node.width = Val::Percent(pct);
    }
}

/// Pure helper — formats the centre progress readout for the given state.
/// Exposed at module scope so the spawn path and the per-frame update
/// path produce the exact same string.
fn format_progress(state: &ReplayPlaybackState) -> String {
    match state.progress() {
        Some((cursor, total)) => format!("Move {cursor} of {total}"),
        None if state.is_completed() => "Replay complete".to_string(),
        None => String::new(),
    }
}

// ---------------------------------------------------------------------------
// Stop button handler
// ---------------------------------------------------------------------------

/// Watches the Stop button for `Interaction::Pressed` transitions. On a
/// click, calls [`stop_replay_playback`] which resets the state to
/// `Inactive`; the next frame's `react_to_state_change` then despawns
/// the overlay.
fn handle_stop_button(
    mut commands: Commands,
    mut state: ResMut<ReplayPlaybackState>,
    buttons: Query<&Interaction, (With<ReplayStopButton>, Changed<Interaction>)>,
) {
    if !buttons.iter().any(|i| *i == Interaction::Pressed) {
        return;
    }
    stop_replay_playback(&mut commands, &mut state);
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

#[cfg(test)]
mod tests {
    use super::*;
    use chrono::NaiveDate;
    use solitaire_core::game_state::{DrawMode, GameMode};
    use solitaire_data::{Replay, ReplayMove};

    /// Build a minimal but well-formed [`Replay`] with `move_count` no-op
    /// `StockClick` entries. Tests only ever read `replay.moves.len()`
    /// (denominator of the progress indicator), so the move kind is
    /// irrelevant beyond producing the right count.
    fn synthetic_replay(move_count: usize) -> Replay {
        Replay::new(
            42,
            DrawMode::DrawOne,
            GameMode::Classic,
            120,
            1_000,
            NaiveDate::from_ymd_opt(2026, 5, 2).expect("valid date"),
            (0..move_count).map(|_| ReplayMove::StockClick).collect(),
        )
    }

    /// Build a test app that has the overlay plugin but **not** the
    /// playback plugin — tests insert `ReplayPlaybackState` manually so
    /// they can drive every state transition deterministically.
    fn headless_app() -> App {
        let mut app = App::new();
        app.add_plugins(MinimalPlugins).add_plugins(ReplayOverlayPlugin);
        app.init_resource::<ReplayPlaybackState>();
        app
    }

    /// Count `ReplayOverlayRoot` entities in the world — the overlay's
    /// presence/absence is the spawn-test's primary observable.
    fn overlay_root_count(app: &mut App) -> usize {
        app.world_mut()
            .query::<&ReplayOverlayRoot>()
            .iter(app.world())
            .count()
    }

    /// Read the current text content of the unique progress-text entity.
    fn progress_text(app: &mut App) -> String {
        let mut q = app
            .world_mut()
            .query_filtered::<&Text, With<ReplayOverlayProgressText>>();
        q.iter(app.world())
            .next()
            .map(|t| t.0.clone())
            .unwrap_or_default()
    }

    /// Read the current text content of the unique banner-label entity.
    fn banner_text(app: &mut App) -> String {
        let mut q = app
            .world_mut()
            .query_filtered::<&Text, With<ReplayOverlayBannerText>>();
        q.iter(app.world())
            .next()
            .map(|t| t.0.clone())
            .unwrap_or_default()
    }

    /// Set the playback resource without going through the playback core.
    fn set_state(app: &mut App, state: ReplayPlaybackState) {
        app.world_mut().insert_resource(state);
    }

    /// Find the unique `ReplayStopButton` entity for the click-handler
    /// test. There must be exactly one.
    fn stop_button_entity(app: &mut App) -> Entity {
        let mut q = app
            .world_mut()
            .query_filtered::<Entity, With<ReplayStopButton>>();
        q.iter(app.world())
            .next()
            .expect("Stop button must exist while overlay is spawned")
    }

    /// Going `Inactive → Playing` spawns exactly one overlay root and
    /// the banner label reads "Replay".
    #[test]
    fn overlay_spawns_when_playback_starts() {
        let mut app = headless_app();
        // First update with the default `Inactive` resource — overlay
        // must not exist yet.
        app.update();
        assert_eq!(overlay_root_count(&mut app), 0);

        set_state(
            &mut app,
            ReplayPlaybackState::Playing {
                replay: synthetic_replay(10),
                cursor: 0,
                secs_to_next: 0.5,
            },
        );
        app.update();

        assert_eq!(
            overlay_root_count(&mut app),
            1,
            "exactly one ReplayOverlayRoot must spawn on Inactive → Playing",
        );
        assert_eq!(banner_text(&mut app), "Replay");
    }

    /// The progress-text entity reads `"Move {cursor} of {total}"` for a
    /// well-formed `Playing` state.
    #[test]
    fn overlay_progress_text_reflects_cursor() {
        let mut app = headless_app();
        set_state(
            &mut app,
            ReplayPlaybackState::Playing {
                replay: synthetic_replay(10),
                cursor: 5,
                secs_to_next: 0.5,
            },
        );
        app.update();

        assert_eq!(progress_text(&mut app), "Move 5 of 10");
    }

    /// Pressing the Stop button resets the state back to `Inactive` and
    /// the next frame's `react_to_state_change` despawns the overlay.
    /// Mirrors the synthetic `Interaction::Pressed` insertion pattern
    /// used elsewhere in the engine for headless click tests.
    #[test]
    fn overlay_stop_button_click_clears_playback() {
        let mut app = headless_app();
        set_state(
            &mut app,
            ReplayPlaybackState::Playing {
                replay: synthetic_replay(10),
                cursor: 0,
                secs_to_next: 0.5,
            },
        );
        app.update();
        assert_eq!(overlay_root_count(&mut app), 1);

        let stop = stop_button_entity(&mut app);
        app.world_mut()
            .entity_mut(stop)
            .insert(Interaction::Pressed);
        // Tick once: the click handler runs late in the frame and resets
        // the state to `Inactive`.
        app.update();

        // State must be back to Inactive.
        let state = app.world().resource::<ReplayPlaybackState>();
        assert!(
            matches!(state, ReplayPlaybackState::Inactive),
            "Stop click must reset ReplayPlaybackState to Inactive; got {state:?}",
        );

        // One more tick — `react_to_state_change` sees the resource
        // change to Inactive and despawns the overlay.
        app.update();
        assert_eq!(
            overlay_root_count(&mut app),
            0,
            "overlay must despawn the frame after state returns to Inactive",
        );
    }

    /// Manually flipping the resource back to `Inactive` (e.g. via the
    /// playback core's auto-clear after `Completed`) tears the overlay
    /// down without any further input.
    #[test]
    fn overlay_despawns_when_playback_returns_to_inactive() {
        let mut app = headless_app();
        set_state(
            &mut app,
            ReplayPlaybackState::Playing {
                replay: synthetic_replay(3),
                cursor: 1,
                secs_to_next: 0.5,
            },
        );
        app.update();
        assert_eq!(overlay_root_count(&mut app), 1);

        set_state(&mut app, ReplayPlaybackState::Inactive);
        app.update();

        assert_eq!(
            overlay_root_count(&mut app),
            0,
            "overlay must despawn on Playing → Inactive transition",
        );
    }

    /// On `Playing → Completed` the banner label updates in place rather
    /// than respawning. The overlay must still be present, and the label
    /// must read "Replay complete".
    #[test]
    fn overlay_text_changes_on_completed() {
        let mut app = headless_app();
        set_state(
            &mut app,
            ReplayPlaybackState::Playing {
                replay: synthetic_replay(7),
                cursor: 7,
                secs_to_next: 0.0,
            },
        );
        app.update();
        assert_eq!(banner_text(&mut app), "Replay");

        set_state(&mut app, ReplayPlaybackState::Completed);
        app.update();

        assert_eq!(
            overlay_root_count(&mut app),
            1,
            "overlay must remain spawned while in Completed state",
        );
        assert_eq!(
            banner_text(&mut app),
            "Replay complete",
            "banner label must swap on Playing → Completed",
        );
    }

    /// Read the current `Node.width` of the unique scrub-fill entity as
    /// a percentage. Assertions can then compare against expected
    /// `cursor / total` ratios without poking ECS internals at the call
    /// site.
    fn scrub_fill_pct(app: &mut App) -> f32 {
        let mut q = app
            .world_mut()
            .query_filtered::<&Node, With<ReplayOverlayScrubFill>>();
        let node = q
            .iter(app.world())
            .next()
            .expect("scrub-fill node must exist while overlay is spawned");
        match node.width {
            Val::Percent(p) => p,
            other => panic!("scrub fill width must be Val::Percent; got {other:?}"),
        }
    }

    /// Pure-helper guard. Locks in the four corners of `scrub_pct` so a
    /// future refactor of `ReplayPlaybackState::progress()` can't
    /// silently regress the visual cue: `Inactive → 0 %`,
    /// `Playing { cursor: 0, total: N } → 0 %`,
    /// `Playing { cursor: N/2, total: N } → 50 %`,
    /// `Completed → 100 %`.
    #[test]
    fn scrub_pct_covers_state_corners() {
        assert_eq!(scrub_pct(&ReplayPlaybackState::Inactive), 0.0);
        assert_eq!(scrub_pct(&ReplayPlaybackState::Completed), 100.0);
        assert_eq!(
            scrub_pct(&ReplayPlaybackState::Playing {
                replay: synthetic_replay(10),
                cursor: 0,
                secs_to_next: 0.5,
            }),
            0.0,
        );
        assert_eq!(
            scrub_pct(&ReplayPlaybackState::Playing {
                replay: synthetic_replay(10),
                cursor: 5,
                secs_to_next: 0.5,
            }),
            50.0,
        );
        assert_eq!(
            scrub_pct(&ReplayPlaybackState::Playing {
                replay: synthetic_replay(10),
                cursor: 10,
                secs_to_next: 0.5,
            }),
            100.0,
        );
    }

    /// End-to-end: the spawn path must paint the scrub fill at the
    /// initial cursor's percentage, and the per-frame `update_scrub_fill`
    /// system must repaint it as the cursor advances. Mirrors the shape
    /// of `overlay_progress_text_reflects_cursor`.
    #[test]
    fn overlay_scrub_fill_tracks_cursor() {
        let mut app = headless_app();
        set_state(
            &mut app,
            ReplayPlaybackState::Playing {
                replay: synthetic_replay(8),
                cursor: 2,
                secs_to_next: 0.5,
            },
        );
        app.update();
        assert_eq!(
            scrub_fill_pct(&mut app),
            25.0,
            "spawn-time fill must reflect the initial cursor",
        );

        set_state(
            &mut app,
            ReplayPlaybackState::Playing {
                replay: synthetic_replay(8),
                cursor: 6,
                secs_to_next: 0.5,
            },
        );
        app.update();
        assert_eq!(
            scrub_fill_pct(&mut app),
            75.0,
            "update_scrub_fill must repaint width on cursor advance",
        );

        set_state(&mut app, ReplayPlaybackState::Completed);
        app.update();
        assert_eq!(
            scrub_fill_pct(&mut app),
            100.0,
            "Completed state must read as a fully-filled track",
        );
    }
}