medias 0.3.4

mod browser;
mod console;
mod egl;
mod gbm;
mod history;
mod input;
mod kms;
mod library;
mod mpv;
mod shell;
mod thumbs;
mod upnp;
mod vk;
mod youtube;

use std::time::{Duration, Instant};

use drm::Device as BasicDevice;
use drm::buffer::DrmFourcc;
use drm::control::Device as ControlDevice;

use crate::gbm::{Allocator, BufferObjectFlags as Use, Scanout};
use kms::{Card, Output};
use youtube::auth::Account;

fn main() {
    let args: Vec<String> = std::env::args().collect();
    if matches!(args.get(1).map(String::as_str), Some("--help" | "-h" | "help")) {
        print_help();
        return;
    }
    if args.get(1).map(String::as_str) == Some("mpv") {
        let url = args.get(2).cloned().unwrap_or_else(default_test_media);
        if let Err(e) = run_mpv(&url) {
            fail(&format!("mpv: {e}"));
        }
        return;
    }
    if args.get(1).map(String::as_str) == Some("video") {
        let dev = args.get(3).map(String::as_str);
        let url = args.get(2).cloned().unwrap_or_else(default_test_media);
        if let Err(e) = run_video(dev, &url) {
            fail(&format!("video: {e}"));
        }
        return;
    }
    if args.get(1).map(String::as_str) == Some("input") {
        run_input(args.get(2).map(String::as_str));
        return;
    }
    if args.get(1).map(String::as_str) == Some("shell") {
        if let Err(e) = run_shell(args.get(2).map(String::as_str)) {
            fail(&format!("shell: {e}"));
        }
        return;
    }
    if args.get(1).map(String::as_str) == Some("comp") {
        let dev = args.get(3).map(String::as_str);
        let url = args.get(2).cloned().unwrap_or_else(default_test_media);
        if let Err(e) = run_compositor(dev, &url) {
            fail(&format!("compositor: {e}"));
        }
        return;
    }
    if args.get(1).map(String::as_str) == Some("bench") {
        if let Err(error) = run_bench(args.get(2).map(String::as_str)) {
            fail(&format!("bench: {error}"));
        }
        return;
    }

    // Default: the media player app. Roots come from --videos/--music flags
    // (repeatable); a /-prefixed arg overrides the display device.
    let home = std::env::var("HOME").unwrap_or_else(|_| ".".into());
    let base = std::path::PathBuf::from(home).join("medias");
    let mut roots: Vec<(String, std::path::PathBuf)> = Vec::new();
    let mut dev: Option<String> = None;
    for a in &args[1..] {
        if let Some(v) = a.strip_prefix("--videos") {
            roots.push(parse_root(v, "Videos", &base));
        } else if let Some(v) = a.strip_prefix("--music") {
            roots.push(parse_root(v, "Music", &base));
        } else if a.starts_with('/') {
            dev = Some(a.clone());
        } else {
            fail(&format!("unknown argument: {a}  (try --help)"));
        }
    }
    if roots.is_empty() {
        roots = vec![
            ("Videos".into(), base.join("Videos")),
            ("Music".into(), base.join("Music")),
        ];
    }
    if let Err(e) = run_app(dev.as_deref(), roots) {
        fail(&format!("app: {e}"));
    }
}

fn open_display(dev: Option<&str>) -> Result<(Card, Output, kms::DisplaySession), String> {
    let (card, path) = match dev {
        Some(p) => (Card::open(p).map_err(|e| format!("open {p}: {e}"))?, p.to_string()),
        None => kms::open_primary().map_err(e2s)?,
    };
    println!("display: {path}");
    let output = Output::discover(&card).map_err(|e| format!("discover on {path}: {e}"))?;
    card.acquire_master_lock().map_err(|e| {
        format!(
            "acquire DRM master on {path}: {e}\n\
             Use an active console VT with access to this device and no \
             desktop/compositor holding it."
        )
    })?;
    let session = kms::DisplaySession::new(&card, &output)
        .map_err(|e| format!("console session: {e}"))?;
    Ok((card, output, session))
}

/// Parse a `--videos`/`--music` value into (label, path). `v` is "" (bare),
/// "=PATH" (label from basename), or "=LABEL=PATH". Relative paths resolve
/// under `base` (~/medias).
fn parse_root(v: &str, default_label: &str, base: &std::path::Path) -> (String, std::path::PathBuf) {
    let spec = v.strip_prefix('=').unwrap_or("");
    if spec.is_empty() {
        return (default_label.to_string(), base.join(default_label));
    }
    let resolve = |p: &str| {
        let pb = std::path::PathBuf::from(p);
        if pb.is_absolute() { pb } else { base.join(pb) }
    };
    match spec.split_once('=') {
        Some((label, path)) => (label.to_string(), resolve(path)),
        None => {
            let path = resolve(spec);
            let label = path
                .file_name()
                .map(|s| s.to_string_lossy().into_owned())
                .unwrap_or_else(|| default_label.to_string());
            (label, path)
        }
    }
}

/// Graphics bring-up benchmarks (milestones 2-3).
fn run_bench(dev: Option<&str>) -> Result<(), String> {
    let (card, output, mut display) = open_display(dev)?;
    let alloc = Allocator::new(&card).map_err(|e| format!("gbm: {e}"))?;

    let (w, h) = output.mode.size();
    println!("mode {}x{}@{}  ui {:?} video {:?}", w, h, output.mode.vrefresh(), output.ui_plane, output.video_plane);

    println!("\n=== Vulkan ===");
    let gpu = match vk::Gpu::new() {
        Ok(g) => {
            println!("chosen: {}  queue_family={}", g.name, g.queue_family);
            Some(g)
        }
        Err(e) => {
            eprintln!("vulkan bring-up failed: {e}");
            None
        }
    };

    println!("\n=== KMS present (CPU) ===");
    run_cpu(&card, &output, &alloc, w.into(), h.into()).map_err(|e| format!("present: {e}"))?;

    if let Some(gpu) = gpu.filter(|_| !console::stopping()) {
        println!("\n=== KMS present (Vulkan render into scanout dmabuf) ===");
        if let Err(e) = run_gpu(&card, &output, &alloc, &gpu, w.into(), h.into()) {
            eprintln!("gpu present: {e}");
        }
    }
    display.restore();
    Ok(())
}

/// Milestone 4a: libmpv engine bring-up. Decode + control plane only (no
/// display, no audio device) — proves create/init/load/events/properties.
fn run_mpv(url: &str) -> Result<(), String> {
    println!("=== libmpv ({url}) ===");
    let m = mpv::Mpv::new()?;
    m.set_option("vo", "null")?; // 4b wires video to a KMS plane
    m.set_option("ao", "null")?;
    m.set_option("hwdec", "no")?; // Pi: drm-prime / v4l2
    m.set_option("msg-level", "all=error")?;
    m.init()?;
    m.loadfile(url)?;

    let start = Instant::now();
    let mut last = -1.0;
    loop {
        match m.wait_event(0.2) {
            mpv::Event::FileLoaded => {
                println!("file loaded: duration={:.2}s", m.get_f64("duration").unwrap_or(0.0));
            }
            mpv::Event::EndFile(_) | mpv::Event::PlaybackError => {
                println!("end-file");
                break;
            }
            mpv::Event::Shutdown => break,
            _ => {}
        }
        if let Some(t) = m.get_f64("time-pos") {
            if t - last >= 0.5 {
                println!("  time-pos {t:.2}s");
                last = t;
            }
        }
        if start.elapsed().as_secs() > 20 {
            println!("timeout");
            break;
        }
    }
    println!("done in {:.1}s", start.elapsed().as_secs_f64());
    Ok(())
}

/// A browsable node: filesystem, UPnP/DLNA or YouTube.
enum Node {
    Dir(std::path::PathBuf),
    Media(std::path::PathBuf),
    UpnpRoot,                                       // discovered UPnP/DLNA media servers
    UpnpDir(std::sync::Arc<upnp::Server>, String),  // a server container (object id; "0" is the root)
    UpnpMedia(String, upnp::Kind),                  // an item's HTTP resource URL
    YtRoot,              // the YouTube app home
    #[cfg(feature = "youtube-tv")]
    YtForYou,            // YouTube's recommendations (YouTube TV sign-in)
    YtFromHistory,       // related videos of recently watched YouTube videos
    YtSubsLatest,        // signed-in: recent uploads from subscriptions, interleaved
    YtSearch,            // opens the query keyboard; submitting runs a live search
    YtTrending,          // most-popular chart (public)
    YtSubs,              // signed-in: subscribed channels
    YtChannel(String),   // a channel's latest uploads (channel id)
    YtPlaylists,         // signed-in: the account's playlists
    YtPlaylist(String),  // a playlist's videos (playlist id)
    YtLiked,             // signed-in: liked videos
    YtSource(String),    // youtube.txt query resolved via yt-dlp (anonymous fallback)
    YtVideo(String),     // a watch URL; played via direct InnerTube streams
    YtSignIn(Account),   // begin the device-auth flow for an account
    YtSignOut(Account),  // drop an account's stored session
}

/// In-progress device-auth sign-in: the account, its OAuth client, the code
/// shown to the user, and the polling schedule.
struct SignIn {
    account: Account,
    creds: youtube::auth::Credentials,
    device: youtube::auth::DeviceCode,
    qr: Option<(usize, Vec<bool>)>, // (side in modules, row-major dark grid)
    status: String,
    next_poll: Instant,
    expires_at: Instant,
}

struct Item {
    name: String,
    node: Node,
    container: bool, // descends on Select (shown with a trailing '/')
    meta: String,    // right-column text (e.g. a video's duration); else history date
    sub: String,     // secondary line (e.g. a video's channel)
    thumb: String,   // thumbnail URL; empty for none
}

impl Item {
    fn new(name: impl Into<String>, node: Node, container: bool) -> Item {
        Item { name: name.into(), node, container, meta: String::new(), sub: String::new(), thumb: String::new() }
    }

    /// A YouTube watch URL; the thumbnail derives from its video id.
    fn video(title: impl Into<String>, url: String) -> Item {
        let thumb = youtube::video_id(&url).map(|id| youtube::thumb_url(&id)).unwrap_or_default();
        Item { thumb, ..Item::new(title, Node::YtVideo(url), false) }
    }
}

struct Level {
    title: String,
    items: Vec<Item>,
    browse: browser::Browser,
    thumbs: bool, // some item has a thumbnail: shown as a thumbnail list or grid
}

impl Level {
    fn new(title: impl Into<String>, items: Vec<Item>) -> Self {
        // Filter text: name plus the secondary line (title and channel).
        let names: Vec<String> = items
            .iter()
            .map(|item| if item.sub.is_empty() { item.name.clone() } else { format!("{} {}", item.name, item.sub) })
            .collect();
        let browse = browser::Browser::new(names.iter().map(String::as_str));
        let thumbs = items.iter().any(|item| !item.thumb.is_empty());
        Self { title: title.into(), items, browse, thumbs }
    }

    /// A query-entry level: an on-screen keyboard whose text is submitted for a
    /// live YouTube search.
    fn query(title: impl Into<String>) -> Self {
        Self { title: title.into(), items: Vec::new(), browse: browser::Browser::query_input(), thumbs: false }
    }

    fn layout(&self, wide: bool) -> shell::Layout {
        match (self.thumbs, wide) {
            (false, _) => shell::Layout::Text,
            (true, false) => shell::Layout::List,
            (true, true) => shell::Layout::Grid,
        }
    }
}

/// The wide (grid) view preference, persisted in ~/medias/.view as "grid" or "list".
fn view_path() -> Option<std::path::PathBuf> {
    Some(std::path::PathBuf::from(std::env::var("HOME").ok()?).join("medias/.view"))
}

fn load_wide_view() -> bool {
    view_path().and_then(|p| std::fs::read_to_string(p).ok()).is_some_and(|s| s.trim() == "grid")
}

fn autoplay_path() -> Option<std::path::PathBuf> {
    Some(std::path::PathBuf::from(std::env::var("HOME").ok()?).join("medias/.autoplay"))
}

/// Play next in folder: on unless ~/medias/.autoplay says "off".
fn load_autoplay() -> bool {
    autoplay_path().and_then(|p| std::fs::read_to_string(p).ok()).is_none_or(|s| s.trim() != "off")
}

fn save_autoplay(on: bool) {
    if let Some(p) = autoplay_path() {
        let _ = std::fs::write(p, if on { "on\n" } else { "off\n" });
    }
}

fn save_wide_view(wide: bool) {
    if let Some(p) = view_path() {
        let _ = std::fs::write(p, if wide { "grid\n" } else { "list\n" });
    }
}

/// Format whole seconds as "H:MM:SS" or "M:SS".
fn fmt_dur(secs: u32) -> String {
    let (h, m, s) = (secs / 3600, (secs % 3600) / 60, secs % 60);
    if h > 0 { format!("{h}:{m:02}:{s:02}") } else { format!("{m}:{s:02}") }
}

// ---- YouTube level builders -----------------------------------------------

fn yt_video_items(videos: Vec<youtube::model::Video>) -> Vec<Item> {
    videos
        .into_iter()
        .map(|v| {
            let meta = if v.duration > 0 { fmt_dur(v.duration) } else { String::new() };
            Item { meta, sub: v.channel.clone(), thumb: youtube::thumb_url(&v.id), ..Item::new(v.title.clone(), Node::YtVideo(v.watch_url()), false) }
        })
        .collect()
}

fn yt_channel_items(channels: Vec<youtube::model::Channel>) -> Vec<Item> {
    channels
        .into_iter()
        .map(|c| Item { thumb: c.thumbs.list().into(), ..Item::new(c.title, Node::YtChannel(c.id), true) })
        .collect()
}

fn yt_playlist_items(playlists: Vec<youtube::model::Playlist>) -> Vec<Item> {
    playlists
        .into_iter()
        .map(|p| {
            let meta = if p.count > 0 { p.count.to_string() } else { String::new() };
            Item { meta, thumb: p.thumbs.list().into(), ..Item::new(p.title, Node::YtPlaylist(p.id), true) }
        })
        .collect()
}

/// YouTube home: For you (YouTube TV sign-in on first open), From your history
/// when YouTube videos were played, Search, Trending, the Data API account
/// sections when signed in, the youtube.txt sources, and the sign-in/out rows.
fn yt_home_items(yt: &youtube::Service, has_history: bool) -> Vec<Item> {
    let mut items = Vec::new();
    #[cfg(feature = "youtube-tv")]
    items.push(Item::new("For you", Node::YtForYou, true));
    if has_history {
        items.push(Item::new("From your history", Node::YtFromHistory, true));
    }
    if yt.signed_in() {
        items.push(Item::new("Latest from subscriptions", Node::YtSubsLatest, true));
    }
    items.push(Item::new("Search", Node::YtSearch, true));
    if yt.data_api_available() {
        items.push(Item::new("Trending", Node::YtTrending, true));
    }
    if yt.signed_in() {
        items.push(Item::new("Subscriptions", Node::YtSubs, true));
        items.push(Item::new("Playlists", Node::YtPlaylists, true));
        items.push(Item::new("Liked videos", Node::YtLiked, true));
    }
    for source in youtube::sources() {
        items.push(Item::new(source.label, Node::YtSource(source.query), true));
    }
    if yt.signed_in() {
        let label = match yt.account() {
            Some(name) => format!("Sign out ({name})"),
            None => "Sign out".into(),
        };
        items.push(Item::new(label, Node::YtSignOut(Account::DataApi), false));
    } else {
        // Shown even without credentials; opening it then explains the one-time
        // OAuth client setup rather than silently doing nothing.
        items.push(Item::new("Sign in", Node::YtSignIn(Account::DataApi), false));
    }
    #[cfg(feature = "youtube-tv")]
    if yt.tv_signed_in() {
        items.push(Item::new("Sign out of YouTube TV", Node::YtSignOut(Account::Tv), false));
    }
    items
}

fn yt_home(yt: &youtube::Service, history: &history::History) -> Level {
    Level::new("YouTube", yt_home_items(yt, !yt_history_ids(history).is_empty()))
}

/// Result of a background load (`spawn_load`).
enum Loaded {
    Level(Level),
    /// Start playback: `key` is the history key and `target` (+ `audio`) what mpv opens.
    Play { key: String, name: String, target: String, audio: Vec<String> }, // audio: edl:// tracks
    Failed(String),
}

/// A load running on a worker thread; the browser shows a spinner until it
/// arrives and Back abandons it.
struct Pending {
    label: String,
    rx: std::sync::mpsc::Receiver<Loaded>,
    started: Instant,
}

fn spawn_load(label: impl Into<String>, job: impl FnOnce() -> Loaded + Send + 'static) -> Pending {
    let (tx, rx) = std::sync::mpsc::channel();
    std::thread::spawn(move || {
        let _ = tx.send(job());
    });
    Pending { label: label.into(), rx, started: Instant::now() }
}

fn level_or_failed(title: String, items: Result<Vec<Item>, String>) -> Loaded {
    match items {
        Ok(items) if items.is_empty() => Loaded::Failed(format!("{title}: nothing found")),
        Ok(items) => Loaded::Level(Level::new(title, items)),
        Err(error) => Loaded::Failed(format!("{title}: {error}")),
    }
}

/// YouTube's recommendations (InnerTube FEwhat_to_watch with the YouTube TV token).
#[cfg(feature = "youtube-tv")]
fn yt_for_you(yt: &mut youtube::Service) -> Pending {
    let token = yt.tv_access_token();
    spawn_load("For you", move || {
        let Some(token) = token else { return Loaded::Failed("For you: YouTube TV sign-in unavailable".into()) };
        let videos = youtube::innertube::recommendations(&token);
        if matches!(&videos, Ok(v) if v.is_empty()) {
            eprintln!("youtube: recommendations empty (MEDIAS_YT_DEBUG=1 dumps the response)");
        }
        level_or_failed("For you".into(), videos.map(yt_video_items))
    })
}

/// Direct InnerTube streams for a watch URL; on failure mpv gets the watch URL
/// (yt-dlp hook). History keys by the watch URL either way.
fn yt_play(url: String, name: String, prefs: youtube::innertube::StreamPrefs) -> Pending {
    spawn_load(name.clone(), move || {
        let direct = youtube::video_id(&url)
            .ok_or_else(|| "no video id in URL".to_string())
            .and_then(|id| youtube::innertube::streams(&id, &prefs));
        let (target, audio) = match direct {
            Ok(streams) => {
                let audio = streams.audio.iter().map(|a| mpv::edl_track(&a.url, &a.lang, &a.title)).collect();
                (streams.video, audio)
            }
            Err(err) => {
                eprintln!("youtube: direct stream failed ({err}); trying yt-dlp");
                (url.clone(), Vec::new())
            }
        };
        Loaded::Play { key: url, name, target, audio }
    })
}

/// Request a device code for an account. None (logged on failure) when the
/// request fails or the account has no OAuth client configured.
fn start_sign_in(yt: &youtube::Service, account: Account) -> Option<SignIn> {
    let creds = yt.sign_in_credentials(account)?;
    match youtube::auth::request_device_code(&creds, account.scope()) {
        Ok(device) => {
            let now = Instant::now();
            Some(SignIn {
                account,
                creds,
                qr: youtube::auth::qr_matrix(&device.scan_url()),
                status: "Waiting for approval…".into(),
                next_poll: now + Duration::from_secs(device.interval.max(1)),
                expires_at: now + Duration::from_secs(device.expires_in.max(60)),
                device,
            })
        }
        Err(error) => {
            eprintln!("youtube sign-in: {error}");
            None
        }
    }
}

/// YouTube video ids in the playback history, most recent first.
fn yt_history_ids(history: &history::History) -> Vec<String> {
    history.recent().into_iter().filter_map(youtube::video_id).collect()
}

/// Recent uploads from the subscribed channels, interleaved round-robin.
/// Bounded in channels and per-channel depth to limit latency; playlistItems is
/// 1 quota unit per call and each page is cached.
fn yt_subs_latest(client: &youtube::api::Client) -> Result<Vec<Item>, String> {
    let lists = client
        .subscriptions()?
        .iter()
        .take(12)
        .filter_map(|c| client.playlist_videos(&youtube::api::uploads_playlist_id(&c.id)).ok())
        .map(|mut videos| {
            videos.truncate(4);
            videos
        })
        .collect();
    let videos = youtube::interleave(lists, &Default::default());
    if videos.is_empty() {
        return Err("no subscription uploads found".into());
    }
    Ok(yt_video_items(videos))
}

/// Fetch a YouTube video/channel/playlist level through the Data API client on
/// a worker thread (the token refresh, if due, runs here).
fn yt_fetch(
    yt: &mut youtube::Service,
    title: &str,
    build: impl FnOnce(&youtube::api::Client) -> Result<Vec<Item>, String> + Send + 'static,
) -> Pending {
    let (title, client) = (title.to_string(), yt.client());
    spawn_load(title.clone(), move || level_or_failed(title, client.and_then(|client| build(&client))))
}

/// yt-dlp-resolved videos of a youtube.txt source or an anonymous search.
fn ytdl_items(query: &str) -> Result<Vec<Item>, String> {
    let videos = youtube::resolve(query).map_err(|e| e.to_string())?;
    Ok(videos.into_iter().map(|v| Item::video(v.title, v.url)).collect())
}

/// Live search: Data API when available, else a yt-dlp `ytsearch` fallback so
/// anonymous users can still search.
fn yt_search(yt: &mut youtube::Service, query: String) -> Pending {
    let client = yt.client().ok().filter(|client| client.usable());
    spawn_load(format!("results for “{query}”"), move || {
        let items = match client {
            Some(client) => client.search(&query).map(yt_video_items),
            None => ytdl_items(&format!("ytsearch25:{query}")),
        };
        level_or_failed(query, items)
    })
}

/// Card secondary line: the item's own (channel), "Folder" for a directory, plus
/// the last-played date.
fn card_sub(it: &Item, played: Option<String>) -> String {
    let folder = matches!(it.node, Node::Dir(_) | Node::UpnpDir(..)) && it.sub.is_empty();
    let base = if folder { "Folder" } else { it.sub.as_str() };
    match played {
        Some(date) if base.is_empty() => format!("Watched {date}"),
        Some(date) => format!("{base} · watched {date}"),
        None => base.to_string(),
    }
}

/// Placeholder symbol for a card without a thumbnail.
fn card_icon(it: &Item) -> shell::Icon {
    match &it.node {
        Node::Media(p) if library::classify(p) == Some(library::Kind::Audio) => shell::Icon::Audio,
        Node::UpnpMedia(_, upnp::Kind::Audio) => shell::Icon::Audio,
        Node::Media(_) | Node::YtVideo(_) | Node::UpnpMedia(..) => shell::Icon::Video,
        Node::Dir(_) | Node::UpnpDir(..) | Node::UpnpRoot => shell::Icon::Folder,
        _ => shell::Icon::None,
    }
}

/// Build a level from a filesystem directory listing. Thumbnail keys are the
/// absolute paths (`thumbs` renders a frame, cover art, or a folder image).
fn lib_items(entries: Vec<library::Entry>) -> Vec<Item> {
    entries
        .into_iter()
        .map(|e| {
            let container = e.kind == library::Kind::Dir;
            let thumb = std::path::absolute(&e.path).unwrap_or_else(|_| e.path.clone()).to_string_lossy().into_owned();
            let node = if container { Node::Dir(e.path) } else { Node::Media(e.path) };
            Item { thumb, ..Item::new(e.name, node, container) }
        })
        .collect()
}

/// One Info press in playback: (bar shown, Info hid it, screen black) after,
/// given the bar's visibility and the two flags before. A bar that timed out
/// counts as not yet hidden by Info, so Info shows it first.
fn info_step(bar: bool, hidden: bool, blank: bool) -> (bool, bool, bool) {
    match (blank, bar, hidden) {
        (true, ..) | (false, false, false) => (true, false, false),
        (false, true, _) => (false, true, false),
        (false, false, true) => (false, false, true),
    }
}

// ---- folder playback queue ------------------------------------------------

/// The playable items (local files, UPnP resources) of the level at stack
/// index `depth`, in its filtered order; `pos` indexes the current one.
struct Queue {
    depth: usize,
    items: Vec<(usize, String, String)>, // (source index, name, path or URL)
    pos: usize,
}

impl Queue {
    fn new(level: &Level, depth: usize, current: usize) -> Option<Queue> {
        let items: Vec<(usize, String, String)> = (0..level.browse.count())
            .filter_map(|filtered| {
                let src = level.browse.source_index(filtered)?;
                let item = &level.items[src];
                let target = match &item.node {
                    Node::Media(path) => path.to_string_lossy().into_owned(),
                    Node::UpnpMedia(url, _) => url.clone(),
                    _ => return None,
                };
                Some((src, item.name.clone(), target))
            })
            .collect();
        let pos = items.iter().position(|(src, ..)| *src == current)?;
        Some(Queue { depth, items, pos })
    }

    /// Move by `step` and return the play request, or None past either end.
    fn step(&mut self, step: isize) -> Option<Loaded> {
        let pos = self.pos.checked_add_signed(step).filter(|&p| p < self.items.len())?;
        self.pos = pos;
        Some(self.play())
    }

    fn play(&self) -> Loaded {
        let (_, name, target) = &self.items[self.pos];
        Loaded::Play { key: target.clone(), name: name.clone(), target: target.clone(), audio: Vec::new() }
    }

    /// Select the current item in its level if that level is still on the stack.
    fn sync_selection(&self, stack: &mut [Level]) {
        let (src, name, _) = &self.items[self.pos];
        if let Some(level) = stack.get_mut(self.depth)
            && level.items.get(*src).is_some_and(|item| item.name == *name)
        {
            level.browse.select_source(*src);
        }
    }
}

// ---- UPnP/DLNA level builders ---------------------------------------------

fn upnp_server_items(servers: Vec<upnp::Server>) -> Vec<Item> {
    servers
        .into_iter()
        .map(|server| {
            let thumb = server.icon.clone();
            let name = server.name.clone();
            let node = Node::UpnpDir(std::sync::Arc::new(server), "0".into());
            Item { thumb, sub: "Media server".into(), ..Item::new(name, node, true) }
        })
        .collect()
}

/// Containers keep the server; items show duration (meta) and artist · album (sub).
fn upnp_items(server: &std::sync::Arc<upnp::Server>, entries: Vec<upnp::Entry>) -> Vec<Item> {
    entries
        .into_iter()
        .map(|entry| match entry {
            upnp::Entry::Container { id, title, .. } => Item::new(title, Node::UpnpDir(server.clone(), id), true),
            upnp::Entry::Item { title, url, kind, art, duration, artist, album } => {
                let sub = [artist, album].into_iter().filter(|s| !s.is_empty()).collect::<Vec<_>>().join(" · ");
                let meta = if duration > 0 { fmt_dur(duration) } else { String::new() };
                Item { thumb: art, sub, meta, ..Item::new(title, Node::UpnpMedia(url, kind), false) }
            }
        })
        .collect()
}

// ---- playback menu (overlaid on the paused video) -------------------------

#[derive(Clone)]
enum Pb {
    Resume,
    Library,
    Stop,
    SeekMenu,
    AudioMenu,
    SubMenu,
    SeekAbs(f64),
    SeekRel(f64),
    SetAid(String),
    SetSid(String),
    Autoplay,
}

struct PbItem {
    name: String,
    node: Pb,
}

struct PbLevel {
    title: String,
    items: Vec<PbItem>,
    selected: usize,
    horizontal: bool, // seek row: Left/Right navigate, OSD stays, repeatable
}

fn pb(name: &str, node: Pb) -> PbItem {
    PbItem { name: name.into(), node }
}

fn pb_root(autoplay: bool) -> PbLevel {
    PbLevel {
        title: "Playback".into(),
        selected: 0,
        horizontal: false,
        items: vec![
            pb("Resume", Pb::Resume),
            pb("Seek", Pb::SeekMenu),
            pb("Audio", Pb::AudioMenu),
            pb("Subtitles", Pb::SubMenu),
            pb(if autoplay { "Play next in folder: on" } else { "Play next in folder: off" }, Pb::Autoplay),
            pb("Browse library", Pb::Library),
            pb("Stop", Pb::Stop),
        ],
    }
}

fn pb_seek() -> PbLevel {
    PbLevel {
        title: "Seek".into(),
        selected: 0,
        horizontal: true,
        items: vec![
            pb("Beginning", Pb::SeekAbs(0.0)),
            pb("-10m", Pb::SeekRel(-600.0)),
            pb("-1m", Pb::SeekRel(-60.0)),
            pb("+1m", Pb::SeekRel(60.0)),
            pb("+10m", Pb::SeekRel(600.0)),
        ],
    }
}

/// mpv track-list entry (audio or subtitle).
fn track_items(m: &mpv::Mpv, kind: &str, off: Option<&str>) -> PbLevel {
    let n = m.get_f64("track-list/count").unwrap_or(0.0) as i64;
    let mut items = Vec::new();
    if let Some(label) = off {
        items.push(pb(label, Pb::SetSid("no".into())));
    }
    for i in 0..n {
        if m.get_string(&format!("track-list/{i}/type")).as_deref() != Some(kind) {
            continue;
        }
        let id = m.get_string(&format!("track-list/{i}/id")).unwrap_or_default();
        let lang = m.get_string(&format!("track-list/{i}/lang")).unwrap_or_default();
        let title = m.get_string(&format!("track-list/{i}/title")).unwrap_or_default();
        let selected = m.get_string(&format!("track-list/{i}/selected")).as_deref() == Some("yes");
        let mut name = format!("{id}");
        if !lang.is_empty() {
            name.push_str(&format!("  {lang}"));
        }
        if !title.is_empty() {
            name.push_str(&format!("  {title}"));
        }
        if selected {
            name.push_str("   *");
        }
        let node = if kind == "audio" { Pb::SetAid(id) } else { Pb::SetSid(id) };
        items.push(pb(&name, node));
    }
    let title = if kind == "audio" { "Audio" } else { "Subtitles" };
    PbLevel { title: title.into(), items, selected: 0, horizontal: false }
}

fn run_app(dev: Option<&str>, roots: Vec<(String, std::path::PathBuf)>) -> Result<(), String> {
    use std::sync::mpsc;

    #[derive(PartialEq)]
    enum Mode {
        Browse, // the content library (opaque)
        Play,   // video on screen + transport
        Menu,   // playback menu overlaid on the paused video
        SignIn, // YouTube device-auth screen (opaque)
    }
    use youtube::auth::Poll;

    println!("=== medias ===");
    for (label, path) in &roots {
        println!("root: {label} -> {}", path.display());
    }

    let (card, output, mut display) = open_display(dev)?;
    if output.video_plane.is_none() {
        return Err("need two planes for the app".into());
    }
    let alloc = Allocator::new(&card).map_err(|e| format!("gbm: {e}"))?;
    let (w, h) = (u32::from(output.mode.size().0), u32::from(output.mode.size().1));
    println!("mode: {w}x{h}@{}", output.mode.vrefresh());

    // Render video at ~1080p and let the display hardware scale it to the mode.
    // On 4K this is ~4x less work for the GPU per frame; invisible for video.
    let vscale = (h / 1080).max(1);
    let (mut vw, mut vh) = (w / vscale, h / vscale);

    let gpu = vk::Gpu::new()?;
    let video = egl::VideoGl::new(&alloc)?;
    let text = gpu.create_text()?;

    // Double-buffered per plane: we always render into the buffer that is NOT
    // currently being scanned out, then flip to it. Single-buffering flickered.
    let mut vbufs = Vec::new(); // video scanout buffers (gbm)
    let mut _vfbos = Vec::new(); // keep the GL FBO imports alive
    let mut vfbo_ids = Vec::new();
    let mut ubufs = Vec::new(); // ui scanout buffers (gbm)
    let mut targets = Vec::new(); // vulkan image imports
    let mut ufbs = Vec::new(); // vulkan framebuffers
    let alloc_video = |vw: u32, vh: u32, vbufs: &mut Vec<_>, vfbos: &mut Vec<_>, ids: &mut Vec<_>| {
        for _ in 0..2 {
            let vb = alloc.alloc(&card, vw, vh, DrmFourcc::Xrgb8888, Use::SCANOUT | Use::RENDERING).map_err(|e| format!("video alloc: {e}"))?;
            let gf = video.import(&vb)?;
            ids.push(video.fbo_id(&gf));
            vfbos.push(gf);
            vbufs.push(vb);
        }
        Ok::<(), String>(())
    };
    alloc_video(vw, vh, &mut vbufs, &mut _vfbos, &mut vfbo_ids)?;
    for _ in 0..2 {
        let (ub, t) = gpu.create_scanout_target(&alloc, &card, &output, w, h, DrmFourcc::Argb8888)?;
        ufbs.push(text.framebuffer(&gpu, &t)?);
        targets.push(t);
        ubufs.push(ub);
    }
    // Plane scaling is driver-dependent (rejected with EINVAL on NVIDIA GTX
    // 1080 Ti at 3840x2160); fall back to rendering video at the mode size.
    if vscale > 1 {
        match output.test_two(&card, vbufs[0].fb, (vw as u16, vh as u16), ubufs[0].fb) {
            Ok(()) => println!("video render: {vw}x{vh} -> hw-scaled to {w}x{h}"),
            Err(e) => {
                println!("video render: {w}x{h} (plane scaling from {vw}x{vh} rejected: {e})");
                for f in _vfbos.drain(..) {
                    video.release(f);
                }
                for b in vbufs.drain(..) {
                    let _ = card.destroy_framebuffer(b.fb);
                }
                vfbo_ids.clear();
                (vw, vh) = (w, h);
                alloc_video(vw, vh, &mut vbufs, &mut _vfbos, &mut vfbo_ids)?;
            }
        }
    }

    let m = mpv::Mpv::new()?;
    m.set_option("vo", "libmpv")?;
    // Audio output. Default ALSA (works as root); MEDIAS_AO can select another,
    // e.g. "pipewire" (needs access to the session's pipewire — see notes).
    let ao = std::env::var("MEDIAS_AO").unwrap_or_else(|_| "alsa,null".into());
    m.set_option("ao", &ao)?;
    // HDMI audio device varies; let the user pin it (`aplay -L` to find it),
    // e.g. MEDIAS_AUDIO_DEVICE=alsa/sysdefault:CARD=vc4hdmi0
    if let Ok(dev) = std::env::var("MEDIAS_AUDIO_DEVICE") {
        m.set_option("audio-device", &dev)?;
    }
    // Hardware decode (Pi 5: HEVC via v4l2; H.264 is software). Override with
    // MEDIAS_HWDEC=no if interop misbehaves.
    let hwdec = std::env::var("MEDIAS_HWDEC").unwrap_or_else(|_| "auto".into());
    m.set_option("hwdec", &hwdec)?;
    m.set_option("idle", "yes")?;
    // YouTube plays direct InnerTube stream URLs. mpv's yt-dlp hook is only the
    // fallback: without try_ytdl_first it runs after a direct open fails, so it
    // never delays the direct URLs. Absolute path: independent of launch PATH.
    let ytdl_path = youtube::ytdl_path();
    m.set_option("ytdl", "yes")?;
    m.set_option("script-opts", &format!("ytdl_hook-ytdl_path={ytdl_path}"))?;
    let ytdl_format =
        std::env::var("MEDIAS_YTDL_FORMAT").unwrap_or_else(|_| "bestvideo[height<=?1080]+bestaudio/best".into());
    m.set_option("ytdl-format", &ytdl_format)?;
    // MEDIAS_MPV_LOG=<path> captures mpv's own verbose log (hook/decode errors).
    if let Ok(path) = std::env::var("MEDIAS_MPV_LOG")
        && !path.is_empty()
    {
        m.set_option("log-file", &path)?;
        m.set_option("msg-level", "all=v")?;
    } else {
        m.set_option("msg-level", "all=error")?;
    }
    m.init()?;
    let rc = m.render_context(egl::mpv_get_proc_address)?;

    let mut root_items: Vec<Item> = roots
        .into_iter()
        .map(|(label, path)| Item::new(label, Node::Dir(path), true))
        .collect();
    root_items.push(Item::new("Media servers", Node::UpnpRoot, true));
    root_items.push(Item::new("YouTube", Node::YtRoot, true));
    let mut stack = vec![Level::new("medias", root_items)];
    let mut pbstack: Vec<PbLevel> = Vec::new(); // playback menu
    let mut mode = Mode::Browse;
    let mut now_title = String::new();
    let mut current_path = String::new(); // path/url of the loaded file
    let mut resume_to: Option<f64> = None; // retained until the resume seek finishes
    let mut resume_seek_started = false;
    let mut history = history::History::load();
    let mut yt = youtube::Service::load();
    let stream_prefs = youtube::innertube::StreamPrefs::from_env();
    let mut signin: Option<SignIn> = None;
    let mut thumb_cache = thumbs::Thumbs::new();
    let mut pending: Option<Pending> = None; // background load behind a spinner
    let mut ready: Option<Loaded> = None; // a result to apply this iteration
    let mut notice: Option<(String, Instant)> = None; // failure message until the Instant
    let mut play_started = Instant::now(); // spinner over the black plane until video_live
    let mut spin_phase = usize::MAX; // last rendered spinner step; MAX: hidden
    let spin_epoch = Instant::now();
    const SPIN_DELAY: Duration = Duration::from_millis(150); // no flash for instant loads
    const NOTICE_SECS: Duration = Duration::from_secs(5);
    let mut wide = load_wide_view(); // thumbnail levels: grid instead of list
    let mut autoplay = load_autoplay(); // natural EOF plays the next queue item
    let mut queue: Option<Queue> = None; // folder of the playing local/UPnP item

    let (tx, rx) = mpsc::channel::<input::Key>();
    let sources = input::spawn(tx, display.owns_vt());
    if !sources.available() {
        return Err("no keyboard or CEC input available; check access to /dev/input/event* and /dev/cec0".into());
    }

    let mut frame = vk::Frame::default();
    let mut vfront = 0usize; // video buffer holding the latest frame (shown now)
    // False from a load until mpv's PLAYBACK_RESTART (after any resume seek): frames
    // are rendered but not flipped, so neither the previous file's last frame nor
    // the pre-resume frame at 0:00 is shown; the plane stays black.
    let mut video_live = false;
    let mut video_redraw = false; // render the current frame even without an update
    let mut modeset = false;

    let mut ui_front = 0usize; // last presented UI buffer
    let mut ui_dirty = true; // re-render the UI only when its content changes
    let mut last_sec = u64::MAX;
    let mut playing = false; // media is loaded (menu pauses it, doesn't unload)
    let mut loaded = false; // false until the pending load reaches FILE_LOADED
    let mut osd_until = Instant::now(); // now-playing bar visible until this time
    let mut info_hidden = false; // Info hid the bar; the next Info blanks the screen
    let mut blank = false; // Play: black UI plane over the video, OSD suppressed
    let mut vol_until = Instant::now(); // volume pill visible until this time
    let mut toast_until = Instant::now(); // transient message (track changes)
    let mut toast = String::new();
    let mut last_vis = (false, false, false); // (bar, vol, toast) last rendered
    let osd_secs = Duration::from_secs(10);
    let stats = std::env::var("MEDIAS_STATS").is_ok();
    let (mut presents, mut vrenders) = (0u32, 0u32);
    let mut last_stats = Instant::now();

    let playback_result = (|| -> Result<(), String> {
    'app: loop {
        if console::stopping() {
            break;
        }
        loop {
            match m.wait_event(0.0) {
                mpv::Event::None => break,
                // The file is ready: resume from the saved position, if any.
                mpv::Event::FileLoaded => {
                    loaded = true;
                    resume_seek_started = false;
                    if let Some(t) = resume_to {
                        if let Err(error) = m.command(&["seek", &t.to_string(), "absolute+exact"]) {
                            eprintln!("resume seek: {error}");
                            resume_to = None;
                        }
                    }
                }
                mpv::Event::Seek if loaded && resume_to.is_some() => resume_seek_started = true,
                mpv::Event::PlaybackRestart => {
                    if loaded && resume_seek_started {
                        resume_to = None;
                        resume_seek_started = false;
                    }
                    // Going live redraws the current frame (a still image renders only once).
                    if !video_live && resume_to.is_none() {
                        video_live = true;
                        video_redraw = true;
                    }
                }
                // Only return to the menu on a natural end; ignore the END_FILE
                // mpv emits when we replace/stop the file ourselves.
                mpv::Event::EndFile(true) if loaded => {
                    loaded = false;
                    history.set_pos(&current_path, 0.0); // watched to the end
                    history.save();
                    playing = false;
                    match queue.as_mut().filter(|_| autoplay).and_then(|q| q.step(1)) {
                        Some(next) => {
                            queue.as_ref().unwrap().sync_selection(&mut stack);
                            ready = Some(next);
                        }
                        None => {
                            mode = Mode::Browse;
                            blank = false;
                        }
                    }
                    ui_dirty = true;
                }
                mpv::Event::PlaybackError => {
                    eprintln!("play: could not open {current_path} (MEDIAS_MPV_LOG=<path> logs mpv's reason)");
                    notice = Some((format!("Could not play {now_title}"), Instant::now() + NOTICE_SECS));
                    loaded = false;
                    playing = false;
                    resume_to = None;
                    mode = Mode::Browse;
                    blank = false;
                    ui_dirty = true;
                    history.save();
                }
                mpv::Event::Shutdown => break 'app,
                _ => {}
            }
        }

        let mut acted = false;
        for key in rx.try_iter() {
            let key = if mode != Mode::Browse && key == input::Key::Char(' ') {
                input::Key::Play
            } else { key };
            acted = true;
            match mode {
                Mode::Browse if pending.is_some() => {
                    // A load is running: Back abandons it; other keys wait.
                    if key == input::Key::Back {
                        pending = None;
                    }
                }
                Mode::Browse => {
                    notice = None;
                    let level = stack.last_mut().unwrap();
                    // Yellow/Info/F4 toggles the list and wide views of thumbnail levels.
                    if key == input::Key::Info && level.thumbs && !level.browse.searching() {
                        wide = !wide;
                        save_wide_view(wide);
                        continue;
                    }
                    let keyboard = level.browse.keyboard().is_some();
                    let (cols, capacity) = shell::browse_shape(w as f32, h as f32, keyboard, level.layout(wide));
                    level.browse.set_columns(cols);
                    match level.browse.handle(key, capacity) {
                        browser::Action::Open(index) => {
                            let l = stack.last().unwrap();
                            let item = &l.items[index];
                            let (name, label) = (item.name.clone(), item.name.clone());
                            match &item.node {
                                Node::Dir(p) => {
                                    let p = p.clone();
                                    pending = Some(spawn_load(name.clone(), move || match library::list(&p) {
                                        Ok(e) => Loaded::Level(Level::new(name, lib_items(e))),
                                        Err(err) => Loaded::Failed(format!("open {}: {err}", p.display())),
                                    }));
                                }
                                Node::UpnpRoot => {
                                    pending = Some(spawn_load("Media servers", || {
                                        match upnp::discover(Duration::from_millis(1500)) {
                                            servers if servers.is_empty() => {
                                                Loaded::Failed("No UPnP/DLNA media servers found".into())
                                            }
                                            servers => Loaded::Level(Level::new("Media servers", upnp_server_items(servers))),
                                        }
                                    }));
                                }
                                Node::UpnpDir(server, id) => {
                                    let (server, id) = (server.clone(), id.clone());
                                    pending = Some(spawn_load(name.clone(), move || {
                                        let items = upnp::browse(&server, &id).map(|e| upnp_items(&server, e));
                                        level_or_failed(name, items)
                                    }));
                                }
                                Node::YtRoot => {
                                    // Fetch the account name once, on first entry while signed in.
                                    if yt.signed_in() && yt.account().is_none() {
                                        yt.refresh_account();
                                    }
                                    stack.push(yt_home(&yt, &history));
                                }
                                #[cfg(feature = "youtube-tv")]
                                Node::YtForYou if !yt.tv_signed_in() => {
                                    // First open: sign in with the YouTube TV client.
                                    signin = start_sign_in(&yt, Account::Tv);
                                    if signin.is_some() {
                                        mode = Mode::SignIn;
                                    }
                                }
                                #[cfg(feature = "youtube-tv")]
                                Node::YtForYou => pending = Some(yt_for_you(&mut yt)),
                                Node::YtFromHistory => {
                                    // Related videos of the last 10 watched, excluding all watched.
                                    let ids = yt_history_ids(&history);
                                    pending = Some(spawn_load("From your history", move || {
                                        let watched = ids.iter().cloned().collect();
                                        let videos = youtube::innertube::from_history(&ids[..ids.len().min(10)], &watched);
                                        level_or_failed("From your history".into(), Ok(yt_video_items(videos)))
                                    }));
                                }
                                Node::YtSubsLatest => {
                                    pending = Some(yt_fetch(&mut yt, "Latest from subscriptions", yt_subs_latest));
                                }
                                Node::YtSearch => stack.push(Level::query("Search")),
                                Node::YtTrending => {
                                    pending = Some(yt_fetch(&mut yt, "Trending", |c| Ok(yt_video_items(c.trending()?))));
                                }
                                Node::YtSubs => {
                                    pending = Some(yt_fetch(&mut yt, "Subscriptions", |c| Ok(yt_channel_items(c.subscriptions()?))));
                                }
                                Node::YtChannel(id) => {
                                    let id = id.clone();
                                    pending = Some(yt_fetch(&mut yt, &label, move |c| Ok(yt_video_items(c.channel_uploads(&id)?))));
                                }
                                Node::YtPlaylists => {
                                    pending = Some(yt_fetch(&mut yt, "Playlists", |c| Ok(yt_playlist_items(c.playlists()?))));
                                }
                                Node::YtPlaylist(id) => {
                                    let id = id.clone();
                                    pending = Some(yt_fetch(&mut yt, &label, move |c| Ok(yt_video_items(c.playlist_videos(&id)?))));
                                }
                                Node::YtLiked => {
                                    pending = Some(yt_fetch(&mut yt, "Liked videos", |c| {
                                        Ok(yt_video_items(c.playlist_videos(youtube::api::LIKED_PLAYLIST)?))
                                    }));
                                }
                                Node::YtSource(q) => {
                                    let q = q.clone();
                                    pending = Some(spawn_load(label.clone(), move || level_or_failed(label, ytdl_items(&q))));
                                }
                                Node::YtSignIn(account) => {
                                    let account = *account;
                                    signin = start_sign_in(&yt, account);
                                    // signin is None without an OAuth client (the Data API
                                    // setup screen) or when the request failed (stay).
                                    if signin.is_some() || yt.sign_in_credentials(account).is_none() {
                                        mode = Mode::SignIn;
                                    }
                                }
                                Node::YtSignOut(account) => {
                                    let account = *account;
                                    yt.sign_out(account);
                                    *stack.last_mut().unwrap() = yt_home(&yt, &history);
                                }
                                Node::Media(_) | Node::UpnpMedia(..) => {
                                    queue = Queue::new(l, stack.len() - 1, index);
                                    ready = queue.as_ref().map(Queue::play);
                                }
                                Node::YtVideo(url) => {
                                    queue = None;
                                    pending = Some(yt_play(url.clone(), name, stream_prefs.clone()));
                                }
                            }
                        }
                        browser::Action::Submit(query) => pending = Some(yt_search(&mut yt, query)),
                        browser::Action::Back => {
                            if stack.len() > 1 {
                                stack.pop();
                            } else if playing {
                                mode = Mode::Play;
                                let _ = m.set_property("pause", "no");
                                osd_until = Instant::now() + osd_secs;
                            } else {
                                break 'app;
                            }
                        }
                        browser::Action::Resume if playing => {
                            mode = Mode::Play;
                            let _ = m.set_property("pause", "no");
                            osd_until = Instant::now() + osd_secs;
                        }
                        _ => {}
                    }
                }
                Mode::Play => {
                    // Info cycles: bar shown -> hidden -> screen black -> bar shown.
                    if key == input::Key::Info {
                        let show;
                        (show, info_hidden, blank) = info_step(Instant::now() < osd_until, info_hidden, blank);
                        osd_until = if show { Instant::now() + osd_secs } else { Instant::now() };
                        ui_dirty = true;
                        continue;
                    }
                    // Volume keeps the screen black; any other key lights it.
                    if blank && !matches!(key, input::Key::Up | input::Key::Down) {
                        blank = false;
                        ui_dirty = true;
                    }
                    if !blank {
                        osd_until = Instant::now() + osd_secs; // any key reveals the OSD
                        info_hidden = false;
                    }
                    match key {
                        // Back opens the content library (video stays loaded, paused).
                        input::Key::Back => {
                            mode = Mode::Browse;
                            let _ = m.set_property("pause", "yes");
                            checkpoint_playback(&m, &mut history, &current_path, loaded && resume_to.is_none());
                        }
                        // OK / Pause open the playback menu (pauses).
                        input::Key::Select | input::Key::Pause => {
                            mode = Mode::Menu;
                            pbstack = vec![pb_root(autoplay)];
                            let _ = m.set_property("pause", "yes");
                            checkpoint_playback(&m, &mut history, &current_path, loaded && resume_to.is_none());
                        }
                        input::Key::Play => {
                            let _ = m.command(&["cycle", "pause"]);
                        }
                        input::Key::Stop => {
                            checkpoint_playback(&m, &mut history, &current_path, loaded && resume_to.is_none());
                            loaded = false;
                            let _ = m.command(&["stop"]);
                            playing = false;
                            mode = Mode::Browse;
                        }
                        input::Key::Audio => {
                            let _ = m.command(&["cycle", "audio"]);
                            let title = m.get_string("current-tracks/audio/title")
                                .or_else(|| m.get_string("current-tracks/audio/lang"))
                                .or_else(|| m.get_string("aid"))
                                .unwrap_or_else(|| "?".into());
                            toast = format!("Audio track: {title}");
                            toast_until = Instant::now() + Duration::from_secs(2);
                        }
                        input::Key::Subtitle => {
                            let _ = m.command(&["cycle", "sub"]);
                            toast = format!("Subtitles: {}", m.get_string("sid").unwrap_or_else(|| "off".into()));
                            toast_until = Instant::now() + Duration::from_secs(2);
                        }
                        input::Key::Left => {
                            let _ = m.command(&["seek", "-10"]);
                        }
                        input::Key::Right => {
                            let _ = m.command(&["seek", "10"]);
                        }
                        input::Key::Prev => {
                            let _ = m.command(&["seek", "-60"]); // CEC rewind
                        }
                        input::Key::Next => {
                            let _ = m.command(&["seek", "60"]); // CEC fast-forward
                        }
                        input::Key::SkipNext | input::Key::Char('>') => {
                            if let Some(next) = queue.as_mut().and_then(|q| q.step(1)) {
                                queue.as_ref().unwrap().sync_selection(&mut stack);
                                ready = Some(next);
                            }
                        }
                        // Previous restarts the item after its first 5 s, as music players do.
                        input::Key::SkipPrev | input::Key::Char('<') => {
                            if m.get_f64("time-pos").unwrap_or(0.0) > 5.0 {
                                let _ = m.command(&["seek", "0", "absolute"]);
                            } else if let Some(prev) = queue.as_mut().and_then(|q| q.step(-1)) {
                                queue.as_ref().unwrap().sync_selection(&mut stack);
                                ready = Some(prev);
                            }
                        }
                        input::Key::Up => {
                            let _ = m.command(&["add", "volume", "5"]);
                            vol_until = Instant::now() + Duration::from_secs(2);
                        }
                        input::Key::Down => {
                            let _ = m.command(&["add", "volume", "-5"]);
                            vol_until = Instant::now() + Duration::from_secs(2);
                        }
                        input::Key::Menu => {
                            mode = Mode::Menu;
                            pbstack = vec![pb_root(autoplay)];
                            let _ = m.set_property("pause", "yes");
                        }
                        _ => {}
                    }
                }
                Mode::Menu => {
                    let (n, horizontal) = {
                        let l = pbstack.last().unwrap();
                        (l.items.len(), l.horizontal)
                    };
                    // Vertical lists navigate Up/Down; the seek row Left/Right.
                    let (prev, next) = if horizontal {
                        (input::Key::Left, input::Key::Right)
                    } else {
                        (input::Key::Up, input::Key::Down)
                    };
                    match key {
                        k if k == prev && n > 0 => {
                            let l = pbstack.last_mut().unwrap();
                            l.selected = (l.selected + n - 1) % n;
                        }
                        k if k == next && n > 0 => {
                            let l = pbstack.last_mut().unwrap();
                            l.selected = (l.selected + 1) % n;
                        }
                        input::Key::PageUp | input::Key::Prev if !horizontal => {
                            let l = pbstack.last_mut().unwrap();
                            l.selected = l.selected.saturating_sub(shell::playback_capacity(w as f32, h as f32));
                        }
                        input::Key::PageDown | input::Key::Next if !horizontal => {
                            let l = pbstack.last_mut().unwrap();
                            l.selected = l.selected.saturating_add(shell::playback_capacity(w as f32, h as f32))
                                .min(n.saturating_sub(1));
                        }
                        input::Key::Home => pbstack.last_mut().unwrap().selected = 0,
                        input::Key::End => pbstack.last_mut().unwrap().selected = n.saturating_sub(1),
                        input::Key::Back => {
                            if pbstack.len() > 1 {
                                pbstack.pop();
                            } else {
                                mode = Mode::Play;
                                let _ = m.set_property("pause", "no");
                                osd_until = Instant::now() + osd_secs;
                            }
                        }
                        // Exits so you're never trapped: resume or stop.
                        input::Key::Play | input::Key::Pause | input::Key::Menu => {
                            mode = Mode::Play;
                            let _ = m.set_property("pause", "no");
                            osd_until = Instant::now() + osd_secs;
                        }
                        input::Key::Stop => {
                            checkpoint_playback(&m, &mut history, &current_path, loaded && resume_to.is_none());
                            loaded = false;
                            let _ = m.command(&["stop"]);
                            playing = false;
                            mode = Mode::Browse;
                        }
                        input::Key::Select if n > 0 => {
                            let node = pbstack.last().unwrap().items[pbstack.last().unwrap().selected].node.clone();
                            match node {
                                Pb::Resume => {
                                    let _ = m.set_property("pause", "no");
                                    mode = Mode::Play;
                                    osd_until = Instant::now() + osd_secs;
                                }
                                Pb::Library => {
                                    checkpoint_playback(&m, &mut history, &current_path, loaded && resume_to.is_none());
                                    mode = Mode::Browse; // stays paused
                                }
                                Pb::Stop => {
                                    checkpoint_playback(&m, &mut history, &current_path, loaded && resume_to.is_none());
                                    loaded = false;
                                    let _ = m.command(&["stop"]);
                                    playing = false;
                                    mode = Mode::Browse;
                                }
                                Pb::Autoplay => {
                                    autoplay = !autoplay;
                                    save_autoplay(autoplay);
                                    let sel = pbstack[0].selected;
                                    pbstack[0] = pb_root(autoplay);
                                    pbstack[0].selected = sel;
                                }
                                Pb::SeekMenu => pbstack.push(pb_seek()),
                                Pb::AudioMenu => pbstack.push(track_items(&m, "audio", None)),
                                Pb::SubMenu => pbstack.push(track_items(&m, "sub", Some("Off"))),
                                // Jump to the start and return to the video.
                                Pb::SeekAbs(t) => {
                                    let _ = m.command(&["seek", &t.to_string(), "absolute"]);
                                    let _ = m.set_property("pause", "no");
                                    mode = Mode::Play;
                                    osd_until = Instant::now() + osd_secs;
                                }
                                // Relative seek stays in the row so it repeats.
                                Pb::SeekRel(d) => {
                                    let _ = m.command(&["seek", &d.to_string()]);
                                }
                                Pb::SetAid(id) => {
                                    let _ = m.set_property("aid", &id);
                                    let sel = pbstack.last().map(|l| l.selected).unwrap_or(0);
                                    if let Some(l) = pbstack.last_mut() {
                                        *l = track_items(&m, "audio", None);
                                        l.selected = sel.min(l.items.len().saturating_sub(1));
                                    }
                                }
                                Pb::SetSid(id) => {
                                    let _ = m.set_property("sid", &id);
                                    let sel = pbstack.last().map(|l| l.selected).unwrap_or(0);
                                    if let Some(l) = pbstack.last_mut() {
                                        *l = track_items(&m, "sub", Some("Off"));
                                        l.selected = sel.min(l.items.len().saturating_sub(1));
                                    }
                                }
                            }
                        }
                        _ => {}
                    }
                }
                Mode::SignIn => {
                    // Back cancels; everything else is ignored while polling.
                    if key == input::Key::Back {
                        signin = None;
                        mode = Mode::Browse;
                        ui_dirty = true;
                    }
                }
            }
        }

        ui_dirty |= acted;

        // Apply a finished background load (or an immediate local play).
        if ready.is_none() && let Some(polled) = pending.as_ref().map(|p| (p.rx.try_recv(), p.label.clone())) {
            match polled {
                (Ok(result), _) => ready = Some(result),
                (Err(std::sync::mpsc::TryRecvError::Disconnected), label) => {
                    ready = Some(Loaded::Failed(format!("{label}: load failed")));
                }
                (Err(std::sync::mpsc::TryRecvError::Empty), _) => {}
            }
            if ready.is_some() {
                pending = None;
            }
        }
        match ready.take() {
            Some(Loaded::Level(level)) => {
                stack.push(level);
                ui_dirty = true;
            }
            Some(Loaded::Failed(message)) => {
                eprintln!("{message}");
                notice = Some((message, Instant::now() + NOTICE_SECS));
                ui_dirty = true;
            }
            Some(Loaded::Play { key, name, target, audio }) => {
                if playing && loaded && resume_to.is_none() {
                    if let Some(t) = m.get_f64("time-pos") {
                        history.set_pos(&current_path, t);
                    }
                    history.save();
                }
                // Replaces (or, for local files, clears) any YouTube audio track.
                let audio: Vec<&str> = audio.iter().map(String::as_str).collect();
                match m.set_audio_files(&audio).and_then(|()| m.loadfile(&target)) {
                    Ok(()) => {
                        resume_to = history.pos(&key);
                        now_title = name;
                        current_path = key.clone();
                        playing = true;
                        loaded = false;
                        resume_seek_started = false;
                        mode = Mode::Play;
                        vfront ^= 1;
                        video.clear(vfbo_ids[vfront]);
                        video_live = false;
                        play_started = Instant::now();
                        let _ = m.set_property("pause", "no");
                        history.touch(&key);
                        history.save();
                        osd_until = Instant::now() + osd_secs;
                    }
                    Err(err) => {
                        eprintln!("play: {err}");
                        notice = Some((format!("Could not play {name}: {err}"), Instant::now() + NOTICE_SECS));
                    }
                }
                ui_dirty = true;
            }
            None => {}
        }

        // Spinner: a 12-step turn per second, shown once a load or a video start
        // has taken SPIN_DELAY; re-render only when the step changes.
        if notice.as_ref().is_some_and(|(_, until)| Instant::now() >= *until) {
            notice = None;
            ui_dirty = true;
        }
        let spinning = pending.as_ref().is_some_and(|p| p.started.elapsed() >= SPIN_DELAY)
            || (mode == Mode::Play && playing && !video_live && play_started.elapsed() >= SPIN_DELAY);
        let phase = if spinning { (spin_epoch.elapsed().as_millis() / 83) as usize % 12 } else { usize::MAX };
        if phase != spin_phase {
            spin_phase = phase;
            ui_dirty = true;
        }
        if thumb_cache.pump(&text, &gpu) && mode == Mode::Browse {
            ui_dirty = true;
        }

        // Device-auth: poll for the user's approval on the server's interval.
        if mode == Mode::SignIn && let Some(si) = signin.as_mut() {
            let now = Instant::now();
            if now >= si.expires_at {
                si.status = "Code expired — press Back".into();
                ui_dirty = true;
            } else if now >= si.next_poll {
                match youtube::auth::poll_once(&si.creds, &si.device.device_code) {
                    Poll::Pending => si.next_poll = now + Duration::from_secs(si.device.interval),
                    Poll::SlowDown => {
                        si.device.interval += 5;
                        si.next_poll = now + Duration::from_secs(si.device.interval);
                    }
                    Poll::Granted(tokens) => {
                        let account = si.account;
                        yt.complete_sign_in(account, tokens);
                        signin = None;
                        *stack.last_mut().unwrap() = yt_home(&yt, &history);
                        // The TV sign-in starts from "For you": continue into it.
                        #[cfg(feature = "youtube-tv")]
                        if account == Account::Tv {
                            pending = Some(yt_for_you(&mut yt));
                        }
                        mode = Mode::Browse;
                        ui_dirty = true;
                    }
                    Poll::Denied => {
                        si.status = "Access denied — press Back".into();
                        ui_dirty = true;
                    }
                    Poll::Expired => {
                        si.status = "Code expired — press Back".into();
                        ui_dirty = true;
                    }
                    Poll::Error(err) => {
                        si.status = format!("Error: {err} — press Back");
                        ui_dirty = true;
                    }
                }
            }
        }

        // Video: render a newly decoded frame into the free buffer and promote
        // it, whenever the video is visible (Play, or the menu overlaid on it —
        // so seeking previews the frame). The opaque library (Browse) skips it.
        if matches!(mode, Mode::Play | Mode::Menu) && (std::mem::take(&mut video_redraw) || rc.frame_ready()) {
            let vback = vfront ^ 1;
            rc.render(vfbo_ids[vback], vw as i32, vh as i32)?;
            video.finish();
            if video_live {
                vfront = vback;
            }
            vrenders += 1;
        }

        // Track the live position for resume (memory only; saved at transitions
        // to avoid per-second SD writes).
        if playing && loaded && resume_to.is_none() {
            if let Some(t) = m.get_f64("time-pos") {
                history.set_pos(&current_path, t);
            }
        }

        // OSD visibility (Play only): bar auto-hides after `osd_secs`, the volume
        // pill and track toast after 2s. Re-render on any visibility change.
        let now = Instant::now();
        let show_bar = mode == Mode::Play && !blank && now < osd_until;
        let show_vol = mode == Mode::Play && !blank && now < vol_until;
        let show_toast = mode == Mode::Play && !blank && now < toast_until;
        if (show_bar, show_vol, show_toast) != last_vis {
            ui_dirty = true;
            last_vis = (show_bar, show_vol, show_toast);
        }
        if show_bar {
            let sec = m.get_f64("time-pos").unwrap_or(0.0) as u64;
            if sec != last_sec {
                last_sec = sec;
                ui_dirty = true;
            }
        }

        // UI: rebuild + re-render only when it changed.
        if ui_dirty {
            match mode {
                Mode::Browse => {
                    let l = stack.last_mut().unwrap();
                    let layout = l.layout(wide);
                    let (cols, capacity) = shell::browse_shape(w as f32, h as f32, l.browse.keyboard().is_some(), layout);
                    l.browse.set_columns(cols);
                    let range = l.browse.window(capacity);
                    let first = range.start;
                    let played = |it: &Item| match &it.node {
                        Node::Media(p) => history.date(&p.to_string_lossy()),
                        Node::YtVideo(u) | Node::UpnpMedia(u, _) => history.date(u),
                        _ => None,
                    };
                    let (mut rows, mut cards) = (Vec::new(), Vec::new());
                    if layout == shell::Layout::Text {
                        rows = range
                            .map(|index| {
                                let it = &l.items[l.browse.source_index(index).unwrap()];
                                let label = if it.container { format!("{}/", it.name) } else { it.name.clone() };
                                // Right column: an item's own meta (e.g. duration), else its last-played date.
                                let right = if !it.meta.is_empty() { it.meta.clone() } else { played(it).unwrap_or_default() };
                                (label, right)
                            })
                            .collect();
                    } else {
                        // Fetch order is newest-first: the next page, then the visible
                        // items last to first, so the first visible item loads first.
                        thumb_cache.begin_frame();
                        let next = range.end..(range.end + capacity).min(l.browse.count());
                        for index in next.rev() {
                            thumb_cache.prefetch(&l.items[l.browse.source_index(index).unwrap()].thumb);
                        }
                        for index in range.rev() {
                            let it = &l.items[l.browse.source_index(index).unwrap()];
                            let sub = card_sub(it, played(it));
                            let thumb = thumb_cache.get(&it.thumb);
                            cards.push(shell::Card { title: it.name.clone(), sub, meta: it.meta.clone(), thumb, icon: card_icon(it) });
                        }
                        cards.reverse();
                    }
                    let view = shell::BrowseView {
                        title: &l.title, layout, rows: &rows, cards: &cards, first,
                        selected: l.browse.selected(), matches: l.browse.count(),
                        total: l.browse.total(), query: l.browse.query(),
                        searching: l.browse.searching(), keyboard: l.browse.keyboard(),
                        search_focused: l.browse.search_focused(),
                    };
                    shell::render_browse(&mut frame, &text, &view, w as f32, h as f32);
                    if let Some(p) = pending.as_ref().filter(|_| spin_phase != usize::MAX) {
                        shell::render_status(&mut frame, &text, &format!("Loading {}…", p.label), Some(spin_phase), w as f32, h as f32);
                    } else if let Some((message, _)) = &notice {
                        shell::render_status(&mut frame, &text, message, None, w as f32, h as f32);
                    }
                }
                Mode::Play if blank => shell::render_blank(&mut frame, &text, w as f32, h as f32),
                Mode::Play => {
                    let pos = m.get_f64("time-pos").unwrap_or(0.0);
                    let dur = m.get_f64("duration").unwrap_or(0.0);
                    let vol = m.get_f64("volume").unwrap_or(0.0);
                    let toast_opt = if show_toast { Some(toast.as_str()) } else { None };
                    shell::render_osd(&mut frame, &text, &now_title, pos, dur, vol, show_bar, show_vol, toast_opt, w as f32, h as f32);
                    if spin_phase != usize::MAX {
                        shell::render_status(&mut frame, &text, &format!("Loading {now_title}…"), Some(spin_phase), w as f32, h as f32);
                    }
                }
                Mode::Menu => {
                    let l = pbstack.last().unwrap();
                    let items: Vec<String> = l.items.iter().map(|it| it.name.clone()).collect();
                    if l.horizontal {
                        let pos = m.get_f64("time-pos").unwrap_or(0.0);
                        let dur = m.get_f64("duration").unwrap_or(0.0);
                        shell::render_seek(&mut frame, &text, &now_title, pos, dur, &items, l.selected, w as f32, h as f32);
                    } else {
                        shell::render_overlay(&mut frame, &text, &l.title, &items, l.selected, w as f32, h as f32);
                    }
                }
                Mode::SignIn => match &signin {
                    Some(si) => shell::render_signin(
                        &mut frame, &text,
                        &si.device.user_code, &si.device.verification_url, &si.status,
                        si.qr.as_ref().map(|(n, m)| (*n, m.as_slice())),
                        w as f32, h as f32,
                    ),
                    None => shell::render_signin_setup(&mut frame, &text, w as f32, h as f32),
                },
            }
            let ui_back = ui_front ^ 1;
            text.render(&gpu, &targets[ui_back], ufbs[ui_back], &frame)?;
            ui_front = ui_back;
            ui_dirty = false;
        }
        if console::stopping() {
            break;
        }
        if modeset {
            output.present_two(&card, vbufs[vfront].fb, (vw as u16, vh as u16), ubufs[ui_front].fb).map_err(e2s)?;
        } else {
            output
                .modeset_two(&card, vbufs[vfront].fb, (vw as u16, vh as u16), ubufs[ui_front].fb)
                .map_err(|e| format!("modeset (video {vw}x{vh}, UI {w}x{h}): {e}"))?;
            modeset = true;
        }
        presents += 1;

        if stats && last_stats.elapsed() >= Duration::from_secs(1) {
            let secs = last_stats.elapsed().as_secs_f64();
            let vf_fps = m.get_f64("estimated-vf-fps").unwrap_or(0.0);
            let drops = m.get_f64("frame-drop-count").unwrap_or(0.0);
            println!(
                "stats: present {:.0}/s  video-render {:.0}/s  mpv vf-fps {vf_fps:.1}  drops {drops:.0}",
                presents as f64 / secs,
                vrenders as f64 / secs,
            );
            presents = 0;
            vrenders = 0;
            last_stats = Instant::now();
        }
    }

    Ok(())
    })();
    finish_playback(&m, &mut history, &current_path, loaded, resume_to.is_some());
    drop(sources);
    display.restore();
    drop(rc);
    drop(m);
    for fb in ufbs {
        gpu.destroy_framebuffer(fb);
    }
    text.destroy(&gpu);
    for t in targets {
        gpu.destroy_target(t);
    }
    for b in vbufs.into_iter().chain(ubufs) {
        let _ = card.destroy_framebuffer(b.fb);
    }
    playback_result
}

/// Menu demo; auto-advances for ten seconds if no input source is available.
fn run_shell(dev: Option<&str>) -> Result<(), String> {
    use std::sync::mpsc;

    println!("=== shell ===");
    let (card, output, mut display) = open_display(dev)?;
    let alloc = Allocator::new(&card).map_err(|e| format!("gbm: {e}"))?;
    let (w, h) = (u32::from(output.mode.size().0), u32::from(output.mode.size().1));

    let gpu = vk::Gpu::new()?;
    let text = gpu.create_text()?;
    let mut buffers = Vec::new();
    let mut targets = Vec::new();
    let mut framebuffers = Vec::new();
    for _ in 0..2 {
        let (buffer, target) = gpu.create_scanout_target(&alloc, &card, &output, w, h, DrmFourcc::Argb8888)?;
        framebuffers.push(text.framebuffer(&gpu, &target)?);
        targets.push(target);
        buffers.push(buffer);
    }

    let (tx, rx) = mpsc::channel::<input::Key>();
    let sources = input::spawn(tx, display.owns_vt());
    let have_input = sources.available();
    println!("input source: {}", if have_input { "device" } else { "none (auto-demo)" });

    let mut menu = shell::Menu::new("medias", &["Movies", "Series", "Music", "YouTube", "Settings"]);
    let mut frame = vk::Frame::default();
    shell::render(&mut frame, &text, &menu, w as f32, h as f32);
    text.render(&gpu, &targets[0], framebuffers[0], &frame)?;
    output.modeset(&card, buffers[0].fb).map_err(e2s)?;
    let mut front = 0usize;

    let start = Instant::now();
    let mut last_auto = Instant::now();
    'ui: loop {
        if console::stopping() {
            break;
        }
        for key in rx.try_iter() {
            match menu.handle_with_page(key, shell::list_capacity(w as f32, h as f32)) {
                shell::Action::Open(i) => println!("open: {}", menu.items[i]),
                shell::Action::Exit => break 'ui,
                shell::Action::None => {}
            }
        }
        if !have_input && last_auto.elapsed() > Duration::from_millis(1200) {
            menu.handle(input::Key::Down);
            last_auto = Instant::now();
        }
        shell::render(&mut frame, &text, &menu, w as f32, h as f32);
        let back = front ^ 1;
        text.render(&gpu, &targets[back], framebuffers[back], &frame)?;
        if console::stopping() {
            break;
        }
        output.present(&card, buffers[back].fb).map_err(e2s)?;
        front = back;
        if !have_input && start.elapsed().as_secs() > 10 {
            break;
        }
    }

    drop(sources);
    display.restore();
    for fb in framebuffers {
        gpu.destroy_framebuffer(fb);
    }
    text.destroy(&gpu);
    for target in targets {
        gpu.destroy_target(target);
    }
    for buffer in buffers {
        card.destroy_framebuffer(buffer.fb).map_err(e2s)?;
    }
    Ok(())
}

/// Milestone 6: read navigation keys from CEC and/or evdev. Reads from the
/// first available source (CEC preferred — it's the TV remote) and prints keys.
fn run_input(evdev_path: Option<&str>) {
    println!("=== input ===");

    match input::Cec::open("/dev/cec0") {
        Ok(mut cec) => {
            println!("CEC /dev/cec0 open; press remote keys (Ctrl-C to stop)");
            loop {
                match cec.next() {
                    Ok(Some(k)) => println!("CEC {k:?}"),
                    Ok(None) => {}
                    Err(e) => {
                        eprintln!("CEC: {e}");
                        break;
                    }
                }
            }
            return;
        }
        Err(e) => println!("CEC /dev/cec0: {e}"),
    }

    let path = evdev_path.unwrap_or("/dev/input/event0");
    match input::Evdev::open(path) {
        Ok(mut dev) => {
            println!("evdev {path} open; press keys (Ctrl-C to stop)");
            loop {
                match dev.next() {
                    Ok(Some(k)) => println!("key {k:?}"),
                    Ok(None) => {}
                    Err(e) => {
                        eprintln!("evdev: {e}");
                        break;
                    }
                }
            }
        }
        Err(e) => {
            println!("evdev {path}: {e}");
            println!("no input source available (expected off-target; CEC/evdev live on the Pi)");
        }
    }
}

/// Synthetic lavfi source: no asset file needed.
fn default_test_media() -> String {
    "av://lavfi:testsrc=size=640x480:rate=30:duration=3".into()
}

/// mpv's OpenGL render API writes a dmabuf-backed FBO scanned out on one plane.
fn run_video(dev: Option<&str>, url: &str) -> Result<(), String> {
    println!("=== video ({url}) ===");
    let (card, output, mut display) = open_display(dev)?;
    let alloc = Allocator::new(&card).map_err(|e| format!("gbm: {e}"))?;
    let (w, h) = output.mode.size();

    let video = egl::VideoGl::new(&alloc)?;
    let mut buffers = Vec::new();
    let mut fbos = Vec::new();
    for _ in 0..2 {
        let buffer = alloc.alloc(&card, w.into(), h.into(), DrmFourcc::Xrgb8888, Use::SCANOUT | Use::RENDERING)
            .map_err(|e| format!("alloc: {e}"))?;
        fbos.push(video.import(&buffer)?);
        buffers.push(buffer);
    }
    println!("mpv -> double-buffered GL -> KMS plane, {w}x{h}");

    let m = mpv::Mpv::new()?;
    m.set_option("vo", "libmpv")?; // required for the render API
    m.set_option("ao", "null")?;
    m.set_option("hwdec", "no")?;
    m.set_option("msg-level", "all=error")?;
    m.init()?;
    let rc = m.render_context(egl::mpv_get_proc_address)?;
    m.loadfile(url)?;

    let start = Instant::now();
    let mut frames = 0u32;
    let mut front = 0usize;
    let mut modeset = false;
    'play: loop {
        if console::stopping() {
            break;
        }
        loop {
            match m.wait_event(0.0) {
                mpv::Event::None => break,
                mpv::Event::EndFile(_) | mpv::Event::PlaybackError | mpv::Event::Shutdown => break 'play,
                mpv::Event::FileLoaded => println!("playing: {:.1}s", m.get_f64("duration").unwrap_or(0.0)),
                _ => {}
            }
        }
        if rc.frame_ready() {
            let back = front ^ 1;
            rc.render(video.fbo_id(&fbos[back]), w.into(), h.into())?;
            video.finish();
            front = back;
            frames += 1;
        }
        if console::stopping() {
            break;
        }
        if modeset {
            output.present(&card, buffers[front].fb).map_err(|e| format!("present: {e}"))?;
        } else if frames > 0 {
            output.modeset(&card, buffers[front].fb).map_err(|e| format!("modeset: {e}"))?;
            modeset = true;
        } else {
            std::thread::sleep(std::time::Duration::from_millis(1));
        }
        if start.elapsed().as_secs() > 20 {
            break;
        }
    }
    let secs = start.elapsed().as_secs_f64();
    println!("rendered {frames} frames in {secs:.1}s ({:.1} fps)", frames as f64 / secs);

    display.restore();
    drop(rc);
    drop(m);
    for buffer in buffers {
        card.destroy_framebuffer(buffer.fb).map_err(|e| format!("destroy fb: {e}"))?;
    }
    Ok(())
}

/// mpv video and the Vulkan UI occupy separate planes in one atomic commit.
fn run_compositor(dev: Option<&str>, url: &str) -> Result<(), String> {
    println!("=== compositor ({url}) ===");
    let (card, output, mut display) = open_display(dev)?;
    if output.video_plane.is_none() {
        return Err("CRTC exposes only one plane; need two for compositing".into());
    }
    let alloc = Allocator::new(&card).map_err(|e| format!("gbm: {e}"))?;
    let (w, h) = (u32::from(output.mode.size().0), u32::from(output.mode.size().1));

    let video = egl::VideoGl::new(&alloc)?;
    let gpu = vk::Gpu::new()?;
    let renderer = gpu.create_renderer()?;
    let mut video_buffers = Vec::new();
    let mut video_fbos = Vec::new();
    let mut ui_buffers = Vec::new();
    let mut ui_targets = Vec::new();
    let mut ui_fbs = Vec::new();
    for _ in 0..2 {
        let buffer = alloc.alloc(&card, w, h, DrmFourcc::Xrgb8888, Use::SCANOUT | Use::RENDERING)
            .map_err(|e| format!("video alloc: {e}"))?;
        video_fbos.push(video.import(&buffer)?);
        video_buffers.push(buffer);
        let (buffer, target) = gpu.create_scanout_target(&alloc, &card, &output, w, h, DrmFourcc::Argb8888)?;
        ui_fbs.push(gpu.framebuffer(&renderer, &target)?);
        ui_targets.push(target);
        ui_buffers.push(buffer);
    }
    println!("double-buffered video and UI planes; {w}x{h}");

    let m = mpv::Mpv::new()?;
    m.set_option("vo", "libmpv")?;
    m.set_option("ao", "null")?;
    m.set_option("hwdec", "no")?;
    m.set_option("loop", "inf")?; // keep video running while we show the UI
    m.set_option("msg-level", "all=error")?;
    m.init()?;
    let rc = m.render_context(egl::mpv_get_proc_address)?;
    m.loadfile(url)?;

    let start = Instant::now();
    let mut frames = 0u32;
    let mut video_front = 0usize;
    let mut ui_front = 0usize;
    let mut video_ready = false;
    let mut modeset = false;
    'play: loop {
        if console::stopping() {
            break;
        }
        loop {
            match m.wait_event(0.0) {
                mpv::Event::None => break,
                mpv::Event::Shutdown => break 'play,
                _ => {}
            }
        }
        if rc.frame_ready() {
            let back = video_front ^ 1;
            rc.render(video.fbo_id(&video_fbos[back]), w as i32, h as i32)?;
            video.finish();
            video_front = back;
            video_ready = true;
        }
        if !video_ready {
            if start.elapsed().as_secs() > 10 {
                return Err("no video frame decoded".into());
            }
            std::thread::sleep(std::time::Duration::from_millis(1));
            continue;
        }
        let t = (start.elapsed().as_secs_f32() * 1.5).sin() * 0.5 + 0.5;
        let back = ui_front ^ 1;
        gpu.draw(&renderer, &ui_targets[back], ui_fbs[back], t)?;
        if console::stopping() {
            break;
        }
        let video_fb = video_buffers[video_front].fb;
        let ui_fb = ui_buffers[back].fb;
        if modeset {
            output.present_two(&card, video_fb, (w as u16, h as u16), ui_fb).map_err(e2s)?;
        } else {
            output.modeset_two(&card, video_fb, (w as u16, h as u16), ui_fb).map_err(e2s)?;
            modeset = true;
        }
        ui_front = back;
        frames += 1;
        if start.elapsed().as_secs() > 10 {
            break;
        }
    }
    let secs = start.elapsed().as_secs_f64();
    println!("composited {frames} frames in {secs:.1}s ({:.1} fps)", frames as f64 / secs);

    display.restore();
    drop(rc);
    drop(m);
    for fb in ui_fbs {
        gpu.destroy_framebuffer(fb);
    }
    gpu.destroy_renderer(renderer);
    for target in ui_targets {
        gpu.destroy_target(target);
    }
    for buffer in video_buffers.into_iter().chain(ui_buffers) {
        card.destroy_framebuffer(buffer.fb).map_err(e2s)?;
    }
    Ok(())
}

fn finish_playback(m: &mpv::Mpv, history: &mut history::History, path: &str, mut loaded: bool, pending_resume: bool) {
    // File properties can disappear before the corresponding END_FILE is queued.
    let drain_timeout = if loaded && m.get_f64("time-pos").is_none() { 0.1 } else { 0.0 };
    loop {
        match m.wait_event(drain_timeout) {
            mpv::Event::None => break,
            mpv::Event::EndFile(true) if loaded => {
                history.set_pos(path, 0.0);
                loaded = false;
            }
            mpv::Event::PlaybackError => loaded = false,
            _ => {}
        }
    }
    checkpoint_playback(m, history, path, loaded && !pending_resume);
}

fn checkpoint_playback(m: &mpv::Mpv, history: &mut history::History, path: &str, loaded: bool) {
    // time-pos disappears after stop/end-file; pending loads retain the cached position.
    if loaded && m.get_string("seeking").as_deref() != Some("yes")
        && let Some(position) = m.get_f64("time-pos") {
        history.set_pos(path, position);
    }
    history.save();
}

fn e2s(e: std::io::Error) -> String {
    e.to_string()
}

/// Milestone 2c: allocate a GPU-renderable scanout buffer, import it into
/// Vulkan, clear it on the GPU each frame, and scan it out.
fn run_gpu(
    card: &Card,
    output: &Output,
    alloc: &Allocator,
    gpu: &vk::Gpu,
    w: u32,
    h: u32,
) -> std::io::Result<()> {
    let (s, target) = gpu.create_scanout_target(alloc, card, output, w, h, DrmFourcc::Xrgb8888)
        .map_err(std::io::Error::other)?;
    println!("scanout bo: modifier={:#x} stride={} offset={}", s.modifier(), s.stride(), s.offset());

    let renderer = gpu.create_renderer().map_err(std::io::Error::other)?;
    let fb = gpu.framebuffer(&renderer, &target).map_err(std::io::Error::other)?;
    println!("imported dmabuf; pipeline + framebuffer ready");

    output.modeset(card, s.fb)?;

    let n = 300;
    let start = Instant::now();
    for i in 0..n {
        if console::stopping() {
            break;
        }
        let t = (i as f32 / n as f32 * std::f32::consts::TAU).sin() * 0.5 + 0.5;
        gpu.draw(&renderer, &target, fb, t).map_err(std::io::Error::other)?;
        output.present(card, s.fb)?;
    }
    report("draw+flip", start, n);

    gpu.destroy_framebuffer(fb);
    gpu.destroy_renderer(renderer);
    gpu.destroy_target(target);
    card.destroy_framebuffer(s.fb)?;
    Ok(())
}

fn run_cpu(card: &Card, output: &Output, alloc: &Allocator, w: u32, h: u32) -> std::io::Result<()> {
    // CPU-filled linear scanout buffers (milestone 2a). The Vulkan render path
    // (2c) will use SCANOUT|RENDERING instead. NVIDIA rejects RENDERING|WRITE
    // together; keep CPU and GPU buffers separate.
    let flags = Use::SCANOUT | Use::WRITE | Use::LINEAR;
    let mut front = alloc.alloc(card, w, h, DrmFourcc::Xrgb8888, flags)?;
    let mut back = alloc.alloc(card, w, h, DrmFourcc::Xrgb8888, flags)?;
    println!("allocated 2x {w}x{h} XRGB8888 scanout buffers");

    fill_gradient(&mut front, 0)?;
    fill_gradient(&mut back, 128)?;

    output.modeset(card, front.fb)?;
    println!("modeset ok\n");

    bench_flips(card, output, &front, &back, 300)?;
    bench_fill_flip(card, output, &mut back, 120)?;

    card.destroy_framebuffer(front.fb)?;
    card.destroy_framebuffer(back.fb)?;
    Ok(())
}

/// Flip between two pre-filled buffers; measures sustained vsync-locked flips.
fn bench_flips(card: &Card, o: &Output, a: &Scanout, b: &Scanout, n: u32) -> std::io::Result<()> {
    let start = Instant::now();
    for i in 0..n {
        if console::stopping() {
            break;
        }
        let fb = if i % 2 == 0 { a.fb } else { b.fb };
        o.present(card, fb)?;
    }
    report("flip only", start, n);
    Ok(())
}

/// Refill then flip each frame; measures CPU fill + commit cost per frame.
fn bench_fill_flip(card: &Card, o: &Output, buf: &mut Scanout, n: u32) -> std::io::Result<()> {
    let start = Instant::now();
    for i in 0..n {
        if console::stopping() {
            break;
        }
        fill_gradient(buf, (i * 4) as u8)?;
        o.present(card, buf.fb)?;
    }
    report("fill+flip", start, n);
    Ok(())
}

fn report(label: &str, start: Instant, n: u32) {
    let secs = start.elapsed().as_secs_f64();
    println!(
        "{label:10} {n} frames in {secs:.3}s  =>  {:.1} fps  ({:.2} ms/frame)",
        n as f64 / secs,
        secs * 1000.0 / n as f64,
    );
}

/// XRGB8888 gradient, `phase` shifts the blue channel for visible animation.
fn fill_gradient(s: &mut Scanout, phase: u8) -> std::io::Result<()> {
    let (w, h) = (s.width as usize, s.height as usize);
    s.fill(|buf, stride| {
        for y in 0..h {
            let row = &mut buf[y * stride..y * stride + w * 4];
            for x in 0..w {
                let p = x * 4;
                row[p] = (x * 255 / w) as u8 ^ phase; // B
                row[p + 1] = (y * 255 / h) as u8; // G
                row[p + 2] = 64; // R
                row[p + 3] = 0; // X
            }
        }
    })
}

fn print_help() {
    print!(
        "\
medias - media player for Raspberry Pi (DRM/KMS + Vulkan + libmpv, no X11)

USAGE:
    medias [OPTIONS] [DEVICE]
                           run the player (default; DEVICE e.g. /dev/dri/card1
                           overrides the auto-detected KMS display node)
    medias <SUBCOMMAND>

OPTIONS (repeatable; each adds a top-menu entry; default: Videos + Music):
    --videos[=[LABEL=]PATH]   a video library root
    --music[=[LABEL=]PATH]    a music library root
       bare            -> Videos / Music under ~/medias
       =PATH           -> entry labeled from PATH's name (relative to ~/medias)
       =LABEL=PATH     -> entry labeled LABEL
    e.g. --videos=Movies=/mnt/movies --videos=Series=series --music=/mnt/music

SUBCOMMANDS:
    (none)                  the media player app: browse + play
    bench [DEVICE]          graphics bring-up benchmarks (KMS/Vulkan present)
    comp [FILE|URL] [DEVICE]  two-plane compositor demo (video + UI overlay)
    video [FILE|URL] [DEVICE] play one file/URL full screen (mpv -> KMS)
    mpv [FILE|URL]           headless libmpv decode/control test (no display)
    shell [DEVICE]          UI shell / menu demo (no video)
    input [EVDEV]           print input events from CEC or evdev
    --help, -h, help        this message

CONTENT (under $HOME/medias):
    Videos/                scanned into the Videos menu
    Music/                 scanned into the Music menu
    upnp.txt               UPnP/DLNA servers outside multicast reach: one
                           description URL per line (e.g.
                           http://10.0.0.5:8200/rootDesc.xml); \"Media
                           servers\" also finds servers via SSDP (1.5 s)
    youtube.txt            YouTube sources, one per line: \"Label | query\"
                           query = ytsearchN:terms, or a channel/playlist URL
    youtube_oauth.json     YouTube sign-in: {{\"client_id\",\"client_secret\",
                           \"api_key\"?}}. The OAuth client must be of type
                           \"TVs and Limited Input devices\". Without it, search
                           still works anonymously via yt-dlp. Credentials may
                           also come from MEDIAS_YT_CLIENT_ID / _CLIENT_SECRET /
                           _API_KEY. The session is stored in .youtube_auth.
    .youtube_tv_auth       \"For you\" session: a second QR sign-in with
                           YouTube's TV client (as the Kodi plugin does), no
                           configuration needed. Only in builds with
                           --features youtube-tv.
    .view                  thumbnail view: \"list\" or \"grid\"
    .cache/thumbs/         thumbnails (YouTube: 30-day reuse; local files:
                           until the file changes)

REMOTE / KEYS:
    menu:  Up/Down move, OK/Enter select, Back up a level
           (at root: back to video, or exit if none is loaded)
           Lists scroll automatically. Left/Right, Channel +/-, or PgUp/PgDn
           move by a page; Home/End select the first/last entry.
    search: Type to filter the current directory, or press / or Ctrl-F.
            Up from the first result focuses search; OK opens the keyboard.
            Down from search returns to results.
           Matching ignores case. Backspace deletes; Enter opens the selection.
           Blue/Menu opens an on-screen keyboard: arrows move, OK types,
           Done returns to results. Back closes the keyboard, leaves the
           search bar, then clears the filter before leaving the directory.
           Search is not recursive.
    thumbnails: library folders and YouTube lists show thumbnails (video frame
           at 15%, embedded or folder cover art, cover/folder/poster image or
           first file for folders). Yellow/Info/F4 toggles a small-thumbnail
           list and a wide grid (4 x 2 at 16:9; arrows move by card, Up from
           the top row focuses search).
    loading: folders, YouTube lists and stream lookups load in the background
           behind a spinner; Back abandons the load. Failures show briefly.
    play:  Left/Right seek +/-10s, Rewind/Fast-Forward +/-60s, Up/Down volume,
           Play toggles pause, Audio/Subtitle quick-cycle tracks, Stop stops.
           OK or Pause open the playback menu; Back opens the file list.
           The now-playing bar hides after 10s. Yellow/Info cycles: bar shown,
           hidden, screen black (audio keeps playing; volume keys keep it
           black, other keys light it), bar shown.
           Next/Previous track (CEC Forward/Backward, terminal > and <) play
           the next/previous file of the folder; Previous after 5s restarts.
           At the end of a local or UPnP file the next one in its folder (in
           the filtered order) plays, unless turned off.
    menu (playback):  Up/Down navigate, OK select, Back up a level / resume.
           Entries: Resume, Seek, Audio and Subtitles (choose track), Play
           next in folder (on/off, kept in ~/medias/.autoplay), Browse
           library, Stop. The Seek row is horizontal (Left/Right); relative
           jumps repeat without closing and keep the time on screen.
    colored/extra buttons: Red=subtitles, Green=audio, Blue=menu, Yellow=info,
           Channel Up/Down = seek +/-60s.
    Playback resumes from the saved per-file position in ~/medias/.history.
    Ctrl-C / Ctrl-Z save the current playback position before cleanup.
    Sources: terminal keyboard text/navigation, HDMI-CEC, and evdev keys.
    Unmapped remote/media key codes are printed to stderr.

ENVIRONMENT:
    MEDIAS_HWDEC=auto|no|...   mpv hardware decode (default auto; `no` = software)
    MEDIAS_AO=<list>           mpv audio output list (default alsa,null;
                               e.g. pipewire)
    MEDIAS_AUDIO_DEVICE=<dev>  mpv audio device (`aplay -L` for names,
                               e.g. alsa/sysdefault:CARD=vc4hdmi0)
    MEDIAS_STATS=1             print per-second playback stats
    MEDIAS_YT_MAX_HEIGHT=<px>  YouTube stream height cap (default 1080)
    MEDIAS_YT_CODECS=<list>    allowed YouTube video codecs, preferred first
                               (default av01,vp9,avc1; Pi: avc1)
    MEDIAS_YT_AUDIO_LANGS=<l>  languages whose YouTube dubs are offered beside
                               the original audio, e.g. de,en (default: from
                               LANGUAGE/LC_ALL/LC_MESSAGES/LANG)
    MEDIAS_YTDL_PATH=<path>    yt-dlp for the playback fallback and anonymous
                               search/sources (default: found in /usr/bin etc.)
    MEDIAS_MPV_LOG=<path>      write mpv's verbose log (playback diagnosis)
    MEDIAS_YT_DEBUG=1          dump the InnerTube browse response to
                               ~/medias/innertube-browse.json

NOTES:
    - All display commands auto-detect the KMS node; DEVICE overrides detection.
    - Run with access to /dev/dri and input devices.
      DRM master requires that no desktop/compositor owns the display.
    - The same command works directly from SSH, Zellij, or a Linux console.
      SSH/Zellij startup does not require sudo or a separate VT launcher.
      On a real console, medias manages graphics mode and VT switching.
    - Ctrl-C, Ctrl-Z, and termination signals exit and restore display state.
      VT switches exit the player when it owns a real console VT.
    - Optional: scripts/medias-vt uses sudo to launch on a separate VT.
    - Video renders at <=1080p and the display scales it (big win at 4K).
    - To use a user PipeWire from root: XDG_RUNTIME_DIR=/run/user/<uid> MEDIAS_AO=pipewire
"
    );
}

fn fail(msg: &str) -> ! {
    eprintln!("{msg}");
    std::process::exit(1);
}

#[cfg(test)]
mod playback_tests {
    use super::*;
    use std::os::unix::process::CommandExt;
    use std::process::{Command, Stdio};
    use std::time::{SystemTime, UNIX_EPOCH};

    struct Fixture(std::path::PathBuf);

    impl Fixture {
        fn new() -> Self {
            let stamp = SystemTime::now().duration_since(UNIX_EPOCH).unwrap().as_nanos();
            let dir = std::env::temp_dir().join(format!("medias-resume-{}-{stamp}", std::process::id()));
            std::fs::create_dir(&dir).unwrap();
            let size = 30u32 * 8000 * 2;
            let mut wave = Vec::new();
            wave.extend(b"RIFF"); wave.extend((size + 36).to_le_bytes()); wave.extend(b"WAVEfmt ");
            wave.extend(16u32.to_le_bytes()); wave.extend(1u16.to_le_bytes()); wave.extend(1u16.to_le_bytes());
            wave.extend(8000u32.to_le_bytes()); wave.extend(16000u32.to_le_bytes());
            wave.extend(2u16.to_le_bytes()); wave.extend(16u16.to_le_bytes());
            wave.extend(b"data"); wave.extend(size.to_le_bytes());
            wave.resize(44 + size as usize, 0);
            std::fs::write(dir.join("silence.wav"), wave).unwrap();
            Self(dir)
        }

        fn media(&self) -> String { self.0.join("silence.wav").to_str().unwrap().to_owned() }
        fn history(&self) -> history::History { history::History::load_from(self.0.join(".history")) }
    }

    impl Drop for Fixture {
        fn drop(&mut self) { let _ = std::fs::remove_dir_all(&self.0); }
    }

    fn headless() -> mpv::Mpv {
        let m = mpv::Mpv::new().unwrap();
        for (name, value) in [("config", "no"), ("load-scripts", "no"), ("terminal", "no"), ("vo", "null"), ("ao", "null"), ("hwdec", "no"), ("idle", "yes"), ("pause", "yes"), ("ytdl", "no")] {
            m.set_option(name, value).unwrap();
        }
        m.init().unwrap();
        m
    }

    /// Network: InnerTube direct streams load in libmpv with scripts and yt-dlp
    /// disabled. `cargo test -- --ignored direct_youtube`.
    #[test]
    #[ignore]
    fn direct_youtube_streams_load_without_ytdlp() {
        // 0e3GPea1Tyg: English original with ~23 dubs.
        let prefs = youtube::innertube::StreamPrefs {
            max_height: 1080,
            codecs: vec!["av01".into(), "vp9".into(), "avc1".into()],
            audio_langs: vec!["de".into()],
        };
        let streams = youtube::innertube::streams("0e3GPea1Tyg", &prefs).unwrap();
        let titles: Vec<&str> = streams.audio.iter().map(|a| a.title.as_str()).collect();
        assert_eq!(titles, ["English (US) (original)", "German (dubbed)"]);
        let m = headless();
        let audio: Vec<String> = streams.audio.iter().map(|a| mpv::edl_track(&a.url, &a.lang, &a.title)).collect();
        m.set_audio_files(&audio.iter().map(String::as_str).collect::<Vec<_>>()).unwrap();
        m.loadfile(&streams.video).unwrap();
        let deadline = Instant::now() + Duration::from_secs(30);
        loop {
            match m.wait_event(0.5) {
                mpv::Event::FileLoaded => break,
                mpv::Event::PlaybackError => panic!("direct stream failed to load"),
                _ => assert!(Instant::now() < deadline, "timed out waiting for FileLoaded"),
            }
        }
        assert_eq!(m.get_string("track-list/count").as_deref(), Some("3"));
        assert_eq!(m.get_string("current-tracks/audio/title").as_deref(), Some("English (US) (original)"));
        assert_eq!(m.get_string("track-list/2/lang").as_deref(), Some("de"));
    }

    fn load(m: &mpv::Mpv, path: &str) {
        m.loadfile(path).unwrap();
        let start = Instant::now();
        while m.wait_event(0.01) != mpv::Event::FileLoaded {
            assert!(start.elapsed() < Duration::from_secs(5));
        }
    }

    fn seek(m: &mpv::Mpv, position: f64) {
        m.command(&["seek", &position.to_string(), "absolute+exact"]).unwrap();
        let start = Instant::now();
        loop {
            if m.get_f64("time-pos").is_some_and(|t| (t - position).abs() < 0.2)
                && m.get_string("seeking").as_deref() != Some("yes") { return; }
            m.wait_event(0.01);
            assert!(start.elapsed() < Duration::from_secs(5));
        }
    }

    #[test]
    fn shutdown_signals_persist_latest_position_before_mpv_destruction() {
        const CHILD: &str = "MEDIAS_RESUME_SIGNAL";
        let Some(number) = std::env::var_os(CHILD) else {
            for signal in [libc::SIGINT, libc::SIGTSTP] {
                let mut command = Command::new(std::env::current_exe().unwrap());
                command.args(["--exact", "playback_tests::shutdown_signals_persist_latest_position_before_mpv_destruction"])
                    .env(CHILD, signal.to_string()).env_remove("SUDO_TTY").stdin(Stdio::null());
                unsafe {
                    command.pre_exec(|| {
                        if libc::setsid() < 0 { return Err(std::io::Error::last_os_error()); }
                        Ok(())
                    });
                }
                assert!(command.status().unwrap().success());
            }
            return;
        };
        let signal: i32 = number.to_str().unwrap().parse().unwrap();
        let console = console::Console::acquire().unwrap();
        assert!(!console.owns_vt());
        let fixture = Fixture::new();
        let path = fixture.media();
        let m = headless();
        load(&m, &path);
        seek(&m, 12.75);
        let mut history = fixture.history();
        history.set_pos(&path, 8.0);
        history.save();
        assert_eq!(unsafe { libc::raise(signal) }, 0);
        assert!(console::stopping());
        finish_playback(&m, &mut history, &path, true, false);
        drop(m);
        let resume = fixture.history().pos(&path).unwrap();
        assert_eq!(resume, 12.0);
        drop(console);
        let m = headless();
        load(&m, &path);
        seek(&m, resume);
        assert!(m.get_f64("time-pos").unwrap() >= 11.8);
    }

    #[test]
    fn paused_resume_seek_reports_completion_before_later_backward_seek() {
        let fixture = Fixture::new();
        let path = fixture.media();
        let m = headless();
        load(&m, &path);
        let start = Instant::now();
        while m.wait_event(0.01) != mpv::Event::PlaybackRestart {
            assert!(start.elapsed() < Duration::from_secs(5));
        }
        m.command(&["seek", "21.5", "absolute+exact"]).unwrap();
        let mut seek_seen = false;
        let start = Instant::now();
        loop {
            match m.wait_event(0.01) {
                mpv::Event::Seek => seek_seen = true,
                mpv::Event::PlaybackRestart => { assert!(seek_seen); break; }
                _ => {}
            }
            assert!(start.elapsed() < Duration::from_secs(5));
        }
        let mut history = fixture.history();
        finish_playback(&m, &mut history, &path, true, false);
        assert_eq!(fixture.history().pos(&path), Some(21.0));
        seek(&m, 9.25);
        finish_playback(&m, &mut history, &path, true, false);
        assert_eq!(fixture.history().pos(&path), Some(9.0));
    }

    #[test]
    fn pending_load_or_resume_retains_cached_position() {
        let fixture = Fixture::new();
        let m = headless();
        load(&m, &fixture.media());
        seek(&m, 12.75);
        let mut history = fixture.history();
        history.set_pos("next-file", 24.0);
        finish_playback(&m, &mut history, "next-file", false, false);
        assert_eq!(fixture.history().pos("next-file"), Some(24.0));
        history.set_pos(&fixture.media(), 21.0);
        finish_playback(&m, &mut history, &fixture.media(), true, true);
        assert_eq!(fixture.history().pos(&fixture.media()), Some(21.0));
    }

    #[test]
    fn stop_preserves_latest_position_and_playback_error_is_not_eof() {
        let fixture = Fixture::new();
        let path = fixture.media();
        let m = headless();
        load(&m, &path);
        seek(&m, 16.5);
        let mut history = fixture.history();
        checkpoint_playback(&m, &mut history, &path, true);
        m.command(&["stop"]).unwrap();
        assert_eq!(fixture.history().pos(&path), Some(16.0));
        m.loadfile(fixture.0.join("missing.wav").to_str().unwrap()).unwrap();
        let start = Instant::now();
        loop {
            let event = m.wait_event(0.01);
            assert_ne!(event, mpv::Event::EndFile(true));
            if event == mpv::Event::PlaybackError { break; }
            assert!(start.elapsed() < Duration::from_secs(5));
        }
        finish_playback(&m, &mut history, &path, false, false);
        assert_eq!(fixture.history().pos(&path), Some(16.0));
    }

    #[test]
    fn pending_natural_eof_clears_resume_on_shutdown() {
        let fixture = Fixture::new();
        let path = fixture.media();
        let m = headless();
        load(&m, &path);
        seek(&m, 29.9);
        let mut history = fixture.history();
        history.set_pos(&path, 29.0);
        m.set_property("pause", "no").unwrap();
        let start = Instant::now();
        while m.get_f64("time-pos").is_some() {
            assert!(start.elapsed() < Duration::from_secs(5));
            std::thread::sleep(Duration::from_millis(5));
        }
        finish_playback(&m, &mut history, &path, true, false);
        assert_eq!(fixture.history().pos(&path), None);
    }
}

#[cfg(test)]
mod render_tests {
    use super::*;

    /// Live + GPU: renders the thumbnail list and grid for related videos of a real
    /// video offscreen; writes BGRA dumps to MEDIAS_SNAPSHOT_DIR (default /tmp).
    #[test]
    #[ignore]
    fn thumbnail_layouts_render_offscreen() {
        let (w, h) = (1920u32, 1080u32);
        let gpu = vk::Gpu::new().unwrap();
        let text = gpu.create_text().unwrap();
        let target = gpu.offscreen_target(w, h).unwrap();
        let fb = text.framebuffer(&gpu, &target).unwrap();
        let videos = youtube::innertube::related("V_uq3v6xK-4").unwrap();
        assert!(videos.len() >= 8, "{} related videos", videos.len());
        let items = yt_video_items(videos);
        let mut cache = thumbs::Thumbs::new();
        let start = Instant::now();
        loop {
            cache.begin_frame();
            let ready = items.iter().take(8).filter(|it| cache.get(&it.thumb).is_some()).count();
            if ready == 8 || start.elapsed() > Duration::from_secs(20) {
                break;
            }
            cache.pump(&text, &gpu);
            std::thread::sleep(Duration::from_millis(50));
        }
        let dir = std::env::var("MEDIAS_SNAPSHOT_DIR").unwrap_or_else(|_| "/tmp".into());
        let mut frame = vk::Frame::default();
        for (name, layout) in [("list", shell::Layout::List), ("grid", shell::Layout::Grid)] {
            cache.begin_frame();
            let cards: Vec<shell::Card> = items
                .iter()
                .map(|it| shell::Card { title: it.name.clone(), sub: it.sub.clone(), meta: it.meta.clone(), thumb: cache.get(&it.thumb), icon: card_icon(it) })
                .collect();
            assert!(cards.iter().take(8).all(|c| c.thumb.is_some()), "thumbnails not loaded");
            let view = shell::BrowseView {
                title: "From your history", layout, rows: &[], cards: &cards, first: 0, selected: 1,
                matches: cards.len(), total: cards.len(), query: "", searching: false,
                search_focused: false, keyboard: None,
            };
            shell::render_browse(&mut frame, &text, &view, w as f32, h as f32);
            text.render(&gpu, &target, fb, &frame).unwrap();
            let pixels = gpu.read_target(&target).unwrap();
            std::fs::write(format!("{dir}/medias-{name}-{w}x{h}.bgra"), &pixels).unwrap();
        }
        gpu.destroy_framebuffer(fb);
        text.destroy(&gpu);
        gpu.destroy_target(target);
    }

    /// GPU: the loading panel over a text level at three spinner steps.
    #[test]
    #[ignore]
    fn loading_spinner_renders_offscreen() {
        let (w, h) = (1920u32, 1080u32);
        let gpu = vk::Gpu::new().unwrap();
        let text = gpu.create_text().unwrap();
        let target = gpu.offscreen_target(w, h).unwrap();
        let fb = text.framebuffer(&gpu, &target).unwrap();
        let rows: Vec<shell::Row> = ["For you", "Search", "Trending"].iter().map(|s| (s.to_string(), String::new())).collect();
        let dir = std::env::var("MEDIAS_SNAPSHOT_DIR").unwrap_or_else(|_| "/tmp".into());
        let mut frame = vk::Frame::default();
        for step in [0, 4, 8] {
            let view = shell::BrowseView {
                title: "YouTube", layout: shell::Layout::Text, rows: &rows, cards: &[], first: 0, selected: 0,
                matches: rows.len(), total: rows.len(), query: "", searching: false, search_focused: false, keyboard: None,
            };
            shell::render_browse(&mut frame, &text, &view, w as f32, h as f32);
            shell::render_status(&mut frame, &text, "Loading For you…", Some(step), w as f32, h as f32);
            text.render(&gpu, &target, fb, &frame).unwrap();
            std::fs::write(format!("{dir}/medias-spinner{step}-{w}x{h}.bgra"), gpu.read_target(&target).unwrap()).unwrap();
        }
        gpu.destroy_framebuffer(fb);
        text.destroy(&gpu);
        gpu.destroy_target(target);
    }

    /// GPU + ffmpeg fixtures: a local directory (video, album folder with
    /// embedded art, track without art) in both views; dumps as above.
    #[test]
    #[ignore]
    fn local_thumbnails_render_offscreen() {
        let root = std::env::temp_dir().join(format!("medias-local-{}", std::process::id()));
        let album = root.join("Some Album");
        std::fs::create_dir_all(&album).unwrap();
        let ffmpeg = |args: &[&str]| {
            assert!(std::process::Command::new("ffmpeg").args(["-v", "error", "-y"]).args(args).status().unwrap().success())
        };
        let path = |p: &std::path::Path| p.to_str().unwrap().to_string();
        ffmpeg(&["-f", "lavfi", "-i", "testsrc2=size=1920x1080:rate=25:duration=20", "-c:v", "libx264", "-preset", "ultrafast", &path(&root.join("A Movie.mkv"))]);
        ffmpeg(&["-f", "lavfi", "-i", "mandelbrot=size=1280x720:rate=25", "-t", "20", "-c:v", "libx264", "-preset", "ultrafast", &path(&root.join("Another Movie.mp4"))]);
        ffmpeg(&["-f", "lavfi", "-i", "sine=duration=5", &path(&root.join("No Art.mp3"))]);
        let art = std::env::temp_dir().join(format!("medias-art-{}.jpg", std::process::id()));
        ffmpeg(&["-f", "lavfi", "-i", "cellauto=s=600x600", "-frames:v", "1", &path(&art)]);
        ffmpeg(&["-i", &path(&root.join("No Art.mp3")), "-i", &path(&art), "-map", "0", "-map", "1", "-c", "copy",
            "-disposition:v", "attached_pic", &path(&album.join("01 Track.mp3"))]);
        std::fs::remove_file(&art).unwrap();
        std::fs::create_dir_all(root.join("Empty Folder")).unwrap();

        let (w, h) = (1920u32, 1080u32);
        let gpu = vk::Gpu::new().unwrap();
        let text = gpu.create_text().unwrap();
        let target = gpu.offscreen_target(w, h).unwrap();
        let fb = text.framebuffer(&gpu, &target).unwrap();
        let items = lib_items(library::list(&root).unwrap());
        assert_eq!(items.len(), 5);
        let mut cache = thumbs::Thumbs::new();
        let start = Instant::now();
        while start.elapsed() < Duration::from_secs(20) {
            cache.begin_frame();
            if items.iter().filter(|it| cache.get(&it.thumb).is_some()).count() == 3 {
                break; // all but "Empty Folder" and "No Art.mp3"
            }
            cache.pump(&text, &gpu);
            std::thread::sleep(Duration::from_millis(50));
        }
        let dir = std::env::var("MEDIAS_SNAPSHOT_DIR").unwrap_or_else(|_| "/tmp".into());
        let mut frame = vk::Frame::default();
        for (name, layout) in [("local-list", shell::Layout::List), ("local-grid", shell::Layout::Grid)] {
            cache.begin_frame();
            let cards: Vec<shell::Card> = items
                .iter()
                .map(|it| shell::Card { title: it.name.clone(), sub: card_sub(it, None), meta: String::new(), thumb: cache.get(&it.thumb), icon: card_icon(it) })
                .collect();
            assert_eq!(cards.iter().filter(|c| c.thumb.is_some()).count(), 3, "thumbnails not loaded");
            let view = shell::BrowseView {
                title: "Videos", layout, rows: &[], cards: &cards, first: 0, selected: 0,
                matches: cards.len(), total: cards.len(), query: "", searching: false,
                search_focused: false, keyboard: None,
            };
            shell::render_browse(&mut frame, &text, &view, w as f32, h as f32);
            text.render(&gpu, &target, fb, &frame).unwrap();
            std::fs::write(format!("{dir}/medias-{name}-{w}x{h}.bgra"), gpu.read_target(&target).unwrap()).unwrap();
        }
        gpu.destroy_framebuffer(fb);
        text.destroy(&gpu);
        gpu.destroy_target(target);
        std::fs::remove_dir_all(&root).unwrap();
    }
}


#[cfg(test)]
mod queue_tests {
    use super::*;

    fn level() -> Level {
        let server = std::sync::Arc::new(upnp::Server {
            name: "nas".into(),
            udn: "uuid:1".into(),
            control: "http://h/ctl".into(),
            service_type: String::new(),
            icon: String::new(),
        });
        Level::new("Album", vec![
            Item::new("CD2", Node::Dir("/m/CD2".into()), true),
            Item::new("01 Intro", Node::Media("/m/01.flac".into()), false),
            Item::new("02 Song", Node::Media("/m/02.flac".into()), false),
            Item::new("03 Remote", Node::UpnpMedia("http://h/3.flac".into(), upnp::Kind::Audio), false),
            Item::video("Clip", "https://www.youtube.com/watch?v=abcdefghijk".into()),
            Item::new("Sub", Node::UpnpDir(server, "9".into()), true),
        ])
    }

    fn target(loaded: Option<Loaded>) -> Option<String> {
        match loaded? {
            Loaded::Play { key, target, .. } => {
                assert_eq!(key, target);
                Some(target)
            }
            _ => None,
        }
    }

    #[test]
    fn queue_steps_through_playable_folder_items_only() {
        let mut stack = vec![level()];
        let mut q = Queue::new(&stack[0], 0, 1).unwrap();
        assert_eq!(q.items.len(), 3); // directories and YouTube are skipped
        assert_eq!(target(Some(q.play())).as_deref(), Some("/m/01.flac"));
        assert_eq!(target(q.step(-1)), None);
        assert_eq!(target(q.step(1)).as_deref(), Some("/m/02.flac"));
        assert_eq!(target(q.step(1)).as_deref(), Some("http://h/3.flac"));
        q.sync_selection(&mut stack);
        assert_eq!(stack[0].browse.source_index(stack[0].browse.selected()), Some(3));
        assert_eq!(target(q.step(1)), None); // the end: back to the browser
        assert!(Queue::new(&stack[0], 0, 0).is_none()); // a directory is not queued
    }

    #[test]
    fn info_cycles_bar_hidden_black_bar() {
        let (mut bar, mut hidden, mut blank) = (true, false, false); // just started
        let mut seen = Vec::new();
        for _ in 0..4 {
            (bar, hidden, blank) = info_step(bar, hidden, blank);
            seen.push((bar, blank));
        }
        assert_eq!(seen, [(false, false), (false, true), (true, false), (false, false)]);
        assert_eq!(info_step(false, false, false), (true, false, false)); // timed out: show first
    }

    #[test]
    fn queue_follows_the_filtered_order() {
        let mut l = level();
        for key in "song".chars().map(input::Key::Char) {
            l.browse.handle(key, 10);
        }
        let mut q = Queue::new(&l, 0, 2).unwrap();
        assert_eq!(q.items.len(), 1);
        assert_eq!(target(q.step(1)), None);
    }
}