nornir 0.4.4

//! egui app — paints the lanes + edges and the "time machine" panel.

use std::path::PathBuf;
use std::sync::OnceLock;

use anyhow::Result;
use eframe::egui::{
    self, Align2, Color32, ColorImage, FontId, Pos2, Rect, Rounding, Sense, Stroke,
    TextureHandle, TextureOptions, Vec2,
};
use uuid::Uuid;

use super::graph::draw_dep_graph;
use super::model::{Timeline, load_timeline};
use super::timetravel::{TimeTravelState, draw_timetravel};

const SPLASH_DURATION_SECS: f32 = 2.5;
const SPLASH_FADE_SECS: f32 = 1.0;
const WATERMARK_ALPHA: u8 = 22;

// Media moved to `.nornir/assets/` in 1e8d062; the old `assets/` path 404'd and
// broke the `viz` build.
static NORNIR_WEBP_BYTES: &[u8] = include_bytes!("../../.nornir/assets/nornir.webp");

fn decode_nornir() -> Option<ColorImage> {
    static CACHE: OnceLock<Option<ColorImage>> = OnceLock::new();
    CACHE
        .get_or_init(|| {
            let img = image::load_from_memory(NORNIR_WEBP_BYTES).ok()?;
            let rgba = img.to_rgba8();
            let (w, h) = (rgba.width() as usize, rgba.height() as usize);
            Some(ColorImage::from_rgba_unmultiplied([w, h], rgba.as_raw()))
        })
        .clone()
}

#[derive(PartialEq, Eq, Clone, Copy)]
enum Tab {
    Timeline,
    DepGraph,
    CallGraph,
    Funnel,
    TimeTravel,
    LiveRun,
    Knowledge,
    Warehouse,
    Search,
    Gates,
    Bench,
}

/// Where the timeline comes from: a local Iceberg warehouse (embedded, opens
/// it directly) or a running `nornir-server` (thin client over the
/// `Viz.Timeline` gRPC). Both yield the same [`Timeline`], so the rest of the
/// app is source-agnostic.
pub enum Source {
    Local(PathBuf),
    Remote { endpoint: String, token: String },
}

impl Source {
    fn load(&self, workspace: &str) -> Result<Timeline> {
        match self {
            Source::Local(root) => load_timeline(root, workspace),
            Source::Remote { endpoint, token } => {
                super::remote::fetch_timeline(endpoint, token, workspace)
            }
        }
    }
}

pub struct UrdrThreadsApp {
    source: Source,
    source_label: String,
    workspace_name: String,
    /// Workspaces offered in the picker (server-registered for remote; just the
    /// current one for local). Switching re-scopes every server-backed tab.
    workspaces: Vec<String>,
    timeline: Result<Timeline>,
    selected: Option<Uuid>,
    last_reload: std::time::Instant,
    tab: Tab,
    started_at: std::time::Instant,
    nornir_tex: Option<TextureHandle>,
    timetravel: TimeTravelState,
    live: super::live::LiveRunState,
    knowledge: super::knowledge::KnowledgeState,
    warehouse: super::warehouse_tab::WarehouseBrowser,
    callgraph: super::callgraph::CallGraphState,
    funnel: super::funnel_tab::FunnelTabState,
    /// Server-backed clickable tabs (remote mode only).
    search: super::ops_tabs::SearchState,
    gates: super::ops_tabs::GatesState,
    bench: super::ops_tabs::BenchState,
    ws_panel: super::ops_tabs::WorkspacePanel,
    /// Configured repo names (for the Gates/Bench repo pickers).
    repos: Vec<String>,
    /// Auto-reload the timeline (and refresh the warehouse table list) on a
    /// timer so a server-monitored workspace animates as it republishes.
    auto_refresh: bool,
    refresh_secs: u64,
}

impl UrdrThreadsApp {
    pub fn new(warehouse_root: PathBuf, workspace_name: String) -> Self {
        Self::with_repos(warehouse_root, workspace_name, PathBuf::new(), Vec::new())
    }

    /// Extended constructor: also seed the Knowledge tab with a workspace
    /// root (the parent containing repo dirs) and the configured repo names.
    pub fn with_repos(
        warehouse_root: PathBuf,
        workspace_name: String,
        workspace_root: PathBuf,
        repos: Vec<String>,
    ) -> Self {
        let log_dir = warehouse_root
            .parent()
            .map(|p| p.join("logs"))
            .unwrap_or_else(|| warehouse_root.join("logs"));
        let label = warehouse_root.display().to_string();
        Self::build(Source::Local(warehouse_root), label, workspace_name, workspace_root, repos, log_dir)
    }

    /// Thin-client constructor: load the timeline from a running `nornir-server`
    /// over gRPC instead of opening a local warehouse. The live-run tab streams
    /// the active release run from the server over `Release.Progress` (no local
    /// log dir needed) — so a viz pointed at a remote server (e.g. over Tailscale)
    /// animates the run in real time, the same as a local one.
    pub fn with_remote(
        endpoint: String,
        token: String,
        workspace_name: String,
        workspace_root: PathBuf,
        repos: Vec<String>,
    ) -> Self {
        let label = format!("server {endpoint}");
        Self::build(
            Source::Remote { endpoint, token },
            label,
            workspace_name,
            workspace_root,
            repos,
            PathBuf::new(),
        )
    }

    fn build(
        source: Source,
        source_label: String,
        mut workspace_name: String,
        workspace_root: PathBuf,
        repos: Vec<String>,
        log_dir: PathBuf,
    ) -> Self {
        // Picker contents come FIRST so the initial selection is a real
        // workspace: remote mode lists the server's registered set and, when
        // launched without an explicit --workspace/NORNIR_WORKSPACE, selects
        // the first one (never injecting a placeholder into the picker). An
        // explicit name stays selectable even if unregistered (e.g. the
        // server's served default workspace).
        let workspaces = match &source {
            Source::Remote { endpoint, token } => {
                let mut ws = match super::remote::list_workspaces(endpoint, token) {
                    Ok(ws) => {
                        eprintln!("nornir-viz: Workspaces.List → {} workspace(s): {ws:?}", ws.len());
                        ws
                    }
                    Err(e) => {
                        eprintln!("nornir-viz: Workspaces.List FAILED (picker empty): {e:#}");
                        Vec::new()
                    }
                };
                ws.sort();
                ws.dedup();
                if workspace_name.is_empty() {
                    if let Some(first) = ws.first() {
                        workspace_name = first.clone();
                        eprintln!("nornir-viz: auto-selected workspace `{workspace_name}`");
                    }
                } else if !ws.iter().any(|w| w == &workspace_name) {
                    ws.push(workspace_name.clone());
                }
                ws
            }
            Source::Local(_) => vec![workspace_name.clone()],
        };

        let timeline = source.load(&workspace_name);
        // Local source → tail the workspace log dir; remote source → stream the
        // run from the server over Release.Progress (the thin-client live tab).
        let live = match &source {
            Source::Remote { endpoint, token } => {
                super::live::LiveRunState::new_remote(endpoint.clone(), token.clone())
            }
            Source::Local(_) => super::live::LiveRunState::new(log_dir),
        };
        // The warehouse browser opens the warehouse directly when local, else
        // browses it over the server's Warehouse.Tables/Scan gRPC.
        let warehouse = match &source {
            Source::Local(p) => super::warehouse_tab::WarehouseBrowser::local(p.clone()),
            Source::Remote { endpoint, token } => super::warehouse_tab::WarehouseBrowser::remote(
                endpoint.clone(),
                token.clone(),
                workspace_name.clone(),
            ),
        };
        let callgraph = match &source {
            Source::Local(p) => super::callgraph::CallGraphState::local(p.clone()),
            Source::Remote { endpoint, token } => super::callgraph::CallGraphState::remote(
                endpoint.clone(),
                token.clone(),
                workspace_name.clone(),
            ),
        };
        let funnel = match &source {
            Source::Local(p) => super::funnel_tab::FunnelTabState::local(p.clone()),
            Source::Remote { endpoint, token } => super::funnel_tab::FunnelTabState::remote(
                endpoint.clone(),
                token.clone(),
                workspace_name.clone(),
            ),
        };
        Self {
            source,
            source_label,
            workspace_name,
            workspaces,
            timeline,
            selected: None,
            last_reload: std::time::Instant::now(),
            tab: Tab::Timeline,
            started_at: std::time::Instant::now(),
            nornir_tex: None,
            timetravel: TimeTravelState::default(),
            live,
            knowledge: super::knowledge::KnowledgeState::new(workspace_root, repos.clone()),
            warehouse,
            callgraph,
            funnel,
            search: super::ops_tabs::SearchState::default(),
            gates: super::ops_tabs::GatesState::default(),
            bench: super::ops_tabs::BenchState::default(),
            ws_panel: super::ops_tabs::WorkspacePanel::default(),
            repos,
            auto_refresh: true,
            refresh_secs: 5,
        }
    }

    fn reload(&mut self) {
        self.timeline = self.source.load(&self.workspace_name);
        self.last_reload = std::time::Instant::now();
    }

    /// The server bundle for the ops tabs (None in local-warehouse mode).
    fn server(&self) -> Option<super::ops_tabs::Server> {
        match &self.source {
            Source::Remote { endpoint, token } => {
                Some(super::ops_tabs::Server { endpoint: endpoint.clone(), token: token.clone() })
            }
            Source::Local(_) => None,
        }
    }

    /// Switch the active workspace (the picker): re-scope every server-backed tab
    /// (timeline, warehouse, call graph) and reload immediately.
    fn switch_workspace(&mut self, ws: String) {
        if ws == self.workspace_name {
            return;
        }
        self.workspace_name = ws.clone();
        self.selected = None;
        self.warehouse.set_workspace(ws.clone());
        self.funnel.set_workspace(ws.clone());
        self.callgraph.set_workspace(ws);
        self.reload();
        self.warehouse.refresh_tables();
    }
}

const LANE_HEIGHT: f32 = 80.0;
const LANE_PAD: f32 = 24.0;
const NODE_RADIUS: f32 = 14.0;
const LEFT_GUTTER: f32 = 140.0;

fn status_color(status: &str) -> Color32 {
    match status {
        s if s.starts_with("succeeded_dry_run") => Color32::from_rgb(200, 160, 60),
        s if s.starts_with("succeeded") => Color32::from_rgb(80, 180, 120),
        "failed_test" => Color32::from_rgb(220, 80, 80),
        "failed_bench" => Color32::from_rgb(220, 130, 60),
        _ => Color32::from_rgb(140, 140, 160),
    }
}

impl eframe::App for UrdrThreadsApp {
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        // Auto-refresh: reload the timeline + warehouse table list on a timer so a
        // server-monitored workspace animates live as the poll loop republishes.
        if self.auto_refresh && self.last_reload.elapsed().as_secs() >= self.refresh_secs {
            self.reload();
            self.warehouse.refresh_tables();
            ctx.request_repaint();
        }
        if self.auto_refresh {
            // Keep the frame loop ticking even when idle so the timer fires.
            ctx.request_repaint_after(std::time::Duration::from_secs(1));
        }

        egui::TopBottomPanel::top("top").show(ctx, |ui| {
            ui.horizontal(|ui| {
                ui.heading("🧵 Urðr Threads");
                ui.separator();
                // Workspace picker — switching re-scopes timeline/warehouse/callgraph.
                let mut chosen = self.workspace_name.clone();
                let label = if chosen.is_empty() { "(default)".to_string() } else { chosen.clone() };
                egui::ComboBox::from_id_source("ws_picker")
                    .selected_text(format!("workspace: {label}"))
                    .show_ui(ui, |ui| {
                        for ws in &self.workspaces {
                            ui.selectable_value(&mut chosen, ws.clone(), ws);
                        }
                    });
                if chosen != self.workspace_name {
                    self.switch_workspace(chosen);
                }
                ui.separator();
                ui.label(format!("source: {}", self.source_label));
                if ui.button("↻ reload").clicked() {
                    self.reload();
                    self.warehouse.refresh_tables();
                }
                ui.checkbox(&mut self.auto_refresh, "live")
                    .on_hover_text(format!("auto-refresh every {}s", self.refresh_secs));
                ui.separator();
                ui.selectable_value(&mut self.tab, Tab::Timeline, "🧵 Timeline");
                ui.selectable_value(&mut self.tab, Tab::DepGraph, "🔗 Dep Graph");
                ui.selectable_value(&mut self.tab, Tab::CallGraph, "🕸 Call Graph");
                ui.selectable_value(&mut self.tab, Tab::Funnel, "🗂 Funnel");
                ui.selectable_value(&mut self.tab, Tab::TimeTravel, "⏳ Time Travel");
                ui.selectable_value(&mut self.tab, Tab::LiveRun, "📡 Live Run");
                ui.selectable_value(&mut self.tab, Tab::Knowledge, "🗺 Knowledge");
                ui.selectable_value(&mut self.tab, Tab::Warehouse, "🗄 Warehouse");
                ui.selectable_value(&mut self.tab, Tab::Search, "🔍 Search");
                ui.selectable_value(&mut self.tab, Tab::Gates, "🚦 Gates");
                ui.selectable_value(&mut self.tab, Tab::Bench, "📈 Bench");
                ui.separator();
                // Workspace info toggle + ⟳ Sync now (remote mode).
                let srv = self.server();
                self.ws_panel.draw_controls(ui, srv.as_ref(), &self.workspace_name);
                ui.label(format!(
                    "(last reload {}s ago)",
                    self.last_reload.elapsed().as_secs()
                ));
            });
        });

        // Side panel: details for the selected release
        egui::SidePanel::right("detail").default_width(360.0).show(ctx, |ui| {
            ui.heading("Time machine");
            ui.separator();
            // Workspace info + sync result (when the ℹ toggle is on).
            self.ws_panel.draw_panel(ui, self.server().as_ref(), &self.workspace_name);
            match (self.selected, &self.timeline) {
                (Some(rid), Ok(tl)) => {
                    ui.label(format!("release_id\n  {rid}"));
                    ui.separator();
                    ui.label("git checkout commands:");
                    for lane in &tl.lanes {
                        if let Some(node) = lane.nodes.iter().find(|n| n.release_id == rid) {
                            let cmd = format!("cd {} && git checkout {}", lane.repo, node.sha);
                            ui.horizontal(|ui| {
                                ui.monospace(&cmd);
                                if ui.button("📋").on_hover_text("copy").clicked() {
                                    ui.output_mut(|o| o.copied_text = cmd.clone());
                                }
                            });
                            let color = status_color(&node.gate_status);
                            ui.colored_label(
                                color,
                                format!(
                                    "  {} • status={} • tests {}/{} • branch={} • dirty={}",
                                    lane.repo,
                                    node.gate_status,
                                    node.tests_passed,
                                    node.tests_failed,
                                    node.branch,
                                    node.dirty,
                                ),
                            );
                            if !node.published_versions.is_empty() {
                                ui.label(format!(
                                    "  published: {}",
                                    node.published_versions
                                        .iter()
                                        .map(|(c, v)| format!("{c}@{v}"))
                                        .collect::<Vec<_>>()
                                        .join(", ")
                                ));
                            }
                            ui.add_space(4.0);
                        }
                    }
                }
                (None, _) => {
                    ui.label("click a node in the timeline →");
                }
                (_, Err(e)) => {
                    ui.colored_label(Color32::RED, format!("load error:\n{e:#}"));
                }
            }
        });

        egui::CentralPanel::default().show(ctx, |ui| {
            // Live Run and Knowledge tabs render even when there's no
            // timeline yet — they work without warehouse data.
            if self.tab == Tab::LiveRun {
                self.live.draw(ui);
                return;
            }
            if self.tab == Tab::Knowledge {
                self.knowledge.draw(ui);
                return;
            }
            if self.tab == Tab::Warehouse {
                self.warehouse.draw(ui);
                return;
            }
            if self.tab == Tab::CallGraph {
                self.callgraph.draw(ui);
                return;
            }
            if self.tab == Tab::Funnel {
                self.funnel.draw(ui);
                return;
            }
            let srv = self.server();
            if self.tab == Tab::Search {
                self.search.draw(ui, srv.as_ref(), &self.workspace_name);
                return;
            }
            if self.tab == Tab::Gates {
                self.gates.draw(ui, srv.as_ref(), &self.workspace_name, &self.repos);
                return;
            }
            if self.tab == Tab::Bench {
                self.bench.draw(ui, srv.as_ref(), &self.workspace_name, &self.repos);
                return;
            }
            match &self.timeline {
            Err(e) => {
                ui.colored_label(Color32::RED, format!("Failed to load warehouse:\n{e:#}"));
            }
            Ok(tl) if tl.is_empty() => {
                ui.label("No releases recorded yet. Run `release_demo_znippy_holger`.");
            }
            Ok(tl) => match self.tab {
                Tab::Timeline => {
                    self.selected = draw_timeline(ui, tl, self.selected);
                }
                Tab::DepGraph => {
                    if self.selected.is_none() {
                        ui.label("Showing latest snapshot — click a release in 🧵 Timeline to time-travel here.");
                    } else if let Some(rid) = self.selected {
                        if let Some(snap) = tl.snapshot_for(&rid) {
                            ui.label(format!(
                                "Pinned to release {} (snapshot {})",
                                rid, snap.snapshot_id
                            ));
                        }
                    }
                    draw_dep_graph(ui, tl, self.selected);
                }
                Tab::TimeTravel => {
                    // Keyboard shortcuts while on this tab.
                    ctx.input(|i| {
                        if i.key_pressed(egui::Key::ArrowRight) {
                            if let Ok(tl) = &self.timeline {
                                if self.timetravel.idx + 1 < tl.release_order.len() {
                                    self.timetravel.idx += 1;
                                }
                            }
                        }
                        if i.key_pressed(egui::Key::ArrowLeft) {
                            self.timetravel.idx = self.timetravel.idx.saturating_sub(1);
                        }
                        if i.key_pressed(egui::Key::Space) {
                            self.timetravel.playing = !self.timetravel.playing;
                            self.timetravel.last_tick = std::time::Instant::now();
                        }
                    });
                    if let Some(rid) = draw_timetravel(ui, tl, &mut self.timetravel) {
                        self.selected = Some(rid);
                    }
                }
                Tab::Search | Tab::Gates | Tab::Bench => unreachable!("handled above"),
                Tab::LiveRun => unreachable!("handled above"),
                Tab::Knowledge => unreachable!("handled above"),
                Tab::Warehouse => unreachable!("handled above"),
                Tab::CallGraph => unreachable!("handled above"),
                Tab::Funnel => unreachable!("handled above"),
            },
            }
        });

        // Splash + watermark overlay (drawn last so it sits on top
        // of everything but doesn't block clicks).
        self.draw_nornir_overlay(ctx);
    }
}

impl UrdrThreadsApp {
    fn ensure_texture(&mut self, ctx: &egui::Context) -> Option<&TextureHandle> {
        if self.nornir_tex.is_none() {
            if let Some(img) = decode_nornir() {
                self.nornir_tex = Some(ctx.load_texture(
                    "nornir-splash",
                    img,
                    TextureOptions::LINEAR,
                ));
            }
        }
        self.nornir_tex.as_ref()
    }

    fn draw_nornir_overlay(&mut self, ctx: &egui::Context) {
        let elapsed = self.started_at.elapsed().as_secs_f32();
        let splash_alpha = if elapsed < SPLASH_DURATION_SECS - SPLASH_FADE_SECS {
            1.0
        } else if elapsed < SPLASH_DURATION_SECS {
            1.0 - (elapsed - (SPLASH_DURATION_SECS - SPLASH_FADE_SECS)) / SPLASH_FADE_SECS
        } else {
            0.0
        };
        // Request continuous repaints during the fade.
        if splash_alpha > 0.0 {
            ctx.request_repaint_after(std::time::Duration::from_millis(16));
        }

        let Some(tex) = self.ensure_texture(ctx) else { return };
        let tex_size = tex.size_vec2();
        let tex_id = tex.id();
        let screen = ctx.screen_rect();

        let painter = ctx.layer_painter(egui::LayerId::new(
            egui::Order::Foreground,
            egui::Id::new("nornir-overlay"),
        ));

        // Persistent watermark — small, bottom-right, very faint.
        let wm_w = 220.0;
        let wm_h = wm_w * (tex_size.y / tex_size.x);
        let wm_rect = Rect::from_min_size(
            Pos2::new(screen.right() - wm_w - 18.0, screen.bottom() - wm_h - 18.0),
            Vec2::new(wm_w, wm_h),
        );
        painter.image(
            tex_id,
            wm_rect,
            Rect::from_min_max(Pos2::ZERO, Pos2::new(1.0, 1.0)),
            Color32::from_white_alpha(WATERMARK_ALPHA),
        );

        // Splash overlay during the first few seconds.
        if splash_alpha > 0.0 {
            // Dim everything behind a translucent veil.
            painter.rect_filled(
                screen,
                Rounding::ZERO,
                Color32::from_rgba_unmultiplied(8, 8, 12, (splash_alpha * 220.0) as u8),
            );
            // Center the artwork at ~60% of the smaller screen dim.
            let max_w = screen.width().min(screen.height()) * 0.6;
            let img_w = max_w.min(tex_size.x);
            let img_h = img_w * (tex_size.y / tex_size.x);
            let center = screen.center();
            let img_rect = Rect::from_center_size(center, Vec2::new(img_w, img_h));
            let a = (splash_alpha * 255.0) as u8;
            painter.image(
                tex_id,
                img_rect,
                Rect::from_min_max(Pos2::ZERO, Pos2::new(1.0, 1.0)),
                Color32::from_white_alpha(a),
            );
            painter.text(
                Pos2::new(center.x, img_rect.bottom() + 24.0),
                Align2::CENTER_TOP,
                "Urðr Threads",
                FontId::proportional(32.0),
                Color32::from_white_alpha(a),
            );
            painter.text(
                Pos2::new(center.x, img_rect.bottom() + 64.0),
                Align2::CENTER_TOP,
                "weaving releases into provenance",
                FontId::proportional(16.0),
                Color32::from_white_alpha((a as u32 * 200 / 255) as u8),
            );
        }
    }
}

fn draw_timeline(ui: &mut egui::Ui, tl: &Timeline, mut selected: Option<Uuid>) -> Option<Uuid> {
    let available = ui.available_size();
    let needed_h = LANE_PAD + tl.lanes.len() as f32 * (LANE_HEIGHT + LANE_PAD);
    let canvas_size = Vec2::new(available.x.max(800.0), needed_h.max(300.0));
    let (rect, response) = ui.allocate_exact_size(canvas_size, Sense::click());
    let painter = ui.painter_at(rect);

    // background
    painter.rect_filled(rect, Rounding::ZERO, Color32::from_rgb(18, 18, 24));

    if tl.release_order.is_empty() {
        return selected;
    }

    let n = tl.release_order.len().max(1);
    let x_step = (rect.width() - LEFT_GUTTER - 40.0) / (n as f32).max(1.0);
    let x_of = |idx: usize| rect.left() + LEFT_GUTTER + 20.0 + idx as f32 * x_step;

    let y_of = |lane_idx: usize| {
        rect.top() + LANE_PAD + lane_idx as f32 * (LANE_HEIGHT + LANE_PAD) + LANE_HEIGHT / 2.0
    };

    // lanes: label + horizontal line + zebra background
    for (li, lane) in tl.lanes.iter().enumerate() {
        let y = y_of(li);
        let lane_rect = Rect::from_min_max(
            Pos2::new(rect.left() + LEFT_GUTTER, y - LANE_HEIGHT / 2.0),
            Pos2::new(rect.right(), y + LANE_HEIGHT / 2.0),
        );
        let zebra = if li % 2 == 0 {
            Color32::from_rgb(28, 28, 36)
        } else {
            Color32::from_rgb(24, 24, 30)
        };
        painter.rect_filled(lane_rect, Rounding::same(4.0), zebra);
        painter.line_segment(
            [
                Pos2::new(rect.left() + LEFT_GUTTER, y),
                Pos2::new(rect.right() - 20.0, y),
            ],
            Stroke::new(1.0, Color32::from_rgb(60, 60, 80)),
        );
        painter.text(
            Pos2::new(rect.left() + 10.0, y),
            Align2::LEFT_CENTER,
            &lane.repo,
            FontId::proportional(18.0),
            Color32::from_rgb(220, 220, 230),
        );
    }

    // weave: for each release column draw cross-repo dep edges between
    // the matching lane nodes (from -> to). Uses the latest snapshot
    // for now (per-release snapshot lookup is a follow-up).
    if let Some(snap) = &tl.latest_snapshot {
        for (col_idx, release_id) in tl.release_order.iter().enumerate() {
            let x = x_of(col_idx);
            for edge in &snap.edges {
                let from_lane = tl.lanes.iter().position(|l| l.repo == edge.from);
                let to_lane = tl.lanes.iter().position(|l| l.repo == edge.to);
                if let (Some(fi), Some(ti)) = (from_lane, to_lane) {
                    let has_from = tl.lanes[fi].nodes.iter().any(|n| n.release_id == *release_id);
                    let has_to = tl.lanes[ti].nodes.iter().any(|n| n.release_id == *release_id);
                    if has_from && has_to {
                        painter.line_segment(
                            [Pos2::new(x, y_of(fi)), Pos2::new(x, y_of(ti))],
                            Stroke::new(
                                2.0,
                                Color32::from_rgba_unmultiplied(180, 140, 220, 160),
                            ),
                        );
                    }
                }
            }
        }
    }

    // nodes (drawn on top of weave)
    for (li, lane) in tl.lanes.iter().enumerate() {
        for node in &lane.nodes {
            let col = tl
                .release_order
                .iter()
                .position(|r| *r == node.release_id)
                .unwrap_or(0);
            let center = Pos2::new(x_of(col), y_of(li));
            let color = status_color(&node.gate_status);
            let is_selected = Some(node.release_id) == selected;
            let r = if is_selected { NODE_RADIUS + 3.0 } else { NODE_RADIUS };
            painter.circle_filled(center, r, color);
            painter.circle_stroke(
                center,
                r,
                Stroke::new(if is_selected { 3.0 } else { 1.0 }, Color32::WHITE),
            );
            if node.dirty {
                painter.text(
                    center + Vec2::new(0.0, NODE_RADIUS + 12.0),
                    Align2::CENTER_TOP,
                    "✱",
                    FontId::proportional(14.0),
                    Color32::YELLOW,
                );
            }
            painter.text(
                center + Vec2::new(0.0, -NODE_RADIUS - 4.0),
                Align2::CENTER_BOTTOM,
                &node.sha[..node.sha.len().min(7)],
                FontId::monospace(11.0),
                Color32::from_rgb(200, 200, 210),
            );

            // hit-test
            if response.clicked() {
                if let Some(pos) = response.interact_pointer_pos() {
                    if pos.distance(center) <= r + 2.0 {
                        selected = Some(node.release_id);
                    }
                }
            }
        }
    }

    selected
}