{% extends "app/templates/base.tmpl" %}

{% block title %}
Graph Console
{% endblock %}

{% block content %}
<nav>
  <div class="title">
    <h1>GRAPH CONSOLE (VERSION: {{version}})</h1>
  </div>
</nav>
<main class="dashboard">
  <!-- flex: 1 1 0 + min-width: 0: size this .dashboard flex item from the
       viewport, never from content — content-driven growth (e.g. the G6
       canvas) would otherwise feed back into column width. -->
  <section class="widget" style="max-width: none; flex: 1 1 0; min-width: 0;">
    <p><a href="/dbg">&larr; Back to debug</a></p>

    <div style="display: flex; gap: 16px; align-items: flex-start;">
    <div style="flex: 0 0 440px; min-width: 360px;">

    <fieldset>
      <legend>Load graph in memory</legend>
      <desc>
        Projects the Penpot file into an in-memory Ladybug database for this
        admin session. Loading a new file replaces the previous one.
      </desc>
      <form id="graph-load-form" method="post" action="/dbg/actions/graph-load">
        <div class="row">
          <input type="text" style="width:420px" name="file-id"
                 placeholder="file-id"
                 value="{% if session %}{{session.file-id}}{% endif %}" />
        </div>
        <div class="row" style="display: flex; gap: 8px;">
          <input type="submit" value="Load" />
          {% if session %}
          <input type="submit" value="Unload" form="graph-unload-form" />
          {% endif %}
        </div>
      </form>
      {% if session %}
      <form id="graph-unload-form" method="post" action="/dbg/actions/graph-unload"></form>
      {% endif %}
    </fieldset>

    <fieldset>
      <legend>Files</legend>
      <desc>Teams &rarr; projects &rarr; files. Click a file to load it.</desc>
      <div id="graph-files-tree" style="font-size: 13px;">Loading&hellip;</div>
    </fieldset>

    {% if session %}
    <fieldset>
      <legend>Loaded session</legend>
      <desc>
        <p>
          File: <b><a id="graph-penpot-link" data-file-id="{{session.file-id}}"
                      target="_blank">{{session.name}}</a></b> ({{session.file-id}})<br />
          Loaded at revision: <b>{{session.revn}}</b><br />
          Graph revision: <b id="graph-sync-revn">{% if session.graph-revn %}{{session.graph-revn}}{% else %}{{session.revn}}{% endif %}</b><br />
          Graph size: <b id="graph-size">…</b><br />
          Schema: <b>{{session.schema-version}}</b><br />
          Loaded at: <b id="graph-loaded-at">{{session.loaded-at}}</b>
        </p>
        <p id="graph-sync-status">
          Feed: <b id="graph-ws-status">connecting…</b>
          <span id="graph-sync-error" style="display:none; margin-left: 1em; color: #b91c1c;"></span>
        </p>
        <form id="graph-reload-form" method="post" action="/dbg/actions/graph-reload">
          <input type="submit" value="Full reload (fallback)" />
        </form>
      </desc>
    </fieldset>

    <fieldset>
      <legend>File changes (live)</legend>
      <desc>
        Subscribes to the workspace WebSocket feed for visibility. The backend
        applies supported changes incrementally to the in-memory Ladybug graph
        via msgbus (<code>:file-change</code>).
      </desc>
      <div id="graph-changelog-empty" style="color: #666;">Waiting for changes…</div>
      <table id="graph-changelog" border="1" cellpadding="4" cellspacing="0"
             style="border-collapse: collapse; width: 100%; display: none;">
        <thead>
          <tr>
            <th>revn</th>
            <th>changes</th>
          </tr>
        </thead>
        <tbody id="graph-changelog-body"></tbody>
      </table>
    </fieldset>

    <fieldset>
      <legend>LadybugDB <a href="https://docs.ladybugdb.com/cypher/"
                            target="_blank">Cypher</a></legend>
      <form id="graph-query-form" method="post" action="/dbg/actions/graph-query">
        <div class="row">
          <textarea name="query" rows="8" style="width:100%; font-family: monospace;"
                    data-default-query="{{default-query}}">{{query}}</textarea>
        </div>
        <div class="row">
          <input type="submit" value="Run query" />
        </div>
      </form>
    </fieldset>

    <div id="graph-query-output">
      {% if error %}
      <fieldset>
        <legend>Error</legend>
        <pre>{{error}}</pre>
      </fieldset>
      {% endif %}

      {% if query-result %}
      <fieldset>
        <legend>Results ({{query-result.row-count}} rows{% if query-result.truncated? %}, truncated{% endif %})</legend>
        <div style="max-height: 45vh; overflow: auto;">
        <table border="1" cellpadding="4" cellspacing="0" style="border-collapse: collapse; width: 100%;">
          <thead>
            <tr>
              {% for column in query-result.columns %}
              <th>{{column}}</th>
              {% endfor %}
            </tr>
          </thead>
          <tbody>
            {% for row in query-result.rows %}
            <tr>
              {% for cell in row %}
              <td><code>{{cell}}</code></td>
              {% endfor %}
            </tr>
            {% endfor %}
          </tbody>
        </table>
        </div>
      </fieldset>
      {% endif %}
    </div>
    {% endif %}

    </div><!-- left column -->

    {% if session %}
    <div id="graph-view-column"
         style="flex: 1 1 auto; min-width: 0;">
      <fieldset id="graph-view-panel">
        <legend>Graph view
          <label style="margin-left: 1em; font-size: 12px; font-weight: normal;">
            <input type="checkbox" id="graph-fold-toggle" /> fold containers
          </label>
          <label style="margin-left: 1em; font-size: 12px; font-weight: normal;">
            <input type="checkbox" id="graph-animate-toggle" /> animate
          </label>
          <label style="margin-left: 1em; font-size: 12px; font-weight: normal;"
                 title="added/removed marks fade out over this many display steps (0 = off)">
            fade: <input type="number" id="graph-diff-steps" min="0" max="20"
                         style="width: 3.5em;" /> steps
          </label>
          <label style="margin-left: 1em; font-size: 12px; font-weight: normal;"
                 title="collapse every container that holds no changed elements">
            <input type="checkbox" id="graph-diff-fold" /> fold unchanged
          </label>
          <label style="margin-left: 1em; font-size: 12px; font-weight: normal;">
            layout: <select id="graph-layout-select"></select>
          </label>
        </legend>
        <desc>
          Live view of the in-memory Ladybug graph (AntV G6); the legend
          shows what is displayed. Double-click folds containers when
          folding is on.
        </desc>
        <div id="graph-legend" style="font-size: 12px; margin: 4px 0;"></div>
        <div id="graph-canvas"
             style="width: 100%; height: 600px; border: 1px solid #ccc; background: #fff; overflow: hidden;"></div>
        <div id="graph-view-status" style="color: #666; font-size: 12px;"></div>
        <div id="graph-node-inspector"
             style="display: none; font-size: 12px; margin-top: 4px; border: 1px solid #ccc;
                    padding: 6px; max-height: 40vh; overflow: auto;"></div>
        <button type="button" id="graph-render-anyway" style="display: none;">Render anyway</button>
        <button type="button" id="graph-filter-reset" style="display: none;">Show full graph</button>
      </fieldset>
    </div>
    {% endif %}

    </div><!-- flex row -->
  </section>
</main>

<style>
  #graph-view-column {
    position: sticky;
    top: 8px;
  }
  /* Fieldsets default to min-inline-size: min-content, so the panel could
     never shrink below its content and grew with the G6 canvas instead
     (content -> fieldset -> column -> canvas feedback). Let it shrink;
     the legend wraps and the canvas clips. */
  #graph-view-panel {
    min-inline-size: 0;
  }
  #graph-view-column.graph-view-expanded {
    position: fixed;
    inset: 0;
    z-index: 1000;
    background: #fff;
    overflow: auto;
    padding: 12px;
    margin: 0;
  }
  #graph-view-column.graph-view-expanded #graph-canvas {
    height: calc(100vh - 160px) !important;
  }
  /* Eye-guiding pulse on just-changed elements: DOM overlay rings over the
     canvas, independent of the G6 animation gate (big graphs render with
     animation off). Two quick beats, then gone. */
  #graph-canvas { position: relative; }
  .graph-pulse {
    position: absolute;
    border: 3px solid;
    border-radius: 50%;
    pointer-events: none;
    animation: graph-pulse 0.6s ease-out 2;
    opacity: 0;
  }
  @keyframes graph-pulse {
    0%   { transform: translate(-50%, -50%) scale(0.5); opacity: 0.9; }
    100% { transform: translate(-50%, -50%) scale(2.1); opacity: 0; }
  }
  #graph-files-tree summary { cursor: pointer; }
  #graph-files-tree ul { margin: 2px 0 4px 0; padding-left: 2em; }
  #graph-files-tree a { text-decoration: none; }
  #graph-files-tree a:hover { text-decoration: underline; }
</style>

<script>
(function () {
  const tree = document.getElementById("graph-files-tree");
  const loadForm = document.getElementById("graph-load-form");
  const loadInput = loadForm ? loadForm.querySelector("input[name=file-id]") : null;
  const penpotLink = document.getElementById("graph-penpot-link");
  if (!tree) return;

  // Make the loaded-session file name a link into the Penpot workspace.
  // The legacy /#/workspace/<project-id>/<file-id> route resolves the team
  // itself, and project-id is already in the files-tree payload; same
  // origin as this page, so no base URL to configure.
  function linkLoadedFile(teams) {
    if (!penpotLink || !penpotLink.dataset.fileId) return;
    const fileId = penpotLink.dataset.fileId;
    teams.forEach(function (team) {
      (team.projects || []).forEach(function (project) {
        (project.files || []).forEach(function (file) {
          if (file.id === fileId) {
            penpotLink.href = "/#/workspace/" + project.id + "/" + file.id;
            penpotLink.title = "Open in Penpot";
          }
        });
      });
    });
  }

  function fileLink(file) {
    const li = document.createElement("li");
    const a = document.createElement("a");
    a.href = "#";
    a.textContent = file.name;
    a.title = file.id;
    a.addEventListener("click", function (ev) {
      ev.preventDefault();
      if (loadInput) {
        loadInput.value = file.id;
        loadForm.submit();
      }
    });
    li.appendChild(a);
    return li;
  }

  fetch("/dbg/actions/graph-files")
    .then(function (resp) {
      if (!resp.ok) throw new Error("graph-files HTTP " + resp.status);
      return resp.json();
    })
    .then(function (data) {
      tree.textContent = "";
      const teams = data.teams || [];
      linkLoadedFile(teams);
      if (!teams.length) {
        tree.textContent = "No files found.";
        return;
      }
      teams.forEach(function (team) {
        const teamEl = document.createElement("details");
        const teamSummary = document.createElement("summary");
        teamSummary.textContent = team.name;
        teamEl.appendChild(teamSummary);
        (team.projects || []).forEach(function (project) {
          const projEl = document.createElement("details");
          projEl.style.marginLeft = "1em";
          const projSummary = document.createElement("summary");
          projSummary.textContent = project.name;
          projEl.appendChild(projSummary);
          const list = document.createElement("ul");
          (project.files || []).forEach(function (file) {
            list.appendChild(fileLink(file));
          });
          projEl.appendChild(list);
          teamEl.appendChild(projEl);
        });
        tree.appendChild(teamEl);
      });
    })
    .catch(function (err) {
      tree.textContent = "Failed to load file tree: " + err;
    });
})();
</script>

{% if session %}
<script src="https://cdn.jsdelivr.net/npm/@antv/g6@5/dist/g6.min.js"></script>
<script>
(function () {
  const fileId = "{{session.file-id}}";
  const sessionId = crypto.randomUUID();
  const wsScheme = location.protocol === "https:" ? "wss:" : "ws:";
  const wsUrl = wsScheme + "//" + location.host
    + "/ws/notifications?session-id=" + sessionId;

  const wsStatus = document.getElementById("graph-ws-status");
  const syncRevnEl = document.getElementById("graph-sync-revn");
  const syncErrorEl = document.getElementById("graph-sync-error");
  const changelog = document.getElementById("graph-changelog");
  const changelogBody = document.getElementById("graph-changelog-body");
  const changelogEmpty = document.getElementById("graph-changelog-empty");

  let ws = null;

  // --- G6 graph view -------------------------------------------------
  // Monochrome entity scheme: chroma = change. All entities share one
  // slate hue; *lightness* separates within-glyph siblings (validated:
  // worst within-glyph pair ΔE 17.5; the chroma floor is deliberately
  // violated — saturated color is reserved for diff marks and would
  // otherwise compete with them). Glyph class carries type identity,
  // direct labels relieve the light-step contrast; SVGRaw is the hollow
  // hexagon instead of a fourth lightness step.
  const NODE_STYLES = {
    "Document":  { color: "#14202e", glyph: "diamond",  size: 28 },
    "Page":      { color: "#2e415a", glyph: "rect",     size: 22 },
    "Frame":     { color: "#22344a", glyph: "hexagon",  size: 18 },
    "Group":     { color: "#5b7089", glyph: "hexagon",  size: 18 },
    "Boolean":   { color: "#93a4b8", glyph: "hexagon",  size: 18 },
    "SVGRaw":    { color: "#8b98a9", glyph: "hexagon",  size: 18, hollow: true },
    "Rectangle": { color: "#93a4b8", glyph: "rect",     size: 14 },
    "Circle":    { color: "#3b5069", glyph: "circle",   size: 14 },
    "Path":      { color: "#5b7089", glyph: "triangle", size: 14 },
    "Text":      { color: "#8b9cb1", glyph: "circle",   size: 14 },
    "Image":     { color: "#5b7089", glyph: "star",     size: 14 },
    "Component": { color: "#8195ab", glyph: "diamond",  size: 20 }
  };
  const FALLBACK_STYLE = { color: "#5b7089", glyph: "circle", size: 14 };
  // Edge style keyed on rel (wire field since slice-3); future edge
  // attributes can feed styling the same way. All rels stay grey (chroma
  // belongs to diff marks); identity comes from `sym`, a compact unicode
  // rel label rendered mid-edge (abacus viewer EDGE_SYM convention) —
  // dash variants alone cannot carry the growing rel roster. IsChildOf
  // is the unlabeled default (the background tree structure).
  // `sym` may be a full rel name: no compact glyph reads as "derived from
  // a template" (∈ wrongly connotes membership), so IsInstanceOf spells
  // itself out; the legend falls back to an arrow for long syms. No
  // dashed edges — the label alone carries rel identity.
  const EDGE_STYLES = {
    "IsChildOf":    { stroke: "#b3b0a8" },
    "IsInstanceOf": { stroke: "#8b98a9", sym: "IsInstanceOf" }
  };
  const FALLBACK_EDGE_STYLE = { stroke: "#b3b0a8" };
  // --- graph diff: add/remove marks with step fade --------------------
  // A "step" is a display-changing refetch (no-op skips age nothing).
  // Added elements get a green halo; removed ones stay in the display as
  // ghosts with a dashed crimson halo and fading opacity (dash + fade
  // carry the added/removed distinction for red-green CVD; the pair
  // validates at deutan ΔE 17.4). Marks fade linearly with age and drop
  // after N steps; N comes from the "fade" box (0 disables the feature).
  // The diff is vs the previous display step, not between arbitrary
  // revisions — true version-to-version diffs await server deltas / the
  // graph-based-VCS work.
  const DIFF_ADDED_COLOR = "#40c057";
  const DIFF_REMOVED_COLOR = "#c2255c";
  let diffMarks = { nodes: {}, edges: {} };

  function diffSteps() {
    const v = parseInt(localStorage.getItem("graph-diff-steps"), 10);
    return Number.isFinite(v) && v >= 0 && v <= 20 ? v : 3;
  }

  function diffEdgeKey(source, rel, target) {
    return source + "|" + (rel || "IsChildOf") + "|" + target;
  }

  function liveMark(marks, key) {
    const m = marks[key];
    return m && m.age < diffSteps() ? m : null;
  }

  // 1.0 at age 0 down to 1/N at age N-1; the mark drops at age N.
  function diffFade(mark) {
    return 1 - mark.age / diffSteps();
  }

  function markDiff(prev, next) {
    if (!diffSteps() || !prev) {
      diffMarks = { nodes: {}, edges: {} };
      return;
    }
    [diffMarks.nodes, diffMarks.edges].forEach(function (marks) {
      Object.keys(marks).forEach(function (k) {
        marks[k].age += 1;
        if (marks[k].age >= diffSteps()) delete marks[k];
      });
    });
    const prevNodes = {};
    prev.nodes.forEach(function (n) { prevNodes[n.id] = n; });
    const nextNodes = {};
    next.nodes.forEach(function (n) { nextNodes[n.id] = n; });
    next.nodes.forEach(function (n) {
      if (!prevNodes[n.id]) diffMarks.nodes[n.id] = { kind: "added", age: 0 };
    });
    prev.nodes.forEach(function (n) {
      if (!nextNodes[n.id]) diffMarks.nodes[n.id] = { kind: "removed", age: 0, node: n };
    });
    const prevEdges = {};
    prev.edges.forEach(function (e) { prevEdges[diffEdgeKey(e.source, e.rel, e.target)] = e; });
    const nextEdges = {};
    next.edges.forEach(function (e) { nextEdges[diffEdgeKey(e.source, e.rel, e.target)] = e; });
    Object.keys(nextEdges).forEach(function (k) {
      if (!prevEdges[k]) diffMarks.edges[k] = { kind: "added", age: 0 };
    });
    Object.keys(prevEdges).forEach(function (k) {
      if (!nextEdges[k]) diffMarks.edges[k] = { kind: "removed", age: 0, edge: prevEdges[k] };
    });
  }

  // Removed elements stay displayed as fading ghosts until their mark
  // expires. Ghosts respect the query filter and re-enter layout and
  // combo derivation through their ghost IsChildOf edges, so they keep
  // their old place in the tree while fading.
  function withGhosts(data) {
    const nodes = data.nodes.slice();
    const present = {};
    nodes.forEach(function (n) { present[n.id] = true; });
    Object.keys(diffMarks.nodes).forEach(function (id) {
      const m = liveMark(diffMarks.nodes, id);
      if (m && m.kind === "removed" && m.node && !present[id]
          && (!graphFilterIds || graphFilterIds.has(id))) {
        nodes.push(m.node);
        present[id] = true;
      }
    });
    const edges = data.edges.slice();
    const have = {};
    edges.forEach(function (e) { have[diffEdgeKey(e.source, e.rel, e.target)] = true; });
    Object.keys(diffMarks.edges).forEach(function (k) {
      const m = liveMark(diffMarks.edges, k);
      if (m && m.kind === "removed" && m.edge && !have[k]
          && present[m.edge.source] && present[m.edge.target]) {
        edges.push(m.edge);
      }
    });
    return { nodes: nodes, edges: edges, revn: data.revn, truncated: data.truncated };
  }

  function nodeMark(id) {
    return liveMark(diffMarks.nodes, id);
  }

  function edgeMark(d) {
    return liveMark(diffMarks.edges, diffEdgeKey(d.source, d.data.rel, d.target));
  }

  function diffColor(m) {
    return m.kind === "added" ? DIFF_ADDED_COLOR : DIFF_REMOVED_COLOR;
  }

  function anyLiveMarks() {
    return Object.keys(diffMarks.nodes).some(function (k) { return liveMark(diffMarks.nodes, k); })
      || Object.keys(diffMarks.edges).some(function (k) { return liveMark(diffMarks.edges, k); });
  }

  // Node ids touched by live marks: marked nodes plus the endpoints of
  // marked edges (edge keys are "src|rel|tgt").
  function liveMarkedNodeIds() {
    const ids = new Set();
    Object.keys(diffMarks.nodes).forEach(function (id) {
      if (liveMark(diffMarks.nodes, id)) ids.add(id);
    });
    Object.keys(diffMarks.edges).forEach(function (k) {
      if (liveMark(diffMarks.edges, k)) {
        const parts = k.split("|");
        ids.add(parts[0]);
        ids.add(parts[2]);
      }
    });
    return ids;
  }

  function diffFoldEnabled() {
    return localStorage.getItem("graph-diff-fold") === "1";
  }

  // One-shot pulse rings on age-0 marks, placed ~post-render (positions
  // are sampled once; pulses don't track pan/zoom during their ~1.2 s).
  function pulseAt(canvasPoint, color, sizePx) {
    const host = document.getElementById("graph-canvas");
    if (!host || !g6graph) return;
    const vp = g6graph.getViewportByCanvas(canvasPoint);
    const el = document.createElement("div");
    el.className = "graph-pulse";
    el.style.borderColor = color;
    el.style.left = vp[0] + "px";
    el.style.top = vp[1] + "px";
    el.style.width = sizePx + "px";
    el.style.height = sizePx + "px";
    host.appendChild(el);
    setTimeout(function () { el.remove(); }, 1400);
  }

  function schedulePulses() {
    if (!diffSteps()) return;
    setTimeout(function () {
      if (!g6graph) return;
      let zoom = 1;
      try { zoom = g6graph.getZoom() || 1; } catch (_err) {}
      Object.keys(diffMarks.nodes).forEach(function (id) {
        const m = diffMarks.nodes[id];
        if (!m || m.age !== 0) return;
        try {
          const p = g6graph.getElementPosition(id);
          pulseAt([p[0], p[1]], diffColor(m),
                  Math.max(18, Math.min(64, 26 * zoom)));
        } catch (_err) { /* hidden in a collapsed combo or gone */ }
      });
      Object.keys(diffMarks.edges).forEach(function (k) {
        const m = diffMarks.edges[k];
        if (!m || m.age !== 0) return;
        const parts = k.split("|");
        try {
          const a = g6graph.getElementPosition(parts[0]);
          const b = g6graph.getElementPosition(parts[2]);
          pulseAt([(a[0] + b[0]) / 2, (a[1] + b[1]) / 2], diffColor(m),
                  Math.max(14, Math.min(48, 18 * zoom)));
        } catch (_err) { /* endpoint hidden or gone */ }
      });
    }, 300);
  }
  // --- end graph diff --------------------------------------------------
  // Legend glyph characters mirroring the G6 node types above.
  const GLYPH_CHARS = { diamond: "◆", rect: "■", hexagon: "⬢",
                        circle: "●", triangle: "▲", star: "★" };
  // Above this many nodes the view is not rendered automatically; the
  // "Render anyway" button forces it (~1.5 s per 2k nodes, measured).
  const RENDER_GUARD_NODES = 4000;
  // G6's entrance/update animation is nice didactics on small graphs but
  // the performance killer at scale (>2 min at 1700 nodes vs ~1.5 s off);
  // keep it only below this node count.
  const ANIMATE_MAX_NODES = 100;
  const LAYOUT_XS = 40;   // horizontal leaf slot spacing
  const LAYOUT_YS = 70;   // vertical rank (depth) spacing

  // Layout dropdown source of truth: name -> G6 layout config, or null for
  // the built-in O(n) tree layout (preset positions from treePositions,
  // fastest, exploits IsChildOf being a tree). The <select> is populated
  // from these keys; add/remove/tune entries here. Pruned 2026-07-16:
  // grid/random/force/fruchterman/force-atlas2 added nothing over this
  // set. combo-combined is the only combo-aware layout: it lays out each
  // combo's members internally, then treats every combo as one super-node
  // in an outer force pass. Non-hierarchical layouts carry overlap
  // parameters (preventOverlap ignores label extents — see
  // DENSE_LABEL_LAYOUTS).
  const LAYOUTS = {
    "tree":          null,
    "antv-dagre":    { type: "antv-dagre", rankdir: "BT", nodesep: 10, ranksep: 40, sortByCombo: true },
    "dagre":         { type: "dagre", rankdir: "BT" },
    "circular":      { type: "circular" },
    "concentric":    { type: "concentric", preventOverlap: true, nodeSize: 32, nodeSpacing: 12 },
    "radial":        { type: "radial", preventOverlap: true, nodeSize: 32, unitRadius: 90 },
    "d3-force":      { type: "d3-force", collide: { radius: 26 } },
    "combo-combined": { type: "combo-combined" }
  };
  const DEFAULT_LAYOUT = "tree";
  // Always-on labels are the residual overlap driver on ring/stress
  // layouts (their collision handling ignores label extents), so these
  // get smaller labels; the hover tooltip carries full identity anywhere.
  const DENSE_LABEL_LAYOUTS = {
    "concentric": true, "radial": true, "d3-force": true
  };

  const graphViewStatus = document.getElementById("graph-view-status");
  let g6graph = null;
  let g6graphLayout = null;
  let g6graphAnimated = null;
  let refetchTimer = null;
  let lastGraphData = null;
  let lastGraphSig = null;
  let renderForced = false;
  let graphFilterIds = null;

  function currentLayoutName() {
    const stored = localStorage.getItem("graph-layout");
    return Object.prototype.hasOwnProperty.call(LAYOUTS, stored) ? stored : DEFAULT_LAYOUT;
  }

  function nodeStyle(table) {
    return NODE_STYLES[table] || FALLBACK_STYLE;
  }

  function edgeStyle(rel) {
    return EDGE_STYLES[rel] || FALLBACK_EDGE_STYLE;
  }

  function comboIdFor(nodeId) {
    return "combo:" + nodeId;
  }

  function foldEnabled() {
    return localStorage.getItem("graph-fold-containers") !== "0";
  }

  // Off ⇒ animation disabled unconditionally, incl. small graphs (the
  // adaptive ≤ ANIMATE_MAX_NODES rule only applies when this is on).
  function animateEnabled() {
    return localStorage.getItem("graph-animate") !== "0";
  }

  // IsChildOf is a tree, so an O(n) tidy layout replaces a generic DAG
  // layout: depth = rank (y), post-order leaf slots = x, parents centered
  // over their children. antv-dagre needed ~7 s at 1700 nodes; this is free.
  function treePositions(nodes, parentOf, childrenOf) {
    const pos = {};
    let slot = 0;
    function place(id, depth) {
      const kids = childrenOf[id] || [];
      if (!kids.length) {
        pos[id] = { x: slot * LAYOUT_XS, y: depth * LAYOUT_YS };
        slot += 1;
        return;
      }
      kids.forEach(function (k) { place(k, depth + 1); });
      const xs = kids.map(function (k) { return pos[k].x; });
      pos[id] = { x: (Math.min.apply(null, xs) + Math.max.apply(null, xs)) / 2,
                  y: depth * LAYOUT_YS };
      slot += 1; // breathing room between adjacent subtrees
    }
    nodes.forEach(function (n) {
      if (!parentOf[n.id]) place(n.id, 0);
    });
    return pos;
  }

  function toG6Data(data, collapsedIds, withCombos, presetPositions, diffFold) {
    const nodes = data.nodes || [];
    const edges = (data.edges || [])
      .slice()
      .sort(function (a, b) { return (a.position || 0) - (b.position || 0); });
    // Hierarchy (tree ranking, combo derivation, fold-ability) comes from
    // IsChildOf only — still a tree by construction. Other rels
    // (IsInstanceOf, …) are overlay edges drawn between positioned nodes.
    const parentOf = {};
    const childrenOf = {};
    edges.forEach(function (e) {
      if ((e.rel || "IsChildOf") !== "IsChildOf") return;
      parentOf[e.source] = e.target;
      (childrenOf[e.target] = childrenOf[e.target] || []).push(e.source);
    });
    // Preset positions only for the built-in tree layout; under a G6
    // layout they would make animated renders flash tree-then-layout.
    const pos = presetPositions ? treePositions(nodes, parentOf, childrenOf) : null;
    // Foldable = has children and has a parent: the IsChildOf root of the
    // loaded graph (today a Document, later maybe a Project or Team) is
    // never a combo — folding the whole graph is useless. Empty containers
    // stay plain nodes.
    const hasCombo = {};
    if (withCombos) {
      nodes.forEach(function (n) {
        if ((childrenOf[n.id] || []).length && parentOf[n.id]) hasCombo[n.id] = true;
      });
    }
    // Diff-fold: derive fold state from the live marks instead of the
    // instance — every combo collapses except those on an ancestor path
    // of (or being) a changed element, so changes stand out of the
    // unchanged mass. Manual double-click fold state is ignored while on.
    if (diffFold && withCombos) {
      collapsedIds = new Set();
      Object.keys(hasCombo).forEach(function (id) { collapsedIds.add(comboIdFor(id)); });
      liveMarkedNodeIds().forEach(function (id) {
        if (hasCombo[id]) collapsedIds.delete(comboIdFor(id));
        let p = parentOf[id];
        while (p) {
          if (hasCombo[p]) collapsedIds.delete(comboIdFor(p));
          p = parentOf[p];
        }
      });
    }
    const combos = [];
    nodes.forEach(function (n) {
      if (!hasCombo[n.id]) return;
      const combo = { id: comboIdFor(n.id), data: { label: n.label, table: n.table } };
      const p = parentOf[n.id];
      if (p && hasCombo[p]) combo.combo = comboIdFor(p);
      // Explicit boolean both ways: setData merges datum props by id on a
      // live instance, so omitting `collapsed` would retain a previous
      // `true` — a change inside a folded combo could then never expand it
      // (the fold-unchanged bug).
      combo.style = { collapsed: !!(collapsedIds && collapsedIds.has(combo.id)) };
      combos.push(combo);
    });
    const g6nodes = nodes.map(function (n) {
      const out = { id: n.id,
                    data: { label: n.label, table: n.table } };
      if (pos) {
        const p = pos[n.id] || { x: 0, y: 0 };
        out.style = { x: p.x, y: p.y };
      }
      if (hasCombo[n.id]) {
        out.combo = comboIdFor(n.id);
      } else if (parentOf[n.id] && hasCombo[parentOf[n.id]]) {
        out.combo = comboIdFor(parentOf[n.id]);
      }
      return out;
    });
    const g6edges = edges.map(function (e) {
      return { source: e.source, target: e.target,
               data: { position: e.position, rel: e.rel || "IsChildOf" } };
    });
    return { nodes: g6nodes, edges: g6edges, combos: combos };
  }

  function collapsedComboIds() {
    if (!g6graph) return new Set();
    try {
      return new Set(g6graph.getComboData()
        .filter(function (c) { return c.style && c.style.collapsed; })
        .map(function (c) { return c.id; }));
    } catch (_err) {
      return new Set();
    }
  }

  function renderGraph(g6data) {
    const layoutName = currentLayoutName();
    const animate = animateEnabled() && g6data.nodes.length <= ANIMATE_MAX_NODES;
    if (g6graph && (g6graphLayout !== layoutName || g6graphAnimated !== animate)) {
      // Layout or animation-mode switch: recreate the graph (cheap);
      // neither is swappable on a live instance.
      try { g6graph.destroy(); } catch (_err) {}
      g6graph = null;
    }
    if (g6graph) {
      g6graph.setData(g6data);
      return g6graph.render().catch(function (_err) {
        /* instance may be destroyed mid-render on rapid toggle/layout switches */
      });
    }
    g6graphLayout = layoutName;
    g6graphAnimated = animate;
    const layoutCfg = LAYOUTS[layoutName];
    const opts = {
      container: "graph-canvas",
      data: g6data,
      autoFit: "view",
      animation: animate,
      padding: 20,
      node: {
        type: function (d) { return nodeStyle(d.data.table).glyph; },
        style: {
          size: function (d) { return nodeStyle(d.data.table).size; },
          fill: function (d) {
            const s = nodeStyle(d.data.table);
            return s.hollow ? "#ffffff" : s.color;
          },
          // Unmarked nodes carry no stroke (hollow ones keep a thin one as
          // their identity); the stroke channel belongs to diff marks:
          // thick colored ring, dashed for removals (the CVD-safe cue).
          stroke: function (d) {
            const m = nodeMark(d.id);
            return m ? diffColor(m) : nodeStyle(d.data.table).color;
          },
          lineWidth: function (d) {
            if (nodeMark(d.id)) return 2.5;
            return nodeStyle(d.data.table).hollow ? 1.5 : 0;
          },
          lineDash: function (d) {
            const m = nodeMark(d.id);
            return m && m.kind === "removed" ? [3, 3] : 0;
          },
          labelText: function (d) { return d.data.label; },
          labelFontSize: function () {
            return DENSE_LABEL_LAYOUTS[currentLayoutName()] ? 7 : 9;
          },
          labelFill: "#0b0b0b",
          labelPlacement: "bottom",
          halo: function (d) { return !!nodeMark(d.id); },
          haloStroke: function (d) {
            const m = nodeMark(d.id);
            return m ? diffColor(m) : "#ffffff";
          },
          haloLineWidth: 12,
          haloStrokeOpacity: function (d) {
            const m = nodeMark(d.id);
            return m ? 0.35 * diffFade(m) : 0;
          },
          opacity: function (d) {
            const m = nodeMark(d.id);
            return m && m.kind === "removed" ? diffFade(m) : 1;
          },
          labelOpacity: function (d) {
            const m = nodeMark(d.id);
            return m && m.kind === "removed" ? diffFade(m) : 1;
          }
        }
      },
      edge: {
        style: {
          stroke: function (d) {
            const m = edgeMark(d);
            return m ? diffColor(m) : edgeStyle(d.data.rel).stroke;
          },
          lineDash: function (d) { return edgeStyle(d.data.rel).lineDash; },
          lineWidth: function (d) {
            const m = edgeMark(d);
            return m ? (m.kind === "removed" ? 2.5 : 2) : 1;
          },
          strokeOpacity: function (d) {
            const m = edgeMark(d);
            return m ? Math.max(diffFade(m), 0.15) : 1;
          },
          labelText: function (d) { return edgeStyle(d.data.rel).sym || ""; },
          labelFontSize: 7,
          labelFill: "#52514e",
          labelBackground: true,
          labelBackgroundFill: "#ffffff",
          labelBackgroundOpacity: 0.75,
          endArrow: true,
          endArrowSize: 6
        }
      },
      combo: {
        type: "rect",
        style: {
          labelText: function (d) { return d.data.label; },
          labelFontSize: 9,
          labelFill: "#52514e",
          labelPlacement: "top",
          stroke: function (d) { return nodeStyle(d.data.table).color; },
          lineWidth: 1,
          fillOpacity: 0.03,
          radius: 4
        }
      },
      behaviors: ["zoom-canvas", "drag-canvas", "drag-element", "collapse-expand"],
      plugins: [{
        key: "toolbar",
        type: "toolbar",
        position: "top-left",
        getItems: function () {
          return [
            { id: "auto-fit", value: "auto-fit" },
            { id: "request-fullscreen", value: "expand" },
            { id: "exit-fullscreen", value: "restore" },
            { id: "export", value: "export-png" }
          ];
        },
        onClick: function (value) {
          if (value === "auto-fit") {
            if (g6graph) g6graph.fitView();
          } else if (value === "expand") {
            setExpanded(true);
          } else if (value === "restore") {
            setExpanded(false);
          } else if (value === "export-png") {
            exportGraphPng();
          }
        }
      }, {
        key: "tooltip",
        type: "tooltip",
        getContent: function (_evt, items) {
          return Promise.resolve(items.map(function (it) {
            const d = it.data || {};
            return "<div><b>" + escapeHtml(d.table || "") + "</b> "
              + escapeHtml(d.label || "") + "<br/><code>"
              + escapeHtml(String(it.id)) + "</code></div>";
          }).join(""));
        }
      }]
    };
    if (layoutCfg) opts.layout = layoutCfg;
    g6graph = new G6.Graph(opts);
    // Re-attached on every instance creation (layout/animation switches
    // destroy and recreate the graph).
    g6graph.on("node:click", function (e) {
      const id = e.target && e.target.id;
      if (id) showNodeInspector(String(id));
    });
    return g6graph.render().catch(function (_err) {
      /* see above */
    });
  }

  // Hand-rolled on purpose: the G6 legend plugin substitutes its own
  // marker set (hexagon→circle, star→cross), breaking glyph identity.
  // Entries reflect the *displayed* data only: node tables in roster
  // order (unknown tables appended with the fallback style), then rels.
  // Clean graph-only capture (no page chrome): the whole laid-out graph
  // regardless of viewport, downloaded as PNG. Also the fast path for
  // agents debugging the console — no full-page screenshot needed.
  function exportGraphPng() {
    if (!g6graph) return;
    g6graph.toDataURL({ mode: "overall" })
      .then(function (dataUrl) {
        const a = document.createElement("a");
        a.href = dataUrl;
        a.download = "graph-" + (lastGraphData ? lastGraphData.revn : "view") + ".png";
        a.click();
      })
      .catch(function (err) {
        graphViewStatus.textContent = "export error: " + err;
      });
  }

  function renderGraphLegend(data) {
    const el = document.getElementById("graph-legend");
    if (!el) return;
    const tables = {};
    (data.nodes || []).forEach(function (n) { tables[n.table] = true; });
    const rels = {};
    (data.edges || []).forEach(function (e) { rels[e.rel || "IsChildOf"] = true; });
    function nodeItem(table, s) {
      return '<span style="margin-right: 1em; white-space: nowrap;">'
        + '<span style="color: ' + s.color + '; font-size: 14px;">'
        + (s.hollow ? "⬡" : (GLYPH_CHARS[s.glyph] || "●")) + '</span> '
        + escapeHtml(table) + "</span>";
    }
    const items = Object.keys(NODE_STYLES)
      .filter(function (t) { return tables[t]; })
      .map(function (t) { return nodeItem(t, NODE_STYLES[t]); });
    Object.keys(tables).sort().forEach(function (t) {
      if (!NODE_STYLES[t]) items.push(nodeItem(t, FALLBACK_STYLE));
    });
    Object.keys(rels).sort().forEach(function (rel) {
      const s = edgeStyle(rel);
      const glyph = (s.sym && s.sym.length <= 2) ? s.sym : (s.lineDash ? "⇢" : "→");
      items.push('<span style="margin-right: 1em; white-space: nowrap;">'
        + '<span style="color: ' + s.stroke + '; font-size: 14px;">'
        + escapeHtml(glyph) + '</span> '
        + escapeHtml(rel) + "</span>");
    });
    if (anyLiveMarks()) {
      items.push('<span style="margin-right: 1em; white-space: nowrap;">'
        + '<span style="color: ' + DIFF_ADDED_COLOR + '; font-size: 14px;">+</span>'
        + ' added</span>');
      items.push('<span style="white-space: nowrap;">'
        + '<span style="color: ' + DIFF_REMOVED_COLOR + '; font-size: 14px;">−</span>'
        + ' removed</span>');
    }
    // join with a space: the spans are nowrap, so the separator is the
    // only soft-wrap opportunity in the legend row
    el.innerHTML = items.join(" ");
  }

  function graphStatusText(data) {
    return data.nodes.length + " nodes, " + data.edges.length + " edges"
      + " (graph revn " + data.revn + ")"
      + (data.truncated ? " — WARNING: truncated at row cap, view is partial" : "");
  }

  // Query filter: induced subgraph of the already-exported graph, selected
  // by node ids found in the last Cypher result. No reconstruction from the
  // query result is needed — ids are enough to slice the cached export.
  function filteredGraphData() {
    if (!graphFilterIds) return lastGraphData;
    const keep = {};
    const nodes = lastGraphData.nodes.filter(function (n) {
      if (graphFilterIds.has(n.id)) { keep[n.id] = true; return true; }
      return false;
    });
    const edges = lastGraphData.edges.filter(function (e) {
      return keep[e.source] && keep[e.target];
    });
    return { nodes: nodes, edges: edges,
             revn: lastGraphData.revn, truncated: lastGraphData.truncated };
  }

  function applyQueryFilter(ids) {
    if (!lastGraphData) return;
    const present = new Set();
    lastGraphData.nodes.forEach(function (n) { if (ids.has(n.id)) present.add(n.id); });
    if (!present.size) {
      graphViewStatus.textContent = "query result matches no nodes in the loaded graph";
      return;
    }
    graphFilterIds = present;
    renderCurrent();
  }

  function renderCurrent() {
    if (!lastGraphData) return;
    const data = filteredGraphData();
    const shown = withGhosts(data);
    renderGraphLegend(shown);
    const anywayBtn = document.getElementById("graph-render-anyway");
    const filterBtn = document.getElementById("graph-filter-reset");
    if (filterBtn) filterBtn.style.display = graphFilterIds ? "inline" : "none";
    const filterNote = graphFilterIds
      ? " — query filter: " + data.nodes.length + " of "
        + lastGraphData.nodes.length + " nodes"
      : "";
    if (shown.nodes.length > RENDER_GUARD_NODES && !renderForced) {
      graphViewStatus.textContent =
        graphStatusText(data) + filterNote + " — too large to render automatically";
      if (anywayBtn) anywayBtn.style.display = "inline";
      return;
    }
    if (anywayBtn) anywayBtn.style.display = "none";
    graphViewStatus.textContent = graphStatusText(data) + filterNote;
    renderGraph(toG6Data(shown, collapsedComboIds(), foldEnabled() || diffFoldEnabled(),
                         LAYOUTS[currentLayoutName()] == null, diffFoldEnabled()));
  }

  function refetchGraph() {
    if (typeof G6 === "undefined") {
      graphViewStatus.textContent = "G6 failed to load (CDN unreachable)";
      return;
    }
    fetch("/dbg/actions/graph-data")
      .then(function (resp) {
        if (resp.status === 404) {
          throw new Error("no graph session (backend restarted?) — reload a file");
        }
        if (!resp.ok) throw new Error("graph-data HTTP " + resp.status);
        return resp.json();
      })
      .then(function (data) {
        // Session-fieldset size line stays live even through skipped
        // repaints (unlike the status line under the canvas). The MiB
        // figure is a resident-size estimate fitted to the measurements
        // in graph_sizes.md: ≈1.1 MiB session floor + ≈5.4 KiB per node
        // (full-schema projection); hover shows per-table counts.
        const sizeEl = document.getElementById("graph-size");
        if (sizeEl) {
          const mib = 1.1 + data.nodes.length * 5.4 / 1024;
          sizeEl.textContent = data.nodes.length + " nodes, "
            + data.edges.length + " edges (≈" + mib.toFixed(1) + " MiB)";
          const counts = {};
          data.nodes.forEach(function (n) {
            counts[n.table] = (counts[n.table] || 0) + 1;
          });
          sizeEl.title = Object.keys(counts).sort().map(function (t) {
            return t + "=" + counts[t];
          }).join(", ") + " — MiB ≈ 1.1 + 5.4 KiB × nodes (measured fit)";
        }
        // Skip the repaint when the display projection is unchanged: a
        // change burst that only touches non-projected attrs (e.g. moving
        // shapes around) bumps revn but not the picture.
        const sig = JSON.stringify([data.nodes, data.edges, data.truncated]);
        if (sig === lastGraphSig) {
          lastGraphData = data;
          return;
        }
        markDiff(lastGraphData, data);
        lastGraphData = data;
        lastGraphSig = sig;
        renderCurrent();
        schedulePulses();
      })
      .catch(function (err) {
        graphViewStatus.textContent = "graph view error: " + err;
      });
  }

  // --- node inspector --------------------------------------------------
  // Click a node → its full attribute row from the graph DB, rendered in
  // a panel under the canvas. Panel over tooltip: the projected tables
  // carry ~80 columns — too much for a tooltip, and the panel persists
  // for side-by-side reading without obstructing the graph.
  function runConsoleQuery(query) {
    const formData = new FormData();
    formData.append("query", query);
    return fetch("/dbg/actions/graph-query", {
      method: "POST",
      headers: { "Accept": "application/json" },
      body: formData
    })
      .then(function (resp) { return resp.text(); })
      .then(function (text) { return parseTransitMap(JSON.parse(text)); });
  }

  function showNodeInspector(id) {
    const panel = document.getElementById("graph-node-inspector");
    if (!panel || !g6graph) return;
    let datum = null;
    try { datum = g6graph.getNodeData(id); } catch (_err) { return; }
    const table = datum && datum.data && datum.data.table;
    const label = (datum && datum.data && datum.data.label) || "";
    // Both values are interpolated into Cypher — accept only what our own
    // export produces (bare table names, UUID ids).
    if (!table || !/^[A-Za-z]+$/.test(table)) return;
    if (!/^[0-9a-f-]{36}$/i.test(id)) return;
    panel.style.display = "block";
    panel.textContent = "loading " + id + "…";
    runConsoleQuery("MATCH (n:`" + table + "` {id: uuid('" + id + "')}) RETURN n.*;")
      .then(function (data) {
        if (data.error) {
          panel.textContent = "inspector error: " + data.error;
          return;
        }
        const result = data["query-result"];
        const rows = (result && result.rows) || [];
        let html = '<div style="display: flex; justify-content: space-between;">'
          + "<b>" + escapeHtml(table) + " " + escapeHtml(label) + "</b>"
          + '<button type="button" id="graph-inspector-close">close</button></div>'
          + '<div style="color: #666;">' + escapeHtml(id) + "</div>";
        if (!rows.length) {
          html += "<div>not in the graph DB (removed?)</div>";
        } else {
          const columns = result.columns || [];
          let hidden = 0;
          html += '<table border="1" cellpadding="2" cellspacing="0"'
            + ' style="border-collapse: collapse; margin-top: 4px;">';
          columns.forEach(function (col, i) {
            const val = rows[0][i];
            // Ladybug's value->clj fallback renders SQL nulls as "NULL".
            if (val === null || val === undefined || val === "" || val === "NULL") {
              hidden += 1;
              return;
            }
            html += "<tr><td><code>" + escapeHtml(col.replace(/^n\./, ""))
              + "</code></td><td><code>" + escapeHtml(String(val))
              + "</code></td></tr>";
          });
          html += "</table>";
          if (hidden) {
            html += '<div style="color: #666;">' + hidden + " empty attrs hidden</div>";
          }
        }
        panel.innerHTML = html;
        document.getElementById("graph-inspector-close")
          .addEventListener("click", function () { panel.style.display = "none"; });
      })
      .catch(function (err) {
        panel.textContent = "inspector error: " + err;
      });
  }
  // --- end node inspector ----------------------------------------------

  function scheduleGraphRefetch() {
    if (refetchTimer) clearTimeout(refetchTimer);
    refetchTimer = setTimeout(function () {
      refetchTimer = null;
      refetchGraph();
    }, 400);
  }
  // --- end G6 graph view ---------------------------------------------

  function encodeTransitUuid(uuid) {
    return "~u" + uuid;
  }

  function encodeSubscribe(fileId) {
    return JSON.stringify({
      "~:type": "~:subscribe-file",
      "~:file-id": encodeTransitUuid(fileId)
    });
  }

  function encodeUnsubscribe(fileId) {
    return JSON.stringify({
      "~:type": "~:unsubscribe-file",
      "~:file-id": encodeTransitUuid(fileId)
    });
  }

  function parseTransitValue(value) {
    if (typeof value === "string") {
      if (value.startsWith("~:")) return value.slice(2);
      if (value.startsWith("~u")) return value.slice(2);
    }
    if (Array.isArray(value)) return value.map(parseTransitValue);
    if (value && typeof value === "object") return parseTransitMap(value);
    return value;
  }

  function parseTransitMap(obj) {
    const out = {};
    for (const [key, value] of Object.entries(obj)) {
      const name = key.startsWith("~:") ? key.slice(2) : key;
      out[name] = parseTransitValue(value);
    }
    return out;
  }

  function summarizeChange(change) {
    const parts = [change.type];
    if (change.id) parts.push("id=" + change.id);
    if (change.obj && change.obj.type) parts.push("shape=" + change.obj.type);
    if (change.operations && change.operations.length) {
      const attrs = change.operations
        .map(function (op) { return op.attr; })
        .filter(Boolean);
      if (attrs.length) parts.push("attrs=" + attrs.join(","));
    }
    return parts.join(" ");
  }

  function summarizeChanges(changes) {
    if (!changes || !changes.length) return "(empty)";
    return changes.map(summarizeChange).join("; ");
  }

  function summarizeSkipped(skipped) {
    if (!skipped) return "";
    const items = Array.isArray(skipped) ? skipped : [skipped];
    return items.map(function (item) {
      if (!item || typeof item !== "object") return String(item);
      const type = item.type || "unknown";
      const reason = item.reason ? " (" + item.reason + ")" : "";
      return String(type) + reason;
    }).join("; ");
  }

  function refreshSyncStatus() {
    fetch("/dbg/actions/graph-sync-status")
      .then(function (resp) { return resp.text(); })
      .then(function (text) {
        const status = parseTransitMap(JSON.parse(text));
        if (status["graph-revn"] !== undefined) {
          syncRevnEl.textContent = String(status["graph-revn"]);
        }
        if (status.sync && status.sync.error) {
          syncErrorEl.style.display = "inline";
          syncErrorEl.textContent = "sync error: " + status.sync.error;
        } else if (status.sync && status.sync["last-skipped"]
                   && summarizeSkipped(status.sync["last-skipped"])) {
          syncErrorEl.style.display = "inline";
          syncErrorEl.textContent =
            "some changes skipped: "
            + summarizeSkipped(status.sync["last-skipped"])
            + " (use full reload if needed)";
        } else {
          syncErrorEl.style.display = "none";
          syncErrorEl.textContent = "";
        }
      })
      .catch(function () {});
  }

  function appendChange(revn, summary) {
    changelogEmpty.style.display = "none";
    changelog.style.display = "table";

    const row = document.createElement("tr");
    const revnCell = document.createElement("td");
    const changesCell = document.createElement("td");

    revnCell.textContent = String(revn);
    changesCell.textContent = summary;
    row.appendChild(revnCell);
    row.appendChild(changesCell);
    changelogBody.appendChild(row);
    row.scrollIntoView({ block: "nearest" });
  }

  function handleMessage(raw) {
    let msg;
    try {
      msg = parseTransitMap(JSON.parse(raw));
    } catch (_err) {
      return;
    }

    if (msg.type !== "file-change" || msg["file-id"] !== fileId) return;

    appendChange(msg.revn, summarizeChanges(msg.changes));
    setTimeout(refreshSyncStatus, 150);
    scheduleGraphRefetch();
  }

  function subscribe() {
    if (ws && ws.readyState === WebSocket.OPEN) {
      ws.send(encodeSubscribe(fileId));
    }
  }

  let wsClosing = false;
  let wsReconnectTimer = null;

  function scheduleReconnect() {
    if (wsClosing || wsReconnectTimer) return;
    wsReconnectTimer = setTimeout(function () {
      wsReconnectTimer = null;
      connect();
    }, 3000);
  }

  function connect() {
    ws = new WebSocket(wsUrl);
    wsStatus.textContent = "connecting…";

    ws.addEventListener("open", function () {
      wsStatus.textContent = "subscribed";
      subscribe();
      // catch up on anything missed while disconnected
      refreshSyncStatus();
      scheduleGraphRefetch();
    });

    ws.addEventListener("message", function (event) {
      handleMessage(event.data);
    });

    ws.addEventListener("close", function () {
      wsStatus.textContent = wsClosing ? "disconnected" : "disconnected — retrying…";
      scheduleReconnect();
    });

    ws.addEventListener("error", function () {
      wsStatus.textContent = "error";
    });
  }

  function escapeHtml(text) {
    return String(text)
      .replace(/&/g, "&amp;")
      .replace(/</g, "&lt;")
      .replace(/>/g, "&gt;")
      .replace(/"/g, "&quot;");
  }

  function renderQueryOutput(data) {
    const output = document.getElementById("graph-query-output");
    if (!output) return;

    if (data.error) {
      output.innerHTML =
        "<fieldset><legend>Error</legend>"
        + "<pre>" + escapeHtml(data.error) + "</pre></fieldset>";
      return;
    }

    const result = data["query-result"];
    if (!result) {
      output.innerHTML = "";
      return;
    }

    const truncated = result["truncated?"] ? ", truncated" : "";
    // Actions bar sits above the table so a long result cannot push the
    // "Show result in graph view" button out of sight; the table itself
    // scrolls inside a capped container.
    let html =
      "<fieldset><legend>Results ("
      + escapeHtml(String(result["row-count"]))
      + " rows" + truncated + ")</legend>"
      + "<div id=\"graph-result-actions\" style=\"margin-bottom: 4px;\"></div>"
      + "<div style=\"max-height: 45vh; overflow: auto;\">"
      + "<table border=\"1\" cellpadding=\"4\" cellspacing=\"0\""
      + " style=\"border-collapse: collapse; width: 100%;\">"
      + "<thead><tr>";

    // filter_* columns feed node ids to the graph-view filter below but
    // are hidden from the table (convention; see default query).
    const columns = result.columns || [];
    const visibleIdx = [];
    columns.forEach(function (column, i) {
      if (!/^filter_/.test(column)) visibleIdx.push(i);
    });
    visibleIdx.forEach(function (i) {
      html += "<th>" + escapeHtml(columns[i]) + "</th>";
    });
    html += "</tr></thead><tbody>";

    (result.rows || []).forEach(function (row) {
      html += "<tr>";
      visibleIdx.forEach(function (i) {
        html += "<td><code>" + escapeHtml(row[i]) + "</code></td>";
      });
      html += "</tr>";
    });

    html += "</tbody></table></div></fieldset>";
    output.innerHTML = html;

    // Offer to view the result as an induced subgraph: any UUID appearing
    // in any result cell selects that node in the loaded graph.
    const uuidRe = /[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/gi;
    const ids = new Set();
    (result.rows || []).forEach(function (row) {
      row.forEach(function (cell) {
        const found = String(cell).match(uuidRe);
        if (found) found.forEach(function (m) { ids.add(m.toLowerCase()); });
      });
    });
    if (ids.size) {
      const btn = document.createElement("button");
      btn.type = "button";
      btn.textContent = "Show result in graph view (" + ids.size + " ids)";
      btn.addEventListener("click", function () { applyQueryFilter(ids); });
      document.getElementById("graph-result-actions").appendChild(btn);
    }
  }

  const queryForm = document.getElementById("graph-query-form");
  if (queryForm) {
    // Keep the query text across page reloads (load/unload/full-reload all
    // re-render the page with the default query). Only restore over the
    // default, never over a server-rendered non-default query.
    const queryInput = queryForm.querySelector("textarea[name=query]");
    const defaultQuery = (queryInput.dataset.defaultQuery || "").trim();
    const storedQuery = localStorage.getItem("graph-query");
    if (storedQuery && storedQuery.trim() !== defaultQuery
        && queryInput.value.trim() === defaultQuery) {
      queryInput.value = storedQuery;
    }
    queryInput.addEventListener("input", function () {
      localStorage.setItem("graph-query", queryInput.value);
    });
    queryForm.addEventListener("submit", function (event) {
      event.preventDefault();
      const formData = new FormData(queryForm);
      fetch("/dbg/actions/graph-query", {
        method: "POST",
        headers: { "Accept": "application/json" },
        body: formData
      })
        .then(function (resp) { return resp.text(); })
        .then(function (text) {
          renderQueryOutput(parseTransitMap(JSON.parse(text)));
        })
        .catch(function (err) {
          renderQueryOutput({ error: String(err) });
        });
    });
  }

  // In-page expand (no Fullscreen API): keeps browser chrome and window
  // manager splits usable while the graph takes the whole page. Entered
  // via the toolbar's expand icon; exited via its exit icon or Esc.
  const graphColumn = document.getElementById("graph-view-column");

  function resizeGraphSoon() {
    setTimeout(function () {
      if (g6graph) {
        const canvas = document.getElementById("graph-canvas");
        try {
          g6graph.setSize(canvas.clientWidth, canvas.clientHeight);
          g6graph.fitView();
        } catch (_err) { /* autoResize covers most cases */ }
      }
    }, 120);
  }

  function setExpanded(expanded) {
    graphColumn.classList.toggle("graph-view-expanded", expanded);
    resizeGraphSoon();
  }

  // Follow container size (G6's autoResize is inert on this build).
  // Safe only because the container's width is viewport-driven and can
  // never follow the canvas: the fieldset's min-content floor is removed
  // (#graph-view-panel min-inline-size: 0) and #graph-canvas clips
  // (overflow: hidden). Without both, observer -> setSize -> wider canvas
  // -> wider column -> observer is a runaway growth loop that also wipes
  // the painted canvas on every step.
  const canvasEl = document.getElementById("graph-canvas");
  if (typeof ResizeObserver !== "undefined" && canvasEl) {
    let resizeRaf = null;
    new ResizeObserver(function () {
      if (resizeRaf) return;
      resizeRaf = requestAnimationFrame(function () {
        resizeRaf = null;
        if (!g6graph) return;
        try {
          const cur = g6graph.getSize();
          const w = canvasEl.clientWidth;
          const h = canvasEl.clientHeight;
          if (!cur || cur[0] !== w || cur[1] !== h) g6graph.setSize(w, h);
        } catch (_err) { /* instance mid-recreate */ }
      });
    }).observe(canvasEl);
  }

  if (graphColumn) {
    document.addEventListener("keydown", function (ev) {
      if (ev.key === "Escape"
          && graphColumn.classList.contains("graph-view-expanded")) {
        setExpanded(false);
      }
    });
  }

  const foldToggle = document.getElementById("graph-fold-toggle");
  if (foldToggle) {
    foldToggle.checked = foldEnabled();
    foldToggle.addEventListener("change", function () {
      localStorage.setItem("graph-fold-containers", foldToggle.checked ? "1" : "0");
      renderCurrent();
    });
  }

  const animateToggle = document.getElementById("graph-animate-toggle");
  if (animateToggle) {
    animateToggle.checked = animateEnabled();
    animateToggle.addEventListener("change", function () {
      localStorage.setItem("graph-animate", animateToggle.checked ? "1" : "0");
      renderCurrent();
    });
  }

  const diffStepsInput = document.getElementById("graph-diff-steps");
  if (diffStepsInput) {
    diffStepsInput.value = String(diffSteps());
    diffStepsInput.addEventListener("change", function () {
      localStorage.setItem("graph-diff-steps", diffStepsInput.value);
      renderCurrent();
    });
  }

  const diffFoldToggle = document.getElementById("graph-diff-fold");
  if (diffFoldToggle) {
    diffFoldToggle.checked = diffFoldEnabled();
    diffFoldToggle.addEventListener("change", function () {
      localStorage.setItem("graph-diff-fold", diffFoldToggle.checked ? "1" : "0");
      renderCurrent();
    });
  }

  const layoutSelect = document.getElementById("graph-layout-select");
  if (layoutSelect) {
    Object.keys(LAYOUTS).forEach(function (name) {
      const opt = document.createElement("option");
      opt.value = name;
      opt.textContent = name;
      layoutSelect.appendChild(opt);
    });
    layoutSelect.value = currentLayoutName();
    layoutSelect.addEventListener("change", function () {
      localStorage.setItem("graph-layout", layoutSelect.value);
      renderCurrent();
    });
  }

  const renderAnywayBtn = document.getElementById("graph-render-anyway");
  if (renderAnywayBtn) {
    renderAnywayBtn.addEventListener("click", function () {
      renderForced = true;
      renderCurrent();
    });
  }

  const filterResetBtn = document.getElementById("graph-filter-reset");
  if (filterResetBtn) {
    filterResetBtn.addEventListener("click", function () {
      graphFilterIds = null;
      renderCurrent();
    });
  }

  // Compact the loaded-at timestamp to local HH:MM; full instant on hover.
  const loadedAtEl = document.getElementById("graph-loaded-at");
  if (loadedAtEl) {
    const d = new Date(loadedAtEl.textContent.trim());
    if (!isNaN(d.getTime())) {
      loadedAtEl.title = loadedAtEl.textContent.trim();
      loadedAtEl.textContent = String(d.getHours()).padStart(2, "0")
        + ":" + String(d.getMinutes()).padStart(2, "0");
    }
  }

  connect();
  refreshSyncStatus();
  refetchGraph();

  window.addEventListener("beforeunload", function () {
    wsClosing = true;
    if (ws && ws.readyState === WebSocket.OPEN) {
      ws.send(encodeUnsubscribe(fileId));
      ws.close();
    }
  });
})();
</script>
{% endif %}
{% endblock %}