/* Brain of Reese — document viewer (phase 10) + the shared document
 * renderer (phase 26).
 *
 * Two jobs:
 *
 *  1. renderDocument(doc, { titleEl, metaEl, contentEl }) — the
 *     EXPORTED rendering core. The /document.html page and the document
 *     modal (assets/document-modal.js, phase 26) both render through it,
 *     so the two surfaces can never drift:
 *
 *       • md / markdown → the shared escape-first renderer (markdown.js)
 *                         in the 72rem centered reading column;
 *       • prose (phase 165, LOCKED A1 — isProseDoc: an image doc's
 *                         description or a txt/text doc) → the content
 *                         as a text node inside <div class="doc-prose">,
 *                         pre-wrap: it WRAPS at the reading column;
 *       • any other     → the raw content as a text node inside
 *                         <pre class="doc-raw"> (mono, horizontal
 *                         scroll — locked A3: code never wraps);
 *       • doc.summary non-empty (phase 36 — phase 30 summaries exist
 *                         only on non-markdown docs) → a labeled
 *                         .doc-summary section ABOVE the content;
 *                         null / empty / whitespace renders nothing, so
 *                         markdown docs and fail-soft rows are
 *                         byte-for-byte unchanged.
 *
 *  2. The /document.html page itself: reads `source`/`path` query
 *     params, fetches the stateless content endpoint
 *     (GET /api/documents/content — database only, no filesystem), and
 *     renders via renderDocument into #doc-title / #doc-meta /
 *     #doc-content. A missing document (unknown pair, missing params,
 *     network error) shows the designed not-found card with a link back
 *     to the Sources page. Phase 79 (task 05): the content endpoint is
 *     require_user-gated — a direct ANONYMOUS URL meets the inline
 *     token gate instead (the page document loads; the gated data does
 *     not): mountGate settles the auth (silent re-auth of a cached
 *     token, then the shared cached whoami) and the boot sequence
 *     (initSharedHeader + load) runs as its onAuthed — only a
 *     signed-in role (admin or token user) ever fetches the content.
 *
 * XSS-safe by construction: markdown is escaped before transform, raw
 * formats are set via textContent, and every document-derived string
 * (title, badges, path — and the phase-148 page strip's alt text and
 * captions) is written with textContent or a property — never
 * innerHTML (innerHTML goes through renderMarkdown, which escapes
 * first).
 *
 * Phase 19: the viewer joins the shared header (assets/header.js) — the
 * whoami fetch is the module's cached promise (one request per page,
 * shared with initSharedHeader's toggling). Phase 34 task 02: the New
 * chat binding is module-owned (assets/header.js, the SINGLE one) — on
 * this non-chat page it clears the phase-14 conversation key and
 * navigates to the chat's empty state.
 *
 * Phase 26 (import safety): the modal module imports renderDocument
 * from THIS file on the chat/sources pages, so everything
 * /document.html-specific runs only when #doc-title exists (the guard
 * around the page block below). Importing renderDocument elsewhere has
 * no side effects: no back-link resolution, no whoami, no content
 * fetch, no New Chat binding.
 *
 * Phase 36: the renderer owns the optional summary panel — a non-empty
 * doc.summary renders as a labeled .doc-summary section above the
 * original content on BOTH surfaces (page + modal) through this one
 * core; the summary text is a text node (XSS contract unchanged).
 *
 * Phase 57 (task 02, D4): the panel gains an ADMIN-ONLY edit
 * affordance (docAdminReady() gate on the module-cached whoami): an
 * Edit button in the panel's header row opens an inline editor
 * (prefilled textarea + Save/Cancel + a role=status live region), and
 * Save PATCHes /api/documents/summary. The section is built for
 * everyone exactly as phase 36 — the public viewer stays
 * byte-for-byte identical (no button, no wiring, no admin-only
 * network call) until the admin gate resolves true.
 *
 * Phase 106 (task 08, D8): the .doc-meta badge row gains the Created
 * badge BEFORE the Indexed one (the owner's verbatim position — the
 * date at the top of a clicked document): `Created <locale date>` via
 * fmtDate(doc.created_at), the full ISO timestamp on the badge's
 * title (the titleEl ellipsis-precision idiom). ONE shared core —
 * the modal and /document.html both render it (no per-surface copy);
 * the date arrives in the same content payload (task 05 added
 * created_at to GET /api/documents/content). The date EDITOR (the
 * admin inline edit + PATCH /api/documents/date) is the task-09
 * section below.
 *
 * Phase 106 (task 09, D7): the badge row gains the ADMIN-ONLY date
 * editor (the phase-57 wireSummaryEdit idiom — the same
 * docAdminReady() gate on the module-cached whoami promise, so no
 * second request per page): an "Edit date" text button after the
 * Created badge (task 08's insertion point) swaps in-place for an
 * inline editor — a native type=date input + Save / Cancel + the
 * muted "Revert to sync" clear affordance (the phase-57 "clear =
 * explicit" contrast) + a role=status live line and a role=alert
 * error line. Save PATCHes /api/documents/date with { source, path,
 * date } and the badge re-renders from the RESPONSE's created_at
 * (never the input's optimistic value); "Revert to sync" sends
 * date: null (the D7 CLEAR — the manual flag drops, the stored date
 * stands until the next sync). An EMPTY date input can't clear (Save
 * disables itself — the explicit Revert is the only clear path, no
 * accidental wipes). §7.4 never-stale: the controls disable
 * immediately on submit (one PATCH at a time); a failure (non-2xx
 * or network) lands the server detail (or the canned retry copy) in
 * the role=alert line, reverts the input to the stored date, and
 * re-enables — the UI never claims a state the server didn't save.
 * A non-admin / token holder / failed whoami keeps the byte-for-byte
 * task-08 badge row (no button, no wiring, no admin-only network
 * call — the phase-57 split). ONE shared core — the modal and
 * /document.html both get it (document-modal.js imports
 * renderDocument from this module — no per-surface copy).
 *
 * Phase 122 (task 04): image documents — when doc.is_image is true,
 * #doc-content renders the persistent bytes FIRST (the <img> block
 * from doc.image_url — the /api/documents/{id}/image route — alt =
 * the summary, the WCAG alt contract; a NULL summary falls back to
 * the title), and the description (doc.content — the ONLY readable
 * text of the doc) follows in the EXISTING plain-content slot below
 * (phase 165: the .doc-prose path — a description IS prose, so it
 * wraps; it was never markdown, and never belonged in the pre). The
 * labeled Summary panel is suppressed for the verbatim-description
 * case (summary === content — the importer invariant; the panel
 * would duplicate the text right below the image); an admin-edited
 * summary (different text) still renders in its panel with the
 * phase-57 edit affordance. An <img> load failure (the route's 404 —
 * the row exists but the copy was lost) swaps the block for a small
 * "Image unavailable" note (role=status): the page still shows the
 * description. ONE shared core — page + modal both get it.
 *
 * Phase 145 (task 03): the meta row's "Original" anchor — when the
 * content payload carries origin_url (a git-sourced document — the
 * task-01 resolver's sanitized repository URL; ABSENT on the wire
 * for non-git documents, whose meta row stays byte-identical to
 * pre-phase), an <a class="doc-origin"> joins the .doc-meta row
 * AFTER the path code and BEFORE the Created badge: href + visible
 * text = the full URL VERBATIM (the copyable-link contract — no
 * decorative label inside the anchor text; the .doc-origin ellipsis
 * clips the display), target=_blank + rel=noopener (the modal's
 * "Full page" escape-hatch idiom), and the title carries the full
 * URL plus ` — branch: <name>` when the payload pins a branch (the
 * pathCode ellipsis-precision idiom). ONE shared core — the modal
 * AND /document.html render it (no per-surface copy); createElement
 * + properties/textContent only (the never-build-HTML rule — no
 * innerHTML).
 *
 * Phase 148 (task 03): the page strip — when the payload carries
 * page_urls (a page-qualifying PDF — the phase-133 fallback class
 * or the phase-140 pictorial class — the task-02 endpoint's exact
 * 1-based /api/documents/{id}/pages/{n} route list; ABSENT on the
 * wire for every other document, so they render the EXACT pre-phase
 * DOM on BOTH surfaces — the load-bearing byte-identity property),
 * #doc-content renders a .doc-pages strip INSTEAD of the text
 * content AND the .doc-summary panel FOR THE PRIMARY CLASS ONLY
 * (phase 163 — the absent/`primary` mode; see the next paragraph):
 * one <figure class="doc-page"> per URL — a lazy <img> (alt = "Page N of <title>", the WCAG alt
 * contract — the title as the fallback context) + a "Page N"
 * <figcaption> — while the meta badge row renders exactly as today.
 * The owner's contract: the per-page descriptions stay in the DB for
 * Q&A (the content/embeddings/summaries are untouched); they are
 * simply not shown to the user — so the Summary panel is NOT built
 * (its admin edit affordance is moot without it). A page whose copy
 * was lost (the route's defensive 404s) swaps ONLY ITS figure's
 * <img> for a "Page N unavailable." note (role=status — the
 * phase-122 image-unavailable idiom, the same muted class); the rest
 * of the strip is untouched (one lost copy never hides the other
 * pages). ONE shared core — the modal AND /document.html get it (no
 * per-surface copy); createElement + properties/textContent only (the
 * never-build-HTML rule — no innerHTML).
 *
 * Phase 163 (task 04, LOCKED A1/A2/A6): the strip's CLASS decides the
 * view. page_strip_mode === "additive" (the pictorial class — a USABLE
 * text layer, so the pages are a convenience, not the content) keeps
 * the TEXT doc EXACTLY as a non-qualifying doc renders it (Summary
 * panel + content — the pre-148 branch reused), and the strip sits one
 * Text/Pages toggle away: a .doc-view-toggle group (role=group,
 * aria-label="Document view", two <button aria-pressed>) above a
 * .doc-views wrapper holding the text view + the strip; Text is
 * pressed by DEFAULT (A6 — never a sparse-ratio flip), Pages flips the
 * wrapper's data-view (CSS shows the strip / hides the text — the
 * strip node stays MOUNTED, its lazy imgs never refetch on flip-flop).
 * The text is NEVER hidden for this class. The absent/"primary" mode
 * (the fallback class — the screenshots ARE the content, and every
 * pre-163 stamped row) keeps the strip-only DOM above byte-identically
 * (the tolerant read: only the exact "additive" string switches on the
 * toggle); falsy page_urls stay untouched. The wrapper exists ONLY on
 * additive docs — every other document's DOM is unchanged. Toggle
 * labels are fixed strings (no doc-derived text); createElement +
 * properties/textContent only.
 *
 * Phase 153 (task 02): the meta row's "Copy path" control — the
 * read-tool `source/path` form in the clipboard with one click
 * (ASSUMPTION A1 — the exact `source/path` the read tool, the
 * chips, and the Sources table use; the paste target is the
 * owner's own tooling). The control is built by the ONE shared
 * renderDocument core (both surfaces — modal AND /document.html —
 * get the SAME icon+text button, AFTER the path code and BEFORE
 * the origin anchor), and each surface wires it with its OWN
 * page-local clipboard helper (the per-page duplication house style
 * — document-modal.js carries the modal's copy; no new shared
 * module): navigator.clipboard.writeText in a try — a non-secure
 * (http) homelab origin rejects the clipboard, so the failure path
 * renders an inline fallback field (input-like, prefilled with the
 * path, selects its full content on focus — the .share-link-
 * fallback pattern) + the status line (the owner-locked fallback
 * wording, path-adapted); success shows a transient VISIBLE status
 * (auto-clears ~4s, the toast idiom — the node is aria-hidden,
 * visual only) and the surface's role=status live region reads the
 * same text (one a11y announcer — the share pattern: #doc-copy-
 * announcer on the page, #doc-modal-desc in the modal). A failed
 * copy NEVER clears the previous state into nothing (the old state
 * is replaced in place, never dropped); a re-click re-attempts.
 * The page's status/field float in a .doc-copy-pop block anchored
 * under the button (the meta row must never wrap or grow the bar
 * — the phase-12/34 contract — so the block is absolutely
 * positioned in the header, never in the row); the modal's sit
 * inline in the wrapping #doc-modal-meta block.
 */

import { bindSharedHeaderControls, fetchIsAdmin, initSharedHeader } from "./header.js";
import { mountGate } from "./token-gate.js"; // phase 79 (task 05): the inline token gate

// The shared header's control bindings (sign-out / mobile hamburger) —
// EXPLICIT init, once per document (header.js is bundle-inlined per
// entry; import-time side effects would double-bind — 2026-09-08 fix).
bindSharedHeaderControls();

/* Phase 39: the page title's display name — window.BOR_BRAND (set at
 * parse time by the classic assets/brand.js, refreshed from
 * /api/config). This is a module, so the global is set by the time this
 * evaluates; the literal is the no-config fallback only. */
const brand = () => window.BOR_BRAND || "Brain of Reese";

function fmtDate(iso) {
  try {
    return new Date(iso).toLocaleString();
  } catch {
    return iso;
  }
}

function contentUrl(s, p) {
  return "/api/documents/content?source=" + encodeURIComponent(s) + "&path=" + encodeURIComponent(p);
}

function metaBadge(cls, text, title) {
  const el = document.createElement("span");
  el.className = cls;
  el.textContent = text;
  // Phase 106 (task 08): optional hover precision — the meta row may
  // clip (nowrap), so the exact value stays reachable on the badge's
  // title (the titleEl ellipsis-precision idiom). Omitted → the
  // pre-phase two-argument shape (the other badges are unchanged).
  if (title !== undefined) el.setAttribute("title", title);
  return el;
}

/* Phase 145 (task 03): the meta row's "Original" anchor — the git
 * origin as a copyable external link (called only when the payload
 * carries origin_url — a non-git document never gets one, so its
 * meta row stays the pre-phase shape). The FULL URL is the anchor's
 * visible text (the copyable-link contract — no decorative label
 * inside the anchor text: a " (branch)" suffix would break
 * copy-paste; the .doc-origin CSS ellipsis clips the display
 * instead), target=_blank + rel=noopener (the modal's "Full page"
 * escape-hatch idiom), and the title carries the full URL — plus
 * ` — branch: <name>` when the payload pins a branch (the pathCode
 * ellipsis-precision idiom). Properties + textContent only — never
 * innerHTML (the XSS contract). */
function originAnchor(doc) {
  const a = document.createElement("a");
  a.className = "doc-origin";
  a.href = doc.origin_url;
  a.target = "_blank";
  a.rel = "noopener";
  a.textContent = doc.origin_url;
  a.setAttribute(
    "title",
    doc.origin_branch ? doc.origin_url + " — branch: " + doc.origin_branch : doc.origin_url,
  );
  return a;
}

/* Phase 153 (task 02): the meta row's "Copy path" control — the
 * icon+text row-action shape (the git-sources.js row-buttons idiom),
 * createElementNS-built (the never-build-HTML rule stands — the
 * module's ONE innerHTML stays the escape-first markdown render).
 * The VISIBLE "Copy path" text IS the accessible name (a redundant
 * aria-label is not carried — WCAG 4.1.2 via the text), the icon is
 * aria-hidden, and type=button (no form submission). The shared
 * renderDocument core builds it (both surfaces — modal AND
 * /document.html — get the same shape; each surface wires it with
 * its own page-local clipboard helper — the per-page duplication
 * house style). */
function copyPathButton() {
  const SVG_NS = "http://www.w3.org/2000/svg";
  const b = document.createElement("button");
  b.type = "button";
  b.className = "doc-copy-path";
  const icon = document.createElementNS(SVG_NS, "svg");
  icon.setAttribute("aria-hidden", "true");
  icon.setAttribute("viewBox", "0 0 24 24");
  icon.setAttribute("fill", "none");
  icon.setAttribute("stroke", "currentColor");
  icon.setAttribute("stroke-width", "1.8");
  icon.setAttribute("stroke-linecap", "round");
  icon.setAttribute("stroke-linejoin", "round");
  const backRect = document.createElementNS(SVG_NS, "rect");
  backRect.setAttribute("x", "9");
  backRect.setAttribute("y", "9");
  backRect.setAttribute("width", "11");
  backRect.setAttribute("height", "11");
  backRect.setAttribute("rx", "2");
  const front = document.createElementNS(SVG_NS, "path");
  front.setAttribute("d", "M5 15V5a2 2 0 0 1 2-2h10");
  icon.append(backRect, front);
  const label = document.createElement("span");
  label.textContent = "Copy path";
  b.append(icon, label);
  return b;
}

/* ---------- prose set (phase 165, task 01 — LOCKED A1) ----------
 * The ONE place the prose rule lives (TODO.md L3: "Need word wrap for
 * image explanations and other long text rather than scrolling
 * horizontally"). The defect: the description used to land in the
 * `pre` and each generated line became one unbreakable line — a
 * horizontal scrollbar where every other text surface wraps.
 *
 * The image arm is UNCONDITIONAL (phase 122 A3: an image doc's
 * `content` IS the vision description — prose by construction,
 * whatever its extension). The `format` arm covers plain-text docs;
 * `doc.format` comes from the server's doc_format() (the lowercased
 * suffix). Code and code-ish formats (py, yaml, json, j2, the quadlet
 * family, pdf — locked A1/A3: phase 116's scroll contract stands)
 * never enter this set. */
const PROSE_FORMATS = new Set(["txt", "text"]);

function isProseDoc(doc) {
  return doc.is_image === true || PROSE_FORMATS.has(doc.format);
}

/* ---------- shared renderer (phase 26, task 02) ----------
 * Populates the three elements every render surface provides: a title,
 * a .doc-meta badge row (source · format · mono path · created ·
 * indexed · chunks — phase 106 (task 08, D8) added created BEFORE
 * indexed), and a content container — an optional .doc-summary
 * section first (phase 36: only when doc.summary is non-empty —
 * markdown docs and fail-soft rows carry none, so they render exactly
 * as before), then .doc-md for md/markdown (the shared escape-first
 * renderer), <div class="doc-prose"> for the prose set (phase 165 —
 * isProseDoc), <pre class="doc-raw"> otherwise. The XSS contract:
 * innerHTML only through renderMarkdown; every document-derived
 * string (summary text included) is a text node. */
export function renderDocument(doc, { titleEl, metaEl, contentEl }) {
  titleEl.textContent = doc.title;
  // Phase 34 task 04: the titlebar title ellipsizes — the full title
  // stays reachable on hover via the `title` attribute.
  titleEl.setAttribute("title", doc.title);

  const pathCode = document.createElement("code");
  pathCode.className = "doc-path";
  pathCode.textContent = doc.path;
  // Phase 153 (task 02): the "Copy path" control — the shared core
  // builds it (BOTH surfaces — modal AND /document.html — get the
  // SAME shape; each surface wires it with its own page-local
  // clipboard helper). It lands AFTER the path code and BEFORE the
  // origin anchor — one more inline item in the row (the modal's
  // wrap rule and the page's clip rule both keep it on their
  // shapes).
  const copyBtn = copyPathButton();
  // Phase 145 (task 03): the "Original" anchor — the git origin as a
  // copyable external link, present ONLY when the content payload
  // carries origin_url (a git-sourced document's sanitized repository
  // URL — the task-01 resolver's output; ABSENT on the wire for
  // non-git documents, so their meta row stays byte-identical to
  // pre-phase). It lands AFTER the path code and BEFORE the Created
  // badge — one more inline item in the row (the modal's wrap rule
  // and the page's clip rule both keep it on their shapes).
  const originItems = doc.origin_url ? [originAnchor(doc)] : [];
  metaEl.replaceChildren(
    metaBadge("doc-source-badge", doc.source),
    metaBadge("format-badge", doc.format),
    pathCode,
    copyBtn,
    ...originItems,
    // Phase 106 (task 08, D8): the Created badge BEFORE the Indexed
    // one (the owner's verbatim position — the date at the top of a
    // clicked document). textContent = the locale date (fmtDate — the
    // Indexed idiom), and the badge's title = the FULL ISO timestamp
    // (the titleEl ellipsis-precision idiom — the row clips, the exact
    // value stays reachable).
    metaBadge("doc-created", `Created ${fmtDate(doc.created_at)}`, doc.created_at),
    metaBadge("doc-indexed", `Indexed ${fmtDate(doc.indexed_at)}`),
    metaBadge("doc-chunks", `${doc.chunks} chunk${doc.chunks === 1 ? "" : "s"}`),
  );

  // Phase 106 (task 09, D7): the ADMIN-ONLY date editor — the
  // module-cached whoami promise (docAdminReady — the SAME single
  // request per page the summary edit shares) gates the wiring, so a
  // non-admin / token holder / failed whoami keeps EXACTLY the task-08
  // badge row: no button, no wiring, no admin-only network call (the
  // phase-57 split). The button lands after the Created badge (task
  // 08's insertion point); the editor itself lives in wireDateEdit.
  void docAdminReady().then((admin) => {
    if (admin) wireDateEdit(metaEl, doc);
  });

  contentEl.replaceChildren();
  // Phase 148 (task 03): the page strip — the payload's page_urls
  // (task 02's endpoint: the exact 1-based route list for a
  // page-qualifying PDF; ABSENT on the wire for every other
  // document) is the ONE branch that replaces the content slot (phase
  // 163: the PRIMARY class only — an "additive" doc falls through to
  // the text rendering with the strip behind a toggle, D4/A1): the
  // markdown/.doc-prose/.doc-raw content block AND the labeled Summary panel
  // (including its admin edit wiring — moot without the panel) are
  // NOT built. The per-page descriptions stay in the DB for Q&A (the
  // importer's content/embeddings/summary are untouched); they are
  // simply not shown to the user (the owner's contract). The meta
  // badge row above renders exactly as pre-phase. null / absent /
  // empty page_urls falls through to the EXACT pre-phase rendering
  // below (byte-identical for every other doc — the load-bearing
  // property).
  const pageUrls = Array.isArray(doc.page_urls) ? doc.page_urls : null;
  const stripEligible = pageUrls !== null && pageUrls.length > 0;
  // Phase 163 (task 04, LOCKED A2): the strip's CLASS picks the view.
  // Only the exact "additive" string switches on the toggle — absent
  // (pre-163 rows, and the omission rule's non-qualifying docs) or
  // "primary" read as primary (the tolerant-reading house rule), so
  // the fallback class keeps the strip-only DOM byte-identically.
  const additive = stripEligible && doc.page_strip_mode === "additive";
  if (stripEligible && !additive) {
    contentEl.appendChild(docPagesStrip(doc, pageUrls));
    return;
  }
  // Phase 163 (task 04, LOCKED A1/A6): an ADDITIVE doc renders the
  // text doc EXACTLY as a non-qualifying one does (Summary panel +
  // content below, reused unchanged) INSIDE a .doc-views wrapper —
  // the Text/Pages toggle above it flips the wrapper's data-view
  // (CSS-driven show/hide, never a re-render); the strip mounts once
  // AFTER the text view and stays mounted across flips (lazy imgs,
  // display:none while hidden, never fetch). Every non-additive doc
  // keeps slot === contentEl — its DOM is byte-identical to pre-phase.
  let views = null;
  let slot = contentEl;
  if (additive) {
    views = document.createElement("div");
    views.className = "doc-views";
    views.setAttribute("data-view", "text"); // LOCKED A6: Text is the default view
    contentEl.append(docViewToggle(views), views);
    slot = views;
  }
  // Phase 122 (task 04): an image document — the persistent bytes
  // render as the <img> block FIRST; the description (= doc.content)
  // follows in the normal content slot below (the plain-content path
  // — the last branch in this function).
  if (doc.is_image) {
    slot.appendChild(docImageBlock(doc));
  }
  // Phase 36: the summary panel — labeled section ABOVE the original
  // content, on BOTH surfaces (page + modal) through this one core.
  // Only a non-empty summary renders: markdown docs carry none (phase
  // 30) and the fail-soft path leaves summary NULL, so both are
  // byte-for-byte unchanged here. Phase 122 (task 04): for an IMAGE
  // doc whose summary IS the verbatim description (summary ===
  // content — the importer invariant), the panel would duplicate the
  // text right below the image, so it is suppressed; an admin-edited
  // summary (different text) still renders with the phase-57 edit
  // affordance.
  const imageSummaryIsContent = doc.is_image && doc.summary === doc.content;
  if (doc.summary && doc.summary.trim() !== "" && !imageSummaryIsContent) {
    const section = document.createElement("section");
    section.className = "doc-summary";
    section.setAttribute("aria-label", "Summary");
    const title = document.createElement("h2");
    title.className = "doc-summary-title";
    title.textContent = "Summary";
    const body = document.createElement("p");
    body.className = "doc-summary-text";
    body.textContent = doc.summary; // text node — XSS contract unchanged
    section.append(title, body);
    slot.appendChild(section);
    // Phase 57 (task 02, D4): the section above is the phase-36 shape
    // for EVERYONE — only an authenticated admin (docAdminReady(), the
    // module-cached whoami promise) then gains the header row + Edit
    // button + editor wiring. Anonymous / fetch failure: the panel is
    // exactly what phase 36 built (byte-for-byte unchanged).
    void docAdminReady().then((admin) => {
      if (admin) wireSummaryEdit(section, doc);
    });
  }
  if (doc.format === "md" || doc.format === "markdown") {
    const wrap = document.createElement("div");
    wrap.className = "doc-md";
    wrap.innerHTML = renderMarkdown(doc.content); // escape-first: XSS-safe
    slot.appendChild(wrap);
  } else if (isProseDoc(doc)) {
    // Phase 165 (task 01, LOCKED A2): the prose arm — a TEXT NODE in
    // the wrapping .doc-prose block (pre-wrap carries the newlines;
    // no markdown parsing of a description). The XSS contract is
    // untouched: the content is never parsed as HTML.
    const prose = document.createElement("div");
    prose.className = "doc-prose";
    prose.textContent = doc.content; // text node: never parsed as HTML
    slot.appendChild(prose);
  } else {
    const pre = document.createElement("pre");
    pre.className = "doc-raw";
    pre.textContent = doc.content; // text node: never parsed as HTML
    slot.appendChild(pre);
  }
  // Phase 163 (task 04): the additive strip mounts once, AFTER the
  // text view, inside the wrapper — hidden by [data-view="text"]
  // (the lazy imgs never fetch until Pages is chosen; the node
  // persists across flips — no refetch).
  if (views !== null) {
    views.appendChild(docPagesStrip(doc, pageUrls));
  }
}

/* ---------- view toggle (phase 163, task 04 — LOCKED A1/A6) ----------
 * The Text/Pages toggle of an ADDITIVE strip doc: one
 * <div class="doc-view-toggle" role="group" aria-label="Document
 * view"> with two <button type="button" class="doc-view-btn"
 * aria-pressed>. Text is pressed initially (A6 — no sparse-ratio
 * default flip). A click mutates ONLY the two aria-pressed states and
 * the .doc-views wrapper's data-view attribute — the CSS shows/hides
 * the text view and the strip (never a re-render, never a refetch).
 * The labels are FIXED strings (no doc-derived text inside the
 * toggle); createElement + properties/textContent only (the
 * never-build-HTML rule — no innerHTML). */
function docViewToggle(viewsEl) {
  const group = document.createElement("div");
  group.className = "doc-view-toggle";
  group.setAttribute("role", "group");
  group.setAttribute("aria-label", "Document view");
  const textBtn = viewToggleButton("Text");
  const pagesBtn = viewToggleButton("Pages");
  const select = (view) => {
    viewsEl.setAttribute("data-view", view);
    textBtn.setAttribute("aria-pressed", view === "text" ? "true" : "false");
    pagesBtn.setAttribute("aria-pressed", view === "pages" ? "true" : "false");
  };
  textBtn.setAttribute("aria-pressed", "true"); // LOCKED A6: Text pressed by default
  pagesBtn.setAttribute("aria-pressed", "false");
  textBtn.addEventListener("click", () => select("text"));
  pagesBtn.addEventListener("click", () => select("pages"));
  group.append(textBtn, pagesBtn);
  return group;
}

function viewToggleButton(label) {
  const btn = document.createElement("button");
  btn.type = "button";
  btn.className = "doc-view-btn";
  btn.textContent = label; // fixed string — never doc-derived
  return btn;
}

/* ---------- image block (phase 122, task 04) ----------
 * The viewer's image block for an ``is_image`` document: the
 * document's PERSISTENT bytes (doc.image_url — the
 * /api/documents/{id}/image route) as a block <img> (max-width 100%;
 * the theme's surface treatment lives in .doc-image). alt = the
 * summary (the vision description — the WCAG alt contract everywhere);
 * a NULL summary (the fail-soft backfill corner) falls back to the
 * title. On a load failure (the route's 404 — the row exists but the
 * copy was lost) the block shows a small "Image unavailable."
 * note (role=status) in its place; the description in the content
 * slot below still renders (the doc is still readable). Properties
 * only (src, alt) — every document-derived value is a text node /
 * property, never innerHTML (the XSS contract, unchanged). */
function docImageBlock(doc) {
  const wrap = document.createElement("div");
  wrap.className = "doc-image";
  const img = document.createElement("img");
  // Phase 181 (task 04, design D6/D7): SVG is a VECTOR image doc. A
  // drawing carrying only a viewBox has NO intrinsic size, so the
  // default replaced-element box (300×150) would sit small inside the
  // full-width .doc-image card; the --vector modifier (the base class
  // is KEPT so every current rule still applies) lets width: 100%
  // span the card — the full-size preview. doc.format is the ONLY
  // place in the app that knows the type: the bytes URL is
  // extension-less and SourceRef carries no format field by design
  // (D7). LOCKED A3: the SVG is NEVER inlined into the DOM —
  // img.src = doc.image_url stays createElement + property
  // assignment (this file's XSS contract, unchanged). Legacy
  // honesty (D6): a row still indexed as TEXT (an .svg under
  // BOR_IMAGES=0, or not yet re-synced) keeps rendering its XML in
  // .doc-raw — the truth about that row (there are no bytes behind
  // it); task 02's kind-mismatch guard converts it on the next sync.
  // Nobody "fixes" that by sniffing the content string.
  img.className =
    doc.format === "svg"
      ? "doc-image-img doc-image-img--vector"
      : "doc-image-img";
  img.src = doc.image_url;
  img.alt =
    typeof doc.summary === "string" && doc.summary.trim() !== ""
      ? doc.summary
      : doc.title;
  img.addEventListener("error", () => {
    const note = document.createElement("p");
    note.className = "doc-image-unavailable";
    note.setAttribute("role", "status");
    note.textContent = "Image unavailable — the file is missing.";
    wrap.replaceChildren(note);
  });
  wrap.appendChild(img);
  return wrap;
}

/* ---------- page strip (phase 148, task 03) ----------
 * The viewer's page strip for a page-qualifying PDF (doc.page_urls
 * non-empty — the task-02 payload: one
 * /api/documents/{id}/pages/{n} route per rendered page, 1-based).
 * A .doc-pages container goes into the content slot INSTEAD of the
 * text content and the Summary panel (the renderDocument branch
 * above) — the owner's contract: the per-page descriptions stay in
 * the DB for Q&A, they are just not displayed. One
 * <figure class="doc-page"> per URL: a lazy <img> (alt =
 * "Page N of <title>" — the WCAG alt contract, the title as the
 * fallback context, the phase-122 image idiom) + a "Page N"
 * <figcaption class="doc-page-num">. A page whose copy was lost
 * (the route's defensive 404) swaps ONLY ITS figure's <img> for a
 * small "Page N unavailable." note (role=status — the phase-122
 * image-unavailable note class, the same muted styling); the rest of
 * the strip is untouched (one lost copy never hides the other pages).
 * createElement + properties/textContent only — every document-
 * derived string (the title in the alt, the note) lands via a
 * property or textContent, never innerHTML (the XSS contract,
 * unchanged). */
function docPagesStrip(doc, pageUrls) {
  const wrap = document.createElement("div");
  wrap.className = "doc-pages";
  pageUrls.forEach((url, i) => {
    const n = i + 1; // 1-based over page_urls (the route list's own numbering)
    const figure = document.createElement("figure");
    figure.className = "doc-page";
    const img = document.createElement("img");
    img.loading = "lazy"; // lazy imgs — a long manual streams down the strip
    img.src = url;
    img.alt = `Page ${n} of ${doc.title}`;
    img.addEventListener("error", () => {
      // The phase-122 idiom (its muted note class, reused): the lost
      // copy's <img> becomes a small "Page N unavailable." note in
      // ITS figure only — the caption and every other page stand.
      const note = document.createElement("p");
      note.className = "doc-image-unavailable";
      note.setAttribute("role", "status");
      note.textContent = `Page ${n} unavailable.`;
      img.replaceWith(note);
    });
    const figcaption = document.createElement("figcaption");
    figcaption.className = "doc-page-num";
    figcaption.textContent = `Page ${n}`;
    figure.append(img, figcaption);
    wrap.appendChild(figure);
  });
  return wrap;
}

/* ---------- summary editing (phase 57, task 02 — D4, admin-only) ----------
 * The .doc-summary panel is the ONE place the stored summary is edited
 * (page + modal through this core). Only an admin (docAdminReady) ever
 * gets the affordance; the public viewer is byte-for-byte unchanged. */

/* The admin gate (D4 — the viewer stays public): the module-cached
 * /api/whoami promise (header.js's fetchIsAdmin — the SAME single
 * request per page the shared header already makes on every surface,
 * so this adds no request of its own). A non-admin or any fetch
 * failure resolves false → the anonymous viewer. */
async function docAdminReady() {
  try {
    return (await fetchIsAdmin()) === true;
  } catch {
    return false;
  }
}

/* The edit affordance on one rendered .doc-summary section. The bare
 * h2 becomes a header row (label left, Edit button right). Edit swaps
 * the .doc-summary-text node for the inline editor — a prefilled
 * textarea (value, never innerHTML — XSS contract), Save / Cancel,
 * and a role=status live region. Save PATCHes /api/documents/summary
 * with { source, path, summary } — the pair comes from the doc object
 * (the same values the modal core carries, document-modal.js). Success
 * re-renders the text node via textContent and announces "Summary
 * updated."; an empty save that clears announces "Summary cleared."
 * and removes the panel a short beat later — the confirmation stays
 * readable, and the renderer only draws the panel for non-empty
 * summaries. Cancel restores the text node. A failure keeps the
 * editor open with the user's text and shows neutral retry copy
 * (phase-55 convention). */
function wireSummaryEdit(section, doc) {
  const title = section.querySelector(".doc-summary-title");
  const body = section.querySelector(".doc-summary-text");
  if (!title || !body) return;

  /* Header row: label left, Edit button right (admin-only — the
   * anonymous section keeps its bare h2). */
  const head = document.createElement("div");
  head.className = "doc-summary-head";
  const editBtn = document.createElement("button");
  editBtn.type = "button";
  editBtn.className = "doc-summary-edit";
  editBtn.textContent = "Edit";
  head.append(title, editBtn);
  section.replaceChildren(head, body);

  /* Editor parts (built once; the textarea is rebuilt on every open so
   * it always starts from the CURRENT stored summary). */
  let editor = null;
  const actions = document.createElement("div");
  actions.className = "doc-summary-actions";
  const saveBtn = document.createElement("button");
  saveBtn.type = "button";
  saveBtn.className = "doc-summary-save";
  saveBtn.textContent = "Save";
  const cancelBtn = document.createElement("button");
  cancelBtn.type = "button";
  cancelBtn.className = "doc-summary-cancel";
  cancelBtn.textContent = "Cancel";
  actions.append(saveBtn, cancelBtn);
  const status = document.createElement("p");
  status.className = "doc-summary-status";
  status.setAttribute("role", "status");
  status.setAttribute("aria-live", "polite");

  /* Back to the display state: the text node re-rendered from the
   * doc object (the CURRENT stored summary), the live region (the
   * announced message), the Edit button available again. If the
   * summary is gone (a clear landed while the editor was open — e.g.
   * Cancel right after a successful empty save) the panel is gone
   * too: the renderer only draws it for non-empty summaries. */
  function closeEditor(message) {
    status.textContent = message;
    editBtn.hidden = false;
    if (typeof doc.summary !== "string" || doc.summary.trim() === "") {
      section.remove();
      return;
    }
    body.textContent = doc.summary; // text node — the CURRENT stored summary
    section.replaceChildren(head, body, status);
    editBtn.focus();
  }

  async function saveSummary() {
    const value = editor.value;
    saveBtn.disabled = true; // one PATCH at a time (never stale)
    status.textContent = "";
    try {
      const res = await fetch("/api/documents/summary", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ source: doc.source, path: doc.path, summary: value }),
      });
      if (!res.ok) {
        // Neutral retry copy (phase-55 convention) — the user's text
        // stays in the editor (the editor stays open on failure).
        status.textContent = "Couldn't update the summary — try again.";
        return;
      }
      const data = await res.json();
      if (data.summary === null) {
        // Cleared (D4): the panel disappears — the renderer only draws
        // it for non-empty summaries. The live-region confirmation
        // stays visible for a short beat before the panel leaves the
        // DOM (a screen reader must be able to read it; the removal
        // is a no-op if the surface re-rendered or closed meanwhile).
        doc.summary = null;
        status.textContent = "Summary cleared.";
        setTimeout(() => section.remove(), 2000);
        return;
      }
      doc.summary = data.summary;
      closeEditor("Summary updated.");
    } catch {
      // Network failure: same neutral shape, the reachable? copy.
      status.textContent = "Couldn't update the summary — is the app reachable?";
    } finally {
      saveBtn.disabled = false;
    }
  }

  function openEditor() {
    editor = document.createElement("textarea");
    editor.className = "doc-summary-editor";
    editor.value = typeof doc.summary === "string" ? doc.summary : ""; // value, never innerHTML
    status.textContent = "";
    editBtn.hidden = true;
    section.replaceChildren(head, editor, actions, status);
    editor.focus();
  }

  editBtn.addEventListener("click", openEditor);
  saveBtn.addEventListener("click", () => {
    void saveSummary();
  });
  cancelBtn.addEventListener("click", () => closeEditor(""));
}

/* ---------- date editing (phase 106, task 09 — D7, admin-only) ----------
 * The .doc-meta badge row (task 08's Created badge) is the ONE place
 * the stored creation date is edited (page + modal through the
 * shared renderDocument core — no per-surface copy). Only an admin
 * (docAdminReady) ever gets the affordance; a non-admin / token
 * holder / failed whoami keeps exactly the task-08 badge row (no
 * button, no wiring, no admin-only network call — the phase-57
 * split). Save PATCHes /api/documents/date with { source, path,
 * date } — a non-empty date sets it (the server normalizes it, D3,
 * and stores the manual flag, D1); the explicit "Revert to sync"
 * affordance sends date: null (the D7 CLEAR — the manual flag drops
 * and the stored date stands until the next sync refreshes it).
 * The badge re-renders from the RESPONSE's created_at — the UI shows
 * exactly what the server stored, never the input's optimistic
 * value. §7.4 never-stale: the controls disable IMMEDIATELY on
 * Save/Revert (no double-submit); a failure (non-2xx or network)
 * lands the server detail (or the canned retry copy) in the
 * role=alert line, reverts the input to the stored date, and
 * re-enables — the UI never claims a state the server didn't save.
 * An EMPTY date input can't clear: Save disables itself on an empty
 * input (the explicit Revert is the only clear path — no accidental
 * wipes). */

/* The server detail of a non-2xx response (the git-sources.js
 * apiDetail shape — the phase-89 error-line idiom: a string detail
 * or the 422 array's first msg), with the neutral fallback for a
 * non-JSON body. */
async function apiDetail(res, fallback) {
  try {
    const data = await res.json();
    if (Array.isArray(data.detail) && data.detail[0] && data.detail[0].msg) {
      return String(data.detail[0].msg);
    }
    if (typeof data.detail === "string" && data.detail) return data.detail;
  } catch {
    /* non-JSON error body */
  }
  return fallback;
}

/* The date editor on one rendered .doc-meta badge row: the "Edit
 * date" text button after the Created badge (admin-only — the public
 * row keeps task 08's shape). Edit swaps the button for the inline
 * editor in place — a native <input type="date"> (value, never
 * innerHTML — XSS contract) prefilled with the stored date's UTC
 * date part, Save / Cancel, the muted "Revert to sync" clear, and
 * the role=status / role=alert live lines. One PATCH at a time (the
 * controls disable before the fetch and re-enable in the finally —
 * every outcome, never stale, PLAN §7.4). */
function wireDateEdit(metaEl, doc) {
  const createdBadge = metaEl.querySelector(".doc-created");
  if (!createdBadge) return;

  /* Edit affordance (admin-only — the public badge row keeps exactly
   * task 08's shape: no button, no wiring). setAttribute, never
   * innerHTML (the document-derived pair is user-storable). */
  const editBtn = document.createElement("button");
  editBtn.type = "button";
  editBtn.className = "doc-date-edit";
  editBtn.textContent = "Edit date";
  editBtn.setAttribute(
    "aria-label",
    `Edit creation date: ${doc.source}/${doc.path}`,
  );
  createdBadge.insertAdjacentElement("afterend", editBtn);

  /* Editor parts (built once; the input is rebuilt on every open so
   * it always starts from the CURRENT stored date). */
  let input = null;
  const box = document.createElement("span");
  box.className = "doc-date-editor";
  const saveBtn = document.createElement("button");
  saveBtn.type = "button";
  saveBtn.className = "doc-date-save";
  saveBtn.textContent = "Save";
  const cancelBtn = document.createElement("button");
  cancelBtn.type = "button";
  cancelBtn.className = "doc-date-cancel";
  cancelBtn.textContent = "Cancel";
  const revertBtn = document.createElement("button");
  revertBtn.type = "button";
  revertBtn.className = "doc-date-revert";
  revertBtn.textContent = "Revert to sync";
  const status = document.createElement("span");
  status.className = "doc-date-status";
  status.setAttribute("role", "status");
  status.setAttribute("aria-live", "polite");
  const errorLine = document.createElement("span");
  errorLine.className = "doc-date-error";
  errorLine.setAttribute("role", "alert");
  errorLine.setAttribute("aria-live", "assertive");

  /* The stored date as a native date-input value: the UTC date part
   * of the stored ISO timestamp (D3 stores UTC timestamptz). */
  function storedValue() {
    return new Date(doc.created_at).toISOString().slice(0, 10);
  }

  /* One PATCH at a time (PLAN §7.4): the controls disable
   * IMMEDIATELY on submit; Save ADDITIONALLY disables on an EMPTY
   * input (the explicit Revert is the only clear path — no
   * accidental wipes). */
  function setControlsLocked(locked) {
    if (input) input.disabled = locked;
    saveBtn.disabled = locked || input.value === "";
    cancelBtn.disabled = locked;
    revertBtn.disabled = locked;
  }

  /* Back to the display state: the badge row + the Edit button (the
   * task-08 shape restored) and focus back on the opener. Idempotent
   * (a stale success-beat timer may call it after a Cancel — the
   * re-insert is a same-position move and the box is already out).
   * The last announcement stays readable a short beat because the
   * caller defers the call (the phase-57 "confirmation stays
   * readable" precedent). */
  function closeEditor() {
    editBtn.hidden = false;
    createdBadge.insertAdjacentElement("afterend", editBtn);
    box.remove();
    editBtn.focus();
  }

  async function saveDate(dateValue) {
    setControlsLocked(true); // one PATCH at a time (never stale)
    errorLine.textContent = "";
    try {
      const r = await fetch("/api/documents/date", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          source: doc.source,
          path: doc.path,
          date: dateValue,
        }),
      });
      if (!r.ok) {
        // The server detail into the role=alert line (the canned
        // retry copy on a non-JSON body); the input reverts to the
        // stored date; the controls re-enable in the finally. The
        // editor stays open — the user's attempt is visible.
        errorLine.textContent = await apiDetail(
          r,
          "Couldn't save the date — try again.",
        );
        input.value = storedValue();
        return;
      }
      const res = await r.json();
      // Response-driven: the badge shows exactly what the server
      // stored (never the input's optimistic value), and the doc
      // object syncs so a re-open prefills the CURRENT date.
      doc.created_at = res.created_at;
      doc.created_at_manual = res.created_at_manual;
      createdBadge.textContent = `Created ${fmtDate(res.created_at)}`;
      createdBadge.setAttribute("title", res.created_at);
      // The confirmation lands AFTER the badge update (the phase-89
      // last-announce order), then the row collapses back to the
      // task-08 shape a short beat later (the announcement stays
      // readable — the status line leaves with the box).
      status.textContent =
        dateValue === null
          ? "Reverted to sync-managed date."
          : `Date saved for ${doc.source}/${doc.path}.`;
      setTimeout(closeEditor, 2000);
    } catch {
      // Network failure: the canned retry copy (the phase-55
      // neutral shape), the input reverts to the stored date, the
      // editor stays open.
      errorLine.textContent = "Couldn't save the date — try again.";
      input.value = storedValue();
    } finally {
      setControlsLocked(false);
    }
  }

  function openEditor() {
    input = document.createElement("input");
    input.type = "date";
    input.className = "doc-date-input";
    input.setAttribute("aria-label", "Document creation date");
    input.value = storedValue(); // value, never innerHTML
    input.addEventListener("input", () => {
      // An EMPTY input can't clear: Save disables (the explicit
      // Revert below is the only clear path — no accidental wipes).
      // The locked state owns the controls while a PATCH is in
      // flight (the input is disabled then, so this can't race it).
      if (!input.disabled) saveBtn.disabled = input.value === "";
    });
    status.textContent = "";
    errorLine.textContent = "";
    box.replaceChildren(input, saveBtn, cancelBtn, revertBtn, status, errorLine);
    editBtn.hidden = true;
    createdBadge.insertAdjacentElement("afterend", box);
    setControlsLocked(false);
    input.focus();
  }

  editBtn.addEventListener("click", openEditor);
  saveBtn.addEventListener("click", () => {
    // Save is only ever enabled with a NON-empty input (the empty
    // state disables it) — the clear path is the explicit Revert.
    void saveDate(input.value);
  });
  cancelBtn.addEventListener("click", () => {
    // Cancel: back to the display state, no PATCH (the stored value
    // is untouched — the badge was never mutated).
    status.textContent = "";
    errorLine.textContent = "";
    closeEditor();
  });
  revertBtn.addEventListener("click", () => {
    void saveDate(null); // the D7 CLEAR: { source, path, date: null }
  });
}

/* ---------- /document.html page (phases 10/13/19) ----------
 * Phase 26: viewer-page-specific — see the import-safety note in the
 * header. The guard is #doc-title: it exists only on this page, so the
 * modal module's `import { renderDocument } from "./document.js"` on
 * the chat/sources pages evaluates none of the code below. */
if (document.querySelector("#doc-title")) {
  const params = new URLSearchParams(window.location.search);
  const source = params.get("source") || "";
  const path = params.get("path") || "";

  const titleEl = document.querySelector("#doc-title");
  const metaEl = document.querySelector("#doc-meta");
  const contentEl = document.querySelector("#doc-content");
  const notFoundEl = document.querySelector("#doc-not-found");
  const mainEl = document.querySelector("#main");
  const backLink = document.querySelector("#doc-back");

  /* Back button (phase 13): the return target comes from the `back`
   * query param, not the browser history — the dedicated page is
   * reachable directly (no history to go back to). The param is honored
   * only for same-origin relative URLs (starts with "/" but not "//"),
   * so absolute (https://…), protocol-relative (//…), and
   * pseudo-protocol (javascript:…) values are rejected; anything else
   * falls back to the Sources page. The static href="/sources.html" in
   * document.html remains the no-JS fallback, and with the href set the
   * anchor's default click behavior IS the deterministic navigation (no
   * browser-history heuristics). */
  const backParam = params.get("back") || "";
  const backTarget =
    backParam.startsWith("/") && !backParam.startsWith("//")
      ? backParam
      : "/sources.html";
  backLink.href = backTarget;
  const backLabel = backLink.querySelector("span");
  if (backLabel) {
    backLabel.textContent =
      backTarget === "/"
        ? "Chat"
        : backTarget === "/sources.html"
          ? "Sources"
          : "Back";
  }

  /* ---------- Copy path (phase 153, task 02) ----------
   * The meta row's "Copy path" control (renderDocument — the shared
   * core — built it after the path code; this page wires it with
   * the page-local helper — the per-page duplication house style:
   * document-modal.js carries the modal's own copy, no new shared
   * module). The copied string is `source + "/" + path` (ASSUMPTION
   * A1 — the exact read-tool form; the same two values the meta row
   * renders). navigator.clipboard.writeText in a try — a non-secure
   * (http) homelab origin rejects the clipboard, so the failure path
   * renders the inline fallback field (input-like, prefilled with
   * the full path, selects its full content on focus — the
   * .share-link-fallback pattern) + the status line "Path ready —
   * copy it from the field." (the owner-locked fallback wording,
   * path-adapted). Success: a transient VISIBLE status "Path
   * copied." (auto-clears ~4s, the toast idiom — the node is
   * aria-hidden, visual only) + the page's #doc-copy-announcer
   * (role=status, the visually-hidden node added for this phase) reads
   * the same text — one a11y announcer (the share pattern). The
   * status/field float in a .doc-copy-pop block anchored under the
   * button (the meta row must never wrap or grow the bar — the
   * phase-12/34 contract — so the block is absolutely positioned in
   * the header, never in the row). A failed copy NEVER clears the
   * previous state into nothing (the old block is replaced in
   * place); a re-click re-attempts. */
  let copyStatusTimer = 0; // the pending auto-clear (the success beat)

  /* The inline fallback field (the .share-link-fallback pattern,
   * input variant): input-like, prefilled with the full path,
   * selects its full content on focus (click or Tab, then
   * Ctrl/Cmd+C). readOnly — the field is a copy surface, not an
   * editor. value, never innerHTML (the path is data — the XSS
   * contract, unchanged). */
  function makePathFallbackField(path) {
    const field = document.createElement("input");
    field.type = "text";
    field.readOnly = true;
    field.className = "doc-path-fallback";
    field.value = path;
    field.setAttribute("aria-label", "Document path");
    field.title = "Document path — click, then copy (Ctrl/Cmd+C)";
    field.addEventListener("focus", () => field.select());
    return field;
  }

  async function copyPathWithFallback(btn, path) {
    /* A re-click re-attempts: the previous block (success or
     * failure) is replaced in place — a failed copy never clears
     * the previous state into nothing (the field is swapped for a
     * new one, never dropped). */
    document.querySelectorAll(".doc-copy-pop").forEach((el) => el.remove());
    let ok = true;
    try {
      await navigator.clipboard.writeText(path);
    } catch {
      ok = false;
    }
    const block = document.createElement("div");
    block.className = "doc-copy-pop";
    const status = document.createElement("p");
    status.className = "doc-copy-status";
    status.setAttribute("aria-hidden", "true"); // visual only — the announcer is the role=status node
    status.textContent = ok ? "Path copied." : "Path ready — copy it from the field.";
    let field = null;
    if (ok) {
      block.appendChild(status);
    } else {
      field = makePathFallbackField(path);
      block.append(field, status);
    }
    /* Anchor under the button: the block floats in the header
     * (sticky = positioned), so it never wraps the meta row or
     * grows the bar (the phase-12/34 contract). */
    const header = document.querySelector("header.doc-header");
    if (header) {
      const br = btn.getBoundingClientRect();
      const hr = header.getBoundingClientRect();
      block.style.top = `${br.bottom - hr.top + 6}px`;
      block.style.left = `${br.left - hr.left}px`;
      header.appendChild(block);
    }
    const announcer = document.querySelector("#doc-copy-announcer");
    if (announcer) announcer.textContent = status.textContent;
    if (ok) {
      clearTimeout(copyStatusTimer);
      copyStatusTimer = setTimeout(() => {
        if (block.isConnected) block.remove();
      }, 4000); // auto-clear ~4s (the toast idiom)
    } else if (field) {
      field.focus({ preventScroll: true }); // selects the path — ready to copy
    }
    return ok;
  }

  /* renderDocument fills the page elements; the page additionally owns
   * the document.title (the modal keeps the page title untouched). */
  function render(doc) {
    renderDocument(doc, { titleEl, metaEl, contentEl });
    /* Phase 153 (task 02): wire the shared core's "Copy path"
     * control with the page-local helper — the copied string is the
     * same two values the meta row renders. */
    const copyBtn = metaEl.querySelector(".doc-copy-path");
    if (copyBtn) {
      copyBtn.addEventListener(
        "click",
        () => void copyPathWithFallback(copyBtn, doc.source + "/" + doc.path),
      );
    }
    document.title = `${doc.title} · ${brand()}`;
  }

  function showNotFound() {
    titleEl.textContent = "Document not found";
    titleEl.removeAttribute("title"); // no stale full-title tooltip
    document.title = `Document not found · ${brand()}`;
    metaEl.replaceChildren();
    contentEl.replaceChildren();
    notFoundEl.hidden = false;
  }

  /* Phase 19 (phase 34 task 03, owner confirmation 2026-08-26): the
   * viewer now carries the SAME standard bar as every other page —
   * nav incl. the admin-only links, the auth pair — toggled on the
   * module's cached whoami (the single whoami per page; fetchIsAdmin
   * is imported for docAdminReady's parity — the same cached promise
   * either way).
   *
   * Phase 79 (task 05): the gate settles the auth FIRST — silent
   * re-auth of a cached token, then the role check (on the shared
   * cached whoami) — and the EXISTING boot sequence runs only on the
   * SETTLED role: onAuthed (the content load) for a signed-in role
   * ONLY (anonymous never fetches the content — the inline gate is
   * the surface, no not-found card for an auth failure; #main is
   * inert while the gate is visible — WCAG, the inert-pair contract),
   * and the shared header boots in the .then AFTER the gate settles
   * for EVERY role (the gate locks #main, not the header — the
   * anonymous contract is byte-identical to the shell: Sign in
   * offered, admin links ship hidden, the steering panel removed).
   * Awaiting the gate first is what makes the header race-free: a
   * silent re-auth lands before the first whoami fires, so the header
   * reads the post-auth role exactly once (no stale anonymous bar for
   * a returning token user, no second whoami). An admin (or a
   * validly cached token user) gets onAuthed immediately — the gate
   * (which ships hidden + inert) never shows. The admin-only edit
   * affordance (docAdminReady() inside renderDocument) stays
   * admin-only — it runs only in the post-auth render path. */
  mountGate(document.getElementById("main"), () => {
    load();
  }).then(() => {
    void initSharedHeader(); // every role — on the SETTLED whoami
  });

  /* The New chat binding is module-owned (assets/header.js, phase 34
   * task 02 — the SINGLE binding): on this non-chat page it clears the
   * phase-14 conversation key and navigates to the chat's empty state. */

  async function load() {
    try {
      if (!source || !path) {
        showNotFound();
        return;
      }
      const r = await fetch(contentUrl(source, path));
      if (!r.ok) {
        showNotFound();
        return;
      }
      render(await r.json());
    } catch {
      showNotFound();
    } finally {
      mainEl.focus(); // move focus to main on load (a11y)
    }
  }

}