/* Brain of Reese — Sources page (knowledge base index view).
 *
 * Wires the real `GET /api/docs` endpoint (import phase): stat cards +
 * full-width document table, or the designed empty state when nothing is
 * indexed yet. Cells are built with DOM APIs (textContent) — never
 * innerHTML with document-derived data (XSS-safe by construction).
 *
 * Phase 19: the page joins the shared header (assets/header.js) — the
 * whoami gate below runs on the module's cached promise (one request per
 * page, shared with the header toggling), and the header gains the New
 * chat button: on a non-chat page "new chat" means going to the chat,
 * fresh (clear the phase-14 conversation key, then navigate to "/").
 *
 * Phase 26: the table's path links open the document in the
 * almost-fullscreen modal overlay (assets/document-modal.js) on the
 * SAME page — no new tab, no navigation. The link keeps its
 * /document.html href as the no-JS / context-menu escape hatch;
 * left-clicks are intercepted (preventDefault) and routed to
 * openDocumentModal. The module is loaded through the relative import
 * below — the header.js single-evaluation design (no direct <script>
 * tag; esbuild inlines it into the page bundle).
 */

import { clearChatStorage, fetchIsAdmin, initSharedHeader } from "./header.js";
import { openDocumentModal } from "./document-modal.js"; // phase 26: row links open the same-page modal

const tbody = document.querySelector("#docs-tbody");
const emptyEl = document.querySelector("#sources-empty");
const tableWrap = document.querySelector(".table-wrap");
const statCards = document.querySelector("#stat-cards");
const gateEl = document.querySelector("#sources-gate");
const statDocs = document.querySelector("#stat-docs");
const statChunks = document.querySelector("#stat-chunks");
const statLast = document.querySelector("#stat-last");

/* Phase 16: whoami BEFORE the docs fetch. Anonymous visitors get the
 * sign-in gate (stat cards + table hidden) and NO /api/docs call — the
 * catalog is admin-only. The document viewer itself stays public (the
 * soft rule), so the gate copy points at what keeps working.
 * Phase 19: the whoami request is the shared header module's cached
 * promise — the same single request initSharedHeader() awaited. */
function isAdmin() {
  return fetchIsAdmin();
}

/* Phase 19: New chat on a non-chat page means "go to the chat, fresh":
 * clear the phase-14 conversation key, then land on the chat page — its
 * empty state, since the conversation is gone from storage. */
const newChatBtn = document.querySelector("#new-chat-btn");
if (newChatBtn) {
  newChatBtn.addEventListener("click", () => {
    clearChatStorage();
    window.location.href = "/";
  });
}

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

/* Viewer link (phase 10) — same encoded URL the chat chips use; both
 * query values are percent-encoded (paths contain slashes, sometimes
 * spaces). Phase 26: this is the href the .doc-link CARRIES (no-JS /
 * context-menu escape hatch) — the left-click opens the same-page modal
 * instead. */
export function documentUrl(source, path) {
  return "/document.html?source=" + encodeURIComponent(source) + "&path=" + encodeURIComponent(path);
}

async function loadDocs() {
  let r;
  try {
    r = await fetch("/api/docs");
  } catch {
    showEmpty();
    return;
  }
  if (!r.ok) {
    showEmpty();
    return;
  }
  const { documents } = await r.json();
  if (!documents.length) {
    showEmpty();
    return;
  }

  tbody.replaceChildren();
  let totalChunks = 0;
  let last = "";
  for (const d of documents) {
    totalChunks += d.chunks;
    if (d.indexed_at > last) last = d.indexed_at;
    tbody.appendChild(makeRow(d));
  }
  statDocs.textContent = String(documents.length);
  statChunks.textContent = String(totalChunks);
  statLast.textContent = last ? fmtDate(last) : "–";
  emptyEl.hidden = true;
  tableWrap.hidden = false;
}

function makeRow(d) {
  const tr = document.createElement("tr");

  const sourceTd = document.createElement("td");
  sourceTd.textContent = d.source; // document-derived text — never innerHTML
  tr.appendChild(sourceTd);

  // Path cell: a link to the document (phase 10), full path as the
  // accessible/hover name (the column is ellipsized). Phase 26: the
  // left-click opens the same-page modal — no new tab (document-modal.js);
  // the href stays as the no-JS / context-menu escape hatch.
  const pathTd = document.createElement("td");
  pathTd.title = d.path; // full path on hover (column is ellipsized)
  const link = document.createElement("a");
  link.className = "doc-link";
  link.href = documentUrl(d.source, d.path);
  link.addEventListener("click", (e) => {
    e.preventDefault(); // no new tab (phase 26) — the modal takes over
    e.stopPropagation();
    openDocumentModal(d.source, d.path, link);
  });
  link.title = d.path; // full path as the link's hover/accessible name
  link.textContent = d.path;
  pathTd.appendChild(link);
  tr.appendChild(pathTd);

  for (const value of [d.title, String(d.chunks), fmtDate(d.indexed_at)]) {
    const td = document.createElement("td");
    td.textContent = value;
    tr.appendChild(td);
  }
  return tr;
}

function showEmpty() {
  statDocs.textContent = "0";
  statChunks.textContent = "0";
  statLast.textContent = "–";
  emptyEl.hidden = false;
  if (tableWrap) tableWrap.hidden = true;
}

/* ---------- Phase 32: the admin "Sync sources" button (§7.4) ----------
 * The "never stale" lifecycle for a long background job:
 *
 *   idle → click → POST /api/sync
 *          202 → "Syncing…" (disabled, aria-busy, spinning icon) + a
 *                2 s poll of GET /api/sync/status — the feedback loop;
 *                409 adopts the in-flight run the same way (one poll
 *                loop at a time, never two);
 *          success → "Synced HH:MM" + last-result counts in #sync-result
 *                    (aria-live — announced to screen readers) + the
 *                    catalog re-fetches live (never a stale table);
 *          failed  → "Sync sources" (retry-ready) + the role="alert"
 *                    banner naming the error.
 *
 * NO client-side hard timeout (phase locked decision): a sync can
 * legitimately run for minutes (clone + embed), so the 2 s poll is the
 * feedback loop and the server state is authoritative — the button is
 * disabled until the run reaches a terminal state, so it can never sit
 * stale OR stuck. On load (admin only) the page re-attaches: a running
 * run re-enters the running state (reload mid-sync), a terminal run
 * renders its last result. A 403 anywhere hides the button (defense in
 * depth — header.js's whoami reveal is the primary gate).
 */
const syncBtn = document.querySelector("#sync-btn");
const syncLabel = document.querySelector("#sync-label");
const syncIcon = syncBtn ? syncBtn.querySelector(".sync-icon") : null;
const syncResult = document.querySelector("#sync-result");
const syncErrorBanner = document.querySelector("#sync-error-banner");
const syncErrorText = document.querySelector("#sync-error-text");

const SYNC_POLL_MS = 2000; // the 2 s status poll (task 02)
let syncPollTimer = null; // at most ONE live poll loop

function stopSyncPolling() {
  if (syncPollTimer !== null) {
    clearTimeout(syncPollTimer);
    syncPollTimer = null;
  }
}

function showSyncError(detail) {
  if (syncErrorText) syncErrorText.textContent = detail || "The sync failed.";
  if (syncErrorBanner) syncErrorBanner.hidden = false;
}

function hideSyncError() {
  if (syncErrorText) syncErrorText.textContent = "";
  if (syncErrorBanner) syncErrorBanner.hidden = true;
}

/* The local HH:MM of finished_at — 24-hour, locale-independent, so the
 * "Synced 14:32" last-result label is deterministic. */
function fmtSyncTime(iso) {
  const d = new Date(iso);
  if (Number.isNaN(d.getTime())) return "";
  const pad = (n) => String(n).padStart(2, "0");
  return `${pad(d.getHours())}:${pad(d.getMinutes())}`;
}

/* The last-result line for #sync-result (aria-live). "added" is ALWAYS
 * announced (the run's headline term); "updated" / "pruned" only when
 * they happened (zero terms omitted); "unchanged" whenever it is
 * non-zero — or whenever nothing was added or updated, so a no-op
 * re-sync reads "0 added · 1 unchanged" instead of an empty live
 * region (the story gate's idempotency check). */
function fmtSyncResult(detail) {
  const d = detail || {};
  const added = d.added || 0;
  const updated = d.updated || 0;
  const parts = [`${added} added`];
  if (updated > 0) parts.push(`${updated} updated`);
  if ((d.unchanged || 0) > 0 || (added === 0 && updated === 0)) {
    parts.push(`${d.unchanged || 0} unchanged`);
  }
  if ((d.pruned || 0) > 0) parts.push(`${d.pruned} pruned`);
  return parts.join(" · ");
}

function enterRunningState() {
  syncBtn.disabled = true;
  syncBtn.setAttribute("aria-busy", "true");
  if (syncIcon) syncIcon.classList.add("is-spinning");
  syncLabel.textContent = "Syncing…";
  if (syncResult) syncResult.textContent = "";
  hideSyncError();
}

/* Settle the button back to clickable + un-spun with the given label. */
function settleSyncButton(label) {
  syncBtn.disabled = false;
  syncBtn.removeAttribute("aria-busy");
  if (syncIcon) syncIcon.classList.remove("is-spinning");
  syncLabel.textContent = label;
}

function applySyncSuccess(status) {
  const time = fmtSyncTime(status.finished_at);
  settleSyncButton(time ? `Synced ${time}` : "Synced");
  if (syncResult) syncResult.textContent = fmtSyncResult(status.detail);
  hideSyncError();
  // The KB just changed — refresh the catalog live so the table, stats,
  // and empty state never sit stale under the "Synced" label (the sync is
  // the page's own action; a reload should not be needed to see it).
  loadDocs();
}

function applySyncFailure(status) {
  settleSyncButton("Sync sources"); // retry-ready
  if (syncResult) syncResult.textContent = "";
  showSyncError(status.error);
}

/* A run can only vanish with a server restart mid-sync (status resets
 * to idle — the phase-accepted behavior): re-enable retry-ready with no
 * banner (there is no error to name; the next click re-syncs).
 * Idempotent — also the post-403 cleanup. */
function applySyncIdle() {
  settleSyncButton("Sync sources");
  if (syncResult) syncResult.textContent = "";
  hideSyncError();
}

/* The 2 s poll loop — the ONLY feedback timer (no client-side hard
 * timeout, phase locked decision). One tick at a time (re-scheduled
 * only while the run is still live, so an in-flight fetch can never
 * overlap the next tick), and startSyncPolling refuses to run a second
 * loop (a 409 adoption or a reload never doubles the polling). */
function startSyncPolling() {
  if (syncPollTimer !== null) return;
  const tick = async () => {
    let status = null;
    let notAdmin = false;
    try {
      const r = await fetch("/api/sync/status");
      if (r.status === 403) notAdmin = true;
      else if (r.ok) status = await r.json();
    } catch {
      /* network blip — the next tick retries (no client timeout to trip) */
    }
    if (notAdmin) {
      // Session lost mid-sync: defense in depth — hide the button.
      stopSyncPolling();
      syncBtn.hidden = true;
      applySyncIdle();
      return;
    }
    if (status && status.state === "success") {
      stopSyncPolling();
      applySyncSuccess(status);
      return;
    }
    if (status && status.state === "failed") {
      stopSyncPolling();
      applySyncFailure(status);
      return;
    }
    if (status && status.state === "idle") {
      // The run died with a server restart — retry-ready, no banner.
      stopSyncPolling();
      applySyncIdle();
      return;
    }
    syncPollTimer = setTimeout(tick, SYNC_POLL_MS);
  };
  syncPollTimer = setTimeout(tick, SYNC_POLL_MS);
}

/* Click → POST /api/sync. 202 starts the run; 409 adopts the in-flight
 * one (started elsewhere — e.g. a second tab); 403 hides the button
 * (defense in depth); anything else names the failure in the banner and
 * leaves the button retry-ready (the never-stale contract). */
async function startSync() {
  let r;
  try {
    r = await fetch("/api/sync", { method: "POST" });
  } catch {
    showSyncError("Could not reach the server to start the sync — try again.");
    return;
  }
  if (r.status === 403) {
    stopSyncPolling();
    syncBtn.hidden = true;
    applySyncIdle();
    return;
  }
  if (r.status === 202 || r.status === 409) {
    enterRunningState();
    startSyncPolling();
    return;
  }
  let detail = "";
  try {
    detail = (await r.json()).detail || "";
  } catch {
    /* non-JSON error body */
  }
  showSyncError(detail || `The server refused to start the sync (${r.status}).`);
}

/* Load-time re-attach (admin only — the IIFE runs this after the
 * whoami gate): a running run re-enters the running state (the user may
 * have reloaded mid-sync), a terminal run renders its last result, idle
 * renders nothing. */
async function initSyncButton() {
  if (!syncBtn) return;
  let status;
  try {
    const r = await fetch("/api/sync/status");
    if (r.status === 403) {
      syncBtn.hidden = true; // defense in depth
      return;
    }
    if (!r.ok) return;
    status = await r.json();
  } catch {
    return; // network blip — the button stays idle and clickable
  }
  if (status.state === "running") {
    enterRunningState();
    startSyncPolling();
  } else if (status.state === "success") {
    applySyncSuccess(status);
  } else if (status.state === "failed") {
    applySyncFailure(status);
  }
  /* idle → nothing to render */
}

if (syncBtn) syncBtn.addEventListener("click", startSync);

(async () => {
  await initSharedHeader(); // phase 19: Sign in/out + Sources link in the shared bar
  if (!(await isAdmin())) {
    // Anonymous: gate in, catalog out, and no /api/docs request at all.
    if (statCards) statCards.hidden = true;
    if (tableWrap) tableWrap.hidden = true;
    if (emptyEl) emptyEl.hidden = true;
    if (gateEl) gateEl.hidden = false;
    return;
  }
  if (gateEl) gateEl.hidden = true;
  loadDocs();
  initSyncButton(); // phase 32: re-attach to a running / last sync run
})();