/* ProdDash admin client.

   Everything here is server-wide: module enable/disable and admin config
   (written to config/modules.json, module re-inited on save), plus named
   layout management. Guarded by the shared passcode when one is set. */

const loginCard = document.getElementById('login-card');
const loginStatus = document.getElementById('login-status');
const passcodeInput = document.getElementById('passcode');
const modulesSection = document.getElementById('modules-section');
const modulesList = document.getElementById('modules-list');
const layoutsSection = document.getElementById('layouts-section');
const layoutsList = document.getElementById('layouts-list');
const toastEl = document.getElementById('toast');
const availableSection = document.getElementById('available-section');
const availableList = document.getElementById('available-list');
const catalogStatus = document.getElementById('catalog-status');
const updateCard = document.getElementById('update-card');
const updateTitle = document.getElementById('update-title');
const updateCopy = document.getElementById('update-copy');
const updateStatus = document.getElementById('update-status');
const updateBtn = document.getElementById('update-btn');
const updateChanges = document.getElementById('update-changes');
const shellVersionEl = document.getElementById('shell-version');
const themeSection = document.getElementById('theme-section');
const themeSwatches = document.getElementById('theme-swatches');
const themeStatus = document.getElementById('theme-status');

/** The shell version the page loaded with — the update flow watches it change. */
let shellVersion = '';

let toastTimer = null;
function toast(msg, isError = false) {
  toastEl.textContent = msg;
  toastEl.classList.toggle('error', isError);
  toastEl.hidden = false;
  clearTimeout(toastTimer);
  toastTimer = setTimeout(() => { toastEl.hidden = true; }, 3200);
}

async function api(path, opts = {}) {
  const res = await fetch(path, {
    ...opts,
    headers: { 'Content-Type': 'application/json', ...(opts.headers || {}) },
  });
  const body = await res.json().catch(() => ({}));
  if (!res.ok) {
    const err = new Error(body.error || `Request failed (${res.status})`);
    err.status = res.status;
    err.authRequired = Boolean(body.authRequired);
    throw err;
  }
  return body;
}

/* ── login ──────────────────────────────────────────────────────────── */

function showLogin() {
  loginCard.hidden = false;
  modulesSection.hidden = true;
  availableSection.hidden = true;
  layoutsSection.hidden = true;
  updateCard.hidden = true;
  themeSection.hidden = true;
  passcodeInput.focus();
}

async function login() {
  loginStatus.textContent = '';
  loginStatus.className = 'admin-status';
  try {
    await api('/api/admin/login', { method: 'POST', body: JSON.stringify({ passcode: passcodeInput.value }) });
    passcodeInput.value = '';
    loginCard.hidden = true;
    await loadState();
  } catch (e) {
    loginStatus.textContent = e.message;
    loginStatus.className = 'admin-status error';
  }
}

document.getElementById('login-btn').addEventListener('click', login);
passcodeInput.addEventListener('keydown', (e) => {
  if (e.key === 'Enter') login();
});

/* ── module cards ───────────────────────────────────────────────────── */

/** moduleId -> { dot, healthEl, toggle } for cheap in-place status refreshes */
const liveEls = new Map();

function healthClass(mod) {
  if (!mod.enabled) return '';
  if (mod.mountError) return 'error';
  return mod.health ? mod.health.status : 'ok';
}

function healthText(mod) {
  if (!mod.enabled) return 'Disabled — hidden from the dashboard picker, server routes unmounted.';
  if (mod.mountError) return '';
  if (mod.health) return mod.health.message || mod.health.status;
  return mod.hasServer ? 'Mounted.' : 'Client-only module (no server part).';
}

function fieldFor(key, spec, value, passwordSet, moduleId) {
  const type = spec?.type || 'string';
  const label = spec?.label || key;
  const field = document.createElement('label');
  field.className = 'field' + (type === 'boolean' ? ' check' : '') + (type === 'switch' ? ' switch-field' : '');
  let read;
  // For boolean/switch fields, the control other fields may depend on
  // (showWhen) — returned so the caller can wire visibility.
  let control = null;
  // For selects: the element (optionsDependsOn sources) and, with an
  // optionsRoute, a function that (re)loads the options.
  let selectEl = null;
  let refetch = null;

  if (type === 'switch') {
    // Same toggle as the module enable switch, inline with its label.
    const toggle = document.createElement('span');
    toggle.className = 'switch';
    const input = document.createElement('input');
    input.type = 'checkbox';
    input.checked = Boolean(value);
    const track = document.createElement('span');
    track.className = 'track';
    toggle.append(input, track);
    const text = document.createElement('span');
    text.className = 'switch-label';
    text.textContent = label;
    field.append(toggle, text);
    read = () => input.checked;
    control = input;
  } else if (type === 'boolean') {
    const input = document.createElement('input');
    input.type = 'checkbox';
    input.checked = Boolean(value);
    field.append(input, document.createTextNode(label));
    read = () => input.checked;
    control = input;
  } else if (type === 'endpoint') {
    // One consistent "Host / IP : Port" control for every module's upstream.
    const span = document.createElement('span');
    span.textContent = label;
    const row = document.createElement('span');
    row.className = 'endpoint-row';
    const host = document.createElement('input');
    host.type = 'text';
    host.className = 'ep-host';
    host.placeholder = 'Host / IP';
    host.autocomplete = 'off';
    host.spellcheck = false;
    host.value = value?.host ? String(value.host) : '';
    const sep = document.createElement('span');
    sep.className = 'ep-sep';
    sep.textContent = ':';
    const port = document.createElement('input');
    port.type = 'number';
    port.className = 'ep-port';
    port.placeholder = 'Port';
    port.min = '1';
    port.max = '65535';
    port.value = value?.port ? String(value.port) : '';
    row.append(host, sep, port);
    field.append(span, row);
    read = () => ({ host: host.value.trim(), port: Number(port.value) || 0 });
  } else if (type === 'select' && (Array.isArray(spec.options) || spec.optionsRoute)) {
    const span = document.createElement('span');
    span.textContent = label;
    const select = document.createElement('select');
    const optValue = (opt) => String(typeof opt === 'object' ? opt.value : opt);
    const fill = (options) => {
      // Keep what the admin has picked but not yet saved across a refill
      // (a dependent select refetching), else the saved value.
      const saved = String(value ?? '');
      const wanted = select.options.length ? select.value : saved;
      select.innerHTML = '';
      // The saved value must stay selectable even when it isn't among the
      // live options (device unplugged, module route down).
      if (saved && !options.some((opt) => optValue(opt) === saved)) {
        options = [{ value: saved, label: `${saved} (saved)` }, ...options];
      }
      // Nothing saved yet → a blank "choose" entry, unless the module already
      // offers a blank option of its own (an "Automatic" default, say).
      if (!saved && !options.some((opt) => optValue(opt) === '')) {
        options = [{ value: '', label: '— choose —' }, ...options];
      }
      // Options may carry a `group` (a folder path, a device class): options
      // sharing one render under a single <optgroup>, in first-seen order.
      const groups = new Map();
      for (const opt of options) {
        const o = document.createElement('option');
        o.value = optValue(opt);
        o.textContent = String(typeof opt === 'object' ? (opt.label ?? opt.value) : opt);
        const g = typeof opt === 'object' && opt.group ? String(opt.group) : '';
        if (!g) {
          select.appendChild(o);
          continue;
        }
        if (!groups.has(g)) {
          const og = document.createElement('optgroup');
          og.label = g;
          groups.set(g, og);
          select.appendChild(og);
        }
        groups.get(g).appendChild(o);
      }
      select.value = options.some((opt) => optValue(opt) === wanted) ? wanted : saved;
    };
    fill(Array.isArray(spec.options) ? spec.options : []);
    if (spec.optionsRoute && moduleId) {
      // Options discovered at runtime (audio devices, ports, sources…):
      // the module serves them from one of its own routes. With
      // optionsDependsOn the caller triggers the fetch (and re-fetches when
      // that other field changes), passing its value as a query parameter.
      refetch = (query) => {
        const qs = query && Object.keys(query).length ? `?${new URLSearchParams(query)}` : '';
        return fetch(`/api/modules/${encodeURIComponent(moduleId)}${spec.optionsRoute}${qs}`)
          .then((res) => (res.ok ? res.json() : null))
          .then((body) => {
            if (Array.isArray(body?.options)) fill(body.options);
          })
          .catch(() => { /* keep the static/saved options */ });
      };
      if (!spec.optionsDependsOn) refetch();
    }
    field.append(span, select);
    read = () => select.value;
    selectEl = select;
  } else if (type === 'color') {
    // A swatch picker; the value is always a #rrggbb string.
    field.classList.add('color-field');
    const span = document.createElement('span');
    span.textContent = label;
    const input = document.createElement('input');
    input.type = 'color';
    const hex = (v, fb) => (/^#[0-9a-fA-F]{6}$/.test(String(v ?? '').trim()) ? String(v).trim().toLowerCase() : fb);
    input.value = hex(value, hex(spec?.default, '#2ee59a'));
    field.append(span, input);
    read = () => input.value;
  } else {
    const span = document.createElement('span');
    span.textContent = label;
    const input = document.createElement('input');
    input.type = type === 'number' ? 'number' : (type === 'password' ? 'password' : 'text');
    if (type === 'password') {
      input.placeholder = passwordSet ? 'Saved — leave blank to keep' : 'Not set';
      input.autocomplete = 'new-password';
    } else {
      input.value = value === undefined || value === null ? '' : String(value);
    }
    field.append(span, input);
    read = () => (type === 'number' ? Number(input.value) : input.value);
  }
  if (spec?.help) {
    // One line of guidance under the control (allowed placeholders, where a
    // value comes from…) — the label stays short.
    const help = document.createElement('small');
    help.className = 'field-help';
    help.textContent = spec.help;
    field.appendChild(help);
  }
  return { field, read, control, selectEl, refetch };
}

/**
 * Does a config group have anything entered? Drives `collapsed: "whenSet"`:
 * a credentials block stays folded once it holds a saved secret or a value
 * other than the schema default, and opens by itself while still empty.
 */
function groupHasValues(fields, mod) {
  return fields.some(({ key, spec }) => {
    const type = spec?.type || 'string';
    if (type === 'password') return Boolean(mod.passwordSet[key]);
    if (type === 'boolean' || type === 'switch') return false;
    const v = mod.config[key];
    if (type === 'endpoint') return Boolean(v?.host);
    if (v === undefined || v === null || String(v) === '') return false;
    return !('default' in (spec || {})) || String(v) !== String(spec.default);
  });
}

/* ── group title row: the ⓘ and the group toggle ────────────────────── */

let groupInfoSeq = 0;

function closeGroupInfos(except) {
  for (const open of document.querySelectorAll('.group-info.is-open')) {
    if (open === except) continue;
    open.classList.remove('is-open');
    open.querySelector('.group-info-btn')?.setAttribute('aria-expanded', 'false');
  }
}

/**
 * configGroups[name].help as an ⓘ beside the group title: click toggles a
 * small popover with the text (hover and keyboard focus show it too), so a
 * group can carry a paragraph without pushing its fields down the page. A
 * real button, labelled, so it works from the keyboard; inside a <summary>
 * it must never fold the group.
 */
function groupInfo(groupName, text) {
  const wrap = document.createElement('span');
  wrap.className = 'group-info';
  const btn = document.createElement('button');
  btn.type = 'button';
  btn.className = 'group-info-btn';
  btn.textContent = 'i';
  btn.setAttribute('aria-label', `About ${groupName}`);
  btn.setAttribute('aria-expanded', 'false');
  const pop = document.createElement('span');
  pop.className = 'group-info-pop';
  pop.id = `group-info-${++groupInfoSeq}`;
  pop.setAttribute('role', 'note');
  pop.textContent = text;
  btn.setAttribute('aria-describedby', pop.id);
  wrap.append(btn, pop);
  const setOpen = (open) => {
    wrap.classList.toggle('is-open', open);
    btn.setAttribute('aria-expanded', open ? 'true' : 'false');
  };
  btn.addEventListener('click', (e) => {
    e.preventDefault(); // a click in a <summary> would otherwise fold the group
    e.stopPropagation();
    const open = !wrap.classList.contains('is-open');
    closeGroupInfos(wrap);
    setOpen(open);
  });
  pop.addEventListener('click', (e) => {
    e.preventDefault();
    e.stopPropagation();
  });
  wrap.addEventListener('keydown', (e) => {
    // Enter / Space activate the button (a click); they must not reach a
    // <summary> above as well. Escape closes and hands focus back.
    if (e.key === ' ' || e.key === 'Enter') e.stopPropagation();
    if (e.key === 'Escape' && wrap.classList.contains('is-open')) {
      e.stopPropagation();
      setOpen(false);
      btn.focus();
    }
  });
  return wrap;
}

// A click anywhere else, or Escape, closes an open popover.
document.addEventListener('pointerdown', (e) => {
  if (!(e.target instanceof Element) || !e.target.closest('.group-info')) closeGroupInfos();
});
document.addEventListener('keydown', (e) => {
  if (e.key === 'Escape') closeGroupInfos();
});

/**
 * configGroups[name].toggle: the named switch/boolean field is the group's
 * on/off. It moves into the title row, right-aligned, and the body dims
 * while it is off (fields stay editable). The field itself is untouched —
 * it is still read on save and still drives showWhen dependents.
 */
function mountGroupToggle(group, field, control) {
  const slot = document.createElement('span');
  slot.className = 'field-group-toggle';
  slot.appendChild(field);
  // Inside a <summary>, flipping the switch must not fold the group.
  slot.addEventListener('click', (e) => e.stopPropagation());
  slot.addEventListener('keydown', (e) => {
    if (e.key === ' ' || e.key === 'Enter') e.stopPropagation();
  });
  group.title.appendChild(slot);
  group.el.classList.add('has-toggle');
  const sync = () => group.el.classList.toggle('is-off', !control.checked);
  control.addEventListener('change', sync);
  sync();
}

function buildModuleCard(mod) {
  const card = document.createElement('section');
  card.className = 'admin-card';

  const head = document.createElement('div');
  head.className = 'module-head';

  const dot = document.createElement('span');
  dot.className = 'dot ' + healthClass(mod);

  const name = document.createElement('span');
  name.className = 'module-name';
  name.textContent = mod.name;

  const version = document.createElement('span');
  version.className = 'module-version';
  version.textContent = mod.version ? 'v' + mod.version : '';

  const source = document.createElement('span');
  source.className = 'module-source';
  source.textContent = mod.source === 'installed' ? 'installed' : 'bundled';
  source.title = mod.source === 'installed'
    ? 'Installed from the repo into the data directory'
    : 'Ships with this copy of ProdDash';

  const spacer = document.createElement('span');
  spacer.className = 'spacer';

  // filled by the catalog when the repo has a newer version
  const updateSlot = document.createElement('span');
  updateSlot.className = 'module-update-slot';

  const uninstall = document.createElement('button');
  uninstall.className = 'btn small danger';
  uninstall.textContent = 'Uninstall';
  uninstall.title = mod.source === 'installed'
    ? 'Remove this module\'s files from the data directory'
    : 'Hide this bundled module from every dashboard (its folder stays with the app)';
  uninstall.addEventListener('click', async () => {
    const what = mod.source === 'installed'
      ? `Uninstall ${mod.name}? Its files are removed from the data directory. Its settings are kept in case you install it again.`
      : `Uninstall ${mod.name}? It disappears from every dashboard and the picker. It ships with ProdDash, so it can be brought back from "Available modules" any time.`;
    if (!window.confirm(what)) return;
    uninstall.disabled = true;
    try {
      await api(`/api/admin/modules/${encodeURIComponent(mod.id)}`, { method: 'DELETE' });
      toast(`${mod.name} uninstalled`);
      await loadState();
    } catch (e) {
      uninstall.disabled = false;
      if (e.authRequired) showLogin();
      else toast(e.message, true);
    }
  });

  const toggleLabel = document.createElement('label');
  toggleLabel.className = 'switch';
  const toggle = document.createElement('input');
  toggle.type = 'checkbox';
  toggle.checked = mod.enabled;
  const track = document.createElement('span');
  track.className = 'track';
  const toggleText = document.createElement('span');
  toggleText.textContent = mod.enabled ? 'Enabled' : 'Disabled';
  toggleLabel.append(toggle, track, toggleText);

  head.append(dot, name, version, source, spacer, updateSlot, toggleLabel, uninstall);
  card.appendChild(head);

  const desc = document.createElement('div');
  desc.className = 'module-desc';
  desc.textContent = mod.description;
  card.appendChild(desc);

  // The module's own words about its upstream ("polling timers on
  // 10.3.11.20:1025") — a readout, so it sits in a bordered monospace box
  // and the state (ok / connecting / error) is its text colour.
  const healthEl = document.createElement('div');
  healthEl.className = 'module-status ' + healthClass(mod);
  healthEl.textContent = healthText(mod);
  card.appendChild(healthEl);

  const mountError = document.createElement('div');
  mountError.className = 'module-mount-error';
  mountError.hidden = !mod.mountError && !mod.incompatible;
  mountError.textContent = mod.incompatible
    ? `Not loaded — ${mod.incompatible}. Update ProdDash from the banner above.`
    : (mod.mountError ? `Failed to start: ${mod.mountError}` : '');
  card.appendChild(mountError);

  liveEls.set(mod.id, { dot, healthEl, toggle, toggleText, mountError, updateSlot });

  toggle.addEventListener('change', async () => {
    try {
      await api(`/api/admin/modules/${encodeURIComponent(mod.id)}/enabled`, {
        method: 'PUT',
        body: JSON.stringify({ enabled: toggle.checked }),
      });
      toggleText.textContent = toggle.checked ? 'Enabled' : 'Disabled';
      toast(`${mod.name} ${toggle.checked ? 'enabled' : 'disabled'}`);
      refreshStatus();
    } catch (e) {
      toggle.checked = !toggle.checked;
      if (e.authRequired) showLogin();
      else toast(e.message, true);
    }
  });

  const schemaKeys = Object.entries(mod.configSchema || {});
  if (schemaKeys.length) {
    const form = document.createElement('div');
    form.className = 'module-form';
    const readers = new Map();
    const controls = new Map(); // key → boolean/switch input (for showWhen)
    const selects = new Map(); // key → select element (optionsDependsOn sources)
    const dependents = []; // { field, when } to show/hide by a control's state
    const optionDeps = []; // { refetch, on } selects whose options follow another field
    const reloaders = []; // re-run every optionsRoute fetch (after a save changed what the module can list)
    const collapsibles = []; // { el, meta, fields } groups that fold
    // Fields render in schema order; a `group` starts a labeled subsection
    // and consecutive same-group fields share it. The manifest's optional
    // `configGroups[name]` adds { collapsed, columns, help, toggle } for
    // that group: help is an ⓘ beside the title, toggle names the switch
    // that is the group's on/off and lives in the title row.
    const groupMeta = mod.configGroups && typeof mod.configGroups === 'object' ? mod.configGroups : {};
    let groupName = null;
    let container = form;
    let currentGroup = null;
    for (const [key, spec] of schemaKeys) {
      const g = spec?.group || '';
      if (g !== groupName) {
        groupName = g;
        currentGroup = null;
        if (g) {
          const meta = groupMeta[g] && typeof groupMeta[g] === 'object' ? groupMeta[g] : {};
          const folds = meta.collapsed !== undefined;
          const group = document.createElement(folds ? 'details' : 'div');
          group.className = 'field-group';
          const title = document.createElement(folds ? 'summary' : 'div');
          title.className = 'field-group-title';
          const titleName = document.createElement('span');
          titleName.className = 'field-group-name';
          titleName.textContent = g;
          title.appendChild(titleName);
          if (meta.help) title.appendChild(groupInfo(g, String(meta.help)));
          group.appendChild(title);
          const body = document.createElement('div');
          body.className = 'field-group-body';
          const cols = Math.min(4, Math.trunc(Number(meta.columns)) || 0);
          if (cols > 1) {
            body.classList.add('is-columns');
            body.style.setProperty('--cols', String(cols));
          }
          group.appendChild(body);
          form.appendChild(group);
          container = body;
          currentGroup = {
            el: group,
            title,
            meta,
            fields: [],
            toggleKey: typeof meta.toggle === 'string' ? meta.toggle : '',
          };
          if (folds) collapsibles.push(currentGroup);
        } else {
          container = form;
        }
      }
      const { field, read, control, selectEl, refetch } = fieldFor(key, spec, mod.config[key], mod.passwordSet[key], mod.id);
      readers.set(key, read);
      if (control) controls.set(key, control);
      if (selectEl) selects.set(key, selectEl);
      if (refetch && spec?.optionsDependsOn) optionDeps.push({ refetch, on: spec.optionsDependsOn });
      else if (refetch) reloaders.push(() => refetch());
      if (spec?.showWhen) dependents.push({ field, when: spec.showWhen });
      if (currentGroup) currentGroup.fields.push({ key, spec });
      if (currentGroup && control && key === currentGroup.toggleKey) {
        // The group's on/off: title row, not the body (never both). A
        // toggle naming a non-boolean field is ignored and renders normally.
        mountGroupToggle(currentGroup, field, control);
      } else {
        container.appendChild(field);
      }
    }
    // A field with showWhen:"K" is visible only while K's toggle is on.
    for (const dep of dependents) {
      const ctl = controls.get(dep.when);
      if (!ctl) continue;
      const sync = () => { dep.field.hidden = !ctl.checked; };
      ctl.addEventListener('change', sync);
      sync();
    }
    // A select with optionsDependsOn:"K" loads its options with K's current
    // value as a query parameter, now and whenever K changes (a plan list
    // that follows the chosen service type).
    for (const dep of optionDeps) {
      const src = selects.get(dep.on) || controls.get(dep.on);
      const run = () => dep.refetch({ [dep.on]: !src ? '' : (src.type === 'checkbox' ? String(src.checked) : src.value) });
      if (src) src.addEventListener('change', run);
      reloaders.push(run);
      run();
    }
    // Collapsible groups: `collapsed: true` starts folded, `false` open,
    // "whenSet" folded only once the group already holds values.
    for (const grp of collapsibles) {
      const c = grp.meta.collapsed;
      grp.el.open = !(c === true || (c === 'whenSet' && groupHasValues(grp.fields, mod)));
    }
    const actions = document.createElement('div');
    actions.className = 'module-actions';
    const save = document.createElement('button');
    const status = document.createElement('span');
    status.className = 'admin-status';
    actions.append(status, save);
    // A card is a status line until someone wants to change something: the
    // form starts folded, and the row at the bottom holds one button that
    // does both jobs — "Configure" opens the form and becomes "Apply", which
    // saves without closing it. The name is the other way in and out.
    card.appendChild(form);
    card.appendChild(actions);
    const openKey = 'proddash:admin:open:' + mod.id;
    const setOpen = (open) => {
      form.hidden = !open;
      status.hidden = !open;
      save.textContent = open ? 'Apply' : 'Configure';
      save.className = open ? 'btn primary' : 'btn';
      try { sessionStorage.setItem(openKey, open ? '1' : '0'); } catch { /* fine */ }
    };
    let wasOpen = false;
    try { wasOpen = sessionStorage.getItem(openKey) === '1'; } catch { /* fine */ }
    setOpen(wasOpen);
    name.classList.add('is-toggle');
    name.title = 'Show or hide this module\'s settings';
    name.tabIndex = 0;
    name.setAttribute('role', 'button');
    name.addEventListener('click', () => setOpen(form.hidden));
    name.addEventListener('keydown', (e) => {
      if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); setOpen(form.hidden); }
    });

    save.addEventListener('click', async () => {
      if (form.hidden) return setOpen(true);
      const config = {};
      for (const [key, read] of readers) config[key] = read();
      save.disabled = true;
      status.textContent = 'Applying…';
      status.className = 'admin-status';
      try {
        await api(`/api/admin/modules/${encodeURIComponent(mod.id)}/config`, {
          method: 'PUT',
          body: JSON.stringify({ config }),
        });
        status.textContent = 'Applied — module re-initialised. Open tiles reconnect on their own.';
        status.className = 'admin-status ok';
        refreshStatus();
        // What the module can list may have changed (credentials just
        // saved → the upstream is reachable now): reload the dynamic selects.
        // The re-init is quick but not instant; give it a beat.
        setTimeout(() => { for (const reload of reloaders) reload(); }, 800);
      } catch (e) {
        status.textContent = e.message;
        status.className = 'admin-status error';
        if (e.authRequired) showLogin();
      } finally {
        save.disabled = false;
      }
    });
  } else {
    const none = document.createElement('div');
    none.className = 'module-form-empty';
    none.textContent = 'No server-wide settings — this module is configured per tile.';
    card.appendChild(none);
  }

  return card;
}

/* ── status refresh (leaves form inputs alone) ──────────────────────── */

async function refreshStatus() {
  let state;
  try {
    state = await api('/api/admin/state');
  } catch {
    return; // transient — the next tick will get it
  }
  for (const mod of state.modules || []) {
    const els = liveEls.get(mod.id);
    if (!els) continue;
    els.dot.className = 'dot ' + healthClass(mod);
    els.healthEl.textContent = healthText(mod);
    els.healthEl.className = 'module-status ' + healthClass(mod);
    if (!mod.incompatible) {
      els.mountError.hidden = !mod.mountError;
      els.mountError.textContent = mod.mountError ? `Failed to start: ${mod.mountError}` : '';
    }
    if (document.activeElement !== els.toggle) {
      els.toggle.checked = mod.enabled;
      els.toggleText.textContent = mod.enabled ? 'Enabled' : 'Disabled';
    }
  }
}

/* ── saved layouts ──────────────────────────────────────────────────── */

async function loadLayouts() {
  let body;
  try {
    body = await api('/api/layouts');
  } catch {
    layoutsSection.hidden = true;
    return;
  }
  layoutsSection.hidden = false;
  layoutsList.innerHTML = '';
  const layouts = body.layouts || [];
  if (!layouts.length) {
    const none = document.createElement('div');
    none.className = 'layouts-empty';
    none.textContent = 'No layouts saved yet. Save one from the dashboard’s Layout menu.';
    layoutsList.appendChild(none);
    return;
  }
  for (const layout of layouts) {
    const row = document.createElement('div');
    row.className = 'layout-row';
    const name = document.createElement('span');
    name.className = 'name';
    name.textContent = layout.name;
    const meta = document.createElement('span');
    meta.className = 'meta';
    meta.textContent = `${layout.tiles} tile${layout.tiles === 1 ? '' : 's'}`
      + (layout.updated ? ` · ${new Date(layout.updated).toLocaleString()}` : '');
    const rename = document.createElement('button');
    rename.className = 'btn';
    rename.textContent = 'Rename';
    rename.addEventListener('click', async () => {
      const next = prompt('New name for this layout:', layout.name);
      if (!next || next.trim() === '' || next === layout.name) return;
      try {
        await api(`/api/layouts/${encodeURIComponent(layout.name)}/rename`, {
          method: 'POST',
          body: JSON.stringify({ name: next.trim() }),
        });
        toast('Layout renamed');
        loadLayouts();
      } catch (e) {
        if (e.authRequired) showLogin();
        else toast(e.message, true);
      }
    });
    const del = document.createElement('button');
    del.className = 'btn';
    del.textContent = 'Delete';
    del.addEventListener('click', async () => {
      if (!confirm(`Delete the layout “${layout.name}”? Browsers using it keep their current tiles.`)) return;
      try {
        await api(`/api/layouts/${encodeURIComponent(layout.name)}`, { method: 'DELETE' });
        toast('Layout deleted');
        loadLayouts();
      } catch (e) {
        if (e.authRequired) showLogin();
        else toast(e.message, true);
      }
    });
    row.append(name, meta, rename, del);
    layoutsList.appendChild(row);
  }
}

/* ── boot ───────────────────────────────────────────────────────────── */

async function loadState() {
  let state;
  try {
    state = await api('/api/admin/state');
  } catch (e) {
    if (e.status === 401 || e.authRequired) {
      showLogin();
      return;
    }
    toast('ProdDash server unreachable — retrying…', true);
    setTimeout(loadState, 4000);
    return;
  }
  loginCard.hidden = true;
  modulesSection.hidden = false;
  availableSection.hidden = false;
  shellVersion = String(state.version || '');
  shellVersionEl.textContent = shellVersion ? 'v' + shellVersion : '';
  const storageNote = document.getElementById('storage-note');
  if (state.dataDir) {
    document.getElementById('storage-path').textContent = state.dataDir;
    storageNote.hidden = false;
  }
  modulesList.innerHTML = '';
  liveEls.clear();
  for (const mod of state.modules || []) {
    modulesList.appendChild(buildModuleCard(mod));
  }
  loadTheme();
  loadLayouts();
  loadCatalog(false);
}

/* ── theme ──────────────────────────────────────────────────────────── */

/* The dashboard palette is a server-wide choice. The server lists the
   presets (GET /api/theme — public, dashboards need it too) and the admin
   page shows them as swatches; picking one POSTs it, applies it here at
   once, and the server's `theme` shell event switches every open dashboard
   — and any other admin page — live. The palettes themselves are
   html[data-theme="…"] variable sets in the shell's style.css, which this
   page shares, so the admin page follows its own choice. */

const LS_THEME = 'proddash:theme';
let themeList = [];
let currentTheme = '';

function applyTheme(id) {
  const theme = String(id || '');
  if (!/^[a-z][a-z0-9-]{0,31}$/.test(theme)) return;
  document.documentElement.dataset.theme = theme;
  try { localStorage.setItem(LS_THEME, theme); } catch { /* private mode — fine */ }
}

// The last-known theme first (shared with the dashboard, same origin), so
// the page doesn't flash the default palette before the server answers.
try { applyTheme(localStorage.getItem(LS_THEME)); } catch { /* fine */ }

function themeName(id) {
  return themeList.find((t) => t.id === id)?.name || id;
}

function renderThemes() {
  themeSwatches.innerHTML = '';
  for (const t of themeList) {
    const current = t.id === currentTheme;
    const btn = document.createElement('button');
    btn.type = 'button';
    btn.className = 'theme-swatch' + (current ? ' is-current' : '');
    btn.setAttribute('role', 'radio');
    btn.setAttribute('aria-checked', current ? 'true' : 'false');
    btn.title = current ? `${t.name} — the current theme` : `Switch every dashboard to ${t.name}`;
    const preview = document.createElement('span');
    preview.className = 'theme-preview';
    preview.style.setProperty('--sw-bg', String(t.colors?.bg || '#000'));
    preview.style.setProperty('--sw-panel', String(t.colors?.panel || '#222'));
    preview.style.setProperty('--sw-accent', String(t.colors?.accent || '#fff'));
    const name = document.createElement('span');
    name.className = 'theme-name';
    name.textContent = t.name;
    btn.append(preview, name);
    btn.addEventListener('click', () => chooseTheme(t.id));
    themeSwatches.appendChild(btn);
  }
}

/**
 * Fetch the server's theme and list. Applied to this page either way (the
 * endpoint is public, so even the login card wears the right palette); the
 * swatch section itself is only revealed for an unlocked page.
 */
async function loadTheme(reveal = true) {
  let body;
  try {
    body = await api('/api/theme');
  } catch {
    if (reveal) themeSection.hidden = true; // a server without themes — nothing to offer
    return;
  }
  themeList = Array.isArray(body.themes) ? body.themes.filter((t) => t && t.id && t.name) : [];
  currentTheme = String(body.theme || '');
  applyTheme(currentTheme);
  renderThemes();
  if (reveal) themeSection.hidden = !themeList.length;
}

loadTheme(false);

async function chooseTheme(id) {
  if (id === currentTheme) return;
  const previous = currentTheme;
  currentTheme = id;
  applyTheme(id); // at once, here — the server's event confirms it everywhere else
  renderThemes();
  themeStatus.textContent = '';
  themeStatus.className = 'admin-status';
  try {
    await api('/api/admin/theme', { method: 'POST', body: JSON.stringify({ theme: id }) });
    themeStatus.textContent = `${themeName(id)} — every open dashboard switched.`;
    themeStatus.className = 'admin-status ok';
  } catch (e) {
    currentTheme = previous;
    applyTheme(previous);
    renderThemes();
    themeStatus.textContent = e.message;
    themeStatus.className = 'admin-status error';
    if (e.authRequired) showLogin();
  }
}

// Follow a theme change made elsewhere (another admin page) live.
let themeEvents = null;
let themeEventsRetry = null;

function subscribeThemeEvents() {
  try { themeEvents?.close(); } catch { /* not open */ }
  themeEvents = new EventSource('/api/events');
  themeEvents.addEventListener('theme', (e) => {
    let theme = '';
    try { theme = String(JSON.parse(e.data).theme || ''); } catch { return; }
    if (!theme || theme === currentTheme) return;
    currentTheme = theme;
    applyTheme(theme);
    renderThemes();
  });
  themeEvents.onerror = () => {
    if (themeEvents.readyState === EventSource.CLOSED) {
      clearTimeout(themeEventsRetry);
      themeEventsRetry = setTimeout(subscribeThemeEvents, 4000);
    }
  };
}

subscribeThemeEvents();

/* ── the repo: available modules, module updates, shell update ──────── */

function fmtTime(ms) {
  return ms ? new Date(ms).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' }) : '';
}

async function loadCatalog(refresh) {
  catalogStatus.className = 'admin-status';
  catalogStatus.textContent = refresh ? 'Checking the repo…' : 'Checking…';
  let cat;
  try {
    cat = await api('/api/admin/catalog' + (refresh ? '?refresh=1' : ''));
  } catch (e) {
    if (e.authRequired) return showLogin();
    catalogStatus.className = 'admin-status error';
    catalogStatus.textContent = e.message;
    return;
  }
  renderShell(cat.shell || {});
  renderAvailable(cat);
}

function renderShell(shell) {
  const remote = shell.remote || {};
  if (remote.error) {
    catalogStatus.className = 'admin-status error';
    catalogStatus.textContent = `Couldn't reach ${shell.repo}: ${remote.error}`;
  } else {
    catalogStatus.className = 'admin-status';
    catalogStatus.textContent = `${shell.repo}@${shell.branch}` +
      (remote.version ? ` · latest ProdDash ${remote.version}` : '') +
      (remote.checkedAt ? ` · checked ${fmtTime(remote.checkedAt)}` : '');
  }
  if (!shell.updateAvailable) {
    updateCard.hidden = true;
    return;
  }
  updateCard.hidden = false;
  updateTitle.textContent = shell.versionBehind
    ? `ProdDash ${remote.version} is available`
    : `New commits on ${shell.branch}`;
  const where = shell.local?.isGit
    ? `a git checkout of ${shell.local.branch} at ${String(shell.local.sha || '').slice(0, 7)}; updating runs git pull`
    : 'not a git checkout; updating unpacks the repo archive over the app folder';
  updateCopy.textContent = `You're running ProdDash ${shell.version} (${where}). Settings and layouts live outside the app folder and are not touched.`;
  updateChanges.href = shell.changesUrl || '#';
  updateBtn.disabled = Boolean(shell.updateBlocker) || updateBtn.dataset.busy === '1';
  if (shell.updateBlocker) {
    updateStatus.className = 'admin-status error';
    updateStatus.textContent = `Can't update from here: ${shell.updateBlocker}.`;
  } else if (updateBtn.dataset.busy !== '1') {
    updateStatus.className = 'admin-status';
    updateStatus.textContent = 'Updating restarts ProdDash; open dashboards reconnect on their own.';
  }
}

function renderAvailable(cat) {
  availableList.innerHTML = '';
  const updates = cat.updates || [];
  // newer versions of installed modules → a button on their card
  for (const els of liveEls.values()) els.updateSlot.innerHTML = '';
  for (const up of updates) {
    const els = liveEls.get(up.id);
    if (!els) continue;
    const btn = document.createElement('button');
    btn.className = 'btn small primary';
    btn.textContent = `Update to v${up.version}`;
    btn.disabled = !up.compatible;
    btn.title = up.compatible ? `Download v${up.version} from the repo` : up.reason;
    btn.addEventListener('click', () => installFromCatalog(up, btn));
    els.updateSlot.appendChild(btn);
  }
  const available = cat.available || [];
  if (!available.length) {
    const none = document.createElement('div');
    none.className = 'layouts-empty';
    none.textContent = cat.shell?.remote?.error
      ? 'The repo could not be reached, and nothing bundled is waiting to be installed.'
      : 'Everything the repo offers is installed.';
    availableList.appendChild(none);
    return;
  }
  for (const item of available) {
    const row = document.createElement('div');
    row.className = 'catalog-row';
    const main = document.createElement('div');
    main.className = 'catalog-main';
    const title = document.createElement('div');
    title.className = 'catalog-title';
    const name = document.createElement('span');
    name.className = 'module-name';
    name.textContent = item.name;
    const version = document.createElement('span');
    version.className = 'module-version';
    version.textContent = item.version ? 'v' + item.version : '';
    const source = document.createElement('span');
    source.className = 'module-source';
    source.textContent = item.source === 'bundled' ? 'bundled' : 'repo';
    source.title = item.source === 'bundled' ? 'Ships with this copy of ProdDash — restoring it downloads nothing' : 'Downloaded from the repo';
    title.append(name, version, source);
    const desc = document.createElement('div');
    desc.className = 'module-desc';
    desc.textContent = item.description || '';
    const req = document.createElement('div');
    req.className = 'module-health' + (item.compatible ? '' : ' error');
    req.textContent = item.compatible
      ? (item.requires ? `Requires ProdDash ${item.requires}` : '')
      : item.reason;
    main.append(title, desc, req);
    const btn = document.createElement('button');
    btn.className = 'btn small primary';
    btn.textContent = 'Install';
    btn.disabled = !item.compatible;
    btn.title = item.compatible ? '' : item.reason;
    btn.addEventListener('click', () => installFromCatalog(item, btn));
    row.append(main, btn);
    availableList.appendChild(row);
  }
}

async function installFromCatalog(item, btn) {
  btn.disabled = true;
  const label = btn.textContent;
  btn.textContent = 'Installing…';
  try {
    const r = await api(`/api/admin/modules/${encodeURIComponent(item.id)}/install`, { method: 'POST', body: '{}' });
    toast(`${item.name} ${r.downloaded ? 'installed' : 'restored'}${r.version ? ' (v' + r.version + ')' : ''}`);
    await loadState();
  } catch (e) {
    btn.disabled = false;
    btn.textContent = label;
    if (e.authRequired) showLogin();
    else toast(e.message, true);
  }
}

document.getElementById('catalog-refresh').addEventListener('click', () => loadCatalog(true));

const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

/** After the update the server exits and comes back; wait for it. */
async function waitForRestart(before) {
  const started = Date.now();
  let sawDown = false;
  while (Date.now() - started < 90000) {
    await sleep(1500);
    try {
      const s = await api('/api/admin/state');
      if (sawDown || s.version !== before) {
        toast(`ProdDash ${s.version} is running`);
        await sleep(600);
        location.reload();
        return;
      }
    } catch (e) {
      if (e.status === 401) { location.reload(); return; } // back up, passcode wanted again
      sawDown = true;
    }
  }
  updateStatus.className = 'admin-status error';
  updateStatus.textContent = 'ProdDash did not come back on its own — start it again on the server, then reload this page.';
  updateBtn.dataset.busy = '';
  updateBtn.disabled = false;
}

updateBtn.addEventListener('click', async () => {
  if (!window.confirm('Update ProdDash now? The server restarts and every open dashboard reconnects a few seconds later.')) return;
  updateBtn.dataset.busy = '1';
  updateBtn.disabled = true;
  updateStatus.className = 'admin-status';
  updateStatus.textContent = 'Updating…';
  const before = shellVersion;
  try {
    const r = await api('/api/admin/update', { method: 'POST', body: '{}' });
    updateStatus.textContent = `Updated ${r.from} → ${r.to || 'latest commit'} via ${r.method}. Restarting…`;
  } catch (e) {
    updateStatus.className = 'admin-status error';
    updateStatus.textContent = e.message;
    updateBtn.dataset.busy = '';
    updateBtn.disabled = false;
    if (e.authRequired) showLogin();
    return;
  }
  await waitForRestart(before);
});

setInterval(() => {
  if (modulesSection.hidden) return;
  refreshStatus();
}, 5000);

loadState();