// Dashboard P3RM1SS10NS tab — the per-agent capabilities + tool-groups
// matrices, with a single page-level "save all" button.
//
// Both tables are fetched on tab activation (`GET /api/capabilities`,
// `GET /api/tool-groups`) and after each save. Columns (caps / groups)
// come from the backend so the UI needs no change when a new one is
// added. Live updates arrive via the `capabilities_changed` /
// `tool_groups_changed` dashboard events (fired after the rebuild-queue
// worker commits the perm JSON file), wired into the entry's mutation
// dispatch table.
//
// Stateless at module scope: each render builds fresh from the fetched
// payload. The agent roster (`containersState`) is the only shared state
// it reads — to union live containers with agents already named in the
// assignments map.
//
// Editing model: checkboxes are diffed against a `data-baseline` captured at
// render time; only changed perm-types per agent are POSTed to
// `POST /api/permissions` as `{ changes: [{agent, tool_groups?, capabilities?}] }`.
// Omitted field = leave untouched; included array = full replace. The backend
// coalesces caps+groups per agent into ONE queue entry (one rebuild, no
// double-rebuild). Batch is atomic — saved→rebuilding only fires on a clean 200.

import { $, el } from './common.js';
import { containersState } from './state.js';

// ── SSE re-render guards ────────────────────────────────────────────
// Skip the live re-render when the operator has unsaved edits in that
// section (or a checkbox focused) — clobbering a half-finished edit set
// is worse than a brief staleness window. The tab-activation re-fetch
// and the post-save re-fetch are the recovery paths; both clear dirty.

export function applyCapabilitiesChanged(ev) {
  const root = $('capabilities-section');
  if (!root) return;
  if (root.contains(document.activeElement)) return;
  if (sectionHasDirty(root)) return;
  renderCapabilities(root, ev);
}
export function applyToolGroupsChanged(ev) {
  const root = $('tool-groups-section');
  if (!root) return;
  if (root.contains(document.activeElement)) return;
  if (sectionHasDirty(root)) return;
  renderToolGroups(root, ev);
}

// A section is dirty if any checkbox diverges from its render-time
// baseline. Cheap DOM scan; no module-level mirror to drift.
function sectionHasDirty(root) {
  for (const cb of root.querySelectorAll('input[type=checkbox]')) {
    if (cb.checked !== (cb.dataset.baseline === '1')) return true;
  }
  return false;
}

export async function fetchAndRenderCapabilities() {
  const root = $('capabilities-section');
  if (!root) return;
  root.replaceChildren();
  root.append(el('p', { class: 'meta' }, 'loading…'));
  try {
    const resp = await fetch('/api/capabilities');
    if (!resp.ok) throw new Error('http ' + resp.status);
    const data = await resp.json();
    renderCapabilities(root, data);
  } catch (err) {
    root.replaceChildren();
    root.append(el('p', { class: 'meta' }, 'fetch failed: ' + err));
  }
}

function renderCapabilities(root, data) {
  root.replaceChildren();
  const { caps, descriptions = {}, assignments, effective = {} } = data;
  if (!caps || !caps.length) {
    root.append(el('p', { class: 'meta' }, '(no capabilities defined)'));
    updateSaveBar();
    return;
  }

  // Agent rows: prefer the backend roster (every manageable agent,
  // default-perms included). Fall back to the live-container ∪ explicit
  // union for older payloads that don't carry `agents`.
  const agentNames = (data.agents && data.agents.length)
    ? [...data.agents]
    : [...new Set([
        ...Array.from(containersState.keys()),
        ...Object.keys(assignments),
      ])].sort();

  if (!agentNames.length) {
    root.append(el('p', { class: 'meta' }, '(no agents)'));
    updateSaveBar();
    return;
  }

  const wrap = el('div', { class: 'cap-table-wrap' });
  const table = el('table', { class: 'cap-table' });

  // Header row.
  const thead = el('thead');
  const hrow = el('tr');
  hrow.append(el('th', { class: 'cap-agent-col' }, 'agent'));
  for (const c of caps) {
    hrow.append(el('th', { class: 'cap-col', title: descriptions[c] || c }, c));
  }
  thead.append(hrow);
  table.append(thead);

  const tbody = el('tbody');
  for (const name of agentNames) {
    // Effective caps (explicit-or-default) drive the checkboxes so
    // default-perms agents show their real grants, not blank.
    const assigned = effective[name] || assignments[name] || [];
    // `containersState` is keyed from `nixos-container list`, which
    // includes stopped-but-configured containers — so a temporarily-stopped
    // agent is NOT stale. Only destroyed/renamed agents are absent here.
    const isStale = !containersState.has(name);
    const tr = el('tr', { class: 'cap-row' + (isStale ? ' perm-row-stale' : ''), 'data-agent': name });

    // Agent name cell.
    const nameTd = el('td', { class: 'cap-agent-col' });
    nameTd.append(el('span', { class: 'cap-agent-name' }, name));
    if (isStale) {
      nameTd.append(el('span', { class: 'perm-stale-label' }, '(not running)'));
      const removeBtn = el('button', {
        type: 'button',
        class: 'perm-remove-btn',
        title: 'remove stale permission entries for ' + name,
      }, '✕ remove');
      removeBtn.addEventListener('click', () => clearStaleAgent(name, root));
      nameTd.append(removeBtn);
    }
    tr.append(nameTd);

    // One checkbox per capability.
    for (const c of caps) {
      const checked = assigned.includes(c);
      const td = el('td', { class: 'cap-col' });
      const cb = el('input', {
        type: 'checkbox',
        class: 'cap-cb',
        'data-cap': c,
        'data-baseline': checked ? '1' : '0',
        'aria-label': c,
      });
      cb.checked = checked;
      cb.addEventListener('change', onCellToggle);
      td.append(cb);
      tr.append(td);
    }

    tbody.append(tr);
  }
  table.append(tbody);
  wrap.append(table);
  root.append(wrap);
  updateSaveBar();
}

export async function fetchAndRenderToolGroups() {
  const root = $('tool-groups-section');
  if (!root) return;
  root.replaceChildren();
  root.append(el('p', { class: 'meta' }, 'loading…'));
  try {
    const resp = await fetch('/api/tool-groups');
    if (!resp.ok) throw new Error('http ' + resp.status);
    const data = await resp.json();
    renderToolGroups(root, data);
  } catch (err) {
    root.replaceChildren();
    root.append(el('p', { class: 'meta' }, 'fetch failed: ' + err));
  }
}

function renderToolGroups(root, data) {
  root.replaceChildren();
  const { groups, descriptions = {}, assignments, effective = {} } = data;
  if (!groups || !groups.length) {
    root.append(el('p', { class: 'meta' }, '(no tool groups defined)'));
    updateSaveBar();
    return;
  }

  // Agent rows: prefer the backend roster (default-perms agents included);
  // fall back to the live-container ∪ explicit union for older payloads.
  const agentNames = (data.agents && data.agents.length)
    ? [...data.agents]
    : [...new Set([
        ...Array.from(containersState.keys()),
        ...Object.keys(assignments),
      ])].sort();

  if (!agentNames.length) {
    root.append(el('p', { class: 'meta' }, '(no agents)'));
    updateSaveBar();
    return;
  }

  const wrap = el('div', { class: 'tg-table-wrap' });
  const table = el('table', { class: 'tg-table' });

  // Header row.
  const thead = el('thead');
  const hrow = el('tr');
  hrow.append(el('th', { class: 'tg-agent-col' }, 'agent'));
  for (const g of groups) {
    hrow.append(el('th', { class: 'tg-group-col', title: descriptions[g] || g }, g));
  }
  thead.append(hrow);
  table.append(thead);

  const tbody = el('tbody');
  for (const name of agentNames) {
    // Effective groups (explicit-or-role-default) drive the checkboxes so
    // a default agent shows its real groups, not blank — and saving keeps
    // them instead of silently stripping the defaults. The "(default)"
    // badge still keys off explicit-assignment presence.
    const assigned = effective[name] || assignments[name] || [];
    const hasExplicit = Object.prototype.hasOwnProperty.call(assignments, name);
    // `containersState` is keyed from `nixos-container list`, which
    // includes stopped-but-configured containers — only destroyed/renamed
    // agents are absent.
    const isStale = !containersState.has(name);
    const tr = el('tr', { class: 'tg-row' + (isStale ? ' perm-row-stale' : ''), 'data-agent': name });

    // Agent name cell.
    const nameTd = el('td', { class: 'tg-agent-col' });
    nameTd.append(el('span', { class: 'tg-agent-name' }, name));
    if (isStale) {
      nameTd.append(el('span', { class: 'perm-stale-label' }, '(not running)'));
      const removeBtn = el('button', {
        type: 'button',
        class: 'perm-remove-btn',
        title: 'remove stale permission entries for ' + name,
      }, '✕ remove');
      removeBtn.addEventListener('click', () => clearStaleAgent(name, root));
      nameTd.append(removeBtn);
    } else if (!hasExplicit) {
      nameTd.append(el('span', { class: 'meta tg-default-label' }, '(default)'));
    }
    tr.append(nameTd);

    // One checkbox per group.
    for (const g of groups) {
      const checked = assigned.includes(g);
      const td = el('td', { class: 'tg-group-col' });
      const cb = el('input', {
        type: 'checkbox',
        class: 'tg-cb',
        'data-group': g,
        'data-baseline': checked ? '1' : '0',
        'aria-label': g,
      });
      cb.checked = checked;
      cb.addEventListener('change', onCellToggle);
      td.append(cb);
      tr.append(td);
    }

    tbody.append(tr);
  }
  table.append(tbody);
  wrap.append(table);
  root.append(wrap);
  updateSaveBar();
}

// ── Save-all wiring ─────────────────────────────────────────────────

// Recompute the save bar on every cell toggle. Also clears any stale
// error/✓ status the bar may be showing from a prior save.
function onCellToggle() {
  clearSaveStatus();
  updateSaveBar();
}

// Collect the sparse change-set: one entry per agent that has at least
// one perm-type diverging from baseline. Only the changed perm-type(s)
// are included so untouched defaults stay defaults (an included array is
// a full replacement → omitting it leaves that file alone).
function collectChanges() {
  const byAgent = new Map(); // agent -> { capabilities?, tool_groups? }
  collectSection($('capabilities-section'), '.cap-row', '.cap-cb', 'cap', 'capabilities', byAgent);
  collectSection($('tool-groups-section'), '.tg-row', '.tg-cb', 'group', 'tool_groups', byAgent);
  const changes = [];
  for (const [agent, obj] of byAgent) changes.push({ agent, ...obj });
  return changes;
}

function collectSection(root, rowSel, cbSel, dataKey, field, byAgent) {
  if (!root) return;
  for (const tr of root.querySelectorAll(rowSel)) {
    const agent = tr.dataset.agent;
    if (!agent) continue;
    let dirty = false;
    const selected = [];
    for (const cb of tr.querySelectorAll(cbSel)) {
      if (cb.checked !== (cb.dataset.baseline === '1')) dirty = true;
      if (cb.checked) selected.push(cb.dataset[dataKey]);
    }
    if (dirty) {
      const obj = byAgent.get(agent) || {};
      obj[field] = selected;
      byAgent.set(agent, obj);
    }
  }
}

function updateSaveBar() {
  const btn = $('perm-save-all');
  if (!btn) return;
  // Don't stomp a transient saving/rebuilding label.
  if (btn.dataset.busy === '1') return;
  const n = collectChanges().length;
  btn.disabled = n === 0;
  btn.textContent = n === 0 ? 'save all' : `save all (${n} agent${n === 1 ? '' : 's'})`;
}

// Remove all explicit permission entries for a stale (non-running)
// agent. Calls DELETE /api/permissions/{agent}, which bypasses the
// roster guard so the stale entries can be cleaned up even though the
// agent isn't in the live container list. Re-fetches both tables after
// the delete so the row disappears immediately.
async function clearStaleAgent(name, sectionRoot) {
  // Disable the row's remove button while the request is in flight to
  // prevent a double-submit.
  const btn = sectionRoot
    ? sectionRoot.querySelector(`[data-agent="${CSS.escape(name)}"] .perm-remove-btn`)
    : null;
  if (btn) btn.disabled = true;
  try {
    const resp = await fetch('/api/permissions/' + encodeURIComponent(name), { method: 'DELETE' });
    if (!resp.ok) {
      const text = await resp.text().catch(() => resp.status);
      setSaveNote('failed to remove ' + name + ': ' + text, true);
      if (btn) btn.disabled = false;
      return;
    }
  } catch (err) {
    setSaveNote('failed to remove ' + name + ': ' + err, true);
    if (btn) btn.disabled = false;
    return;
  }
  // Re-fetch both sections so the stale row disappears.
  await Promise.all([fetchAndRenderCapabilities(), fetchAndRenderToolGroups()]);
}

function clearSaveStatus() {
  const note = $('perm-save-note');
  if (note) { note.textContent = ''; note.classList.remove('perm-save-err'); }
}

function setSaveNote(text, isErr) {
  const note = $('perm-save-note');
  if (!note) return;
  note.textContent = text;
  note.classList.toggle('perm-save-err', !!isErr);
}

async function saveAll() {
  const btn = $('perm-save-all');
  if (!btn) return;
  const changes = collectChanges();
  if (!changes.length) return;
  btn.dataset.busy = '1';
  btn.disabled = true;
  btn.textContent = 'saving…';
  clearSaveStatus();
  try {
    const r = await fetch('/api/permissions', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ changes }),
    });
    if (!r.ok) {
      const txt = await r.text();
      btn.dataset.busy = '';
      btn.disabled = false;
      btn.textContent = 'save all';
      setSaveNote('save failed: ' + (txt || ('http ' + r.status)), true);
      updateSaveBar();
      return;
    }
    // Atomic 200: the whole batch landed. Show a rebuilding hint and
    // re-fetch both tables once the queue worker has committed — that
    // resets baselines (dirty clears) and the bar disables itself.
    const n = changes.length;
    btn.textContent = 'queued ✓';
    setSaveNote(`rebuilding ${n} agent${n === 1 ? '' : 's'}…`, false);
    setTimeout(() => {
      btn.dataset.busy = '';
      fetchAndRenderCapabilities();
      fetchAndRenderToolGroups();
    }, 900);
  } catch (err) {
    btn.dataset.busy = '';
    btn.disabled = false;
    btn.textContent = 'save all';
    setSaveNote('save failed: ' + String(err), true);
    updateSaveBar();
  }
}

// Bind the page-level save button once. Called from the dashboard entry
// after the DOM is ready (the button lives in the static permissions
// pane markup, so it exists before any fetch).
export function initPermissions() {
  const btn = $('perm-save-all');
  if (btn && !btn.dataset.bound) {
    btn.dataset.bound = '1';
    btn.addEventListener('click', saveAll);
  }
}