// 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 { $ } from "./common.js";
import { el } from "@hive/shared/dom.js";
import { containersState } from "./state.js";
import { asyncBtn } from "@hive/shared/forms.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) {
  const btn = sectionRoot
    ? sectionRoot.querySelector(
        `[data-agent="${CSS.escape(name)}"] .perm-remove-btn`,
      )
    : null;
  const doDelete = async () => {
    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);
        return;
      }
      // Re-fetch both sections so the stale row disappears.
      await Promise.all([
        fetchAndRenderCapabilities(),
        fetchAndRenderToolGroups(),
      ]);
    } catch (err) {
      setSaveNote("failed to remove " + name + ": " + err, true);
    }
  };
  // asyncBtn guards double-submit; fall through without guard when there
  // is no button (e.g. called programmatically without a DOM context).
  // Return the promise so callers can await clearStaleAgent() if needed.
  if (btn) return asyncBtn(btn, doDelete);
  await doDelete();
}

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);
  }
}