arc-tabgroups-shim.js

// ──────────────────────────────────────────────────────────────────
// Arc Tab Groups Shim
//
// Arc exposes the Chrome Tab Groups API surface (chrome.tabGroups is an
// object, chrome.tabs.group is a function, TAB_GROUP_ID_NONE === -1), BUT the
// calls never resolve: chrome.tabs.group() hangs forever. The Claude
// extension's automation layer ("MCP tab group") funnels every
// tabs_context_mcp / navigate through createGroup() -> chrome.tabs.group(), so
// the MCP tool never resolves and the request times out.
//
// Empirically (service-worker console):
//   STEP created 1204885098
//   STEP ERR TIMEOUT tabs.group      <-- chrome.tabs.group() never returns
//
// This shim replaces the tab-group methods in place with a fully in-memory
// emulation keyed by synthetic group IDs. It tracks membership itself and
// intercepts chrome.tabs.query({groupId}) / chrome.tabs.get() so the rest of
// the extension keeps working unmodified. Visual grouping is cosmetic and Arc
// doesn't render tab groups anyway, so emulation is sufficient. State is
// mirrored to chrome.storage.session so it survives service-worker restarts.
//
// Loaded in the service worker (where mcpPermissions + the bridge websocket +
// the tab-group manager run). Methods are overridden in place rather than
// replacing chrome.tabGroups wholesale, which is more likely to succeed when
// the native namespace object is present but non-configurable.
// ──────────────────────────────────────────────────────────────────

(function () {
  "use strict";

  if (typeof chrome === "undefined" || !chrome.tabs) return;
  if (globalThis.__arcTabGroupsShimInstalled) return;

  console.log("[Arc TabGroups Shim] installing in-memory tab group emulation");

  var NONE = -1;
  var nextGroupId = 900001;
  // groupId -> { title, color, collapsed, windowId, tabIds:Set<number> }
  var groups = new Map();
  // tabId -> groupId
  var tabToGroup = new Map();

  var Color = {
    grey: "grey", blue: "blue", red: "red", yellow: "yellow",
    green: "green", pink: "pink", purple: "purple", cyan: "cyan", orange: "orange",
    GREY: "grey", BLUE: "blue", RED: "red", YELLOW: "yellow",
    GREEN: "green", PINK: "pink", PURPLE: "purple", CYAN: "cyan", ORANGE: "orange"
  };

  // ── Persistence (survive MV3 service-worker restarts) ───────────────
  var STORE_KEY = "__arcEmulatedTabGroups";

  function save() {
    try {
      var arr = [];
      groups.forEach(function (g, id) {
        arr.push({
          id: id, title: g.title, color: g.color, collapsed: g.collapsed,
          windowId: g.windowId, tabIds: Array.from(g.tabIds)
        });
      });
      return chrome.storage.session.set({
        __arcEmulatedTabGroups: { nextGroupId: nextGroupId, groups: arr }
      });
    } catch (e) { return Promise.resolve(); }
  }

  var ready = (async function load() {
    try {
      var d = await chrome.storage.session.get(STORE_KEY);
      var saved = d && d[STORE_KEY];
      if (saved) {
        if (saved.nextGroupId) nextGroupId = saved.nextGroupId;
        (saved.groups || []).forEach(function (g) {
          groups.set(g.id, {
            title: g.title, color: g.color, collapsed: g.collapsed,
            windowId: g.windowId, tabIds: new Set(g.tabIds)
          });
          g.tabIds.forEach(function (t) { tabToGroup.set(t, g.id); });
        });
      }
    } catch (e) { /* storage.session unavailable → in-memory only */ }
  })();

  function groupObj(id) {
    var g = groups.get(id);
    if (!g) throw new Error("No group with id " + id);
    return {
      id: id, title: g.title || "", color: g.color || "orange",
      collapsed: !!g.collapsed, windowId: g.windowId
    };
  }

  // ── Native references (used only for non-group tab operations) ──────
  var nativeQuery = chrome.tabs.query.bind(chrome.tabs);
  var nativeGet = chrome.tabs.get.bind(chrome.tabs);

  // ── chrome.tabs.group ───────────────────────────────────────────────
  chrome.tabs.group = async function (opts) {
    await ready;
    opts = opts || {};
    var tabIds = [].concat(opts.tabIds || []);
    var gid = opts.groupId;
    var windowId = opts.createProperties && opts.createProperties.windowId;

    if (gid == null || !groups.has(gid)) {
      if (gid == null) gid = nextGroupId++;
      if (windowId == null && tabIds.length) {
        try { var t0 = await nativeGet(tabIds[0]); windowId = t0.windowId; } catch (e) {}
      }
      groups.set(gid, {
        title: "", color: "orange", collapsed: false,
        windowId: windowId, tabIds: new Set()
      });
    }
    var g = groups.get(gid);
    tabIds.forEach(function (t) { g.tabIds.add(t); tabToGroup.set(t, gid); });
    await save();
    return gid;
  };

  // ── chrome.tabs.ungroup ─────────────────────────────────────────────
  chrome.tabs.ungroup = async function (tabIds) {
    await ready;
    [].concat(tabIds || []).forEach(function (t) {
      var gid = tabToGroup.get(t);
      if (gid != null) {
        var g = groups.get(gid);
        if (g) g.tabIds.delete(t);
        tabToGroup.delete(t);
      }
    });
    await save();
  };

  // ── chrome.tabs.query (intercept groupId filter, else pass through) ──
  function doQuery(info) {
    return (async function () {
      await ready;
      if (info && info.groupId != null) {
        // Native Arc can't resolve group filters; serve from our tracking.
        if (groups.has(info.groupId)) {
          var g = groups.get(info.groupId);
          var out = [];
          var ids = Array.from(g.tabIds);
          for (var i = 0; i < ids.length; i++) {
            try { var t = await nativeGet(ids[i]); t.groupId = info.groupId; out.push(t); }
            catch (e) { /* tab gone; drop it */ g.tabIds.delete(ids[i]); tabToGroup.delete(ids[i]); }
          }
          return out;
        }
        // Unknown group: return everything native, filtered by our tracking.
        var clone = Object.assign({}, info);
        delete clone.groupId;
        var res = await nativeQuery(clone);
        return res.filter(function (t) { return tabToGroup.get(t.id) === info.groupId; });
      }
      return nativeQuery(info);
    })();
  }

  chrome.tabs.query = function (info, cb) {
    var p = doQuery(info);
    if (typeof cb === "function") { p.then(cb, function () { cb([]); }); return; }
    return p;
  };

  // ── chrome.tabs.get (overlay emulated groupId) ──────────────────────
  chrome.tabs.get = function (id, cb) {
    var p = (async function () {
      var t = await nativeGet(id);
      var gid = tabToGroup.get(id);
      if (gid != null) t.groupId = gid;
      else if (t.groupId == null) t.groupId = NONE;
      return t;
    })();
    if (typeof cb === "function") { p.then(cb, function () { cb(undefined); }); return; }
    return p;
  };

  // ── chrome.tabGroups method overrides (in place) ────────────────────
  function installTabGroups() {
    var tg = chrome.tabGroups;
    if (!tg) {
      try { chrome.tabGroups = {}; tg = chrome.tabGroups; }
      catch (e) { tg = null; }
    }
    if (!tg) { globalThis.__arcTabGroups = {}; tg = globalThis.__arcTabGroups; }

    function set(k, v) { try { tg[k] = v; } catch (e) {} }

    set("get", async function (id) { await ready; return groupObj(id); });
    set("query", async function (info) {
      await ready;
      var out = [];
      groups.forEach(function (g, id) {
        var o = groupObj(id);
        if (info) {
          if (info.windowId != null && o.windowId !== info.windowId) return;
          if (info.color != null && o.color !== info.color) return;
          if (info.title != null && o.title !== info.title) return;
          if (info.collapsed != null && o.collapsed !== info.collapsed) return;
        }
        out.push(o);
      });
      return out;
    });
    set("update", async function (id, props) {
      await ready;
      var g = groups.get(id);
      if (!g) throw new Error("No group with id " + id);
      if (props) {
        if (props.title != null) g.title = props.title;
        if (props.color != null) g.color = props.color;
        if (props.collapsed != null) g.collapsed = props.collapsed;
      }
      await save();
      return groupObj(id);
    });
    set("move", async function (id) { await ready; return groupObj(id); });

    if (typeof tg.TAB_GROUP_ID_NONE === "undefined") set("TAB_GROUP_ID_NONE", NONE);
    if (!tg.Color) set("Color", Color);
    ["onCreated", "onUpdated", "onMoved", "onRemoved"].forEach(function (k) {
      if (!tg[k]) set(k, { addListener: function () {}, removeListener: function () {} });
    });
  }
  installTabGroups();

  // Keep membership clean when tabs close.
  try {
    if (chrome.tabs.onRemoved && chrome.tabs.onRemoved.addListener) {
      chrome.tabs.onRemoved.addListener(function (tabId) {
        var gid = tabToGroup.get(tabId);
        if (gid != null) {
          var g = groups.get(gid);
          if (g) g.tabIds.delete(tabId);
          tabToGroup.delete(tabId);
          save();
        }
      });
    }
  } catch (e) {}

  globalThis.__arcTabGroupsShimInstalled = true;
  console.log("[Arc TabGroups Shim] active");
})();