[Init] Initial commit - NetMesh terminal manager

application/state/sessionSnapshotStore.ts

@@ -0,0 +1,203 @@
+import { useSyncExternalStore } from 'react';
+
+import type { TerminalSession, Workspace } from '../../domain/models';
+import type { LogView } from './logViewState';
+import type { useSessionState } from './useSessionState';
+
+type SessionState = ReturnType<typeof useSessionState>;
+
+type Listener = () => void;
+
+/**
+ * Session/workspace catalog for shell surfaces. `activeTabId` is intentionally
+ * absent — it lives in `activeTabStore` so tab switches stay off this path.
+ */
+export type SessionSnapshot = {
+  sessions: readonly TerminalSession[];
+  /** Sessions with no workspace and not hidden from tabs; TopTabs renders these. */
+  orphanSessions: readonly TerminalSession[];
+  workspaces: readonly Workspace[];
+  logViews: readonly LogView[];
+  draggingSessionId: string | null;
+  sessionRenameTarget: TerminalSession | null;
+  workspaceRenameTarget: Workspace | null;
+};
+
+/**
+ * Session mutators the shell needs. Derived from the hook return so the store
+ * contract cannot drift from `useSessionState`.
+ */
+export type SessionSnapshotActions = Pick<
+  SessionState,
+  | 'setActiveTabId'
+  | 'closeSession'
+  | 'closeSessions'
+  | 'closeWorkspace'
+  | 'openLogView'
+  | 'closeLogView'
+  | 'setDraggingSessionId'
+  | 'startSessionRename'
+  | 'renameSessionInline'
+  | 'submitSessionRename'
+  | 'resetSessionRename'
+  | 'startWorkspaceRename'
+  | 'submitWorkspaceRename'
+  | 'resetWorkspaceRename'
+  | 'removeSessionFromWorkspace'
+  | 'setWorkspaceFocusedSession'
+  | 'toggleWorkspaceViewMode'
+  // Terminal / chrome mutators previously read only via App session runtime.
+  | 'createLocalTerminal'
+  | 'createSerialSession'
+  | 'connectToHost'
+  | 'updateSessionStatus'
+  | 'updateSessionFontSize'
+  | 'clearSessionFontSizeOverride'
+  | 'createWorkspaceWithHosts'
+  | 'createWorkspaceFromSessions'
+  | 'addSessionToWorkspace'
+  | 'appendHostToWorkspace'
+  | 'appendLocalTerminalToWorkspace'
+  | 'createWorkspaceFromTargets'
+  | 'updateSplitSizes'
+  | 'splitSession'
+  | 'reorderWorkspaceSessions'
+  | 'moveFocusInWorkspace'
+  | 'runSnippet'
+  | 'getOrderedWorkTabs'
+  | 'reorderTabs'
+  | 'toggleBroadcast'
+  | 'isBroadcastEnabled'
+  | 'toggleGlobalBroadcast'
+  | 'isGlobalBroadcastEnabled'
+  | 'canUseGlobalBroadcast'
+  | 'copySession'
+  | 'copyWorkspace'
+  | 'createSessionFromCloneSource'
+  | 'updateSessionRestoreCwd'
+  | 'getSessionRestoreCwd'
+  | 'updateSessionDynamicTitle'
+  | 'updateSessionCodingCliProvider'
+>;
+
+const EMPTY_SESSIONS: readonly TerminalSession[] = Object.freeze([]);
+const EMPTY_WORKSPACES: readonly Workspace[] = Object.freeze([]);
+const EMPTY_LOG_VIEWS: readonly LogView[] = Object.freeze([]);
+
+export const EMPTY_SESSION_SNAPSHOT: SessionSnapshot = Object.freeze({
+  sessions: EMPTY_SESSIONS,
+  orphanSessions: EMPTY_SESSIONS,
+  workspaces: EMPTY_WORKSPACES,
+  logViews: EMPTY_LOG_VIEWS,
+  draggingSessionId: null,
+  sessionRenameTarget: null,
+  workspaceRenameTarget: null,
+});
+
+const SNAPSHOT_KEYS = Object.keys(EMPTY_SESSION_SNAPSHOT) as (keyof SessionSnapshot)[];
+
+export function sessionSnapshotsEqual(
+  prev: SessionSnapshot,
+  next: SessionSnapshot,
+): boolean {
+  return SNAPSHOT_KEYS.every((key) => prev[key] === next[key]);
+}
+
+/**
+ * External store for the session catalog so TopTabs, the terminal layer and
+ * the host tree can subscribe directly instead of receiving sessions through
+ * the App domain bags.
+ */
+class SessionSnapshotStore {
+  private snapshot: SessionSnapshot = EMPTY_SESSION_SNAPSHOT;
+  private actions: SessionSnapshotActions | null = null;
+  private listeners = new Set<Listener>();
+  private actionListeners = new Set<Listener>();
+
+  getSnapshot = (): SessionSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setSnapshot(next: SessionSnapshot): void {
+    if (sessionSnapshotsEqual(this.snapshot, next)) return;
+    this.snapshot = next;
+    for (const listener of this.listeners) {
+      listener();
+    }
+  }
+
+  getActions = (): SessionSnapshotActions | null => this.actions;
+
+  subscribeActions = (listener: Listener): (() => void) => {
+    this.actionListeners.add(listener);
+    return () => {
+      this.actionListeners.delete(listener);
+    };
+  };
+
+  setActions(next: SessionSnapshotActions | null): void {
+    if (this.actions === next) return;
+    this.actions = next;
+    for (const listener of this.actionListeners) {
+      listener();
+    }
+  }
+}
+
+export const sessionSnapshotStore = new SessionSnapshotStore();
+
+export function publishSessionSnapshot(snapshot: SessionSnapshot): void {
+  sessionSnapshotStore.setSnapshot(snapshot);
+}
+
+export function getSessionSnapshot(): SessionSnapshot {
+  return sessionSnapshotStore.getSnapshot();
+}
+
+export function subscribeSessionSnapshot(listener: Listener): () => void {
+  return sessionSnapshotStore.subscribe(listener);
+}
+
+export function registerSessionSnapshotActions(
+  actions: SessionSnapshotActions | null,
+): void {
+  sessionSnapshotStore.setActions(actions);
+}
+
+export function getSessionSnapshotActions(): SessionSnapshotActions | null {
+  return sessionSnapshotStore.getActions();
+}
+
+export function subscribeSessionSnapshotActions(listener: Listener): () => void {
+  return sessionSnapshotStore.subscribeActions(listener);
+}
+
+/** Subscribe to the whole session catalog. Prefer a narrower selector hook. */
+export function useSessionSnapshot(): SessionSnapshot {
+  return useSyncExternalStore(
+    subscribeSessionSnapshot,
+    getSessionSnapshot,
+    getSessionSnapshot,
+  );
+}
+
+/** Subscribe to one session field so unrelated session churn stays out. */
+export function useSessionSnapshotField<K extends keyof SessionSnapshot>(
+  field: K,
+): SessionSnapshot[K] {
+  const read = () => getSessionSnapshot()[field];
+  return useSyncExternalStore(subscribeSessionSnapshot, read, read);
+}
+
+export function useSessionSnapshotActions(): SessionSnapshotActions | null {
+  return useSyncExternalStore(
+    subscribeSessionSnapshotActions,
+    getSessionSnapshotActions,
+    getSessionSnapshotActions,
+  );
+}