claude-code

web/lib/collaboration/presence.ts

@@ -0,0 +1,115 @@
+import type { CollabUser } from "./socket";
+
+// ─── Types ────────────────────────────────────────────────────────────────────
+
+export interface CursorState {
+  userId: string;
+  position: number;
+  selectionStart?: number;
+  selectionEnd?: number;
+  updatedAt: number;
+}
+
+export interface PresenceState {
+  users: Map<string, CollabUser>;
+  cursors: Map<string, CursorState>;
+  typing: Set<string>; // user IDs currently typing
+}
+
+// ─── Factory ──────────────────────────────────────────────────────────────────
+
+export function createPresenceState(): PresenceState {
+  return {
+    users: new Map(),
+    cursors: new Map(),
+    typing: new Set(),
+  };
+}
+
+// ─── Updaters (all return new state, immutable) ───────────────────────────────
+
+export function presenceAddUser(
+  state: PresenceState,
+  user: CollabUser
+): PresenceState {
+  return { ...state, users: new Map(state.users).set(user.id, user) };
+}
+
+export function presenceRemoveUser(
+  state: PresenceState,
+  userId: string
+): PresenceState {
+  const users = new Map(state.users);
+  users.delete(userId);
+  const cursors = new Map(state.cursors);
+  cursors.delete(userId);
+  const typing = new Set(state.typing);
+  typing.delete(userId);
+  return { users, cursors, typing };
+}
+
+export function presenceSyncUsers(
+  state: PresenceState,
+  users: CollabUser[]
+): PresenceState {
+  const map = new Map<string, CollabUser>();
+  users.forEach((u) => map.set(u.id, u));
+  return { ...state, users: map };
+}
+
+export function presenceUpdateCursor(
+  state: PresenceState,
+  userId: string,
+  position: number,
+  selectionStart?: number,
+  selectionEnd?: number
+): PresenceState {
+  const cursor: CursorState = {
+    userId,
+    position,
+    selectionStart,
+    selectionEnd,
+    updatedAt: Date.now(),
+  };
+  return { ...state, cursors: new Map(state.cursors).set(userId, cursor) };
+}
+
+export function presenceSetTyping(
+  state: PresenceState,
+  userId: string,
+  isTyping: boolean
+): PresenceState {
+  const typing = new Set(state.typing);
+  if (isTyping) {
+    typing.add(userId);
+  } else {
+    typing.delete(userId);
+  }
+  return { ...state, typing };
+}
+
+// ─── Helpers ──────────────────────────────────────────────────────────────────
+
+const USER_COLORS = [
+  "#ef4444",
+  "#f97316",
+  "#eab308",
+  "#22c55e",
+  "#06b6d4",
+  "#3b82f6",
+  "#8b5cf6",
+  "#ec4899",
+];
+
+export function getUserColor(index: number): string {
+  return USER_COLORS[index % USER_COLORS.length];
+}
+
+export function getInitials(name: string): string {
+  return name
+    .split(" ")
+    .map((n) => n[0])
+    .slice(0, 2)
+    .join("")
+    .toUpperCase();
+}