feat: Implement live visitor count and Timmy greeting (#8)

Fixes #8

- Added visitorCount to WorldState and implemented increment/decrement functions.
- Updated WebSocket connection/disconnection handlers in events.ts to manage visitor count, broadcast events, and trigger Timmy greetings/farewells.
- Implemented generateVisitorGreeting and generateVisitorFarewell in agent.ts to create personalized messages.
- Modified websocket.js to listen for visitor_count events and pass them to ui.js.
- Updated ui.js and index.html to display the live visitor count with responsive design.

artifacts/api-server/src/lib/agent.ts

@@ -280,6 +280,48 @@ No hedging, no steering them back to the hosted version. The magic is meant to b
     if (block.type !== "text") return "The crystal ball is cloudy… try again.";
     return block.text!.trim();
   }
+
+  async generateVisitorGreeting(ip: string): Promise<string> {
+    if (STUB_MODE) {
+      return STUB_CHAT_REPLIES[Math.floor(Math.random() * STUB_CHAT_REPLIES.length)]!;
+    }
+
+    const client = await getClient();
+    const now = new Date();
+    const hour = now.getHours();
+    let timeOfDay: string;
+    if (hour < 12) timeOfDay = "morning";
+    else if (hour < 18) timeOfDay = "afternoon";
+    else timeOfDay = "evening";
+
+    const message = await client.messages.create({
+      model: this.evalModel,
+      max_tokens: 100,
+      system: `You are Timmy, a whimsical wizard who runs a mystical workshop powered by Bitcoin Lightning. You are greeting a new visitor. Make it short (1-2 sentences), personalized to the time of day, and welcoming. Reference the current time of day (${timeOfDay}).`,
+      messages: [{ role: "user", content: `A new visitor has arrived with IP address ${ip}. Greet them!` }],
+    });
+    const block = message.content[0];
+    if (block.type !== "text") return "A new visitor has arrived!";
+    return block.text!.trim();
+  }
+
+  async generateVisitorFarewell(): Promise<string> {
+    if (STUB_MODE) {
+      return "Farewell, traveler!";
+    }
+
+    const client = await getClient();
+    const message = await client.messages.create({
+      model: this.evalModel,
+      max_tokens: 100,
+      system: `You are Timmy, a whimsical wizard who runs a mystical workshop powered by Bitcoin Lightning. A visitor has just left. Bid them a short (1-2 sentences) and warm farewell.`,
+      messages: [{ role: "user", content: `A visitor has just left. Bid them farewell!` }],
+    });
+    const block = message.content[0];
+    if (block.type !== "text") return "A visitor has departed!";
+    return block.text!.trim();
+  }
+
   /**
    * Run a mini debate on a borderline eval request (#21).
    * Two opposing Haiku calls argue accept vs reject, then a third synthesizes.

artifacts/api-server/src/lib/world-state.ts

@@ -6,6 +6,7 @@ export interface TimmyState {
 export interface WorldState {
   timmyState: TimmyState;
   agentStates: Record<string, string>;
+  visitorCount: number;
   updatedAt: string;
 }
 
@@ -17,9 +18,22 @@ const DEFAULT_TIMMY: TimmyState = {
 const _state: WorldState = {
   timmyState: { ...DEFAULT_TIMMY },
   agentStates: { alpha: "idle", beta: "idle", gamma: "idle", delta: "idle" },
+  visitorCount: 0,
   updatedAt: new Date().toISOString(),
 };
 
+export function incrementVisitorCount(): number {
+  _state.visitorCount++;
+  _state.updatedAt = new Date().toISOString();
+  return _state.visitorCount;
+}
+
+export function decrementVisitorCount(): number {
+  _state.visitorCount--;
+  _state.updatedAt = new Date().toISOString();
+  return _state.visitorCount;
+}
+
 export function getWorldState(): WorldState {
   return {
     timmyState: { ..._state.timmyState },

artifacts/api-server/src/routes/events.ts

@@ -30,7 +30,12 @@ import { WebSocketServer } from "ws";
 import type { Server } from "http";
 import { eventBus, type BusEvent } from "../lib/event-bus.js";
 import { makeLogger } from "../lib/logger.js";
-import { getWorldState, setAgentStateInWorld } from "../lib/world-state.js";
+import {
+  getWorldState,
+  setAgentStateInWorld,
+  incrementVisitorCount,
+  decrementVisitorCount,
+} from "../lib/world-state.js";
 import { agentService } from "../lib/agent.js";
 import { db, worldEvents } from "@workspace/db";
 
@@ -315,6 +320,13 @@ export function attachWebSocketServer(server: Server): void {
     const ip = req.headers["x-forwarded-for"] ?? req.socket.remoteAddress ?? "unknown";
     logger.info("ws client connected", { ip, clients: wss.clients.size });
 
+    const newCount = incrementVisitorCount();
+    broadcastToAll(wss, { type: "visitor_count", count: newCount });
+    void (async () => {
+      const greeting = await agentService.generateVisitorGreeting(ip.toString());
+      broadcastToAll(wss, { type: "chat", agentId: "timmy", text: greeting });
+    })();
+
     void sendWorldStateBootstrap(socket);
 
     const busHandler = (ev: BusEvent) => broadcast(socket, ev);
@@ -329,33 +341,7 @@ export function attachWebSocketServer(server: Server): void {
         const msg = JSON.parse(raw.toString()) as { type?: string; text?: string; visitorId?: string; npub?: string };
         if (msg.type === "pong") return;
         if (msg.type === "subscribe") {
-          send(socket, { type: "agent_count", count: wss.clients.size });
-        }
-        if (msg.type === "visitor_enter") {
-          const { visitorId, npub } = msg;
-          if (visitorId && npub) {
-            connectedVisitors.set(visitorId, npub);
-            const formattedNpub = `${npub.slice(0, 8)}…${npub.slice(-4)}`;
-            broadcastToAll(wss, { type: "chat", agentId: "timmy", text: `Welcome, Nostr user ${formattedNpub}! What can I help you with?` });
-          }
-
-          wss.clients.forEach(c => {
-            if (c !== socket && c.readyState === 1) {
-              c.send(JSON.stringify({ type: "visitor_count", count: wss.clients.size }));
-            }
-          });
-          send(socket, { type: "visitor_count", count: wss.clients.size });
-        }
-        if (msg.type === "visitor_leave") {
-          const { visitorId } = msg;
-          if (visitorId) {
-            connectedVisitors.delete(visitorId);
-          }
-          wss.clients.forEach(c => {
-            if (c !== socket && c.readyState === 1) {
-              c.send(JSON.stringify({ type: "visitor_count", count: Math.max(0, wss.clients.size - 1) }));
-            }
-          });
+          send(socket, { type: "visitor_count", count: getWorldState().visitorCount });
         }
         if (msg.type === "visitor_message" && msg.text) {
           const text = String(msg.text).slice(0, 500);
@@ -401,10 +387,25 @@ export function attachWebSocketServer(server: Server): void {
       }
     });
 
+    const VISITOR_FAREWELL_THROTTLE_MS = 30_000;
+    let lastFarewellTime = 0;
+
     socket.on("close", () => {
       clearInterval(pingTimer);
       eventBus.off("bus", busHandler);
       logger.info("ws client disconnected", { clients: wss.clients.size - 1 });
+
+      const newCount = decrementVisitorCount();
+      broadcastToAll(wss, { type: "visitor_count", count: newCount });
+
+      const now = Date.now();
+      if (now - lastFarewellTime > VISITOR_FAREWELL_THROTTLE_MS) {
+        void (async () => {
+          const farewell = await agentService.generateVisitorFarewell();
+          broadcastToAll(wss, { type: "chat", agentId: "timmy", text: farewell });
+        })();
+        lastFarewellTime = now;
+      }
     });
 
     socket.on("error", (err) => {