Files
timmy-tower/artifacts/mobile/context/TimmyContext.tsx
Alexander Whitestone b9a9d44da6
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feat: add AppState-aware WebSocket reconnect on mobile foreground
When the app returns from background, check if the WebSocket is still
open. If not, close the stale socket and reconnect with reset backoff.
Proactively close the WS when backgrounding to save battery and avoid
OS killing it mid-frame. Add "reconnecting" connection status with
amber pulsing badge so users see the app is re-establishing connection.

Fixes #33

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-22 21:50:40 -04:00

307 lines
8.4 KiB
TypeScript

import React, {
createContext,
useCallback,
useContext,
useEffect,
useMemo,
useRef,
useState,
} from "react";
import { AppState, Platform } from "react-native";
export type TimmyMood = "idle" | "thinking" | "working" | "speaking";
export type WsEvent = {
id: string;
type: string;
timestamp: number;
agentId?: string;
jobId?: string;
text?: string;
state?: string;
count?: number;
};
export type ConnectionStatus = "connecting" | "connected" | "disconnected" | "reconnecting" | "error";
type TimmyContextValue = {
timmyMood: TimmyMood;
connectionStatus: ConnectionStatus;
recentEvents: WsEvent[];
send: (msg: object) => void;
sendVisitorMessage: (text: string) => void;
visitorId: string;
};
const TimmyContext = createContext<TimmyContextValue | null>(null);
const MAX_EVENTS = 100;
const BASE_URL = process.env.EXPO_PUBLIC_DOMAIN ?? "";
const VISITOR_ID =
Date.now().toString() + Math.random().toString(36).substr(2, 9);
function getWsUrl(): string {
let domain = BASE_URL;
if (!domain) {
domain = "localhost:8080";
}
domain = domain.replace(/^https?:\/\//, "");
domain = domain.replace(/\/$/, "");
const proto = domain.startsWith("localhost") ? "ws" : "wss";
return `${proto}://${domain}/api/ws`;
}
function deriveMood(agentStates: Record<string, string>): TimmyMood {
if (agentStates["gamma"] === "working") return "working";
if (
agentStates["beta"] === "thinking" ||
agentStates["alpha"] === "thinking"
)
return "thinking";
if (Object.values(agentStates).some((s) => s !== "idle")) return "working";
return "idle";
}
export function TimmyProvider({ children }: { children: React.ReactNode }) {
const [timmyMood, setTimmyMood] = useState<TimmyMood>("idle");
const [connectionStatus, setConnectionStatus] =
useState<ConnectionStatus>("connecting");
const [recentEvents, setRecentEvents] = useState<WsEvent[]>([]);
const wsRef = useRef<WebSocket | null>(null);
const retryTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
const retryCountRef = useRef(0);
const agentStatesRef = useRef<Record<string, string>>({
alpha: "idle",
beta: "idle",
gamma: "idle",
delta: "idle",
});
const speakingTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
const addEvent = useCallback((evt: Omit<WsEvent, "id" | "timestamp">) => {
const entry: WsEvent = {
id: Date.now().toString() + Math.random().toString(36).substr(2, 6),
timestamp: Date.now(),
...evt,
};
setRecentEvents((prev) => [entry, ...prev].slice(0, MAX_EVENTS));
}, []);
const connectWs = useCallback(() => {
if (wsRef.current) {
wsRef.current.onclose = null;
wsRef.current.onerror = null;
wsRef.current.close();
wsRef.current = null;
}
const url = getWsUrl();
setConnectionStatus("connecting");
let ws: WebSocket;
try {
ws = new WebSocket(url);
} catch {
setConnectionStatus("error");
scheduleRetry();
return;
}
wsRef.current = ws;
ws.onopen = () => {
retryCountRef.current = 0;
setConnectionStatus("connected");
ws.send(
JSON.stringify({
type: "visitor_enter",
visitorId: VISITOR_ID,
visitorName: "Mobile Visitor",
})
);
};
ws.onmessage = (e) => {
let msg: Record<string, unknown>;
try {
msg = JSON.parse(e.data);
} catch {
return;
}
const type = msg.type as string;
if (type === "ping") {
ws.send(JSON.stringify({ type: "pong" }));
return;
}
if (type === "world_state") {
const states = (msg.agentStates as Record<string, string>) ?? {};
agentStatesRef.current = {
...agentStatesRef.current,
...states,
};
setTimmyMood(deriveMood(agentStatesRef.current));
return;
}
if (type === "agent_state") {
const agentId = msg.agentId as string;
const state = msg.state as string;
agentStatesRef.current = {
...agentStatesRef.current,
[agentId]: state,
};
setTimmyMood(deriveMood(agentStatesRef.current));
addEvent({ type, agentId, state });
return;
}
if (type === "chat") {
const agentId = msg.agentId as string;
const text = msg.text as string;
addEvent({ type, agentId, text });
if (agentId === "timmy" || !agentId) {
if (speakingTimerRef.current) clearTimeout(speakingTimerRef.current);
setTimmyMood("speaking");
const duration = Math.max(2000, (text?.length ?? 50) * 50);
speakingTimerRef.current = setTimeout(() => {
setTimmyMood(deriveMood(agentStatesRef.current));
}, duration);
}
return;
}
if (type === "job_started" || type === "job_completed") {
addEvent({
type,
jobId: msg.jobId as string,
agentId: msg.agentId as string,
});
return;
}
if (type === "visitor_count") {
addEvent({ type, count: msg.count as number });
return;
}
};
ws.onclose = () => {
setConnectionStatus("disconnected");
scheduleRetry();
};
ws.onerror = () => {
setConnectionStatus("error");
};
}, [addEvent]);
const scheduleRetry = useCallback(() => {
if (retryTimerRef.current) clearTimeout(retryTimerRef.current);
const delay = Math.min(1000 * Math.pow(2, retryCountRef.current), 30000);
retryCountRef.current += 1;
retryTimerRef.current = setTimeout(() => {
connectWs();
}, delay);
}, [connectWs]);
useEffect(() => {
connectWs();
return () => {
if (retryTimerRef.current) clearTimeout(retryTimerRef.current);
if (speakingTimerRef.current) clearTimeout(speakingTimerRef.current);
if (wsRef.current) {
wsRef.current.onclose = null;
wsRef.current.close();
}
};
}, [connectWs]);
// AppState-aware WebSocket reconnect on foreground
useEffect(() => {
if (Platform.OS === "web") return;
const appStateRef = { current: AppState.currentState };
const subscription = AppState.addEventListener("change", (nextAppState) => {
const wasBackground =
appStateRef.current === "background" ||
appStateRef.current === "inactive";
const isNowActive = nextAppState === "active";
if (wasBackground && isNowActive) {
// App returned to foreground — check if WS is still alive
const ws = wsRef.current;
if (!ws || ws.readyState !== WebSocket.OPEN) {
// Cancel any pending retry so we don't create duplicates
if (retryTimerRef.current) {
clearTimeout(retryTimerRef.current);
retryTimerRef.current = null;
}
retryCountRef.current = 0;
setConnectionStatus("reconnecting");
connectWs();
}
} else if (nextAppState === "background") {
// Proactively close the WS to avoid OS killing it mid-frame
if (retryTimerRef.current) {
clearTimeout(retryTimerRef.current);
retryTimerRef.current = null;
}
if (wsRef.current) {
wsRef.current.onclose = null;
wsRef.current.onerror = null;
wsRef.current.close();
wsRef.current = null;
}
setConnectionStatus("disconnected");
}
appStateRef.current = nextAppState;
});
return () => {
subscription.remove();
};
}, [connectWs]);
const send = useCallback((msg: object) => {
if (wsRef.current && wsRef.current.readyState === WebSocket.OPEN) {
wsRef.current.send(JSON.stringify(msg));
}
}, []);
const sendVisitorMessage = useCallback(
(text: string) => {
if (wsRef.current && wsRef.current.readyState === WebSocket.OPEN) {
wsRef.current.send(
JSON.stringify({ type: "visitor_message", visitorId: VISITOR_ID, text })
);
setTimmyMood("thinking");
}
},
[]
);
const value = useMemo(
() => ({
timmyMood,
connectionStatus,
recentEvents,
send,
sendVisitorMessage,
visitorId: VISITOR_ID,
}),
[timmyMood, connectionStatus, recentEvents, send, sendVisitorMessage]
);
return (
<TimmyContext.Provider value={value}>{children}</TimmyContext.Provider>
);
}
export function useTimmy() {
const ctx = useContext(TimmyContext);
if (!ctx) throw new Error("useTimmy must be used within TimmyProvider");
return ctx;
}