| 1 | "use client"; |
| 2 | |
| 3 | import { useCallback, useEffect, useReducer, useRef, useState } from "react"; |
| 4 | import { |
| 5 | INITIAL_CONNECTION_STATE, |
| 6 | backoffDelayMs, |
| 7 | nextConnectionState, |
| 8 | shouldProbe, |
| 9 | type ConnectionState, |
| 10 | } from "@/lib/connection-state"; |
| 11 | import { fill, getChrome, getStates } from "@/lib/i18n/dictionaries"; |
| 12 | |
| 13 | /** |
| 14 | * Offline / reconnect banner for the signed-in shell. |
| 15 | * |
| 16 | * State meaning lives in lib/connection-state.ts; this component owns the |
| 17 | * browser events, the probe, and the timers. The probe is a real request to |
| 18 | * a first-party endpoint (`/api/facts`, `Cache-Control: no-store`), so |
| 19 | * "back online" means the server answered — never the browser's guess |
| 20 | * alone. No data is faked while disconnected: the banner says actions are |
| 21 | * paused, and the page underneath keeps whatever it last rendered. |
| 22 | */ |
| 23 | export function ConnectionBanner({ |
| 24 | locale, |
| 25 | probeUrl = "/api/facts", |
| 26 | /** Periodic heartbeat while online; 0 disables it. */ |
| 27 | heartbeatMs = 60_000, |
| 28 | }: { |
| 29 | locale: string; |
| 30 | probeUrl?: string; |
| 31 | heartbeatMs?: number; |
| 32 | }) { |
| 33 | const t = getStates(locale); |
| 34 | const chrome = getChrome(locale); |
| 35 | const [state, dispatch] = useReducer(nextConnectionState, INITIAL_CONNECTION_STATE); |
| 36 | const [dismissedRestored, setDismissedRestored] = useState(false); |
| 37 | const timer = useRef<number | null>(null); |
| 38 | const inFlight = useRef(false); |
| 39 | |
| 40 | const probe = useCallback(async () => { |
| 41 | if (inFlight.current) return; |
| 42 | inFlight.current = true; |
| 43 | dispatch({ type: "probe-start" }); |
| 44 | try { |
| 45 | const controller = new AbortController(); |
| 46 | const timeout = window.setTimeout(() => controller.abort(), 8_000); |
| 47 | const res = await fetch(probeUrl, { |
| 48 | method: "GET", |
| 49 | cache: "no-store", |
| 50 | signal: controller.signal, |
| 51 | headers: { Accept: "application/json" }, |
| 52 | }); |
| 53 | window.clearTimeout(timeout); |
| 54 | dispatch({ type: res.ok ? "probe-ok" : "probe-failed", at: Date.now() }); |
| 55 | } catch { |
| 56 | dispatch({ type: "probe-failed", at: Date.now() }); |
| 57 | } finally { |
| 58 | inFlight.current = false; |
| 59 | } |
| 60 | }, [probeUrl]); |
| 61 | |
| 62 | // Browser network events. |
| 63 | useEffect(() => { |
| 64 | if (typeof navigator !== "undefined" && navigator.onLine === false) { |
| 65 | dispatch({ type: "browser-offline" }); |
| 66 | } |
| 67 | const onOnline = () => { |
| 68 | dispatch({ type: "browser-online" }); |
| 69 | void probe(); |
| 70 | }; |
| 71 | const onOffline = () => dispatch({ type: "browser-offline" }); |
| 72 | window.addEventListener("online", onOnline); |
| 73 | window.addEventListener("offline", onOffline); |
| 74 | return () => { |
| 75 | window.removeEventListener("online", onOnline); |
| 76 | window.removeEventListener("offline", onOffline); |
| 77 | }; |
| 78 | }, [probe]); |
| 79 | |
| 80 | // Retry schedule while reconnecting/degraded; heartbeat while online. |
| 81 | useEffect(() => { |
| 82 | if (timer.current !== null) window.clearTimeout(timer.current); |
| 83 | timer.current = null; |
| 84 | if (shouldProbe(state)) { |
| 85 | timer.current = window.setTimeout(() => void probe(), backoffDelayMs(state.attempt)); |
| 86 | } else if (state.status === "online" && heartbeatMs > 0) { |
| 87 | timer.current = window.setTimeout(() => void probe(), heartbeatMs); |
| 88 | } |
| 89 | return () => { |
| 90 | if (timer.current !== null) window.clearTimeout(timer.current); |
| 91 | }; |
| 92 | }, [state, probe, heartbeatMs]); |
| 93 | |
| 94 | // "Back online" shows briefly, then clears itself. |
| 95 | useEffect(() => { |
| 96 | if (!state.restored) return; |
| 97 | setDismissedRestored(false); |
| 98 | const id = window.setTimeout(() => dispatch({ type: "restored-seen" }), 4_000); |
| 99 | return () => window.clearTimeout(id); |
| 100 | }, [state.restored]); |
| 101 | |
| 102 | const view = bannerView(state, dismissedRestored); |
| 103 | if (!view) return null; |
| 104 | |
| 105 | const copy = { |
| 106 | offline: { title: t.offlineTitle, body: t.offlineBody }, |
| 107 | reconnecting: { |
| 108 | title: t.reconnectingTitle, |
| 109 | body: fill(t.reconnectingBody, { attempt: state.attempt + 1 }), |
| 110 | }, |
| 111 | degraded: { title: t.degradedTitle, body: t.degradedBody }, |
| 112 | restored: { title: t.onlineTitle, body: t.onlineBody }, |
| 113 | }[view]; |
| 114 | |
| 115 | const lastChecked = |
| 116 | state.lastCheckedAt !== null |
| 117 | ? fill(t.lastChecked, { |
| 118 | time: new Date(state.lastCheckedAt).toLocaleTimeString(chrome.dateLocale, { |
| 119 | hour: "2-digit", |
| 120 | minute: "2-digit", |
| 121 | second: "2-digit", |
| 122 | }), |
| 123 | }) |
| 124 | : null; |
| 125 | |
| 126 | return ( |
| 127 | <div |
| 128 | className={`connection-banner connection-banner-${view}`} |
| 129 | role={view === "offline" ? "alert" : "status"} |
| 130 | aria-live={view === "offline" ? "assertive" : "polite"} |
| 131 | data-connection={state.status} |
| 132 | > |
| 133 | <span className="connection-mark" aria-hidden="true" /> |
| 134 | <div className="connection-copy"> |
| 135 | <p className="connection-title">{copy.title}</p> |
| 136 | <p className="connection-body"> |
| 137 | {copy.body} |
| 138 | {lastChecked && view !== "restored" && ( |
| 139 | <span className="connection-checked"> · {lastChecked}</span> |
| 140 | )} |
| 141 | </p> |
| 142 | </div> |
| 143 | <div className="connection-actions"> |
| 144 | {view === "restored" ? ( |
| 145 | <button |
| 146 | type="button" |
| 147 | className="connection-button" |
| 148 | onClick={() => setDismissedRestored(true)} |
| 149 | > |
| 150 | {t.dismiss} |
| 151 | </button> |
| 152 | ) : ( |
| 153 | <button |
| 154 | type="button" |
| 155 | className="connection-button connection-button-primary" |
| 156 | onClick={() => void probe()} |
| 157 | disabled={state.status === "offline"} |
| 158 | aria-busy={state.status === "reconnecting"} |
| 159 | > |
| 160 | {t.retryNow} |
| 161 | </button> |
| 162 | )} |
| 163 | </div> |
| 164 | </div> |
| 165 | ); |
| 166 | } |
| 167 | |
| 168 | type BannerView = "offline" | "reconnecting" | "degraded" | "restored"; |
| 169 | |
| 170 | /** Which banner (if any) a state renders. Exported for tests. */ |
| 171 | export function bannerView(state: ConnectionState, dismissedRestored: boolean): BannerView | null { |
| 172 | if (state.status === "online") { |
| 173 | return state.restored && !dismissedRestored ? "restored" : null; |
| 174 | } |
| 175 | return state.status; |
| 176 | } |
| 177 |