Files
webmail/lib/offline/state.ts
T
Linus Rath 4b60fcc1e6 fix: make the offline outbox never send twice, never lose mail silently and never skip a plugin #523
The review of offline mode found ways to send a message twice, to lose
unsent mail without a word, and to send mail without its signing,
encryption or check plugin. This fixes them and the smaller findings:

- each outbox message is taken for sending in one database transaction
  under a Web Lock per account; only a failure before the submission
  request (SendNotStartedError from the client) puts it back, any other
  one marks it "may have gone out"; read-backs after the submission no
  longer fail a send; a send of a closed tab turns uncertain after a minute
- every sign-out the user didn't confirm names the deleted messages on
  the sign-in page, or in a toast when another account stays signed in
- nothing is queued while an enabled plugin isn't running (after a start
  without the network none can); the composer says why
- the outbox waits for a fresh policy and holds messages the rules have
  since made stricter (a required label, a required send check)
- another tab switching offline mode off sticks: only switching it on
  may create the database
- only attachments of kept messages are kept, filed with their message,
  deleted with it and under the cap between syncs; file names and types
  are sealed; folders that went away leave the scope, and a folder that
  couldn't be asked keeps its mail without holding the others back
- a group scope that forbids offline mode waits until the account's
  groups are known; one server down no longer holds another's mail
- an offline start only when the server is really unreachable, and the
  real sign-in follows by itself once it answers
- the service worker files pages and chunks under the build that served
  them, and the shell list of another build isn't kept under this one
- a raw send counts as the composer's only from the plugin running its
  takeover, for that identity
- errors and refusals are in all languages; the banner tells "offline"
  from "server can't be reached"; outbox buttons name their message;
  changes and messages go in the order they were made
2026-11-01 14:19:54 +01:00

102 lines
3.3 KiB
TypeScript

/**
* What offline mode (#523) shows: which accounts keep mail on this device,
* whether the browser is offline, what waits in the outbox, how much the
* cache uses. The switch itself ("Keep mail on this device") is per account
* and per browser, in localStorage, never synced: it is off until the user
* turns it on here.
*/
import { create } from 'zustand';
import type { OutboxEntry, OutboxError } from './queue';
/** localStorage: the local account ids that keep mail on this device. */
export const OFFLINE_ACCOUNTS_KEY = 'bulwark-offline-accounts';
export interface OutboxRow {
id: number;
account: string;
createdAt: number;
subject: string;
to: string[];
status: OutboxEntry['status'];
error?: OutboxError;
}
interface OfflineState {
/** Accounts with "Keep mail on this device" on. */
enabled: string[];
/** The browser says it has no network. */
browserOffline: boolean;
/** Mail servers (their URLs) that couldn't be reached at the last request. */
downServers: string[];
/** The app started without the server, from the mail on this device. */
startedOffline: boolean;
outbox: OutboxRow[];
pendingChanges: number;
usageBytes: number;
/** Accounts whose mail is being brought onto the device right now. */
syncing: string[];
lastSyncedAt: Record<string, number>;
}
function readEnabled(): string[] {
try {
const raw = typeof localStorage === 'undefined' ? null : localStorage.getItem(OFFLINE_ACCOUNTS_KEY);
const parsed = raw ? JSON.parse(raw) : [];
return Array.isArray(parsed) ? parsed.filter((id): id is string => typeof id === 'string') : [];
} catch {
return [];
}
}
export const useOfflineStore = create<OfflineState>()(() => ({
enabled: readEnabled(),
browserOffline: typeof navigator !== 'undefined' && navigator.onLine === false,
downServers: [],
startedOffline: false,
outbox: [],
pendingChanges: 0,
usageBytes: 0,
syncing: [],
lastSyncedAt: {},
}));
export function writeEnabled(enabled: string[]): void {
useOfflineStore.setState({ enabled });
try {
if (enabled.length) localStorage.setItem(OFFLINE_ACCOUNTS_KEY, JSON.stringify(enabled));
else localStorage.removeItem(OFFLINE_ACCOUNTS_KEY);
} catch {
/* storage unavailable */
}
}
export function serverKey(url: string): string {
return url.replace(/\/+$/, '').toLowerCase();
}
/** The browser is offline, or this mail server (any, without one) couldn't be reached. */
export function isOfflineNow(serverUrl?: string): boolean {
const { browserOffline, downServers } = useOfflineStore.getState();
if (browserOffline) return true;
return serverUrl ? downServers.includes(serverKey(serverUrl)) : downServers.length > 0;
}
export function setServerDown(serverUrl: string, down: boolean): boolean {
const key = serverKey(serverUrl);
const { downServers } = useOfflineStore.getState();
const was = downServers.includes(key);
if (was !== down) useOfflineStore.setState({ downServers: down ? [...downServers, key] : downServers.filter((s) => s !== key) });
return was;
}
/** The switch as another tab left it (it changed in localStorage there). */
export function readEnabledFrom(raw: string | null): string[] {
try {
const parsed = raw ? JSON.parse(raw) : [];
return Array.isArray(parsed) ? parsed.filter((id): id is string => typeof id === 'string') : [];
} catch {
return [];
}
}