webmail/lib/desktop/types.ts

/**
 * The desktop app's preload bridge as the webmail sees it. Feature checks ask
 * `window.bulwarkDesktop?.<area>`; in a browser the object isn't there.
 *
 * The shell side lives in the desktop repo (src/shared/bridge.ts), a copy of
 * this contract. Add a member here and there together. A breaking change bumps
 * `version`; adding a member doesn't.
 */

import type { PolicySnapshot } from './policy-schema';

export const DESKTOP_BRIDGE_VERSION = 1;

export type DesktopWindowType = 'main' | 'message' | 'composer' | 'settings';

export interface DesktopWindowInfo {
  id: number;
  type: DesktopWindowType;
  title: string;
  focused: boolean;
}

export interface DesktopWindowsBridge {
  /**
   * Opens a pop-out window itself. The name is the window's identity: opening
   * the same name again focuses the window that has it. Left out, the page uses
   * window.open with a features string, which the shell's window-open handler
   * sees too.
   */
  open?: (url: string, options: { name: string; width: number; height: number }) => void;
  /** One window per message: opening it again focuses it. */
  openMessage?: (target: { url: string; emailId: string }) => void;
  openComposer?: (target: { url: string; name?: string }) => void;
  /** Focuses a window from `list()`, or the main window with no id. */
  focus?: (id?: number) => void;
  list?: () => Promise<DesktopWindowInfo[]>;
  /** Fires when a window opens, closes, retitles or takes the focus. Returns the unsubscribe. */
  onChanged?: (listener: (windows: DesktopWindowInfo[]) => void) => () => void;
}

export interface DesktopThemeBridge {
  /** The page's colours, for title bar buttons and the first frame of new windows. */
  set: (theme: { dark: boolean; background: string; foreground?: string }) => void;
  /** Fires when the OS switches between light and dark. Returns the unsubscribe. */
  onSystemChange?: (listener: (system: { dark: boolean; highContrast: boolean }) => void) => () => void;
}

export interface DesktopMenuBridge {
  /**
   * What the app menu shows as enabled or checked, by command id. The shell
   * keeps the last state per window and applies it when that window has focus.
   */
  setState: (state: Record<string, boolean | { enabled?: boolean; checked?: boolean }>) => void;
}

export interface DesktopShellBridge {
  /** http, https and mailto only. */
  openExternal: (url: string) => void;
}

export type DesktopServerPrepareResult =
  | { ok: true; approved: boolean }
  | { ok: false; reason: 'declined' | 'invalid' | 'policy' };

export interface DesktopServersBridge {
  /**
   * Call before signing in to a server. Asks the user first when it is on the
   * LAN or plain http, and lets the app reach it. Standalone mode only.
   */
  prepare: (serverUrl: string) => Promise<DesktopServerPrepareResult>;
  /**
   * The sign-in worked, so the server stays: what `prepare` added lasts only until
   * the app quits before this. Other origins a session names get a prompt.
   */
  noteSession: (
    serverUrl: string,
    urls: { apiUrl?: string; downloadUrl?: string; uploadUrl?: string; eventSourceUrl?: string },
  ) => void;
  /** A sign-in that failed, or the last account on this server signing out. */
  forget?: (serverUrl: string, reason: 'failed' | 'signed-out') => void;
}

export interface DesktopLifecycleBridge {
  /**
   * Before a window closes or the app quits, the shell asks the page to save what
   * it has and waits a few seconds. A window with no handler closes at once.
   */
  onFlushRequest: (handler: () => Promise<unknown>) => () => void;
}

export type DesktopBrowserSignInResult =
  | { ok: true; code: string; state: string }
  | { ok: false; error: string };

export interface DesktopAuthBridge {
  /** Starts a short-lived loopback listener for one sign-in. */
  beginBrowserSignIn: () => Promise<{ flowId: string; redirectUri: string }>;
  /** Opens the system browser on `authorizeUrl` and waits for the redirect. */
  completeBrowserSignIn: (flowId: string, authorizeUrl: string) => Promise<DesktopBrowserSignInResult>;
  cancelBrowserSignIn: (flowId: string) => void;
}

export type DesktopPluginInstallResult =
  | { ok: true; id: string; version: string }
  | { ok: false; error: string; code?: string };

export interface DesktopPluginsBridge {
  /**
   * Installs from the directory through the local admin API, with its signature
   * and hash checks, after a native prompt. No version means the latest. The
   * renderer never holds an admin session. Standalone only.
   */
  install: (slug: string, version?: string) => Promise<DesktopPluginInstallResult>;
}

export interface DesktopPolicyBridge {
  /** What's in force now. Synchronous: a page can read it in its first render. */
  get: () => PolicySnapshot;
  onChange: (listener: (snapshot: PolicySnapshot) => void) => () => void;
}

export interface BulwarkDesktopBridge {
  version: number;
  platform: 'win32' | 'darwin' | 'linux';
  mode?: 'standalone' | 'instance';
  windows?: DesktopWindowsBridge;
  theme?: DesktopThemeBridge;
  menu?: DesktopMenuBridge;
  shell?: DesktopShellBridge;
  lifecycle?: DesktopLifecycleBridge;
  policy?: DesktopPolicyBridge;
  servers?: DesktopServersBridge;
  auth?: DesktopAuthBridge;
  plugins?: DesktopPluginsBridge;
}

declare global {
  interface Window {
    bulwarkDesktop?: BulwarkDesktopBridge;
  }
}