Add workspace client adapters

src/workspace.ts

@@ -75,6 +75,18 @@ export type HostedSession = {
   user: HostedUser | null
 }
 
+export type WorkspaceClient = {
+  loadSnapshot(): Promise<Partial<WorkspaceSnapshot> | null>
+  saveSnapshot(snapshot: WorkspaceSnapshot): Promise<void>
+}
+
+export type AuthClient = {
+  enabled: boolean
+  loadSession(): Promise<HostedSession>
+  login(username: string, password: string): Promise<HostedSession>
+  logout(): Promise<void>
+}
+
 export function hostedWorkspaceEnabled() {
   return remoteWorkspaceEnabled
 }
@@ -159,9 +171,7 @@ export function selectActiveSessionId(sessions: StudySession[], requestedId?: st
 }
 
 export async function loadWorkspaceSnapshot(): Promise<WorkspaceSnapshot> {
-  const remoteSnapshot = remoteWorkspaceEnabled ? await loadRemoteWorkspaceSnapshot() : null
-  const localSnapshot = remoteSnapshot ? null : loadLocalWorkspaceSnapshot()
-  const source = remoteSnapshot ?? localSnapshot
+  const source = await getWorkspaceClient().loadSnapshot()
   const sessions = normalizeSessions(source?.sessions)
   const activeSessionId = selectActiveSessionId(sessions, source?.activeSessionId)
 
@@ -173,9 +183,7 @@ export async function loadWorkspaceSnapshot(): Promise<WorkspaceSnapshot> {
 }
 
 export function saveWorkspaceSnapshot(snapshot: WorkspaceSnapshot): Promise<void> {
-  saveLocalWorkspaceSnapshot(snapshot)
-  if (!remoteWorkspaceEnabled) return Promise.resolve()
-  return saveRemoteWorkspaceSnapshot(snapshot)
+  return getWorkspaceClient().saveSnapshot(snapshot)
 }
 
 function loadLocalWorkspaceSnapshot(): Partial<WorkspaceSnapshot> {
@@ -234,8 +242,49 @@ async function saveRemoteWorkspaceSnapshot(snapshot: WorkspaceSnapshot) {
   }
 }
 
-export async function loadHostedSession(): Promise<HostedSession> {
-  if (!remoteWorkspaceEnabled) return { authenticated: false, user: null }
+const localWorkspaceClient: WorkspaceClient = {
+  loadSnapshot: async () => loadLocalWorkspaceSnapshot(),
+  saveSnapshot: async (snapshot) => {
+    saveLocalWorkspaceSnapshot(snapshot)
+  },
+}
+
+const hostedWorkspaceClient: WorkspaceClient = {
+  loadSnapshot: async () => {
+    const remoteSnapshot = await loadRemoteWorkspaceSnapshot()
+    return remoteSnapshot ?? loadLocalWorkspaceSnapshot()
+  },
+  saveSnapshot: async (snapshot) => {
+    saveLocalWorkspaceSnapshot(snapshot)
+    await saveRemoteWorkspaceSnapshot(snapshot)
+  },
+}
+
+const inactiveAuthClient: AuthClient = {
+  enabled: false,
+  loadSession: async () => ({ authenticated: false, user: null }),
+  login: async () => {
+    throw new Error('Hosted login is not enabled in this workspace mode.')
+  },
+  logout: async () => undefined,
+}
+
+const hostedAuthClient: AuthClient = {
+  enabled: true,
+  loadSession: loadRemoteHostedSession,
+  login: loginRemoteHostedWorkspace,
+  logout: logoutRemoteHostedWorkspace,
+}
+
+export function getWorkspaceClient(): WorkspaceClient {
+  return remoteWorkspaceEnabled ? hostedWorkspaceClient : localWorkspaceClient
+}
+
+export function getAuthClient(): AuthClient {
+  return remoteWorkspaceEnabled ? hostedAuthClient : inactiveAuthClient
+}
+
+async function loadRemoteHostedSession(): Promise<HostedSession> {
   const response = await fetch(`${remoteWorkspaceApiBase}/session`, {
     credentials: 'include',
   })
@@ -245,7 +294,7 @@ export async function loadHostedSession(): Promise<HostedSession> {
   return response.json() as Promise<HostedSession>
 }
 
-export async function loginHostedWorkspace(username: string, password: string): Promise<HostedSession> {
+async function loginRemoteHostedWorkspace(username: string, password: string): Promise<HostedSession> {
   const response = await fetch(`${remoteWorkspaceApiBase}/login`, {
     method: 'POST',
     credentials: 'include',
@@ -260,8 +309,7 @@ export async function loginHostedWorkspace(username: string, password: string):
   return response.json() as Promise<HostedSession>
 }
 
-export async function logoutHostedWorkspace(): Promise<void> {
-  if (!remoteWorkspaceEnabled) return
+async function logoutRemoteHostedWorkspace(): Promise<void> {
   const response = await fetch(`${remoteWorkspaceApiBase}/logout`, {
     method: 'POST',
     credentials: 'include',
@@ -270,3 +318,15 @@ export async function logoutHostedWorkspace(): Promise<void> {
     throw new Error(`Unable to log out: ${response.status} ${response.statusText}`)
   }
 }
+
+export function loadHostedSession(): Promise<HostedSession> {
+  return getAuthClient().loadSession()
+}
+
+export function loginHostedWorkspace(username: string, password: string): Promise<HostedSession> {
+  return getAuthClient().login(username, password)
+}
+
+export function logoutHostedWorkspace(): Promise<void> {
+  return getAuthClient().logout()
+}