Add office editor provider

src/api.ts

@@ -0,0 +1,21 @@
+import { createFetchWrapper } from '@KTXC'
+
+export interface LaunchSession {
+  actionUrl: string
+  accessToken: string
+  accessTokenTtl: number
+  officeOrigin: string
+  mode: 'view'
+}
+
+const api = createFetchWrapper()
+export const launch = (resource: string): Promise<LaunchSession> => api.post('/m/service_wopi/sessions', { resource })
+
+export function validateSession(session: LaunchSession): void {
+  const action = new URL(session.actionUrl)
+  if (action.protocol !== 'https:' || action.origin !== session.officeOrigin || action.username || action.password
+    || session.mode !== 'view' || !/^[a-f0-9]{64}$/.test(session.accessToken)
+    || !Number.isSafeInteger(session.accessTokenTtl) || session.accessTokenTtl <= Date.now()) {
+    throw new Error('Invalid office session.')
+  }
+}