Move the Portal Backend client to Common

The module is a plain service client with no dependency on the hosted platform, and CosmosClient and MetricEvents already hand roll their own Portal Backend calls, so Common is where a shared client belongs.

src/Common/PortalBackendClient.ts

@@ -0,0 +1,45 @@
+import { configContext } from "../ConfigContext";
+import { AccessInputMetadata } from "../Contracts/DataModels";
+import { HttpHeaders } from "./Constants";
+
+export async function fetchAccessData(portalToken: string): Promise<AccessInputMetadata> {
+  const headers = new Headers();
+  // Portal encrypted token API quirk: The token header must be URL encoded
+  headers.append(HttpHeaders.guestAccessToken, encodeURIComponent(portalToken));
+  headers.append(HttpHeaders.authorization, encodeURIComponent(portalToken));
+  const url: string = `${configContext.PORTAL_BACKEND_ENDPOINT}/api/connectionstring/runtimeproxy/accessinputmetadata`;
+  const options = {
+    method: "GET",
+    headers: headers,
+  };
+
+  return fetch(url, options)
+    .then((response) => response.json())
+    .catch((error) => console.error(error));
+}
+
+export async function fetchEncryptedToken(connectionString: string): Promise<string> {
+  const headers = new Headers();
+  headers.append(HttpHeaders.connectionString, connectionString);
+  headers.append(HttpHeaders.authorization, connectionString);
+  const url = configContext.PORTAL_BACKEND_ENDPOINT + "/api/connectionstring/token/generatetoken";
+  const response = await fetch(url, { headers, method: "POST" });
+  if (!response.ok) {
+    throw response;
+  }
+
+  const encryptedTokenResponse: string = await response.json();
+  return decodeURIComponent(encryptedTokenResponse);
+}
+
+export async function isAccountRestrictedForConnectionStringLogin(connectionString: string): Promise<boolean> {
+  const headers = new Headers();
+  headers.append(HttpHeaders.connectionString, connectionString);
+  const url = configContext.PORTAL_BACKEND_ENDPOINT + "/api/guest/accountrestrictions/checkconnectionstringlogin";
+  const response = await fetch(url, { headers, method: "POST" });
+  if (!response.ok) {
+    throw response;
+  }
+
+  return (await response.text()).toLowerCase() === "true";
+}