Refactor of authentication code. Added configuration file selectable authentication method. Selectable from built-in Azure Identity, and custom PCA using MSAL.

src/graph/index.ts

@@ -3,3 +3,22 @@
 export * from "./auth.ts";
 export * from "./app.ts";
 export * from "./sp.ts";
+
+import { loadAuthConfig, loadConfig } from "../index.ts";
+import { Client } from "@microsoft/microsoft-graph-client";
+
+import { getMsalAuthProvider, getAzureIdentityAuthProvider } from "./auth.ts";
+
+export async function getGraphClient(): Promise<Client> {
+  const config = await loadConfig();
+
+  const authConfig = await loadAuthConfig("public-config");
+  const authProvider =
+    config.authMode === "azure-identity"
+      ? getAzureIdentityAuthProvider(authConfig.tenantId, authConfig.clientId)
+      : getMsalAuthProvider(authConfig.tenantId, authConfig.clientId);
+
+  return Client.init({
+    authProvider: authProvider,
+  });
+}