feat: init and fork some code from angular-auth-oidc-client

src/config/loader/config-loader.ts

@@ -0,0 +1,53 @@
+import { Provider } from 'injection-js';
+import { forkJoin, Observable, of } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { OpenIdConfiguration } from '../openid-configuration';
+
+export class OpenIdConfigLoader {
+  loader?: Provider;
+}
+
+export abstract class StsConfigLoader {
+  abstract loadConfigs(): Observable<OpenIdConfiguration[]>;
+}
+
+export class StsConfigStaticLoader implements StsConfigLoader {
+  constructor(
+    private readonly passedConfigs: OpenIdConfiguration | OpenIdConfiguration[]
+  ) {}
+
+  loadConfigs(): Observable<OpenIdConfiguration[]> {
+    if (Array.isArray(this.passedConfigs)) {
+      return of(this.passedConfigs);
+    }
+
+    return of([this.passedConfigs]);
+  }
+}
+
+export class StsConfigHttpLoader implements StsConfigLoader {
+  constructor(
+    private readonly configs$:
+      | Observable<OpenIdConfiguration>
+      | Observable<OpenIdConfiguration>[]
+      | Observable<OpenIdConfiguration[]>
+  ) {}
+
+  loadConfigs(): Observable<OpenIdConfiguration[]> {
+    if (Array.isArray(this.configs$)) {
+      return forkJoin(this.configs$);
+    }
+
+    const singleConfigOrArray = this.configs$ as Observable<unknown>;
+
+    return singleConfigOrArray.pipe(
+      map((value: unknown) => {
+        if (Array.isArray(value)) {
+          return value as OpenIdConfiguration[];
+        }
+
+        return [value] as OpenIdConfiguration[];
+      })
+    );
+  }
+}