[PM-5979] Refactor EnvironmentService (#8040)

Refactor environment service to emit a single observable. This required significant changes to how the environment service behaves and tackles much of the tech debt planned for it.

apps/web/src/app/platform/web-environment.service.ts

@@ -0,0 +1,62 @@
+import { ReplaySubject } from "rxjs";
+
+import { AccountService } from "@bitwarden/common/auth/abstractions/account.service";
+import {
+  Environment,
+  Region,
+  RegionConfig,
+  Urls,
+} from "@bitwarden/common/platform/abstractions/environment.service";
+import { Utils } from "@bitwarden/common/platform/misc/utils";
+import {
+  CloudEnvironment,
+  DefaultEnvironmentService,
+  SelfHostedEnvironment,
+} from "@bitwarden/common/platform/services/default-environment.service";
+import { StateProvider } from "@bitwarden/common/platform/state";
+
+/**
+ * Web specific environment service. Ensures that the urls are set from the window location.
+ */
+export class WebEnvironmentService extends DefaultEnvironmentService {
+  constructor(
+    private win: Window,
+    stateProvider: StateProvider,
+    accountService: AccountService,
+  ) {
+    super(stateProvider, accountService);
+
+    // The web vault always uses the current location as the base url
+    const urls = process.env.URLS as Urls;
+    urls.base ??= this.win.location.origin;
+
+    // Find the region
+    const domain = Utils.getDomain(this.win.location.href);
+    const region = this.availableRegions().find((r) => Utils.getDomain(r.urls.webVault) === domain);
+
+    let environment: Environment;
+    if (region) {
+      environment = new WebCloudEnvironment(region, urls);
+    } else {
+      environment = new SelfHostedEnvironment(urls);
+    }
+
+    // Override the environment observable with a replay subject
+    const subject = new ReplaySubject<Environment>(1);
+    subject.next(environment);
+    this.environment$ = subject.asObservable();
+  }
+
+  // Web cannot set environment
+  async setEnvironment(region: Region, urls?: Urls): Promise<Urls> {
+    return;
+  }
+}
+
+class WebCloudEnvironment extends CloudEnvironment {
+  constructor(config: RegionConfig, urls: Urls) {
+    super(config);
+    // We override the urls to avoid CORS issues
+    this.urls = urls;
+  }
+}