refactor(ui-server-auth,server): use better design of signin page

apps/ui-server-auth/src/modules/server-auth-context.ts

@@ -0,0 +1,41 @@
+import { SERVER_URL } from '@proj-airi/stage-ui/libs/server'
+
+export interface ServerAuthBootstrapContext {
+  apiServerUrl: string
+  currentUrl: string
+  oidcCallback?: {
+    code: string
+    error: string
+    errorDescription: string
+    state: string
+  }
+}
+
+const SCRIPT_ID = 'airi-server-auth-context'
+
+let cachedContext: ServerAuthBootstrapContext | null | undefined
+
+export function getServerAuthBootstrapContext(): ServerAuthBootstrapContext | null {
+  if (cachedContext !== undefined)
+    return cachedContext
+
+  const element = document.getElementById(SCRIPT_ID)
+  if (!element) {
+    cachedContext = null
+    return cachedContext
+  }
+
+  try {
+    const parsed = JSON.parse(element.textContent ?? '') as Partial<ServerAuthBootstrapContext>
+    cachedContext = {
+      apiServerUrl: parsed.apiServerUrl ?? SERVER_URL,
+      currentUrl: parsed.currentUrl ?? window.location.href,
+      oidcCallback: parsed.oidcCallback,
+    }
+    return cachedContext
+  }
+  catch {
+    cachedContext = null
+    return cachedContext
+  }
+}