feat(auth): implement Facebook identity binding on external entry

src/lib/navigation/__tests__/external_entry.test.ts

@@ -5,6 +5,7 @@ import { ROUTES } from "@/router/routes";
 import {
   resolveExternalEntryPromotionType,
   resolveExternalEntryTarget,
+  shouldBindExternalFacebookIdentity,
 } from "../external_entry";
 
 describe("external entry navigation", () => {
@@ -31,6 +32,69 @@ describe("external entry navigation", () => {
   });
 });
 
+describe("external entry facebook identity binding", () => {
+  it("binds only a ready real-user session with an external id", () => {
+    expect(
+      shouldBindExternalFacebookIdentity({
+        hasInitialized: true,
+        isLoading: false,
+        loginStatus: "email",
+        asid: "asid-1",
+      }),
+    ).toBe(true);
+    expect(
+      shouldBindExternalFacebookIdentity({
+        hasInitialized: true,
+        isLoading: false,
+        loginStatus: "google",
+        asid: "asid-1",
+      }),
+    ).toBe(true);
+    expect(
+      shouldBindExternalFacebookIdentity({
+        hasInitialized: true,
+        isLoading: false,
+        loginStatus: "facebook",
+        psid: "psid-1",
+      }),
+    ).toBe(true);
+  });
+
+  it("skips guest, notLoggedIn, loading, and empty identity inputs", () => {
+    expect(
+      shouldBindExternalFacebookIdentity({
+        hasInitialized: true,
+        isLoading: false,
+        loginStatus: "guest",
+        asid: "asid-1",
+      }),
+    ).toBe(false);
+    expect(
+      shouldBindExternalFacebookIdentity({
+        hasInitialized: true,
+        isLoading: false,
+        loginStatus: "notLoggedIn",
+        psid: "psid-1",
+      }),
+    ).toBe(false);
+    expect(
+      shouldBindExternalFacebookIdentity({
+        hasInitialized: true,
+        isLoading: true,
+        loginStatus: "google",
+        asid: "asid-1",
+      }),
+    ).toBe(false);
+    expect(
+      shouldBindExternalFacebookIdentity({
+        hasInitialized: true,
+        isLoading: false,
+        loginStatus: "google",
+      }),
+    ).toBe(false);
+  });
+});
+
 describe("external entry promotion", () => {
   it("accepts only explicit promotion mode and supported message types", () => {
     expect(

src/lib/navigation/external_entry.ts

@@ -3,6 +3,7 @@
 import { AuthStorage } from "@/data/storage/auth/auth_storage";
 import { UserStorage } from "@/data/storage/user/user_storage";
 import type { PendingChatPromotionType } from "@/data/storage/navigation";
+import type { LoginStatus } from "@/data/dto/auth";
 import { ROUTES } from "@/router/routes";
 
 export type ExternalEntryTarget =
@@ -26,6 +27,33 @@ export interface ExternalEntryPromotionInput {
   promotionType?: string | null;
 }
 
+export interface ExternalFacebookIdentityBindingInput {
+  hasInitialized: boolean;
+  isLoading: boolean;
+  loginStatus: LoginStatus;
+  asid?: string | null;
+  psid?: string | null;
+}
+
+export function shouldBindExternalFacebookIdentity({
+  hasInitialized,
+  isLoading,
+  loginStatus,
+  asid,
+  psid,
+}: ExternalFacebookIdentityBindingInput): boolean {
+  const isRealUser =
+    loginStatus === "email" ||
+    loginStatus === "google" ||
+    loginStatus === "facebook";
+  return (
+    hasInitialized &&
+    !isLoading &&
+    isRealUser &&
+    (hasValue(asid) || hasValue(psid))
+  );
+}
+
 export function resolveExternalEntryPromotionType({
   mode,
   promotionType,