feat: add explicit license selection and status visibility (#6751)

packages/core/src/code_assist/setup.ts

@@ -13,6 +13,7 @@ import {
 } from './types.js';
 import { CodeAssistServer } from './server.js';
 import { OAuth2Client } from 'google-auth-library';
+import { AuthType } from '../core/contentGenerator.js';
 
 export class ProjectIdRequiredError extends Error {
   constructor() {
@@ -22,6 +23,41 @@ export class ProjectIdRequiredError extends Error {
   }
 }
 
+export class ProjectAccessError extends Error {
+  constructor(projectId: string, details?: string) {
+    super(
+      `Failed to access GCP project "${projectId}" for Gemini Code Assist.\n` +
+        `${details || ''}\n` +
+        `Please verify:\n` +
+        `1. The project ID is correct\n` +
+        `2. You have the necessary permissions for this project\n` +
+        `3. The Gemini for Cloud API is enabled for this project\n` +
+        `\n` +
+        `To use a different project:\n` +
+        `  export GOOGLE_CLOUD_PROJECT=<your-project-id>\n` +
+        `\n` +
+        `To use Free Tier instead, run /auth and select "Login with Google - Free Tier"`,
+    );
+  }
+}
+
+export class LicenseMismatchError extends Error {
+  constructor(expected: string, actual: string) {
+    super(
+      `License type mismatch detected.\n` +
+        `You selected: ${expected}\n` +
+        `But the server returned: ${actual}\n` +
+        `\n` +
+        `This may indicate:\n` +
+        `1. The project doesn't have a valid GCA license\n` +
+        `2. You don't have access to the specified project\n` +
+        `3. The project configuration is incorrect\n` +
+        `\n` +
+        `Please verify your project settings or contact your administrator.`,
+    );
+  }
+}
+
 export interface UserData {
   projectId: string;
   userTier: UserTierId;
@@ -29,11 +65,20 @@ export interface UserData {
 
 /**
  *
- * @param projectId the user's project id, if any
- * @returns the user's actual project id
+ * @param client OAuth2 client
+ * @param authType the authentication type being used
+ * @returns the user's actual project id and tier
  */
-export async function setupUser(client: OAuth2Client): Promise<UserData> {
-  const projectId = process.env['GOOGLE_CLOUD_PROJECT'] || undefined;
+export async function setupUser(
+  client: OAuth2Client,
+  authType: AuthType,
+): Promise<UserData> {
+  // Only use GOOGLE_CLOUD_PROJECT for GCA login or Cloud Shell
+  const projectId =
+    authType === AuthType.LOGIN_WITH_GOOGLE_GCA ||
+    authType === AuthType.CLOUD_SHELL
+      ? process.env['GOOGLE_CLOUD_PROJECT'] || undefined
+      : undefined;
   const caServer = new CodeAssistServer(client, projectId, {}, '', undefined);
   const coreClientMetadata: ClientMetadata = {
     ideType: 'IDE_UNSPECIFIED',
@@ -41,22 +86,56 @@ export async function setupUser(client: OAuth2Client): Promise<UserData> {
     pluginType: 'GEMINI',
   };
 
-  const loadRes = await caServer.loadCodeAssist({
-    cloudaicompanionProject: projectId,
-    metadata: {
-      ...coreClientMetadata,
-      duetProject: projectId,
-    },
-  });
+  let loadRes: LoadCodeAssistResponse;
+  try {
+    loadRes = await caServer.loadCodeAssist({
+      cloudaicompanionProject: projectId,
+      metadata: {
+        ...coreClientMetadata,
+        duetProject: projectId,
+      },
+    });
+  } catch (error) {
+    // If GCA login failed with a project, throw a clear error
+    if (authType === AuthType.LOGIN_WITH_GOOGLE_GCA && projectId) {
+      throw new ProjectAccessError(
+        projectId,
+        error instanceof Error ? error.message : 'Authentication failed',
+      );
+    }
+    throw error;
+  }
 
   if (loadRes.currentTier) {
+    // Check for license mismatch - GCA selected but Free Tier returned
+    if (
+      authType === AuthType.LOGIN_WITH_GOOGLE_GCA &&
+      loadRes.currentTier.id === UserTierId.FREE
+    ) {
+      throw new LicenseMismatchError('Gemini Code Assist (GCA)', 'Free Tier');
+    }
+
     if (!loadRes.cloudaicompanionProject) {
       if (projectId) {
+        // GCA with project but no cloudaicompanionProject means project access issue
+        if (authType === AuthType.LOGIN_WITH_GOOGLE_GCA) {
+          throw new ProjectAccessError(
+            projectId,
+            'The project exists but is not configured for Gemini Code Assist',
+          );
+        }
         return {
           projectId,
           userTier: loadRes.currentTier.id,
         };
       }
+      // For Free Tier login, don't require project ID
+      if (authType === AuthType.LOGIN_WITH_GOOGLE) {
+        return {
+          projectId: '',
+          userTier: loadRes.currentTier.id,
+        };
+      }
       throw new ProjectIdRequiredError();
     }
     return {
@@ -67,8 +146,16 @@ export async function setupUser(client: OAuth2Client): Promise<UserData> {
 
   const tier = getOnboardTier(loadRes);
 
+  // Check for license mismatch during onboarding
+  if (
+    authType === AuthType.LOGIN_WITH_GOOGLE_GCA &&
+    tier.id === UserTierId.FREE
+  ) {
+    throw new LicenseMismatchError('Gemini Code Assist (GCA)', 'Free Tier');
+  }
+
   let onboardReq: OnboardUserRequest;
-  if (tier.id === UserTierId.FREE) {
+  if (tier.id === UserTierId.FREE || authType === AuthType.LOGIN_WITH_GOOGLE) {
     // The free tier uses a managed google cloud project. Setting a project in the `onboardUser` request causes a `Precondition Failed` error.
     onboardReq = {
       tierId: tier.id,
@@ -95,18 +182,42 @@ export async function setupUser(client: OAuth2Client): Promise<UserData> {
 
   if (!lroRes.response?.cloudaicompanionProject?.id) {
     if (projectId) {
+      // GCA with project but onboarding didn't return a project
+      if (authType === AuthType.LOGIN_WITH_GOOGLE_GCA) {
+        throw new ProjectAccessError(
+          projectId,
+          'Failed to onboard to Gemini Code Assist with this project',
+        );
+      }
       return {
         projectId,
         userTier: tier.id,
       };
     }
+    // For Free Tier login, don't require project ID
+    if (authType === AuthType.LOGIN_WITH_GOOGLE) {
+      return {
+        projectId: '',
+        userTier: tier.id,
+      };
+    }
     throw new ProjectIdRequiredError();
   }
 
-  return {
+  // Final validation: ensure GCA users don't get Free Tier
+  const finalUserData = {
     projectId: lroRes.response.cloudaicompanionProject.id,
     userTier: tier.id,
   };
+
+  if (
+    authType === AuthType.LOGIN_WITH_GOOGLE_GCA &&
+    finalUserData.userTier === UserTierId.FREE
+  ) {
+    throw new LicenseMismatchError('Gemini Code Assist (GCA)', 'Free Tier');
+  }
+
+  return finalUserData;
 }
 
 function getOnboardTier(res: LoadCodeAssistResponse): GeminiUserTier {