feat: support guest session (#919)

lib/ai/entitlements.ts

@@ -0,0 +1,29 @@
+import type { UserType } from '@/app/(auth)/auth';
+import type { ChatModel } from './models';
+
+interface Entitlements {
+  maxMessagesPerDay: number;
+  availableChatModelIds: Array<ChatModel['id']>;
+}
+
+export const entitlementsByUserType: Record<UserType, Entitlements> = {
+  /*
+   * For users without an account
+   */
+  guest: {
+    maxMessagesPerDay: 20,
+    availableChatModelIds: ['chat-model', 'chat-model-reasoning'],
+  },
+
+  /*
+   * For users with an account
+   */
+  regular: {
+    maxMessagesPerDay: 100,
+    availableChatModelIds: ['chat-model', 'chat-model-reasoning'],
+  },
+
+  /*
+   * TODO: For users with an account and a paid membership
+   */
+};

lib/ai/models.ts

@@ -1,6 +1,6 @@
 export const DEFAULT_CHAT_MODEL: string = 'chat-model';
 
-interface ChatModel {
+export interface ChatModel {
   id: string;
   name: string;
   description: string;

lib/constants.ts

@@ -1,11 +1,13 @@
 import { generateDummyPassword } from './db/utils';
 
 export const isProductionEnvironment = process.env.NODE_ENV === 'production';
-
+export const isDevelopmentEnvironment = process.env.NODE_ENV === 'development';
 export const isTestEnvironment = Boolean(
   process.env.PLAYWRIGHT_TEST_BASE_URL ||
     process.env.PLAYWRIGHT ||
     process.env.CI_PLAYWRIGHT,
 );
 
+export const guestRegex = /^guest-\d+$/;
+
 export const DUMMY_PASSWORD = generateDummyPassword();

lib/db/queries.ts

@@ -3,6 +3,7 @@ import 'server-only';
 import {
   and,
   asc,
+  count,
   desc,
   eq,
   gt,
@@ -27,6 +28,7 @@ import {
   type Chat,
 } from './schema';
 import type { ArtifactKind } from '@/components/artifact';
+import { generateUUID } from '../utils';
 import { generateHashedPassword } from './utils';
 
 // Optionally, if not using email/pass login, you can
@@ -57,6 +59,21 @@ export async function createUser(email: string, password: string) {
   }
 }
 
+export async function createGuestUser() {
+  const email = `guest-${Date.now()}`;
+  const password = generateHashedPassword(generateUUID());
+
+  try {
+    return await db.insert(user).values({ email, password }).returning({
+      id: user.id,
+      email: user.email,
+    });
+  } catch (error) {
+    console.error('Failed to create guest user in database');
+    throw error;
+  }
+}
+
 export async function saveChat({
   id,
   userId,
@@ -422,3 +439,34 @@ export async function updateChatVisiblityById({
     throw error;
   }
 }
+
+export async function getMessageCountByUserId({
+  id,
+  differenceInHours,
+}: { id: string; differenceInHours: number }) {
+  try {
+    const twentyFourHoursAgo = new Date(
+      Date.now() - differenceInHours * 60 * 60 * 1000,
+    );
+
+    const [stats] = await db
+      .select({ count: count(message.id) })
+      .from(message)
+      .innerJoin(chat, eq(message.chatId, chat.id))
+      .where(
+        and(
+          eq(chat.userId, id),
+          gte(message.createdAt, twentyFourHoursAgo),
+          eq(message.role, 'user'),
+        ),
+      )
+      .execute();
+
+    return stats?.count ?? 0;
+  } catch (error) {
+    console.error(
+      'Failed to get message count by user id for the last 24 hours from database',
+    );
+    throw error;
+  }
+}