use lowdb for faster iteration; use strings for ids and camelCase for field names for consistency

.gitignore

@@ -140,3 +140,5 @@ dist
 # aws-cdk
 .cdk.staging
 cdk.out
+
+db.json

database/lowdb.ts

@@ -0,0 +1,30 @@
+import { Low } from "lowdb";
+import { JSONFile } from "lowdb/node";
+
+export type Conversation = {
+  id: string;
+  title: string;
+  userId: string;
+};
+
+type DB = {
+  conversations: Array<Conversation>;
+  messages: Array<{
+    id: string;
+    conversationId: string;
+    content: string;
+    role: "user" | "assistant" | "system" | "data";
+    index: number;
+    createdAt: string;
+    runningSummary?: string;
+  }>;
+};
+
+export const db = new Low<DB>(new JSONFile("db.json"), {
+  conversations: [],
+  messages: [],
+});
+/** Initialize the database. Sets `db.data` to the default state if the file doesn't exist. */
+await db.read();
+/** Write the database to the file, in case it didn't exist before. */
+await db.write();

package.json

@@ -31,6 +31,8 @@
     "hono": "^4.8.2",
     "immer": "^10.1.1",
     "kysely": "^0.28.2",
+    "lowdb": "^7.0.1",
+    "nanoid": "^5.1.5",
     "pg": "^8.16.3",
     "react": "^19.1.0",
     "react-dom": "^19.1.0",

pages/chat/@id/+Page.tsx

@@ -17,13 +17,12 @@ import {
 import { usePageContext } from "vike-react/usePageContext";
 import { useData } from "vike-react/useData";
 import type { Data } from "./+data";
-import type { ConversationsId } from "../../../database/generated/public/Conversations";
 import type { CommittedMessage, DraftMessage } from "../../../types";
 import Markdown from "react-markdown";
 
 export default function ChatPage() {
   const pageContext = usePageContext();
-  const conversationId = Number(pageContext.routeParams.id) as ConversationsId;
+  const conversationId = pageContext.routeParams.id;
   const conversationTitle = useStore(
     (state) => state.conversations.find((c) => c.id === conversationId)?.title,
   );
@@ -126,7 +125,7 @@ export default function ChatPage() {
                     content: response.insertedAssistantMessage?.content,
                     index: response.insertedAssistantMessage?.index,
                     runningSummary:
-                      response.insertedAssistantMessage?.running_summary ||
+                      response.insertedAssistantMessage?.runningSummary ||
                       undefined,
                   } as CommittedMessage,
                 ];
@@ -185,17 +184,18 @@ function Messages({
             bdrs="md"
           >
             <div>
-              {"index" in message ? message.index : ""}
+              {"index" in message ? message.index : ""} {message.role}
-              {message.role}
             </div>
             <Markdown>{message.content}</Markdown>
+          </Box>
           {"runningSummary" in message && (
+            <Box w="75%" bd="dotted" p="md" bdrs="md">
               <div>
                 <strong>Running Summary:</strong>
                 <Markdown>{message.runningSummary}</Markdown>
               </div>
-            )}
             </Box>
+          )}
         </Group>
       ))}
     </Stack>

pages/chat/@id/+data.ts

@@ -7,10 +7,10 @@ export const data = async (pageContext: PageContextServer) => {
   const { id } = pageContext.routeParams;
   const caller = createCaller({});
   const conversation = await caller.fetchConversation({
-    id: Number(id),
+    id,
   });
   const messages = await caller.fetchMessages({
-    conversationId: Number(id),
+    conversationId: id,
   });
   return { conversation, messages };
 };

pages/chat/trpc.ts

@@ -17,9 +17,8 @@ import { env } from "../../server/env.js";
 //   ConsistencyLevelEnum,
 //   type NumberArrayId,
 // } from "@zilliz/milvus2-sdk-node";
-import { db } from "../../database/postgres";
+import { db } from "../../database/lowdb";
-import type { ConversationsId } from "../../database/generated/public/Conversations";
+import { nanoid } from "nanoid";
-import type { UsersId } from "../../database/generated/public/Users";
 
 const mainSystemPrompt = ({
   systemPrompt,
@@ -47,75 +46,64 @@ const openrouter = createOpenRouter({
 
 export const chat = router({
   listConversations: publicProcedure.query(async () => {
-    const rows = await db.selectFrom("conversations").selectAll().execute();
+    const rows = await db.data.conversations;
     return rows;
   }),
   fetchConversation: publicProcedure
-    .input((x) => x as { id: number })
+    .input((x) => x as { id: string })
     .query(async ({ input: { id } }) => {
-      const row = await db
+      const row = await db.data.conversations.find((c) => c.id === id);
-        .selectFrom("conversations")
-        .selectAll()
-        .where("id", "=", id as ConversationsId)
-        .executeTakeFirst();
       return row;
     }),
   createConversation: publicProcedure.mutation(async () => {
     const title = "New Conversation";
-    const row = await db
+    const row = {
-      .insertInto("conversations")
+      id: nanoid(),
-      .values({
       title,
-        user_id: 1 as UsersId,
+      userId: "1",
-      })
+    };
-      .returningAll()
+    await db.data.conversations.push(row);
-      .executeTakeFirst();
+    db.write();
     return row;
   }),
   deleteConversation: publicProcedure
-    .input((x) => x as { id: number })
+    .input((x) => x as { id: string })
     .mutation(async ({ input: { id } }) => {
-      const result = await db
+      await db.data.conversations.splice(
-        .deleteFrom("conversations")
+        db.data.conversations.findIndex((c) => c.id === id),
-        .where("id", "=", Number(id) as ConversationsId)
+        1,
-        .execute();
+      );
-      return result;
+      db.write();
+      return { ok: true };
     }),
   updateConversationTitle: publicProcedure
     .input(
       (x) =>
         x as {
-          id: number;
+          id: string;
           title: string;
         },
     )
     .mutation(async ({ input: { id, title } }) => {
-      const result = await db
+      const conversation = await db.data.conversations.find((c) => c.id === id);
-        .updateTable("conversations")
+      if (!conversation) throw new Error("Conversation not found");
-        .set({ title })
+      conversation.title = title;
-        .where("id", "=", Number(id) as ConversationsId)
+      db.write();
-        .execute();
+      return { ok: true };
-      return result[0];
     }),
   fetchMessages: publicProcedure
-    .input((x) => x as { conversationId: number })
+    .input((x) => x as { conversationId: string })
     .query(async ({ input: { conversationId } }) => {
-      const rows = await db
+      const rows = await db.data.messages.filter(
-        .selectFrom("messages")
+        (m) => m.conversationId === conversationId,
-        .selectAll()
+      );
-        .where("conversation_id", "=", conversationId as ConversationsId)
+      return rows as Array<CommittedMessage>;
-        .execute();
-      return rows.map((row) => ({
-        ...row,
-        conversationId: conversationId as ConversationsId,
-        runningSummary: row.running_summary,
-      })) as Array<CommittedMessage>;
     }),
   sendMessage: publicProcedure
     .input(
       (x) =>
         x as {
-          conversationId: number;
+          conversationId: string;
           messages: Array<DraftMessage | CommittedMessage>;
           systemPrompt: string;
           parameters: OtherParameters;
@@ -140,17 +128,17 @@ export const chat = router({
                 .runningSummary as string)
             : "";
         /** Save the incoming message to the database. */
-        const insertedUserMessage = await db
+        const insertedUserMessage: CommittedMessage = {
-          .insertInto("messages")
+          id: nanoid(),
-          .values({
+          conversationId,
-            conversation_id: conversationId as ConversationsId,
           content: messages[messages.length - 1].content,
           role: "user" as const,
           index: messages.length - 1,
-            created_at: new Date().toISOString(),
+          createdAt: new Date().toISOString(),
-          })
+        };
-          .returning(["id", "index"])
+        await db.data.messages.push(insertedUserMessage);
-          .executeTakeFirst();
+        // do not db.write() until the end
+
         /** Generate a new message from the model, but hold-off on adding it to
          * the database until we produce the associated running-summary, below.
          * The model should be given the conversation summary thus far, and of
@@ -249,18 +237,17 @@ export const chat = router({
               tools: undefined,
               ...parameters,
             });
-        const insertedAssistantMessage = await db
+        const insertedAssistantMessage: CommittedMessage = {
-          .insertInto("messages")
+          id: nanoid(),
-          .values({
+          conversationId,
-            conversation_id: conversationId as ConversationsId,
           content: mainResponse.text,
-            running_summary: runningSummaryResponse.text,
+          runningSummary: runningSummaryResponse.text,
           role: "assistant" as const,
           index: messages.length,
-            created_at: new Date().toISOString(),
+          createdAt: new Date().toISOString(),
-          })
+        };
-          .returningAll()
+        await db.data.messages.push(insertedAssistantMessage);
-          .executeTakeFirst();
+        await db.write();
         /** TODO: notify the caller, somehow, that some messages were saved to
          * the database and/or were outfitted with runningSummaries, so the
          * caller can update its UI state. */

pnpm-lock.yaml

@@ -68,6 +68,12 @@ importers:
       kysely:
         specifier: ^0.28.2
         version: 0.28.2
+      lowdb:
+        specifier: ^7.0.1
+        version: 7.0.1
+      nanoid:
+        specifier: ^5.1.5
+        version: 5.1.5
       pg:
         specifier: ^8.16.3
         version: 8.16.3
@@ -1903,6 +1909,10 @@ packages:
   longest-streak@3.1.0:
     resolution: {integrity: sha512-9Ri+o0JYgehTaVBBDoMqIl8GXtbWg711O3srftcHhZ0dqnETqLaoIK0x17fUw9rFSlK/0NlsKe0Ahhyl5pXE2g==}
 
+  lowdb@7.0.1:
+    resolution: {integrity: sha512-neJAj8GwF0e8EpycYIDFqEPcx9Qz4GUho20jWFR7YiFeXzF1YMLdxB36PypcTSPMA+4+LvgyMacYhlr18Zlymw==}
+    engines: {node: '>=18'}
+
   lru-cache@10.4.3:
     resolution: {integrity: sha512-JNAzZcXrCt42VGLuYz0zfAzDfAvJWW6AfYlDBQyDV5DClI2m5sAmK+OIO7s59XfsRsWHp02jAJrRadPRGTt6SQ==}
 
@@ -2071,6 +2081,11 @@ packages:
     engines: {node: ^10 || ^12 || ^13.7 || ^14 || >=15.0.1}
     hasBin: true
 
+  nanoid@5.1.5:
+    resolution: {integrity: sha512-Ir/+ZpE9fDsNH0hQ3C68uyThDXzYcim2EqcZ8zn8Chtt1iylPT9xXJB0kPCnqzgcEGikO9RxSrh63MsmVCU7Fw==}
+    engines: {node: ^18 || >=20}
+    hasBin: true
+
   node-releases@2.0.19:
     resolution: {integrity: sha512-xxOWJsBKtzAq7DY0J+DTzuz58K8e7sJbdgwkbMWQe8UYB6ekmsQ45q0M/tJDsGaZmbC+l7n57UV8Hl5tHxO9uw==}
 
@@ -2682,6 +2697,10 @@ packages:
   stacktracey@2.1.8:
     resolution: {integrity: sha512-Kpij9riA+UNg7TnphqjH7/CzctQ/owJGNbFkfEeve4Z4uxT5+JapVLFXcsurIfN34gnTWZNJ/f7NMG0E8JDzTw==}
 
+  steno@4.0.2:
+    resolution: {integrity: sha512-yhPIQXjrlt1xv7dyPQg2P17URmXbuM5pdGkpiMB3RenprfiBlvK415Lctfe0eshk90oA7/tNq7WEiMK8RSP39A==}
+    engines: {node: '>=18'}
+
   stoppable@1.1.0:
     resolution: {integrity: sha512-KXDYZ9dszj6bzvnEMRYvxgeTHU74QBFL54XKtP3nyMuJ81CFYtABZ3bAzL2EdFUaEwJOBOgENyFj3R7oTzDyyw==}
     engines: {node: '>=4', npm: '>=6'}
@@ -4688,6 +4707,10 @@ snapshots:
 
   longest-streak@3.1.0: {}
 
+  lowdb@7.0.1:
+    dependencies:
+      steno: 4.0.2
+
   lru-cache@10.4.3: {}
 
   lru-cache@11.1.0: {}
@@ -4981,6 +5004,8 @@ snapshots:
 
   nanoid@3.3.11: {}
 
+  nanoid@5.1.5: {}
+
   node-releases@2.0.19: {}
 
   normalize-range@0.1.2: {}
@@ -5606,6 +5631,8 @@ snapshots:
       as-table: 1.0.55
       get-source: 2.0.12
 
+  steno@4.0.2: {}
+
   stoppable@1.1.0: {}
 
   string-width@4.2.3:

state.ts

@@ -11,7 +11,7 @@ export const defaultParameters = {
 
 export const useStore = create<Store>()(
   immer((set, get) => ({
-    selectedConversationId: 0 as ConversationsId,
+    selectedConversationId: "",
     conversations: [],
     messages: [],
     message: "",

types.ts

@@ -1,32 +1,29 @@
 import type { Message as UIMessage } from "ai";
 import type { generateText } from "ai";
-import type {
+import type { Conversation } from "./database/lowdb.js";
-  Conversations,
-  ConversationsId,
-} from "./database/generated/public/Conversations";
 
 export type OtherParameters = Omit<
   Parameters<typeof generateText>[0],
   "model" | "messages" | "abortSignal"
 >;
 
-export type ConversationUI = Conversations & {};
+export type ConversationUI = Conversation & {};
 
 export type Store = {
   /** This is a string because Milvus sends it as a string, and the value
    * overflows the JS integer anyway. */
-  selectedConversationId: ConversationsId;
+  selectedConversationId: string;
   conversations: Array<ConversationUI>;
   messages: Array<DraftMessage | CommittedMessage>;
   message: string;
   systemPrompt: string;
   parameters: OtherParameters;
   loading: boolean;
-  setConversationId: (conversationId: ConversationsId) => void;
+  setConversationId: (conversationId: string) => void;
   setConversationTitle: (conversationTitle: string) => void;
   setConversations: (conversations: Array<ConversationUI>) => void;
   addConversation: (conversation: ConversationUI) => void;
-  removeConversation: (conversationId: ConversationsId) => void;
+  removeConversation: (conversationId: string) => void;
   setMessages: (messages: Array<DraftMessage | CommittedMessage>) => void;
   setMessage: (message: string) => void;
   setSystemPrompt: (systemPrompt: string) => void;
@@ -35,11 +32,12 @@ export type Store = {
 };
 
 /** The message while it's being typed in the input box. */
-export type DraftMessage = Omit<UIMessage, "id">;
+export type DraftMessage = Omit<UIMessage, "id" | "createdAt">;
 /** The message after it's been saved to the database. */
 export type CommittedMessage = DraftMessage & {
-  id: number;
+  id: string;
-  conversationId: ConversationsId;
+  conversationId: string;
   index: number;
   runningSummary?: string;
+  createdAt: string;
 };