From 5ff430fe34866b3dd6b184048c87ec200e9c63a5 Mon Sep 17 00:00:00 2001
From: steven <stevenlgtm@gmail.com>
Date: Thu, 16 Mar 2023 17:01:38 +0800
Subject: [PATCH] feat: implement stores and basic chat logic

---
 components/ChatView/MessageView.tsx           | 13 +++
 components/ChatView/Sidebar.tsx               | 32 +++++++
 components/ChatView/Textarea.tsx              | 59 ++++++++++++
 components/ChatView/index.tsx                 | 28 ++++++
 components/Icon.tsx                           |  3 +
 package.json                                  |  9 +-
 pages/_app.tsx                                |  2 +-
 pages/api/chat.ts                             |  7 +-
 pages/chat.tsx                                | 11 +--
 pages/index.tsx                               | 10 +-
 pnpm-lock.yaml                                | 92 ++++++++++++++++++-
 store/chat.ts                                 | 31 +++++++
 store/index.ts                                |  3 +
 store/message.ts                              | 14 +++
 store/user.ts                                 | 36 ++++++++
 pages/styles/globals.css => styles/global.css |  0
 types/chat.ts                                 |  6 ++
 types/common.ts                               |  2 +
 types/index.ts                                |  4 +
 types/message.ts                              |  9 ++
 types/user.ts                                 | 13 +++
 utils/index.ts                                |  5 +
 {pages/api => utils}/openai-api.ts            |  1 +
 23 files changed, 372 insertions(+), 18 deletions(-)
 create mode 100644 components/ChatView/MessageView.tsx
 create mode 100644 components/ChatView/Sidebar.tsx
 create mode 100644 components/ChatView/Textarea.tsx
 create mode 100644 components/ChatView/index.tsx
 create mode 100644 components/Icon.tsx
 create mode 100644 store/chat.ts
 create mode 100644 store/index.ts
 create mode 100644 store/message.ts
 create mode 100644 store/user.ts
 rename pages/styles/globals.css => styles/global.css (100%)
 create mode 100644 types/chat.ts
 create mode 100644 types/common.ts
 create mode 100644 types/index.ts
 create mode 100644 types/message.ts
 create mode 100644 types/user.ts
 create mode 100644 utils/index.ts
 rename {pages/api => utils}/openai-api.ts (99%)

diff --git a/components/ChatView/MessageView.tsx b/components/ChatView/MessageView.tsx
new file mode 100644
index 0000000..1d52385
--- /dev/null
+++ b/components/ChatView/MessageView.tsx
@@ -0,0 +1,13 @@
+import { Message } from "../../types";
+
+interface Props {
+  message: Message;
+}
+
+const Message = (props: Props) => {
+  const message = props.message;
+
+  return <div>{message.content}</div>;
+};
+
+export default Message;
diff --git a/components/ChatView/Sidebar.tsx b/components/ChatView/Sidebar.tsx
new file mode 100644
index 0000000..72ca290
--- /dev/null
+++ b/components/ChatView/Sidebar.tsx
@@ -0,0 +1,32 @@
+import { useChatStore, useUserStore } from "../../store";
+import { User } from "../../types";
+
+const Sidebar = () => {
+  const userStore = useUserStore();
+  const chatStore = useChatStore();
+
+  const handleAssistantClick = (user: User) => {
+    for (const chat of chatStore.chatList) {
+      if (chat.userId === user.id) {
+        chatStore.setCurrentChat(chat);
+        return;
+      }
+    }
+    chatStore.createChat(user);
+  };
+
+  return (
+    <div className="w-full border-r p-2">
+      <h2>Assistant list</h2>
+      <div>
+        {userStore.assistantList.map((assistant) => (
+          <p onClick={() => handleAssistantClick(assistant)} key={assistant.id}>
+            {assistant.name}
+          </p>
+        ))}
+      </div>
+    </div>
+  );
+};
+
+export default Sidebar;
diff --git a/components/ChatView/Textarea.tsx b/components/ChatView/Textarea.tsx
new file mode 100644
index 0000000..cb50e13
--- /dev/null
+++ b/components/ChatView/Textarea.tsx
@@ -0,0 +1,59 @@
+import axios from "axios";
+import { useRef, useState } from "react";
+import { useChatStore, useMessageStore, useUserStore } from "../../store";
+import { UserRole } from "../../types";
+import { generateUUID } from "../../utils";
+import Icon from "../Icon";
+
+const Textarea = () => {
+  const userStore = useUserStore();
+  const chatStore = useChatStore();
+  const messageStore = useMessageStore();
+  const [value, setValue] = useState<string>("");
+  const textareaRef = useRef<HTMLTextAreaElement>(null);
+
+  const handleChange = (e: React.ChangeEvent<HTMLTextAreaElement>) => {
+    setValue(e.target.value);
+  };
+
+  const handleSend = async () => {
+    if (!chatStore.currentChat) {
+      return;
+    }
+
+    const currentChat = chatStore.currentChat;
+    messageStore.addMessage({
+      id: generateUUID(),
+      chatId: currentChat.id,
+      creatorId: userStore.currentUser.id,
+      createdAt: Date.now(),
+      content: value,
+    });
+    setValue("");
+    textareaRef.current!.value = "";
+
+    const messageList = messageStore.getState().messageList.filter((message) => message.chatId === currentChat.id);
+    const { data } = await axios.post<string>("/api/chat", {
+      messages: messageList.map((message) => ({
+        role: message.creatorId === userStore.currentUser.id ? UserRole.User : UserRole.Assistant,
+        content: message.content,
+      })),
+    });
+    messageStore.addMessage({
+      id: generateUUID(),
+      chatId: currentChat.id,
+      creatorId: currentChat.userId,
+      createdAt: Date.now(),
+      content: data,
+    });
+  };
+
+  return (
+    <div className="w-full h-auto border-t relative">
+      <textarea ref={textareaRef} className="w-full h-full outline-none pt-2 px-2 resize-none" onChange={handleChange} rows={1} />
+      <Icon.Send className="absolute bottom-2 right-2" onClick={handleSend} />
+    </div>
+  );
+};
+
+export default Textarea;
diff --git a/components/ChatView/index.tsx b/components/ChatView/index.tsx
new file mode 100644
index 0000000..74e96e9
--- /dev/null
+++ b/components/ChatView/index.tsx
@@ -0,0 +1,28 @@
+import { useChatStore, useMessageStore, useUserStore } from "../../store";
+import MessageView from "./MessageView";
+import Sidebar from "./Sidebar";
+import Textarea from "./Textarea";
+
+const ChatView = () => {
+  const chatStore = useChatStore();
+  const userStore = useUserStore();
+  const messageStore = useMessageStore();
+  const currentChat = chatStore.currentChat;
+  const chatTitle = currentChat ? userStore.getAssistantById(currentChat.userId)?.name : "No chat";
+  const messageList = messageStore.messageList.filter((message) => message.chatId === currentChat?.id);
+
+  return (
+    <div className="w-full max-w-full lg:max-w-3xl border rounded-md grid grid-cols-[192px_1fr]">
+      <Sidebar />
+      <main className="w-full">
+        <p className="w-full text-center py-2 border-b">{chatTitle}</p>
+        <div className="py-2">
+          {messageList.length === 0 ? <p>no message</p> : messageList.map((message) => <MessageView key={message.id} message={message} />)}
+        </div>
+        <Textarea />
+      </main>
+    </div>
+  );
+};
+
+export default ChatView;
diff --git a/components/Icon.tsx b/components/Icon.tsx
new file mode 100644
index 0000000..56882fe
--- /dev/null
+++ b/components/Icon.tsx
@@ -0,0 +1,3 @@
+import * as Icon from "lucide-react";
+
+export default Icon;
diff --git a/package.json b/package.json
index 82055e1..9334cf0 100644
--- a/package.json
+++ b/package.json
@@ -8,15 +8,22 @@
   },
   "dependencies": {
     "@vercel/analytics": "^0.1.11",
+    "axios": "^1.3.4",
+    "csstype": "^3.1.1",
     "highlight.js": "^11.7.0",
+    "lucide-react": "^0.125.0",
     "next": "^13.2.4",
     "openai": "^3.0.0",
     "react": "^18.2.0",
-    "react-dom": "^18.2.0"
+    "react-dom": "^18.2.0",
+    "react-hot-toast": "^2.4.0",
+    "uuid": "^9.0.0",
+    "zustand": "^4.3.6"
   },
   "devDependencies": {
     "@types/node": "^18.11.18",
     "@types/react": "^18.0.26",
+    "@types/uuid": "^9.0.1",
     "autoprefixer": "^10.4.13",
     "eslint": "8.20.0",
     "eslint-config-next": "12.2.3",
diff --git a/pages/_app.tsx b/pages/_app.tsx
index 90defae..5a8e3d8 100644
--- a/pages/_app.tsx
+++ b/pages/_app.tsx
@@ -1,7 +1,7 @@
 import { AppProps } from "next/app";
 import React from "react";
 import { Analytics } from "@vercel/analytics/react";
-import "./styles/globals.css";
+import "../styles/global.css";
 
 function MyApp({ Component, pageProps }: AppProps) {
   return (
diff --git a/pages/api/chat.ts b/pages/api/chat.ts
index 11da40c..7000a66 100644
--- a/pages/api/chat.ts
+++ b/pages/api/chat.ts
@@ -1,18 +1,17 @@
 import { NextApiRequest, NextApiResponse } from "next";
-import openai, { ChatCompletionResponse } from "./openai-api";
+import openai from "../../utils/openai-api";
 
-const handler = async (req: NextApiRequest, res: NextApiResponse<ChatCompletionResponse>) => {
+const handler = async (req: NextApiRequest, res: NextApiResponse) => {
   const completionResponse = await openai.createChatCompletion({
     model: "gpt-3.5-turbo",
     messages: req.body.messages,
     max_tokens: 2000,
     temperature: 0,
-    top_p: 1.0,
     frequency_penalty: 0.0,
     presence_penalty: 0.0,
   });
 
-  res.status(200).json({ message: completionResponse.data.choices[0].message! });
+  res.status(200).json(completionResponse.data.choices[0].message?.content || "");
 };
 
 // TODO(steven): Implement a generic getChatPrompt function that takes in a
diff --git a/pages/chat.tsx b/pages/chat.tsx
index 11fe0db..eb6584e 100644
--- a/pages/chat.tsx
+++ b/pages/chat.tsx
@@ -1,12 +1,9 @@
 import { NextPage } from "next";
 import Head from "next/head";
-import React, { useEffect } from "react";
+import React from "react";
+import ChatView from "../components/ChatView";
 
 const ChatPage: NextPage = () => {
-  useEffect(() => {
-    // todo
-  }, []);
-
   return (
     <div>
       <Head>
@@ -15,7 +12,9 @@ const ChatPage: NextPage = () => {
         <link rel="icon" href="/favicon.ico" />
       </Head>
 
-      <main className="flex flex-col items-center justify-center m-20">WIP</main>
+      <main className="w-full min-h-screen flex flex-col items-center justify-center">
+        <ChatView />
+      </main>
     </div>
   );
 };
diff --git a/pages/index.tsx b/pages/index.tsx
index ca261a8..4b459bc 100644
--- a/pages/index.tsx
+++ b/pages/index.tsx
@@ -12,12 +12,12 @@ const HomePage: NextPage = () => {
         <link rel="icon" href="/favicon.ico" />
       </Head>
 
-      <main className="flex min-h-screen flex-col items-center justify-center bg-black">
-        <div className="flex flex-col items-center justify-center gap-12 px-4 py-16">
-          <h1 className="text-5xl font-extrabold tracking-tight text-white sm:text-6xl">ChatDBA</h1>
-          <div className="grid grid-cols-1 gap-4">
+      <main className="w-full min-h-screen flex flex-col items-center justify-center">
+        <div className="flex flex-col items-center justify-center px-4 py-16">
+          <h1 className="text-5xl font-extrabold sm:text-6xl">ChatDBA</h1>
+          <div className="grid grid-cols-1 mt-8">
             <Link className="flex max-w-xs flex-col rounded-xl bg-gray-800 p-4 px-6 text-white hover:opacity-80" href="/chat">
-              <h3 className="text-2xl font-medium">Chat →</h3>
+              <h3 className="text-xl font-medium">Chat →</h3>
             </Link>
           </div>
         </div>
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index dd6f3e7..26f3819 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -3,30 +3,44 @@ lockfileVersion: 5.4
 specifiers:
   '@types/node': ^18.11.18
   '@types/react': ^18.0.26
+  '@types/uuid': ^9.0.1
   '@vercel/analytics': ^0.1.11
   autoprefixer: ^10.4.13
+  axios: ^1.3.4
+  csstype: ^3.1.1
   eslint: 8.20.0
   eslint-config-next: 12.2.3
   highlight.js: ^11.7.0
+  lucide-react: ^0.125.0
   next: ^13.2.4
   openai: ^3.0.0
   postcss: ^8.4.20
   react: ^18.2.0
   react-dom: ^18.2.0
+  react-hot-toast: ^2.4.0
   tailwindcss: ^3.2.4
   typescript: ^4.9.4
+  uuid: ^9.0.0
+  zustand: ^4.3.6
 
 dependencies:
   '@vercel/analytics': 0.1.11_react@18.2.0
+  axios: 1.3.4
+  csstype: 3.1.1
   highlight.js: 11.7.0
+  lucide-react: 0.125.0_react@18.2.0
   next: 13.2.4_biqbaboplfbrettd7655fr4n2y
   openai: 3.2.1
   react: 18.2.0
   react-dom: 18.2.0_react@18.2.0
+  react-hot-toast: 2.4.0_owo25xnefcwdq3zjgtohz6dbju
+  uuid: 9.0.0
+  zustand: 4.3.6_react@18.2.0
 
 devDependencies:
   '@types/node': 18.15.3
   '@types/react': 18.0.28
+  '@types/uuid': 9.0.1
   autoprefixer: 10.4.14_postcss@8.4.21
   eslint: 8.20.0
   eslint-config-next: 12.2.3_bqegqxcnsisudkhpmmezgt6uoa
@@ -257,6 +271,10 @@ packages:
     resolution: {integrity: sha512-hppQEBDmlwhFAXKJX2KnWLYu5yMfi91yazPb2l+lbJiwW+wdo1gNeRA+3RgNSO39WYX2euey41KEwnqesU2Jew==}
     dev: true
 
+  /@types/uuid/9.0.1:
+    resolution: {integrity: sha512-rFT3ak0/2trgvp4yYZo5iKFEPsET7vKydKF+VRCxlQ9bpheehyAJH89dAkaLEq/j/RZXJIqcgsmPJKUP1Z28HA==}
+    dev: true
+
   /@typescript-eslint/parser/5.55.0_bqegqxcnsisudkhpmmezgt6uoa:
     resolution: {integrity: sha512-ppvmeF7hvdhUUZWSd2EEWfzcFkjJzgNQzVST22nzg958CR+sphy8A6K7LXQZd6V75m1VKjp+J4g/PCEfSCmzhw==}
     engines: {node: ^12.22.0 || ^14.17.0 || >=16.0.0}
@@ -498,6 +516,16 @@ packages:
       - debug
     dev: false
 
+  /axios/1.3.4:
+    resolution: {integrity: sha512-toYm+Bsyl6VC5wSkfkbbNB6ROv7KY93PEBBL6xyDczaIHasAiv4wPqQ/c4RjoQzipxRD2W5g21cOqQulZ7rHwQ==}
+    dependencies:
+      follow-redirects: 1.15.2
+      form-data: 4.0.0
+      proxy-from-env: 1.1.0
+    transitivePeerDependencies:
+      - debug
+    dev: false
+
   /axobject-query/3.1.1:
     resolution: {integrity: sha512-goKlv8DZrK9hUh975fnHzhNIO4jUnFCfv/dszV5VwUGDFjI6vQ2VwoyjYjYNEbBE8AH87TduWP5uyDR1D+Iteg==}
     dependencies:
@@ -624,7 +652,6 @@ packages:
 
   /csstype/3.1.1:
     resolution: {integrity: sha512-DJR/VvkAvSZW9bTouZue2sSxDwdTN92uHjqeKVm+0dAqdfNykRzQ95tay8aXMBAAPpUiq4Qcug2L7neoRh2Egw==}
-    dev: true
 
   /damerau-levenshtein/1.0.8:
     resolution: {integrity: sha512-sdQSFB7+llfUcQHUQO3+B8ERRj0Oa4w9POWMI/puGtuf7gFywGmkaLCElnudfTiKZV+NvHqL0ifzdrI8Ro7ESA==}
@@ -1306,6 +1333,14 @@ packages:
       slash: 3.0.0
     dev: true
 
+  /goober/2.1.12_csstype@3.1.1:
+    resolution: {integrity: sha512-yXHAvO08FU1JgTXX6Zn6sYCUFfB/OJSX8HHjDSgerZHZmFKAb08cykp5LBw5QnmyMcZyPRMqkdyHUSSzge788Q==}
+    peerDependencies:
+      csstype: ^3.0.10
+    dependencies:
+      csstype: 3.1.1
+    dev: false
+
   /gopd/1.0.1:
     resolution: {integrity: sha512-d65bNlIadxvpb/A2abVdlqKqV563juRnZ1Wtk6s1sIR8uNsXR70xqIzVqxVf1eTqDunwT2MkczEeaezCKTZhwA==}
     dependencies:
@@ -1623,6 +1658,14 @@ packages:
       yallist: 4.0.0
     dev: true
 
+  /lucide-react/0.125.0_react@18.2.0:
+    resolution: {integrity: sha512-tadphtB6TPytEitR9vX75hqu9PQT/uz5RcvXMq976nC190eukAM9+cHMgBxfvfEGDXwIhIT9aFxTUGdAjxw9uQ==}
+    peerDependencies:
+      react: ^16.5.1 || ^17.0.0 || ^18.0.0
+    dependencies:
+      react: 18.2.0
+    dev: false
+
   /merge2/1.4.1:
     resolution: {integrity: sha512-8q7VEgMJW4J8tcfVPy8g09NcQwZdbwFEqhe/WZkoIzjn/3TGDwtOCYtXGxA3O8tPzpczCCDgv+P2P5y00ZJOOg==}
     engines: {node: '>= 8'}
@@ -1965,6 +2008,10 @@ packages:
       react-is: 16.13.1
     dev: true
 
+  /proxy-from-env/1.1.0:
+    resolution: {integrity: sha512-D+zkORCbA9f1tdWRK0RaCR3GPv50cMxcrz4X8k5LTSUD1Dkw47mKJEZQNunItRTkWwgtaUSo1RVFRIG9ZXiFYg==}
+    dev: false
+
   /punycode/2.3.0:
     resolution: {integrity: sha512-rRV+zQD8tVFys26lAGR9WUuS4iUAngJScM+ZRSKtvl5tKeZ2t5bvdNFdNHBW9FWR4guGHlgmsZ1G7BSm2wTbuA==}
     engines: {node: '>=6'}
@@ -1989,6 +2036,20 @@ packages:
       scheduler: 0.23.0
     dev: false
 
+  /react-hot-toast/2.4.0_owo25xnefcwdq3zjgtohz6dbju:
+    resolution: {integrity: sha512-qnnVbXropKuwUpriVVosgo8QrB+IaPJCpL8oBI6Ov84uvHZ5QQcTp2qg6ku2wNfgJl6rlQXJIQU5q+5lmPOutA==}
+    engines: {node: '>=10'}
+    peerDependencies:
+      react: '>=16'
+      react-dom: '>=16'
+    dependencies:
+      goober: 2.1.12_csstype@3.1.1
+      react: 18.2.0
+      react-dom: 18.2.0_react@18.2.0
+    transitivePeerDependencies:
+      - csstype
+    dev: false
+
   /react-is/16.13.1:
     resolution: {integrity: sha512-24e6ynE2H+OKt4kqsOvNd8kBpV65zoxbA4BVsEOB3ARVWQki/DHzaUoC5KuON/BiccDaCCTZBuOcfZs70kR8bQ==}
     dev: true
@@ -2343,10 +2404,23 @@ packages:
       punycode: 2.3.0
     dev: true
 
+  /use-sync-external-store/1.2.0_react@18.2.0:
+    resolution: {integrity: sha512-eEgnFxGQ1Ife9bzYs6VLi8/4X6CObHMw9Qr9tPY43iKwsPw8xE8+EFsf/2cFZ5S3esXgpWgtSCtLNS41F+sKPA==}
+    peerDependencies:
+      react: ^16.8.0 || ^17.0.0 || ^18.0.0
+    dependencies:
+      react: 18.2.0
+    dev: false
+
   /util-deprecate/1.0.2:
     resolution: {integrity: sha512-EPD5q1uXyFxJpCrLnCc1nHnq3gOa6DZBocAIiI2TaSCA7VCJ1UJDMagCzIkXNsUYfD1daK//LTEQ8xiIbrHtcw==}
     dev: true
 
+  /uuid/9.0.0:
+    resolution: {integrity: sha512-MXcSTerfPa4uqyzStbRoTgt5XIe3x5+42+q1sDuy3R5MDk66URdLMOZe5aPX/SQd+kuYAh0FdP/pO28IkQyTeg==}
+    hasBin: true
+    dev: false
+
   /v8-compile-cache/2.3.0:
     resolution: {integrity: sha512-l8lCEmLcLYZh4nbunNZvQCJc5pv7+RCwa8q/LdUx8u7lsWvPDKmpodJAJNwkAhJC//dFY48KuIEmjtd4RViDrA==}
     dev: true
@@ -2412,3 +2486,19 @@ packages:
     resolution: {integrity: sha512-r3vXyErRCYJ7wg28yvBY5VSoAF8ZvlcW9/BwUzEtUsjvX/DKs24dIkuwjtuprwJJHsbyUbLApepYTR1BN4uHrg==}
     engines: {node: '>= 6'}
     dev: true
+
+  /zustand/4.3.6_react@18.2.0:
+    resolution: {integrity: sha512-6J5zDxjxLE+yukC2XZWf/IyWVKnXT9b9HUv09VJ/bwGCpKNcaTqp7Ws28Xr8jnbvnZcdRaidztAPsXFBIqufiw==}
+    engines: {node: '>=12.7.0'}
+    peerDependencies:
+      immer: '>=9.0'
+      react: '>=16.8'
+    peerDependenciesMeta:
+      immer:
+        optional: true
+      react:
+        optional: true
+    dependencies:
+      react: 18.2.0
+      use-sync-external-store: 1.2.0_react@18.2.0
+    dev: false
diff --git a/store/chat.ts b/store/chat.ts
new file mode 100644
index 0000000..650bfb2
--- /dev/null
+++ b/store/chat.ts
@@ -0,0 +1,31 @@
+import { create } from "zustand";
+import { Chat, User } from "../types";
+import { generateUUID } from "../utils";
+
+const defaultChat: Chat = {
+  id: generateUUID(),
+  userId: "assistant-chatgpt",
+};
+
+interface ChatState {
+  chatList: Chat[];
+  currentChat: Chat;
+  createChat: (user: User) => void;
+  setCurrentChat: (chat: Chat) => void;
+}
+
+export const useChatStore = create<ChatState>((set) => ({
+  chatList: [],
+  currentChat: defaultChat,
+  createChat: (user: User) => {
+    const chat = {
+      id: generateUUID(),
+      userId: user.id,
+    };
+    set((state) => ({
+      chatList: [...state.chatList, chat],
+      currentChat: chat,
+    }));
+  },
+  setCurrentChat: (chat: Chat) => set(() => ({ currentChat: chat })),
+}));
diff --git a/store/index.ts b/store/index.ts
new file mode 100644
index 0000000..5e5bd31
--- /dev/null
+++ b/store/index.ts
@@ -0,0 +1,3 @@
+export * from "./user";
+export * from "./chat";
+export * from "./message";
diff --git a/store/message.ts b/store/message.ts
new file mode 100644
index 0000000..1820d7e
--- /dev/null
+++ b/store/message.ts
@@ -0,0 +1,14 @@
+import { create } from "zustand";
+import { Message } from "../types";
+
+interface MessageState {
+  messageList: Message[];
+  getState: () => MessageState;
+  addMessage: (message: Message) => void;
+}
+
+export const useMessageStore = create<MessageState>((set, get) => ({
+  messageList: [],
+  getState: () => get(),
+  addMessage: (message: Message) => set((state) => ({ messageList: [...state.messageList, message] })),
+}));
diff --git a/store/user.ts b/store/user.ts
new file mode 100644
index 0000000..46fcda7
--- /dev/null
+++ b/store/user.ts
@@ -0,0 +1,36 @@
+import { create } from "zustand";
+import { Id, User, UserRole } from "../types";
+
+const assistantList: User[] = [
+  {
+    id: "assistant-chatgpt",
+    name: "Origin ChatGPT",
+    description: "",
+    avatar: "",
+    role: UserRole.Assistant,
+  },
+];
+
+const localUser: User = {
+  id: "local-user",
+  name: "Local user",
+  description: "",
+  avatar: "",
+  role: UserRole.User,
+};
+
+interface UserState {
+  // We can think assistants are special users.
+  assistantList: User[];
+  currentUser: User;
+  getAssistantById: (id: string) => User | undefined;
+}
+
+export const useUserStore = create<UserState>((set) => ({
+  assistantList: assistantList,
+  currentUser: localUser,
+  getAssistantById: (id: Id) => {
+    const user = assistantList.find((user) => user.id === id);
+    return user || undefined;
+  },
+}));
diff --git a/pages/styles/globals.css b/styles/global.css
similarity index 100%
rename from pages/styles/globals.css
rename to styles/global.css
diff --git a/types/chat.ts b/types/chat.ts
new file mode 100644
index 0000000..dc4c99e
--- /dev/null
+++ b/types/chat.ts
@@ -0,0 +1,6 @@
+import { Id } from "./common";
+
+export interface Chat {
+  id: string;
+  userId: Id;
+}
diff --git a/types/common.ts b/types/common.ts
new file mode 100644
index 0000000..e5bada3
--- /dev/null
+++ b/types/common.ts
@@ -0,0 +1,2 @@
+export type Id = string;
+export type Timestamp = number;
diff --git a/types/index.ts b/types/index.ts
new file mode 100644
index 0000000..ff6f2e3
--- /dev/null
+++ b/types/index.ts
@@ -0,0 +1,4 @@
+export * from "./common";
+export * from "./user";
+export * from "./chat";
+export * from "./message";
diff --git a/types/message.ts b/types/message.ts
new file mode 100644
index 0000000..1cfe635
--- /dev/null
+++ b/types/message.ts
@@ -0,0 +1,9 @@
+import { Id, Timestamp } from "./";
+
+export interface Message {
+  id: Id;
+  chatId: string;
+  creatorId: Id;
+  createdAt: Timestamp;
+  content: string;
+}
diff --git a/types/user.ts b/types/user.ts
new file mode 100644
index 0000000..85b3a35
--- /dev/null
+++ b/types/user.ts
@@ -0,0 +1,13 @@
+export enum UserRole {
+  System = "system",
+  User = "user",
+  Assistant = "assistant",
+}
+
+export interface User {
+  id: string;
+  name: string;
+  description: string;
+  avatar: string;
+  role: UserRole;
+}
diff --git a/utils/index.ts b/utils/index.ts
new file mode 100644
index 0000000..5e43db9
--- /dev/null
+++ b/utils/index.ts
@@ -0,0 +1,5 @@
+import { v4 as uuidv4 } from "uuid";
+
+export const generateUUID = () => {
+  return uuidv4();
+};
diff --git a/pages/api/openai-api.ts b/utils/openai-api.ts
similarity index 99%
rename from pages/api/openai-api.ts
rename to utils/openai-api.ts
index 008ba2f..97c21b8 100644
--- a/pages/api/openai-api.ts
+++ b/utils/openai-api.ts
@@ -7,6 +7,7 @@ export interface ChatCompletionResponse {
 const configuration = new Configuration({
   apiKey: process.env.OPENAI_API_KEY,
 });
+
 const openai = new OpenAIApi(configuration);
 
 export default openai;