feat: implement stores and basic chat logic

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;
+  },
+}));