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import type { FormEvent } from 'react'import { CloseOutlined } from '@ant-design/icons'import { a, useTransition } from '@react-spring/web'import { Radio } from 'antd'import { Provider, atom, useAtom, useSetAtom } from 'jotai'import { atomFamily } from 'jotai/utils'import { nanoid } from 'nanoid'
type Param = { id: string; title?: string }const todoAtomFamily = atomFamily(  (param: Param) =>    atom({ title: param.title || 'No title', completed: false }),  (a: Param, b: Param) => a.id === b.id)
const filterAtom = atom('all')const todosAtom = atom<string[]>([])const filteredAtom = atom((get) => {  const filter = get(filterAtom)  const todos = get(todosAtom)  if (filter === 'all') return todos  else if (filter === 'completed')    return todos.filter((id) => get(todoAtomFamily({ id })).completed)  else return todos.filter((id) => !get(todoAtomFamily({ id })).completed)})
const TodoItem = ({  id,  remove,}: {  id: string  remove: (id: string) => void}) => {  const [item, setItem] = useAtom(todoAtomFamily({ id }))  const toggleCompleted = () => setItem({ ...item, completed: !item.completed })  return (    <>      <input        type="checkbox"        checked={item.completed}        onChange={toggleCompleted}      />      <span style={{ textDecoration: item.completed ? 'line-through' : '' }}>        {item.title}      </span>      <CloseOutlined onClick={() => remove(id)} />    </>  )}
const Filter = () => {  const [filter, set] = useAtom(filterAtom)  return (    <Radio.Group onChange={(e) => set(e.target.value)} value={filter}>      <Radio value="all">All</Radio>      <Radio value="completed">Completed</Radio>      <Radio value="incompleted">Incompleted</Radio>    </Radio.Group>  )}
const Filtered = ({ remove }: { remove: (id: string) => void }) => {  const [todos] = useAtom(filteredAtom)  const transitions = useTransition(todos, {    keys: (id: string) => id,    from: { opacity: 0, height: 0 },    enter: { opacity: 1, height: 40 },    leave: { opacity: 0, height: 0 },  })  return transitions((style, id) => (    <a.div className="item" style={style}>      <TodoItem id={id} remove={remove} />    </a.div>  ))}
const TodoList = () => {  // Use `useSetAtom` to avoid re-render  // const [, setTodos] = useAtom(todosAtom)  const setTodos = useSetAtom(todosAtom)  const remove = (id: string) => {    setTodos((prev) => prev.filter((item) => item !== id))    todoAtomFamily.remove({ id })  }  const add = (e: FormEvent<HTMLFormElement>) => {    e.preventDefault()    const title = e.currentTarget.inputTitle.value    e.currentTarget.inputTitle.value = ''    const id = nanoid()    todoAtomFamily({ id, title })    setTodos((prev) => [...prev, id])  }  return (    <form onSubmit={add}>      <Filter />      <input name="inputTitle" placeholder="Type ..." />      <Filtered remove={remove} />    </form>  )}
const serializeAtom = atom<  null,  | { type: 'serialize'; callback: (value: string) => void }  | { type: 'deserialize'; value: string }>(null, (get, set, action) => {  if (action.type === 'serialize') {    const todos = get(todosAtom)    const todoMap: Record<string, { title: string; completed: boolean }> = {}    todos.forEach((id) => {      todoMap[id] = get(todoAtomFamily({ id }))    })    const obj = {      todos,      todoMap,      filter: get(filterAtom),    }    action.callback(JSON.stringify(obj))  } else if (action.type === 'deserialize') {    const obj = JSON.parse(action.value)    // needs error handling and type checking    set(filterAtom, obj.filter)    obj.todos.forEach((id: string) => {      const todo = obj.todoMap[id]      set(todoAtomFamily({ id, ...todo }), todo)    })    set(todosAtom, obj.todos)  }})
const Persist = () => {  const [, dispatch] = useAtom(serializeAtom)  const save = () => {    dispatch({      type: 'serialize',      callback: (value) => {        localStorage.setItem('serializedTodos', value)      },    })  }  const load = () => {    const value = localStorage.getItem('serializedTodos')    if (value) {      dispatch({ type: 'deserialize', value })    }  }  return (    <div>      <button onClick={save}>Save to localStorage</button>      <button onClick={load}>Load from localStorage</button>    </div>  )}
export default function App() {  return (    <Provider>      <h1>Jōtai</h1>      <TodoList />      <h3>Persist</h3>      <Persist />    </Provider>  )}