Add editing and marking as complete functionality to the todos.js file with coding example Next.js 13

 Here is an example of how you might add editing and marking as complete functionality to the todos.js file:

import React, { useState } from 'react'

export default function Todos() {

  const [todos, setTodos] = useState([])

  const [newTodo, setNewTodo] = useState('')

  const [editingIndex, setEditingIndex] = useState(-1)

  const [editingTodo, setEditingTodo] = useState('')

  function handleSubmit(e) {

    e.preventDefault()

    if (editingIndex === -1) {

      setTodos([...todos, newTodo])

      setNewTodo('')

    } else {

      const updatedTodos = [...todos]

      updatedTodos[editingIndex] = editingTodo

      setTodos(updatedTodos)

      setEditingIndex(-1)

      setEditingTodo('')

    }

  }

  function handleDelete(index) {

    setTodos(todos.filter((_, i) => i !== index))

  }

  function handleEdit(index) {

    setEditingIndex(index)

    setEditingTodo(todos[index])

  }

  function handleMarkComplete(index) {

    const updatedTodos = [...todos]

    updatedTodos[index] = { ...updatedTodos[index], complete: true }

    setTodos(updatedTodos)

  }

  return (

    <div>

      <form onSubmit={handleSubmit}>

        {editingIndex === -1 ? (

          <input 

            type="text" 

            value={newTodo} 

            onChange={e => setNewTodo(e.target.value)} 

            placeholder="Add a new todo" 

          />

        ) : (

          <input 

            type="text" 

            value={editingTodo} 

            onChange={e => setEditingTodo(e.target.value)}

          />

        )}

        <button type="submit">

          {editingIndex === -1 ? 'Add' : 'Update'}

        </button>

      </form>

      <ul>

        {todos.map((todo, index) => (

          <li key={index}>

            {todo.complete ? <s>{todo.text}</s> : todo.text}

            <button onClick={() => handleEdit(index)}>Edit</button>

            <button onClick={() => handleDelete(index)}>Delete</button>

            <button onClick={() => handleMarkComplete(index)}>Mark as Complete</button>

          </li>

        ))}

      </ul>

    </div>

  )

}

In this example, I've added two new state variables editingIndex and editingTodo to keep track of the index of the todo being edited and the current text of the todo being edited.

I've added a new function handleEdit which updates