인프런 커뮤니티 질문&답변

import { useState, useEffect, useRef, useMemo } from "react";
import "./App.css";
import DiaryEditor from "./DiaryEditor";
import DiaryList from "./DiaryList";
import OptimizeTest from "./OptimizeTest";

const App = () => {
  const [data, setData] = useState([]);
  const dataId = useRef(0);

  const getData = async () => {
    const res = await fetch(
      "https://jsonplaceholder.typicode.com/comments"
    ).then((res) => res.json());

    const initData = res.slice(0, 10).map((it) => {
      return {
        author: it.email,
        content: it.body,
        emotion: Math.floor(Math.random() * 5) + 1,
        created_date: new Date().getTime(),
        id: dataId.current++,
      };
    });
    setData(initData);
    console.log(initData);
  };
  useEffect(() => {
    getData();
  }, []);

  const onCreate = (author, content, emotion) => {
    const created_date = new Date().getTime();
    const newItem = {
      author,
      content,
      emotion,
      created_date,
      id: dataId.current,
    };
    dataId.current += 1;
    setData([newItem, ...data]);
  };

  const onRemove = (targetId) => {
    const newDiaryList = data.filter((it) => it.id !== targetId);
    console.log(newDiaryList);
    setData(newDiaryList);
  };

  const onChange = (targetId, newContent) => {
    for (let i in data) {
      if (data[i].id === targetId) {
        data[i].content = newContent;
      }
    }
    setData([...data]);
  };

  const getAnalysis = useMemo(() => {
    console.log("일기 분석 시작 ");
    const goodCount = data.filter((it) => it.emotion >= 3).length;
    const badCount = data.length - goodCount;
    const goodRatio = (goodCount / data.length) * 100;
    return { goodCount, badCount, goodRatio };
  }, [data.length]);

  const { goodCount, badCount, goodRatio } = getAnalysis;

  return (
    <div className="App">
      <OptimizeTest />
      <DiaryEditor onCreate={onCreate} />
      <div>전체 일기 : {data.length}</div>
      <div>좋은 감정 점수 개수: {goodCount}</div>
      <div>나쁜 감정 점수 개수: {badCount}</div>
      <div>좋은 감정 점수 비율: {goodRatio}%</div>
      <DiaryList onRemove={onRemove} onChange={onChange} diaryList={data} />
    </div>
  );
};

export default App;