beforeEnter: (to, before, next) => {
  const currentMovieId = to.params.currentMovieId;
  if (store.state.moviedetail.currentMovie[`${currentMovieId}`]) {
    store.commit(types.LOADING_FLAG, false);
    next();
    return;
  }
  store.commit(types.LOADING_FLAG, true);
  currentMovie(currentMovieId).then((currentMovieDetail) => {
    // 成功则commit后台接口的数据，并把NET_ERROR的数据置空，并把加载中的状态置为false。
    const id = currentMovieDetail.id;
    store.commit(types.CURRENT_MOVIE, {
      [`${id}`]: currentMovieDetail,
      ...store.state.moviedetail.currentMovie,
    });
    store.commit(types.LOADING_FLAG, false);
    store.commit(types.NET_STATUS, '');
    document.title = `${currentMovieDetail.title} - 电影 - 豆瓣`;
  }).catch((error) => {
    document.title = '出错啦 Oops… - 豆瓣';
    store.commit(types.NET_STATUS, error);
    store.commit(types.LOADING_FLAG, false);
  });
  next();
}

computed: {
  ...mapState({
    tagData(state) {
      return state.tag.tagData[`${this.$route.params.currentTagId}`];
    },
  }),

  subjects() {
    return this.tagData.subjects.slice(
      (this.currentPage - 1) * 10,
      this.currentPage * 10,
    );
  },
},

methods: {
  ...mapActions(['getMoreTagData']),
  changePage(flag) {
    const currentTagId = this.$route.params.currentTagId;
    const { start, count } = this.tagData;
    // 第一页不能往前翻页，最后一页不能往后翻页。
    if ((this.currentPage === 1 && flag === 'reduce') ||
      (this.currentPage === Math.ceil(this.tagData.total / 10) && flag === 'add')
    ) {
      return;
    }
    if (flag === 'add') {
      this.currentPage = this.currentPage + 1;
      // 每次请求十条数据
      this.getMoreTagData({
        tag: currentTagId,
        count: 10,
        start: count + start,
      });
      // 需要使用localStorge保存当前的页码信息，再次进入可以有这个页码信息。
      const doubanMovieCurrentPage = JSON.parse(window.localStorage.doubanMovieCurrentPage);
      window.localStorage.doubanMovieCurrentPage = JSON.stringify({
        ...doubanMovieCurrentPage,
        [`${currentTagId}`]: this.currentPage,
      });
    } else {
      this.currentPage = this.currentPage - 1;
    }
    window.scrollTo(0, 0);
  },

handleScroll() {
  // 函数的作用是滚动加载电影详情信息
  // 判断是否为请求后台中的状态，如果是则返回
  const { start, count, total } = this.currentSeeMore;
  if (!this.requestFlag) {
    return;
  }
  // 不同浏览器top展现会不一致
  let top = window.document.documentElement.scrollTop;
  if (top === 0) {
    top = document.body.scrollTop;
  }
  const clientHeight = document.getElementById('app').clientHeight;
  const innerHeight = window.innerHeight;
  const proportion = top / (clientHeight - innerHeight);
  // 但如果已把所有数据加载完毕了，则不请求
  if (proportion > 0.6 && (start + count) < total) {
    this.getMoreData({
      count,
      start: start + count,
      title: this.$route.params.title,
    });
    this.requestFlag = false;
  }
}

scrolling() {
  // scrolling函数用于作函数节流
  if (this.scrollFlag) {
    return;
  }
  this.scrollFlag = true;
  setTimeout(() => {
    this.handleScroll();
    this.scrollFlag = false;
  }, 20);
}

async action({ store, params }) {
  // 判断store里的id和当前id是否一致，若一致，则不请求后台
  console.log("chapter")
  const chapterInfos = store.getState().home.chapterInfos;
  if (Object.keys(chapterInfos).length === 0 ||
    chapterInfos.subject.id !== parseInt(params.chapter, 10)) {
    await store.dispatch(chapter(params.chapter));
  }
}

beforeEnter: (to, before, next) => {
  document.title = '电影 - 豆瓣';
  if (Object.keys(store.state.home.homeData).length !== 0) {
    store.commit(types.LOADING_FLAG, false);
    next();
    return;
  }
  store.commit(types.LOADING_FLAG, true);
  Promise.all([
    hotMovie(8, 0),
    commingSoon(8, 0),
    top250(8, 0),
    usBox(8, 0),
  ]).then((homeData) => {
    // 成功则commit后台接口的数据，并把NET_ERROR的数据置空，并把加载中的状态置为false。
    store.commit(types.HOME_DATA, homeData);
    store.commit(types.LOADING_FLAG, false);
    store.commit(types.NET_STATUS, '');
  }).catch((error) => {
    document.title = '出错啦 Oops… - 豆瓣';
    store.commit(types.NET_STATUS, error);
    store.commit(types.LOADING_FLAG, false);
  });
  next();
}

import serverConfig from './serverConfig';

const Ajax = url => new Promise((resolve, reject) => {
  const xhr = new XMLHttpRequest();
  xhr.open('GET', url);
  xhr.send(null);
  xhr.onreadystatechange = () => {
    if (xhr.readyState === 4) {
      if (xhr.status === 200) {
        resolve(JSON.parse(xhr.responseText));
      } else {
        reject(`错误: ${xhr.status}`);
      }
    }
  };
});

// 影院热映
export const hotMovie = (count, start) =>
  Ajax(`${serverConfig}/v2/movie/in_theaters?count=${count}&start=${start}`);
// 即将上映
export const commingSoon = (count, start) =>
  Ajax(`${serverConfig}/v2/movie/coming_soon?count=${count}&start=${start}`);
// top250
export const top250 = (count, start) =>
  Ajax(`${serverConfig}/v2/movie/top250?count=${count}&start=${start}`);
// 北美票房榜
export const usBox = (count, start) =>
  Ajax(`${serverConfig}/v2/movie/us_box?count=${count}&start=${start}`);
// 当前电影详情信息
export const currentMovie = currentMovieId =>
  Ajax(`${serverConfig}/v2/movie/subject/${currentMovieId}`);
// 当前标签详情信息
export const getTagData = (tag, count, start) =>
  Ajax(`${serverConfig}/v2/movie/search?tag=${tag}&count=${count}&start=${start}`);

(function (doc, win) {
  var docEl = doc.documentElement,
    resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
    recalc = function () {
      var clientWidth = docEl.clientWidth > 750 ? 360 : docEl.clientWidth ;
      if (!clientWidth) return;
      docEl.style.fontSize = clientWidth / 750 * 100 + 'px';
    };
  if (!doc.addEventListener) return;
  doc.addEventListener('DOMContentLoaded', recalc, false);
  if (docEl.clientWidth > 750) return;
  win.addEventListener(resizeEvt, recalc, false);
})(document, window);