lemmy/ui/src/components/main.tsx

import { Component, linkEvent } from 'inferno';
import { Link } from 'inferno-router';
import { Subscription } from "rxjs";
import { retryWhen, delay, take } from 'rxjs/operators';
import { UserOperation, CommunityUser, GetFollowedCommunitiesResponse, ListCommunitiesForm, ListCommunitiesResponse, Community, SortType, GetSiteResponse, ListingType, SiteResponse, GetPostsResponse, CreatePostLikeResponse, Post, GetPostsForm } from '../interfaces';
import { WebSocketService, UserService } from '../services';
import { PostListings } from './post-listings';
import { SiteForm } from './site-form';
import { msgOp, repoUrl, mdToHtml, fetchLimit, routeSortTypeToEnum, routeListingTypeToEnum, postRefetchSeconds } from '../utils';
import { i18n } from '../i18next';
import { T } from 'inferno-i18next';

interface MainState {
  subscribedCommunities: Array<CommunityUser>;
  trendingCommunities: Array<Community>;
  site: GetSiteResponse;
  showEditSite: boolean;
  loading: boolean;
  posts: Array<Post>;
  type_: ListingType;
  sort: SortType;
  page: number;
}

export class Main extends Component<any, MainState> {

  private subscription: Subscription;
  private postFetcher: any;
  private emptyState: MainState = {
    subscribedCommunities: [],
    trendingCommunities: [],
    site: {
      op: null,
      site: {
        id: null,
        name: null,
        creator_id: null,
        creator_name: null,
        published: null,
        number_of_users: null,
        number_of_posts: null,
        number_of_comments: null,
        number_of_communities: null,
      },
      admins: [],
      banned: [],
      online: null,
    },
    showEditSite: false,
    loading: true,
    posts: [],
    type_: this.getListingTypeFromProps(this.props),
    sort: this.getSortTypeFromProps(this.props),
    page: this.getPageFromProps(this.props),
  }

  getListingTypeFromProps(props: any): ListingType {
    return (props.match.params.type) ? 
      routeListingTypeToEnum(props.match.params.type) : 
      UserService.Instance.user ? 
      ListingType.Subscribed : 
      ListingType.All;
  }

  getSortTypeFromProps(props: any): SortType {
    return (props.match.params.sort) ? 
      routeSortTypeToEnum(props.match.params.sort) : 
      SortType.Hot;
  }

  getPageFromProps(props: any): number {
    return (props.match.params.page) ? Number(props.match.params.page) : 1;
  }

  constructor(props: any, context: any) {
    super(props, context);

    this.state = this.emptyState;
    this.handleEditCancel = this.handleEditCancel.bind(this);

    this.subscription = WebSocketService.Instance.subject
    .pipe(retryWhen(errors => errors.pipe(delay(3000), take(10))))
    .subscribe(
      (msg) => this.parseMessage(msg),
        (err) => console.error(err),
        () => console.log('complete')
    );

    WebSocketService.Instance.getSite();

    if (UserService.Instance.user) {
      WebSocketService.Instance.getFollowedCommunities();
    }

    let listCommunitiesForm: ListCommunitiesForm = {
      sort: SortType[SortType.Hot],
      limit: 6
    }

    WebSocketService.Instance.listCommunities(listCommunitiesForm);

    this.keepFetchingPosts();
  }

  componentWillUnmount() {
    this.subscription.unsubscribe();
    clearInterval(this.postFetcher);
  }

  // Necessary for back button for some reason
  componentWillReceiveProps(nextProps: any) {
    if (nextProps.history.action == 'POP' || nextProps.history.action == 'PUSH') {
      this.state.type_ = this.getListingTypeFromProps(nextProps);
      this.state.sort = this.getSortTypeFromProps(nextProps);
      this.state.page = this.getPageFromProps(nextProps);
      this.setState(this.state);
      this.fetchPosts();
    }
  }

  render() {
    return (
      <div class="container">
        <div class="row">
          <div class="col-12 col-md-8">
            {this.posts()}
          </div>
          <div class="col-12 col-md-4">
            {this.my_sidebar()}
          </div>
        </div>
      </div>
    )
  }
    
  my_sidebar() {
    return(
      <div>
        {!this.state.loading &&
          <div>
            <div class="card border-secondary mb-3">
              <div class="card-body">
                {this.trendingCommunities()}
                {UserService.Instance.user && this.state.subscribedCommunities.length > 0 && 
                  <div>
                    <h5>
                      <T i18nKey="subscribed_to_communities">#<Link class="text-white" to="/communities">#</Link></T>
                    </h5> 
                    <ul class="list-inline"> 
                      {this.state.subscribedCommunities.map(community =>
                        <li class="list-inline-item"><Link to={`/c/${community.community_name}`}>{community.community_name}</Link></li>
                      )}
                    </ul>
                  </div>
                }
                <Link class="btn btn-sm btn-secondary btn-block" 
                  to="/create_community">
                  <T i18nKey="create_a_community">#</T>
                </Link>
              </div>
            </div>
            {this.sidebar()}
            {this.landing()}
          </div>
        }
      </div>
    )
  }

  trendingCommunities() {
    return (
      <div>
        <h5>
          <T i18nKey="trending_communities">#<Link class="text-white" to="/communities">#</Link></T>
        </h5>
        <ul class="list-inline"> 
          {this.state.trendingCommunities.map(community =>
            <li class="list-inline-item"><Link to={`/c/${community.name}`}>{community.name}</Link></li>
          )}
        </ul>
      </div>
    )
  }

  sidebar() {
    return (
      <div>
        {!this.state.showEditSite ?
          this.siteInfo() :
          <SiteForm
            site={this.state.site.site} 
            onCancel={this.handleEditCancel} 
          />
        }
      </div>
    )
  }

  updateUrl() {
    let typeStr = ListingType[this.state.type_].toLowerCase();
    let sortStr = SortType[this.state.sort].toLowerCase();
    this.props.history.push(`/home/type/${typeStr}/sort/${sortStr}/page/${this.state.page}`);
  }

  siteInfo() {
    return (
      <div>
        <div class="card border-secondary mb-3">
          <div class="card-body">
            <h5 class="mb-0">{`${this.state.site.site.name}`}</h5>
            {this.canAdmin && 
              <ul class="list-inline mb-1 text-muted small font-weight-bold"> 
                <li className="list-inline-item">
                  <span class="pointer" onClick={linkEvent(this, this.handleEditClick)}>
                    <T i18nKey="edit">#</T>
                  </span>
                </li>
              </ul>
            }
            <ul class="my-2 list-inline">
              <li className="list-inline-item badge badge-secondary">
                <T i18nKey="number_online" interpolation={{count: this.state.site.online}}>#</T>
              </li>
              <li className="list-inline-item badge badge-secondary">
                <T i18nKey="number_of_users" interpolation={{count: this.state.site.site.number_of_users}}>#</T>
              </li>
              <li className="list-inline-item badge badge-secondary">
                <T i18nKey="number_of_communities" interpolation={{count: this.state.site.site.number_of_communities}}>#</T>
              </li>
              <li className="list-inline-item badge badge-secondary">
                <T i18nKey="number_of_posts" interpolation={{count: this.state.site.site.number_of_posts}}>#</T>
              </li>
              <li className="list-inline-item badge badge-secondary">
                <T i18nKey="number_of_comments" interpolation={{count: this.state.site.site.number_of_comments}}>#</T>
              </li>
              <li className="list-inline-item">
                <Link className="badge badge-secondary" to="/modlog">
                  <T i18nKey="modlog">#</T>
                </Link>
              </li>
            </ul>
            <ul class="mt-1 list-inline small mb-0"> 
              <li class="list-inline-item">
                <T i18nKey="admins" class="d-inline">#</T>:
                </li>
                {this.state.site.admins.map(admin =>
                  <li class="list-inline-item"><Link class="text-info" to={`/u/${admin.name}`}>{admin.name}</Link></li>
                )}
              </ul>
            </div>
          </div>
          {this.state.site.site.description && 
            <div class="card border-secondary mb-3">
              <div class="card-body">
                <div className="md-div" dangerouslySetInnerHTML={mdToHtml(this.state.site.site.description)} />
              </div>
            </div>
          }
        </div>
    )
  }

  landing() {
    return (
      <div class="card border-secondary">
        <div class="card-body">
          <h5>
            <T i18nKey="powered_by" class="d-inline">#</T>
            <svg class="icon mx-2"><use xlinkHref="#icon-mouse">#</use></svg>
            <a href={repoUrl}>Lemmy<sup>beta</sup></a>
          </h5>
          <p class="mb-0">
            <T i18nKey="landing_0">#<a href="https://en.wikipedia.org/wiki/Social_network_aggregation">#</a><a href="https://en.wikipedia.org/wiki/Fediverse">#</a><br></br><code>#</code><br></br><b>#</b><br></br><a href={repoUrl}>#</a><br></br><a href="https://www.rust-lang.org">#</a><a href="https://actix.rs/">#</a><a href="https://infernojs.org">#</a><a href="https://www.typescriptlang.org/">#</a>
          </T>
        </p>
      </div>
    </div>
    )
  }

  posts() {
    return (
      <div>
        {this.state.loading ? 
        <h5><svg class="icon icon-spinner spin"><use xlinkHref="#icon-spinner"></use></svg></h5> : 
        <div>
          {this.selects()}
          <PostListings posts={this.state.posts} showCommunity />
          {this.paginator()}
        </div>
        }
      </div>
    )
  }

  selects() {
    return (
      <div className="mb-3">
        <div class="btn-group btn-group-toggle">
          <label className={`btn btn-sm btn-secondary 
            ${this.state.type_ == ListingType.Subscribed && 'active'}
            ${UserService.Instance.user == undefined ? 'disabled' : 'pointer'}
            `}>
            <input type="radio" 
              value={ListingType.Subscribed}
              checked={this.state.type_ == ListingType.Subscribed}
              onChange={linkEvent(this, this.handleTypeChange)}
              disabled={UserService.Instance.user == undefined}
            />
            {i18n.t('subscribed')}
          </label>
          <label className={`pointer btn btn-sm btn-secondary ${this.state.type_ == ListingType.All && 'active'}`}>
            <input type="radio" 
              value={ListingType.All}
              checked={this.state.type_ == ListingType.All}
              onChange={linkEvent(this, this.handleTypeChange)}
            /> 
            {i18n.t('all')}
          </label>
        </div>
        <select value={this.state.sort} onChange={linkEvent(this, this.handleSortChange)} class="ml-2 custom-select custom-select-sm w-auto">
          <option disabled><T i18nKey="sort_type">#</T></option>
          <option value={SortType.Hot}><T i18nKey="hot">#</T></option>
          <option value={SortType.New}><T i18nKey="new">#</T></option>
          <option disabled>─────</option>
          <option value={SortType.TopDay}><T i18nKey="top_day">#</T></option>
          <option value={SortType.TopWeek}><T i18nKey="week">#</T></option>
          <option value={SortType.TopMonth}><T i18nKey="month">#</T></option>
          <option value={SortType.TopYear}><T i18nKey="year">#</T></option>
          <option value={SortType.TopAll}><T i18nKey="all">#</T></option>
        </select>
      </div>
    )
  }

  paginator() {
    return (
      <div class="my-2">
        {this.state.page > 1 && 
          <button class="btn btn-sm btn-secondary mr-1" onClick={linkEvent(this, this.prevPage)}><T i18nKey="prev">#</T></button>
        }
        <button class="btn btn-sm btn-secondary" onClick={linkEvent(this, this.nextPage)}><T i18nKey="next">#</T></button>
      </div>
    );
  }

  get canAdmin(): boolean {
    return UserService.Instance.user && this.state.site.admins.map(a => a.id).includes(UserService.Instance.user.id);
  }

  handleEditClick(i: Main) {
    i.state.showEditSite = true;
    i.setState(i.state);
  }

  handleEditCancel() {
    this.state.showEditSite = false;
    this.setState(this.state);
  }

  nextPage(i: Main) { 
    i.state.page++;
    i.state.loading = true;
    i.setState(i.state);
    i.updateUrl();
    i.fetchPosts();
    window.scrollTo(0,0);
  }

  prevPage(i: Main) { 
    i.state.page--;
    i.state.loading = true;
    i.setState(i.state);
    i.updateUrl();
    i.fetchPosts();
    window.scrollTo(0,0);
  }

  handleSortChange(i: Main, event: any) {
    i.state.sort = Number(event.target.value);
    i.state.page = 1;
    i.state.loading = true;
    i.setState(i.state);
    i.updateUrl();
    i.fetchPosts();
    window.scrollTo(0,0);
  }

  handleTypeChange(i: Main, event: any) {
    i.state.type_ = Number(event.target.value);
    i.state.page = 1;
    i.state.loading = true;
    i.setState(i.state);
    i.updateUrl();
    i.fetchPosts();
    window.scrollTo(0,0);
  }

  keepFetchingPosts() {
    this.fetchPosts();
    this.postFetcher = setInterval(() => this.fetchPosts(), postRefetchSeconds);
  }

  fetchPosts() {
    let getPostsForm: GetPostsForm = {
      page: this.state.page,
      limit: fetchLimit,
      sort: SortType[this.state.sort],
      type_: ListingType[this.state.type_]
    }
    WebSocketService.Instance.getPosts(getPostsForm);
  }

  parseMessage(msg: any) {
    console.log(msg);
    let op: UserOperation = msgOp(msg);
    if (msg.error) {
      alert(i18n.t(msg.error));
      return;
    } else if (op == UserOperation.GetFollowedCommunities) {
      let res: GetFollowedCommunitiesResponse = msg;
      this.state.subscribedCommunities = res.communities;
      this.setState(this.state);
    } else if (op == UserOperation.ListCommunities) {
      let res: ListCommunitiesResponse = msg;
      this.state.trendingCommunities = res.communities;
      this.setState(this.state);
    } else if (op == UserOperation.GetSite) {
      let res: GetSiteResponse = msg;

      // This means it hasn't been set up yet
      if (!res.site) {
        this.context.router.history.push("/setup");
      }
      this.state.site.admins = res.admins;
      this.state.site.site = res.site;
      this.state.site.banned = res.banned;
      this.state.site.online = res.online;
      this.setState(this.state);
      document.title = `${WebSocketService.Instance.site.name}`;

    } else if (op == UserOperation.EditSite) {
      let res: SiteResponse = msg;
      this.state.site.site = res.site;
      this.state.showEditSite = false;
      this.setState(this.state);
    } else if (op == UserOperation.GetPosts) {
      let res: GetPostsResponse = msg;
      this.state.posts = res.posts;
      this.state.loading = false;
      this.setState(this.state);
    } else if (op == UserOperation.CreatePostLike) {
      let res: CreatePostLikeResponse = msg;
      let found = this.state.posts.find(c => c.id == res.post.id);
      found.my_vote = res.post.my_vote;
      found.score = res.post.score;
      found.upvotes = res.post.upvotes;
      found.downvotes = res.post.downvotes;
      this.setState(this.state);
    }
  }
}