lemmy/ui/src/components/post.tsx

import { Component, linkEvent } from 'inferno';
import { Link } from 'inferno-router';
import { Subscription } from "rxjs";
import { retryWhen, delay, take } from 'rxjs/operators';
import { UserOperation, Community, Post as PostI, GetPostResponse, PostResponse, Comment, CommentForm as CommentFormI, CommentResponse, CommentLikeForm, CommentSortType, CreatePostLikeResponse, CommunityUser, CommunityResponse } from '../interfaces';
import { WebSocketService, UserService } from '../services';
import { msgOp, hotRank,mdToHtml } from '../utils';
import { MomentTime } from './moment-time';
import { PostListing } from './post-listing';
import { Sidebar } from './sidebar';
import * as autosize from 'autosize';

interface CommentNodeI {
  comment: Comment;
  children?: Array<CommentNodeI>;
};

interface PostState {
  post: PostI;
  comments: Array<Comment>;
  commentSort: CommentSortType;
  community: Community;
  moderators: Array<CommunityUser>;
  scrolled: boolean;
}

export class Post extends Component<any, PostState> {

  private subscription: Subscription;
  private emptyState: PostState = {
    post: null,
    comments: [],
    commentSort: CommentSortType.Hot,
    community: null,
    moderators: [],
    scrolled: false
  }

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

    this.state = this.emptyState;

    let postId = Number(this.props.match.params.id);

    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.getPost(postId);
  }

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

  componentDidMount() {
    autosize(document.querySelectorAll('textarea'));
  }

  componentDidUpdate(lastProps: any, lastState: PostState, snapshot: any) {
    if (!this.state.scrolled && lastState.comments.length > 0 && window.location.href.includes('#comment-')) {
      let id = window.location.hash.split("#")[2];
      var elmnt = document.getElementById(`${id}`);
      elmnt.scrollIntoView(); 
      this.state.scrolled = true;
    }
  }

  render() {
    return (
      <div class="container">
        {this.state.post && 
          <div class="row">
            <div class="col-12 col-sm-8 col-lg-7 mb-3">
              <PostListing post={this.state.post} showBody showCommunity editable />
              <div className="mb-2" />
              <CommentForm postId={this.state.post.id} />
              {this.sortRadios()}
              {this.commentsTree()}
            </div>
            <div class="col-12 col-sm-4 col-lg-3 mb-3">
              {this.state.comments.length > 0 && this.newComments()}
            </div>
            <div class="col-12 col-sm-12 col-lg-2">
              {this.sidebar()}
            </div>
          </div>
        }
      </div>
    )
  }

  sortRadios() {
    return (
      <div class="btn-group btn-group-toggle mb-3">
        <label className={`btn btn-sm btn-secondary ${this.state.commentSort === CommentSortType.Hot && 'active'}`}>Hot
          <input type="radio" value={CommentSortType.Hot}
          checked={this.state.commentSort === CommentSortType.Hot} 
          onChange={linkEvent(this, this.handleCommentSortChange)}  />
        </label>
        <label className={`btn btn-sm btn-secondary ${this.state.commentSort === CommentSortType.Top && 'active'}`}>Top
          <input type="radio" value={CommentSortType.Top}
          checked={this.state.commentSort === CommentSortType.Top} 
          onChange={linkEvent(this, this.handleCommentSortChange)}  />
        </label>
        <label className={`btn btn-sm btn-secondary ${this.state.commentSort === CommentSortType.New && 'active'}`}>New
          <input type="radio" value={CommentSortType.New}
          checked={this.state.commentSort === CommentSortType.New} 
          onChange={linkEvent(this, this.handleCommentSortChange)}  />
        </label>
      </div>
    )
  }

  newComments() {
    return (
      <div class="sticky-top">
        <h4>New Comments</h4>
        {this.state.comments.map(comment => 
          <CommentNodes nodes={[{comment: comment}]} noIndent />
        )}
      </div>
    )
  }

  sidebar() {
    return ( 
      <div class="sticky-top">
        <Sidebar community={this.state.community} moderators={this.state.moderators} />
      </div>
    );
  }
  
  handleCommentSortChange(i: Post, event) {
    i.state.commentSort = Number(event.target.value);
    i.setState(i.state);
  }

  private buildCommentsTree(): Array<CommentNodeI> {
    let map = new Map<number, CommentNodeI>();
    for (let comment of this.state.comments) {
      let node: CommentNodeI = {
        comment: comment,
        children: []
      };
      map.set(comment.id, { ...node });
    }
    let tree: Array<CommentNodeI> = [];
    for (let comment of this.state.comments) {
      if( comment.parent_id ) {
        map.get(comment.parent_id).children.push(map.get(comment.id));
      } 
      else {
        tree.push(map.get(comment.id));
      }
    }

    this.sortTree(tree);

    return tree;
  }

  sortTree(tree: Array<CommentNodeI>) {

    if (this.state.commentSort == CommentSortType.Top) {
      tree.sort((a, b) => b.comment.score - a.comment.score);
    } else if (this.state.commentSort == CommentSortType.New) {
      tree.sort((a, b) => b.comment.published.localeCompare(a.comment.published));
    } else if (this.state.commentSort == CommentSortType.Hot) {
      tree.sort((a, b) => hotRank(b.comment) - hotRank(a.comment));
    }

    for (let node of tree) {
      this.sortTree(node.children);
    }

  }

  commentsTree() {
    let nodes = this.buildCommentsTree();
    return (
      <div className="">
        <CommentNodes nodes={nodes} />
      </div>
    );
  }

  parseMessage(msg: any) {
    console.log(msg);
    let op: UserOperation = msgOp(msg);
    if (msg.error) {
      alert(msg.error);
      return;
    } else if (op == UserOperation.GetPost) {
      let res: GetPostResponse = msg;
      this.state.post = res.post;
      this.state.comments = res.comments;
      this.state.community = res.community;
      this.state.moderators = res.moderators;
      this.setState(this.state);
    } else if (op == UserOperation.CreateComment) {
      let res: CommentResponse = msg;
      this.state.comments.unshift(res.comment);
      this.setState(this.state);
    } else if (op == UserOperation.EditComment) {
      let res: CommentResponse = msg;
      let found = this.state.comments.find(c => c.id == res.comment.id);
      found.content = res.comment.content;
      found.updated = res.comment.updated;
      this.setState(this.state);
    }
    else if (op == UserOperation.CreateCommentLike) {
      let res: CommentResponse = msg;
      let found: Comment = this.state.comments.find(c => c.id === res.comment.id);
      found.score = res.comment.score;
      found.upvotes = res.comment.upvotes;
      found.downvotes = res.comment.downvotes;
      if (res.comment.my_vote !== null) 
        found.my_vote = res.comment.my_vote;
      this.setState(this.state);
    } else if (op == UserOperation.CreatePostLike) {
      let res: CreatePostLikeResponse = msg;
      this.state.post.my_vote = res.post.my_vote;
      this.state.post.score = res.post.score;
      this.state.post.upvotes = res.post.upvotes;
      this.state.post.downvotes = res.post.downvotes;
      this.setState(this.state);
    } else if (op == UserOperation.EditPost) {
      let res: PostResponse = msg;
      this.state.post = res.post;
      this.setState(this.state);
    } else if (op == UserOperation.EditCommunity) {
      let res: CommunityResponse = msg;
      this.state.community = res.community;
      this.state.post.community_id = res.community.id;
      this.state.post.community_name = res.community.name;
      this.setState(this.state);
    } else if (op == UserOperation.FollowCommunity) {
      let res: CommunityResponse = msg;
      this.state.community.subscribed = res.community.subscribed;
      this.state.community.number_of_subscribers = res.community.number_of_subscribers;
      this.setState(this.state);
    }

  }
}

interface CommentNodesState {
}

interface CommentNodesProps {
  nodes: Array<CommentNodeI>;
  noIndent?: boolean;
}

export class CommentNodes extends Component<CommentNodesProps, CommentNodesState> {

  constructor(props, context) {
    super(props, context);
  }

  render() {
    return (
      <div className="comments">
        {this.props.nodes.map(node =>
          <CommentNode node={node} noIndent={this.props.noIndent} />
        )}
      </div>
    )
  }
}


interface CommentNodeState {
  showReply: boolean;
  showEdit: boolean;
}

interface CommentNodeProps {
  node: CommentNodeI;
  noIndent?: boolean;
}

export class CommentNode extends Component<CommentNodeProps, CommentNodeState> {

  private emptyState: CommentNodeState = {
    showReply: false,
    showEdit: false
  }

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

    this.state = this.emptyState;
    this.handleReplyCancel = this.handleReplyCancel.bind(this);
    this.handleCommentLike = this.handleCommentLike.bind(this);
    this.handleCommentDisLike = this.handleCommentDisLike.bind(this);
  }

  render() {
    let node = this.props.node;
    return (
      <div id={`comment-${node.comment.id}`} className={`comment ${node.comment.parent_id  && !this.props.noIndent ? 'ml-4' : ''}`}>
        <div className="float-left small text-center">
          <div className={`pointer upvote ${node.comment.my_vote == 1 ? 'text-info' : 'text-muted'}`} onClick={linkEvent(node, this.handleCommentLike)}>▲</div>
          <div>{node.comment.score}</div>
          <div className={`pointer downvote ${node.comment.my_vote == -1 && 'text-danger'}`} onClick={linkEvent(node, this.handleCommentDisLike)}>▼</div>
        </div>
        <div className="details ml-4">
          <ul class="list-inline mb-0 text-muted small">
            <li className="list-inline-item">
              <Link to={`/user/${node.comment.creator_id}`}>{node.comment.creator_name}</Link>
            </li>
            <li className="list-inline-item">
              <span>(
                <span className="text-info">+{node.comment.upvotes}</span>
                <span> | </span>
                <span className="text-danger">-{node.comment.downvotes}</span>
                <span>) </span>
              </span>
            </li>
            <li className="list-inline-item">
              <span><MomentTime data={node.comment} /></span>
            </li>
          </ul>
          {this.state.showEdit && <CommentForm node={node} edit onReplyCancel={this.handleReplyCancel} />}
          {!this.state.showEdit &&
            <div>
              <div className="md-div" dangerouslySetInnerHTML={mdToHtml(node.comment.content)} />
              <ul class="list-inline mb-1 text-muted small font-weight-bold">
                <li className="list-inline-item">
                  <span class="pointer" onClick={linkEvent(this, this.handleReplyClick)}>reply</span>
                </li>
                {this.myComment && 
                  <li className="list-inline-item">
                    <span class="pointer" onClick={linkEvent(this, this.handleEditClick)}>edit</span>
                  </li>
                }
                {this.myComment &&
                  <li className="list-inline-item">
                    <span class="pointer" onClick={linkEvent(this, this.handleDeleteClick)}>delete</span>
                  </li>
                }
                <li className="list-inline-item">
                  <Link className="text-muted" to={`/post/${node.comment.post_id}#comment-${node.comment.id}`}>link</Link>
                </li>
              </ul>
            </div>
          }
        </div>
        {this.state.showReply && <CommentForm node={node} onReplyCancel={this.handleReplyCancel} />}
        {this.props.node.children && <CommentNodes nodes={this.props.node.children} />}
      </div>
    )
  }

  private get myComment(): boolean {
    return UserService.Instance.loggedIn && this.props.node.comment.creator_id == UserService.Instance.user.id;
  }

  handleReplyClick(i: CommentNode, event) {
    i.state.showReply = true;
    i.setState(i.state);
  }

  handleEditClick(i: CommentNode, event) {
    i.state.showEdit = true;
    i.setState(i.state);
  }

  handleDeleteClick(i: CommentNode, event) {
    let deleteForm: CommentFormI = {
      content: "*deleted*",
      edit_id: i.props.node.comment.id,
      post_id: i.props.node.comment.post_id,
      parent_id: i.props.node.comment.parent_id,
      auth: null
    };
    WebSocketService.Instance.editComment(deleteForm);
  }

  handleReplyCancel(): any {
    this.state.showReply = false;
    this.state.showEdit = false;
    this.setState(this.state);
  }


  handleCommentLike(i: CommentNodeI, event) {

    let form: CommentLikeForm = {
      comment_id: i.comment.id,
      post_id: i.comment.post_id,
      score: (i.comment.my_vote == 1) ? 0 : 1
    };
    WebSocketService.Instance.likeComment(form);
  }

  handleCommentDisLike(i: CommentNodeI, event) {
    let form: CommentLikeForm = {
      comment_id: i.comment.id,
      post_id: i.comment.post_id,
      score: (i.comment.my_vote == -1) ? 0 : -1
    };
    WebSocketService.Instance.likeComment(form);
  }
}

interface CommentFormProps {
  postId?: number;
  node?: CommentNodeI;
  onReplyCancel?();
  edit?: boolean;
}

interface CommentFormState {
  commentForm: CommentFormI;
  buttonTitle: string;
}

export class CommentForm extends Component<CommentFormProps, CommentFormState> {

  private emptyState: CommentFormState = {
    commentForm: {
      auth: null,
      content: null,
      post_id: this.props.node ? this.props.node.comment.post_id : this.props.postId
    },
    buttonTitle: !this.props.node ? "Post" : this.props.edit ? "Edit" : "Reply"
  }

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

    this.state = this.emptyState;

    if (this.props.node) {
      if (this.props.edit) {
        this.state.commentForm.edit_id = this.props.node.comment.id;
        this.state.commentForm.parent_id = this.props.node.comment.parent_id;
        this.state.commentForm.content = this.props.node.comment.content;
      } else {
        // A reply gets a new parent id
        this.state.commentForm.parent_id = this.props.node.comment.id;
      }
    }  
  }

  componentDidMount() {
    autosize(document.querySelectorAll('textarea'));
  }

  render() {
    return (
      <div>
        <form onSubmit={linkEvent(this, this.handleCommentSubmit)}>
          <div class="form-group row">
            <div class="col-sm-12">
              <textarea class="form-control" value={this.state.commentForm.content} onInput={linkEvent(this, this.handleCommentContentChange)} placeholder="Comment here" required />
            </div>
          </div>
          <div class="row">
            <div class="col-sm-12">
              <button type="submit" class="btn btn-sm btn-secondary mr-2">{this.state.buttonTitle}</button>
              {this.props.node && <button type="button" class="btn btn-sm btn-secondary" onClick={linkEvent(this, this.handleReplyCancel)}>Cancel</button>}
            </div>
          </div>
        </form>
      </div>
    );
  }

  handleCommentSubmit(i: CommentForm, event) {
    if (i.props.edit) {
      WebSocketService.Instance.editComment(i.state.commentForm);
    } else {
      WebSocketService.Instance.createComment(i.state.commentForm);
    }

    i.state.commentForm.content = undefined;
    i.setState(i.state);
    event.target.reset();
    if (i.props.node) {
      i.props.onReplyCancel();
    }
  }

  handleCommentContentChange(i: CommentForm, event) {
    i.state.commentForm.content = event.target.value;
    i.setState(i.state);
  }

  handleReplyCancel(i: CommentForm, event) {
    i.props.onReplyCancel();
  }
}