Masto/app/javascript/flavours/glitch/components/status_content.jsx

import PropTypes from "prop-types";
import { PureComponent } from "react";

import { FormattedMessage, injectIntl } from "react-intl";

import classnames from "classnames";

import ImmutablePropTypes from "react-immutable-proptypes";
import { connect } from "react-redux";

import { Icon } from "flavours/glitch/components/icon";
import { autoPlayGif } from "flavours/glitch/initial_state";
import { decode as decodeIDNA } from "flavours/glitch/utils/idna";

import Permalink from "./permalink";

const textMatchesTarget = (text, origin, host) => {
  return (text === origin || text === host
          || text.startsWith(origin + "/") || text.startsWith(host + "/")
          || "www." + text === host || ("www." + text).startsWith(host + "/"));
};

const isLinkMisleading = (link) => {
  let linkTextParts = [];

  // Reconstruct visible text, as we do not have much control over how links
  // from remote software look, and we can't rely on `innerText` because the
  // `invisible` class does not set `display` to `none`.

  const walk = (node) => {
    switch (node.nodeType) {
      case Node.TEXT_NODE:
        linkTextParts.push(node.textContent);
        break;
      case Node.ELEMENT_NODE:
        if (node.classList.contains("invisible")) {
          return;
        }
        const children = node.childNodes;
        for (let i = 0; i < children.length; i++) {
          walk(children[i]);
        }
        break;
    }
  };

  walk(link);

  const linkText = linkTextParts.join("");
  const targetURL = new URL(link.href);

  if (targetURL.protocol === "magnet:") {
    return !linkText.startsWith("magnet:");
  }

  if (targetURL.protocol === "xmpp:") {
    return !(linkText === targetURL.href || "xmpp:" + linkText === targetURL.href);
  }

  // The following may not work with international domain names
  if (textMatchesTarget(linkText, targetURL.origin, targetURL.host) || textMatchesTarget(linkText.toLowerCase(), targetURL.origin, targetURL.host)) {
    return false;
  }

  // The link hasn't been recognized, maybe it features an international domain name
  const hostname = decodeIDNA(targetURL.hostname).normalize("NFKC");
  const host = targetURL.host.replace(targetURL.hostname, hostname);
  const origin = targetURL.origin.replace(targetURL.host, host);
  const text = linkText.normalize("NFKC");
  return !(textMatchesTarget(text, origin, host) || textMatchesTarget(text.toLowerCase(), origin, host));
};


class StatusContent extends PureComponent {

  static contextTypes = {
    identity: PropTypes.object,
  };

  static propTypes = {
    status: ImmutablePropTypes.map.isRequired,
    expanded: PropTypes.bool,
    collapsed: PropTypes.bool,
    onExpandedToggle: PropTypes.func,
    onTranslate: PropTypes.func,
    media: PropTypes.node,
    extraMedia: PropTypes.node,
    mediaIcons: PropTypes.arrayOf(PropTypes.string),
    parseClick: PropTypes.func,
    disabled: PropTypes.bool,
    onUpdate: PropTypes.func,
    tagLinks: PropTypes.bool,
    rewriteMentions: PropTypes.string,
  };

  static defaultProps = {
    tagLinks: true,
    rewriteMentions: "no",
  };

  state = {
    hidden: true,
  };

  _updateStatusLinks () {
    const node = this.contentsNode;
    const { tagLinks, rewriteMentions } = this.props;

    if (!node) {
      return;
    }

    const links = node.querySelectorAll("a");

    for (var i = 0; i < links.length; ++i) {
      let link = links[i];
      if (link.classList.contains("status-link")) {
        continue;
      }
      link.classList.add("status-link");

      let mention = this.props.status.get("mentions").find(item => link.href === item.get("url"));

      if (mention) {
        link.addEventListener("click", this.onMentionClick.bind(this, mention), false);
        link.setAttribute("title", `@${mention.get("acct")}`);
        if (rewriteMentions !== "no") {
          while (link.firstChild) {
            link.removeChild(link.firstChild);
          }
          link.appendChild(document.createTextNode("@"));
          const acctSpan = document.createElement("span");
          acctSpan.textContent = rewriteMentions === "acct" ? mention.get("acct") : mention.get("username");
          link.appendChild(acctSpan);
        }
      } else if (link.textContent[0] === "#" || (link.previousSibling && link.previousSibling.textContent && link.previousSibling.textContent[link.previousSibling.textContent.length - 1] === "#")) {
        link.addEventListener("click", this.onHashtagClick.bind(this, link.text), false);
      } else {
        link.addEventListener("click", this.onLinkClick.bind(this), false);
        link.setAttribute("title", link.href);
        link.classList.add("unhandled-link");

        link.setAttribute("target", "_blank");
        link.setAttribute("rel", "noopener nofollow noreferrer");

        try {
          if (tagLinks && isLinkMisleading(link)) {
            // Add a tag besides the link to display its origin

            const url = new URL(link.href);
            const tag = document.createElement("span");
            tag.classList.add("link-origin-tag");
            switch (url.protocol) {
              case "xmpp:":
                tag.textContent = `[${url.href}]`;
                break;
              case "magnet:":
                tag.textContent = "(magnet)";
                break;
              default:
                tag.textContent = `[${url.host}]`;
            }
            link.insertAdjacentText("beforeend", " ");
            link.insertAdjacentElement("beforeend", tag);
          }
        } catch (e) {
          // The URL is invalid, remove the href just to be safe
          if (tagLinks && e instanceof TypeError) {
            link.removeAttribute("href");
          }
        }
      }
    }
  }

  handleMouseEnter = ({ currentTarget }) => {
    if (autoPlayGif) {
      return;
    }

    const emojis = currentTarget.querySelectorAll(".custom-emoji");

    for (var i = 0; i < emojis.length; i++) {
      let emoji = emojis[i];
      emoji.src = emoji.getAttribute("data-original");
    }
  };

  handleMouseLeave = ({ currentTarget }) => {
    if (autoPlayGif) {
      return;
    }

    const emojis = currentTarget.querySelectorAll(".custom-emoji");

    for (var i = 0; i < emojis.length; i++) {
      let emoji = emojis[i];
      emoji.src = emoji.getAttribute("data-static");
    }
  };

  componentDidMount () {
    this._updateStatusLinks();
  }

  componentDidUpdate () {
    this._updateStatusLinks();
    if (this.props.onUpdate) {
      this.props.onUpdate();
    }
  }

  onLinkClick = (e) => {
    if (this.props.collapsed) {
      if (this.props.parseClick) {
        this.props.parseClick(e);
      }
    }
  };

  onMentionClick = (mention, e) => {
    if (this.props.parseClick) {
      this.props.parseClick(e, `/@${mention.get("acct")}`);
    }
  };

  onHashtagClick = (hashtag, e) => {
    hashtag = hashtag.replace(/^#/, "");

    if (this.props.parseClick) {
      this.props.parseClick(e, `/tags/${hashtag}`);
    }
  };

  handleMouseDown = (e) => {
    this.startXY = [e.clientX, e.clientY];
  };

  handleMouseUp = (e) => {
    const { parseClick, disabled } = this.props;

    if (disabled || !this.startXY) {
      return;
    }

    const [ startX, startY ] = this.startXY;
    const [ deltaX, deltaY ] = [Math.abs(e.clientX - startX), Math.abs(e.clientY - startY)];

    let element = e.target;
    while (element !== e.currentTarget) {
      if (["button", "video", "a", "label", "canvas"].includes(element.localName) || element.getAttribute("role") === "button") {
        return;
      }
      element = element.parentNode;
    }

    if (deltaX + deltaY < 5 && e.button === 0 && parseClick) {
      parseClick(e);
    }

    this.startXY = null;
  };

  handleSpoilerClick = (e) => {
    e.preventDefault();

    if (this.props.onExpandedToggle) {
      this.props.onExpandedToggle();
    } else {
      this.setState({ hidden: !this.state.hidden });
    }
  };

  handleTranslate = () => {
    this.props.onTranslate();
  };

  setContentsRef = (c) => {
    this.contentsNode = c;
  };

  render () {
    const {
      status,
      media,
      extraMedia,
      mediaIcons,
      parseClick,
      disabled,
      tagLinks,
      rewriteMentions,
    } = this.props;

    const hidden = this.props.onExpandedToggle ? !this.props.expanded : this.state.hidden;

    const content = { __html: status.getIn(["translation", "contentHtml"]) || status.get("contentHtml") };
    const spoilerContent = { __html: status.getIn(["translation", "spoilerHtml"]) || status.get("spoilerHtml") };
    const language = status.getIn(["translation", "language"]) || status.get("language");
    const classNames = classnames("status__content", {
      "status__content--with-action": parseClick && !disabled,
      "status__content--with-spoiler": status.get("spoiler_text").length > 0,
    });


    if (status.get("spoiler_text").length > 0) {
      let mentionsPlaceholder = "";

      const mentionLinks = status.get("mentions").map(item => (
        <Permalink
          to={`/@${item.get("acct")}`}
          href={item.get("url")}
          key={item.get("id")}
          className='mention'
        >
          @<span>{item.get("username")}</span>
        </Permalink>
      )).reduce((aggregate, item) => [...aggregate, item, " "], []);

      let toggleText = null;
      if (hidden) {
        toggleText = [
          <FormattedMessage
            id='status.show_more'
            defaultMessage='Show more'
            key='0'
          />,
        ];
        if (mediaIcons) {
          mediaIcons.forEach((mediaIcon, idx) => {
            toggleText.push(
              <Icon
                className='status__content__spoiler-icon'
                id={mediaIcon}
                aria-hidden='true'
                key={`icon-${idx}`}
              />,
            );
          });
        }
      } else {
        toggleText = (
          <FormattedMessage
            id='status.show_less'
            defaultMessage='Show less'
            key='0'
          />
        );
      }

      if (hidden) {
        mentionsPlaceholder = <div>{mentionLinks}</div>;
      }

      return (
        <div className={classNames} tabIndex={0} onMouseDown={this.handleMouseDown} onMouseUp={this.handleMouseUp}>
          <span dangerouslySetInnerHTML={spoilerContent} className='translate' lang={language} />
          {" "}
          <button type='button' className='status__content__spoiler-link' onClick={this.handleSpoilerClick} aria-expanded={!hidden}>
            <Icon id={hidden ? "eye-closed" : "eye"} />
            {toggleText}
          </button>

          {mentionsPlaceholder}

          <div className={`status__content__spoiler ${!hidden ? "status__content__spoiler--visible" : ""}`}>
            <div
              ref={this.setContentsRef}
              key={`contents-${tagLinks}`}
              tabIndex={!hidden ? 0 : null}
              dangerouslySetInnerHTML={content}
              className='status__content__text translate'
              onMouseEnter={this.handleMouseEnter}
              onMouseLeave={this.handleMouseLeave}
              lang={language}
            />
            {media}
          </div>

          {extraMedia}
        </div>
      );
    } else if (parseClick) {
      return (
        <div
          className={classNames}
          onMouseDown={this.handleMouseDown}
          onMouseUp={this.handleMouseUp}
          tabIndex={0}
        >
          <div
            ref={this.setContentsRef}
            key={`contents-${tagLinks}-${rewriteMentions}`}
            dangerouslySetInnerHTML={content}
            className='status__content__text translate'
            tabIndex={0}
            onMouseEnter={this.handleMouseEnter}
            onMouseLeave={this.handleMouseLeave}
            lang={language}
          />
          {media}
          {extraMedia}
        </div>
      );
    } else {
      return (
        <div
          className='status__content'
          tabIndex={0}
        >
          <div
            ref={this.setContentsRef}
            key={`contents-${tagLinks}`}
            className='status__content__text translate'
            dangerouslySetInnerHTML={content}
            tabIndex={0}
            onMouseEnter={this.handleMouseEnter}
            onMouseLeave={this.handleMouseLeave}
            lang={language}
          />
          {media}
          {extraMedia}
        </div>
      );
    }
  }

}

export default connect()(injectIntl(StatusContent));