show-similar-submissions.js

import compareUrls from "compare-urls";

import { monthNames } from "../libs/utils";

function getSimilarSubmissions(storyLink, metadata) {
  // eslint-disable-next-line no-async-promise-executor
  return new Promise(async (resolve) => {
    const API_URL =
      "https://hn.algolia.com/api/v1/search_by_date?tags=story&restrictSearchableAttributes=url&query=";
    const safeStoryLink = encodeURI(storyLink);

    const results = [];
    const rawResults = await fetch(API_URL + safeStoryLink)
      .then((res) => res.json())
      .then((obj) => obj.hits);

    if (!rawResults) {
      return resolve(results);
    }

    for (const result of rawResults) {
      // eslint-disable-next-line eqeqeq
      if (result.objectID == metadata.item.id) {
        continue;
      }

      if (
        !result.url ||
        !compareUrls(result.url.split("://").pop(), storyLink)
      ) {
        continue;
      }

      if (
        !metadata.options.showDiscussionsWithNoComments &&
        result.num_comments === 0
      ) {
        continue;
      }

      const date = new Date(result.created_at);
      const renderedDate = `${
        monthNames[date.getMonth()]
      } ${date.getDate()}, ${date.getFullYear()}`;

      results.push({
        link: `https://news.ycombinator.com/item?id=${result.objectID}`,
        title: result.title,
        date: renderedDate,
        comments: result.num_comments,
        points: result.points,
      });
    }

    resolve(results);
  });
}

async function init(metadata) {
  if (metadata.item.type !== "story") {
    return false;
  }

  const storyLink = document
    .querySelector("span.titleline a")
    .href.split("://")
    .pop();
  const results = await getSimilarSubmissions(storyLink, metadata);

  if (results.length === 0) {
    return false;
  }

  const discussionRow = document.createElement("tr");
  discussionRow.innerHTML = `
		<td class='__rhn__discussions-row'>
			<p>Discussions on similar submissions:</p>
			<ol></ol>
		</td>
	`;

  const dicussionRowList = discussionRow.querySelector(":scope > td ol");

  for (const result of results) {
    dicussionRowList.innerHTML += `
			<li><a href="${result.link}">${result.title}</a> (${result.date} &mdash; ${
      result.points
    } points, ${result.comments} comments)</li>
		`;
  }

  const rowContainingFooter = document.querySelector("tr#pagespace").nextSibling
    .nextSibling;
  rowContainingFooter.parentElement.insertBefore(
    discussionRow,
    rowContainingFooter
  );

  return true;
}

const details = {
  id: "show-similar-submissions",
  pages: {
    include: ["/item"],
    exclude: [],
  },
  loginRequired: false,
  init,
};

export default details;