/* https://github.com/oom-components/mastodon-comments, under MIT License */
// © https://phosphoricons.com/
export const icons = {
  reblog:
    `<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 256 256" fill="none" stroke="currentColor" stroke-width="24"><polyline points="200 88 224 64 200 40"/><path d="M32,128A64,64,0,0,1,96,64H224"/><polyline points="56 168 32 192 56 216"/><path d="M224,128a64,64,0,0,1-64,64H32"/></svg>`,
  favourite:
    `<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 256 256" fill="currentColor"><path d="M240,94c0,70-103.79,126.66-108.21,129a8,8,0,0,1-7.58,0C119.79,220.66,16,164,16,94A62.07,62.07,0,0,1,78,32c20.65,0,38.73,8.88,50,23.89C139.27,40.88,157.35,32,178,32A62.07,62.07,0,0,1,240,94Z"/></svg>`,
  author:
    `<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 256 256" fill="currentColor" class="comment-author"><path d="M128,24A104,104,0,1,0,232,128,104.11,104.11,0,0,0,128,24Zm45.66,85.66-56,56a8,8,0,0,1-11.32,0l-24-24a8,8,0,0,1,11.32-11.32L112,148.69l50.34-50.35a8,8,0,0,1,11.32,11.32Z"></path></svg>`,

  // @ https://simpleicons.org/
  mastodon:
    `<svg role="img" width="16" height="16" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Mastodon</title><path d="M23.268 5.313c-.35-2.578-2.617-4.61-5.304-5.004C17.51.242 15.792 0 11.813 0h-.03c-3.98 0-4.835.242-5.288.309C3.882.692 1.496 2.518.917 5.127.64 6.412.61 7.837.661 9.143c.074 1.874.088 3.745.26 5.611.118 1.24.325 2.47.62 3.68.55 2.237 2.777 4.098 4.96 4.857 2.336.792 4.849.923 7.256.38.265-.061.527-.132.786-.213.585-.184 1.27-.39 1.774-.753a.057.057 0 0 0 .023-.043v-1.809a.052.052 0 0 0-.02-.041.053.053 0 0 0-.046-.01 20.282 20.282 0 0 1-4.709.545c-2.73 0-3.463-1.284-3.674-1.818a5.593 5.593 0 0 1-.319-1.433.053.053 0 0 1 .066-.054c1.517.363 3.072.546 4.632.546.376 0 .75 0 1.125-.01 1.57-.044 3.224-.124 4.768-.422.038-.008.077-.015.11-.024 2.435-.464 4.753-1.92 4.989-5.604.008-.145.03-1.52.03-1.67.002-.512.167-3.63-.024-5.545zm-3.748 9.195h-2.561V8.29c0-1.309-.55-1.976-1.67-1.976-1.23 0-1.846.79-1.846 2.35v3.403h-2.546V8.663c0-1.56-.617-2.35-1.848-2.35-1.112 0-1.668.668-1.67 1.977v6.218H4.822V8.102c0-1.31.337-2.35 1.011-3.12.696-.77 1.608-1.164 2.74-1.164 1.311 0 2.302.5 2.962 1.498l.638 1.06.638-1.06c.66-.999 1.65-1.498 2.96-1.498 1.13 0 2.043.395 2.74 1.164.675.77 1.012 1.81 1.012 3.12z"/></svg>`,

  pleroma:
    `<svg role="img" width="16" height="16" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Pleroma</title><path d="M6.36 0A1.868 1.868 0 004.49 1.868V24h5.964V0zm7.113 0v12h4.168a1.868 1.868 0 001.868-1.868V0zm0 18.036V24h4.168a1.868 1.868 0 001.868-1.868v-4.096Z"/></svg>`,

  bluesky:
    `<svg role="img" width="16" height="16" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Bluesky</title><path d="M12 10.8c-1.087-2.114-4.046-6.053-6.798-7.995C2.566.944 1.561 1.266.902 1.565.139 1.908 0 3.08 0 3.768c0 .69.378 5.65.624 6.479.815 2.736 3.713 3.66 6.383 3.364.136-.02.275-.039.415-.056-.138.022-.276.04-.415.056-3.912.58-7.387 2.005-2.83 7.078 5.013 5.19 6.87-1.113 7.823-4.308.953 3.195 2.05 9.271 7.733 4.308 4.267-4.308 1.172-6.498-2.74-7.078a8.741 8.741 0 0 1-.415-.056c.14.017.279.036.415.056 2.67.297 5.568-.628 6.383-3.364.246-.828.624-5.79.624-6.478 0-.69-.139-1.861-.902-2.206-.659-.298-1.664-.62-4.3 1.24C16.046 4.748 13.087 8.687 12 10.8Z"/></svg>`,
};

export default class SocialComments extends HTMLElement {
  comments = {};

  async connectedCallback() {
    const lang = this.closest("[lang]")?.lang || navigator.language || "en";

    this.dateTimeFormatter = new Intl.DateTimeFormat(lang, {
      dateStyle: "medium",
      timeStyle: "short",
    });

    const mastodon = this.getAttribute("mastodon") || this.getAttribute("src");
    const bluesky = this.getAttribute("bluesky");

    await Promise.all([
      mastodon && this.#fetchMastodon(new URL(mastodon)),
      bluesky && this.#fetchBluesky(new URL(bluesky)),
    ]);

    this.refresh();
  }

  refresh() {
    const comments = [
      ...this.comments.mastodon || [],
      ...this.comments.bluesky || [],
    ].sort(
      (a, b) => new Date(a.createdAt) - new Date(b.createdAt),
    );

    if (comments.length) {
      this.innerHTML = "";
      this.render(this, comments);
    }
  }

  async #fetchBluesky(url) {
    const { pathname } = url;

    const [, handle, rkey] = pathname.match(
      /\/profile\/([\w\.]+)\/post\/(\w+)/,
    );

    if (!handle || !rkey) {
      return;
    }

    const options = {
      ttl: Number(this.getAttribute("cache") || 0),
    };

    const didData = await fetchJSON(
      `https://public.api.bsky.app/xrpc/com.atproto.identity.resolveHandle?handle=${handle}`,
      options,
    );
    const uri = `at://${didData.did}/app.bsky.feed.post/${rkey}`;

    this.comments.bluesky = dataFromBluesky(
      await fetchJSON(
        `https://public.api.bsky.app/xrpc/app.bsky.feed.getPostThread?uri=${uri}`,
        options,
      ),
    );
  }

  async #fetchMastodon(url) {
    const { origin, pathname } = url;
    let id;

    const source = pathname.includes("/notice/") ? "pleroma" : "mastodon";

    if (source === "pleroma") {
      [, id] = pathname.match(/^\/notice\/([^\/?#]+)/);
    } else {
      [, id] = pathname.match(/\/(\d+)$/);
    }

    if (!id) {
      return;
    }

    const token = this.getAttribute("token");
    const options = {
      ttl: Number(this.getAttribute("cache") || 0),
    };
    if (token) {
      options.headers = {
        Authorization: `Bearer ${token}`,
      };
    }

    const user = url.pathname.split("/")[1];
    const author = `${user}@${url.hostname}`;

    const comments = dataFromMastodon(
      await fetchJSON(
        new URL(`${origin}/api/v1/statuses/${id}/context`),
        options,
      ),
      author,
      source,
    );

    this.comments.mastodon = comments.filter((comment) =>
      comment.parent === id
    );
  }

  render(container, replies) {
    const ul = document.createElement("ul");

    for (const reply of replies) {
      const comment = document.createElement("li");
      comment.innerHTML = this.renderComment(reply);

      if (reply.replies.length) {
        this.render(comment, reply.replies);
      }
      ul.appendChild(comment);
    }

    container.appendChild(ul);
  }

  renderComment(comment) {
    return `
        <article class="comment" id="comment-${comment.id}">
          <footer class="comment-footer">
            <a href="${comment.author.url}" class="comment-user">
              <img class="comment-avatar" src="${comment.author.avatar}" alt="${comment.author.alt}'s avatar" width="200" height="200">
              ${comment.isMine ? icons.author : ""}
              <strong class="comment-username">
                ${comment.author.name}
              </strong>
              <em class="comment-useraddress">${comment.author.handler}</em>
            </a>
            <a href="${comment.url}" class="comment-address">
              <time class="comment-time" title="${comment.createdAt.toISOString()}">
                ${this.dateTimeFormatter.format(comment.createdAt)}
                ${icons[comment.source]}
              </time>
            </a>
          </footer>
          <div class="comment-body">
            ${comment.content}

            <p class="comment-counts">
              ${
      comment.boosts ? `<span>${icons.reblog} ${comment.boosts}</span>` : ""
    }
              ${
      comment.likes ? `<span>${icons.favourite} ${comment.likes}</span>` : ""
    }
            </p>
          </div>
        </article>
      `;
  }
}

function formatEmojis(html, emojis) {
  emojis.forEach(({ shortcode, static_url, url }) => {
    html = html.replace(
      `:${shortcode}:`,
      `<picture>
        <source srcset="${url}" media="(prefers-reduced-motion: no-preference)">
        <img src="${static_url}" alt=":${shortcode}:" title=":${shortcode}:" width="16" height="16">
      </picture>`,
    );
  });
  return html;
}

async function fetchJSON(url, options = {}) {
  const headers = new Headers();

  if (options.headers) {
    for (const [key, value] of Object.entries(options.headers)) {
      headers.set(key, value);
    }
  }

  if (typeof caches === "undefined") {
    return await (await fetch(url), { headers }).json();
  }

  const cache = await caches.open("mastodon-comments");
  let cached = await cache.match(url);

  if (cached && options.ttl) {
    const cacheTime = new Date(cached.headers.get("x-cached-at"));
    const diff = Date.now() - cacheTime.getTime();

    if (diff <= options.ttl * 1000) {
      return await cached.json();
    }
  }

  try {
    const response = await fetch(url, { headers });
    const body = await response.json();

    cached = new Response(JSON.stringify(body));
    cached.headers.set("x-cached-at", new Date());
    cached.headers.set("content-type", "application/json; charset=utf-8");
    await cache.put(url, cached);
    return body;
  } catch {
    if (cached) {
      return await cached.json();
    }
  }
}

function dataFromMastodon(data, author, source) {
  const comments = new Map();

  // Transform data to a more usable format
  for (const comment of data.descendants) {
    if (comment.visibility !== "public") {
      continue;
    }

    const { account } = comment;
    const handler = `@${account.username}@${new URL(account.url).hostname}`;
    comments.set(comment.id, {
      id: comment.id,
      isMine: author === handler,
      source,
      url: comment.url,
      parent: comment.in_reply_to_id,
      createdAt: new Date(comment.created_at),
      content: formatEmojis(comment.content, comment.emojis),
      author: {
        name: formatEmojis(account.display_name, account.emojis),
        handler,
        url: account.url,
        avatar: account.avatar_static,
        alt: account.display_name,
      },
      boosts: comment.reblogs_count,
      likes: comment.favourites_count,
      replies: [],
    });
  }

  // Group comments by parent
  for (const comment of comments.values()) {
    if (comment.parent && comments.has(comment.parent)) {
      comments.get(comment.parent).replies.push(comment);
    }
  }

  return Array.from(comments.values());
}

function dataFromBluesky(data) {
  const { thread } = data;

  return blueskyComments(
    thread.post.author.did,
    thread.post.cid,
    thread.replies,
  );
}

function blueskyComments(author, parent, comments) {
  return comments.map((reply) => {
    const { post, replies } = reply;
    const rkey = post.uri.split("/").pop();
    return {
      id: post.cid,
      isMine: post.author.did === author,
      source: "bluesky",
      url: `https://bsky.app/profile/${post.author.handle}/post/${rkey}`,
      parent,
      createdAt: new Date(post.record.createdAt),
      content: post.record.text,
      author: {
        name: post.author.displayName,
        handler: post.author.handle,
        url: `https://bsky.app/profile/${post.author.handle}`,
        avatar: post.author.avatar,
        alt: post.author.displayName,
      },
      boosts: post.repostCount,
      likes: post.likeCount,
      replies: blueskyComments(author, post.cid, replies || []),
    };
  });
}
