feat(matrix/fediverse): allow users to directly reply on Fediverse posts from Matrix, using <mx-reply> on our new meta field.

feat(matrix/fediverse): allow users to favorite, reblog, and redact Fediverse posts from Matrix, using m.reaction on our new meta field.
feat(fediverse): add suggestions for follow/unfollow commands.
refactor(matrix/fediverse): add meta field for commands by reaction, and commands by reply.
refactor(fediverse): relax polling on timeline/notifs thru new handling.

commands/fediverse/post.js

@@ -1,19 +1,90 @@
-exports.runQuery = function (matrixClient, room, userInput) {
-  axios({
+const qs = require('qs');
+const FormData = require('form-data');
+
+const emojis = { public: '🌐', unlisted: '📝', private: '🔒️', direct: '✉️' };
+exports.visibilityEmoji = (v) => emojis[v] || v;
+
+const getFilename = (header) => {
+  if (typeof header !== 'string') return null;
+  try {
+    const m = header.match(/inline; filename(?:=(.+)|\*=utf-8''(.+))/);
+    return !m ? null : m[2] && decodeURIComponent(m[2]) || m[1];
+  } catch (e) {
+    return null;
+  }
+};
+
+const mediaDownload = async (url, { whitelist, blacklist }) => {
+  const media = await axios({ method: 'GET', url, responseType: 'arraybuffer' });
+  if (media.statusText !== 'OK' || blacklist.includes(media.headers['content-type'])) throw media;
+  if (whitelist.length && !whitelist.includes(media.headers['content-type'])) throw media;
+  return {
+    data: media.data,
+    filename: getFilename(media.headers['content-disposition']),
+    mimetype: media.headers['content-type'],
+  };
+};
+
+const mediaUpload = async ({ domain }, { data, filename, mimetype }) => {
+  const form = new FormData();
+  form.append('file', data, {
+    filename: filename || 'upload',
+    contentType: mimetype,
+  });
+  const upload = await axios({
+    method: 'POST',
+    url: `${domain}/api/v1/media`,
+    headers: form.getHeaders({ Authorization: `Bearer ${fediverse.auth.access_token}` }),
+    data: form,
+  });
+  if (upload.statusText !== 'OK') throw upload;
+  return upload.data.id;
+};
+
+const run = async (roomId, content, replyId, mediaURL, subject) => {
+  let mediaId = null;
+  if (mediaURL) {
+    const media = await mediaDownload(mediaURL, config.fediverse.mimetypes);
+    mediaId = await mediaUpload(config.fediverse, media);
+  }
+  const response = await axios({
     method: 'POST',
     url: `${config.fediverse.domain}/api/v1/statuses`,
-    headers: { Authorization: `Bearer ${fediverse_auth.access_token}` },
-    data: { status: userInput, content_type: `text/markdown` },
-  }).then((response) => {
-    matrixClient.sendHtmlNotice(room.roomId,
-      '',
-      `<b>
-      <blockquote><i>${response.data.content}<br>
-      (id: ${response.data.id}</a>)
-      </blockquote><br>`);
-  })
-    .catch((e) => {
-      matrixClient.sendHtmlNotice(room.roomId,
-        '', `${e}`);
-    });
+    headers: { Authorization: `Bearer ${fediverse.auth.access_token}`, 'Content-Type': 'application/x-www-form-urlencoded' },
+    data: qs.stringify({
+      status: content,
+      content_type: 'text/markdown',
+      media_ids: mediaURL && [mediaId] || undefined,
+      in_reply_to_id: replyId || undefined,
+      spoiler_text: subject || undefined,
+    }, { arrayFormat: 'brackets' }),
+  });
+  return fediverse.utils.sendEventWithMeta(roomId, `<a href="${response.data.url}">${response.data.id}</a>`, `redact ${response.data.id}`);
+};
+
+exports.runQuery = async (roomId, userInput, { isReply, hasMedia, hasSubject }) => {
+  try {
+    const chunks = userInput.trim().split(' ');
+    if (!chunks.length || chunks.length < !!isReply + !!hasMedia) throw '';
+    let replyId = null;
+    let mediaURL = null;
+    const subject = hasSubject ? config.fediverse.subject : null;
+    if (isReply) {
+      replyId = chunks[0];
+      chunks.shift();
+    }
+    if (hasMedia) {
+      let url = new URL(chunks[0]);
+      chunks.shift();
+      if (url.protocol === 'mxc:' && url.hostname && url.pathname)
+        url = new URL(`${config.matrix.domain}/_matrix/media/r0/download/${url.hostname}${url.pathname}`);
+      if (url.protocol !== 'https:') throw '';
+      if (!config.matrix.domains.includes(url.hostname)) throw '';
+      if (!/^\/_matrix\/media\/r0\/download\/[^/]+\/[^/]+\/?$/.test(url.pathname)) throw '';
+      mediaURL = url.toString();
+    }
+    return await run(roomId, chunks.join(' '), replyId, mediaURL, subject);
+  } catch (e) {
+    return matrixClient.sendHtmlNotice(roomId, 'Sad!', '<strong>Sad!</strong>').catch(() => {});
+  }
 };