Revamp post filtering system (#18058)

* Add model for custom filter keywords

* Use CustomFilterKeyword internally

Does not change the API

* Fix /filters/edit and /filters/new

* Add migration tests

* Remove whole_word column from custom_filters (covered by custom_filter_keywords)

* Redesign /filters

Instead of a list, present a card that displays more information and handles
multiple keywords per filter.

* Redesign /filters/new and /filters/edit to add and remove keywords

This adds a new gem dependency: cocoon, as well as a npm dependency:
cocoon-js-vanilla. Those are used to easily populate and remove form fields
from the user interface when manipulating multiple keyword filters at once.

* Add /api/v2/filters to edit filter with multiple keywords

Entities:
- `Filter`: `id`, `title`, `filter_action` (either `hide` or `warn`), `context`
  `keywords`
- `FilterKeyword`: `id`, `keyword`, `whole_word`

API endpoits:
- `GET /api/v2/filters` to list filters (including keywords)
- `POST /api/v2/filters` to create a new filter
  `keywords_attributes` can also be passed to create keywords in one request
- `GET /api/v2/filters/:id` to read a particular filter
- `PUT /api/v2/filters/:id` to update a new filter
  `keywords_attributes` can also be passed to edit, delete or add keywords in
   one request
- `DELETE /api/v2/filters/:id` to delete a particular filter
- `GET /api/v2/filters/:id/keywords` to list keywords for a filter
- `POST /api/v2/filters/:filter_id/keywords/:id` to add a new keyword to a
   filter
- `GET /api/v2/filter_keywords/:id` to read a particular keyword
- `PUT /api/v2/filter_keywords/:id` to edit a particular keyword
- `DELETE /api/v2/filter_keywords/:id` to delete a particular keyword

* Change from `irreversible` boolean to `action` enum

* Remove irrelevent `irreversible_must_be_within_context` check

* Fix /filters/new and /filters/edit with update for filter_action

* Fix Rubocop/Codeclimate complaining about task names

* Refactor FeedManager#phrase_filtered?

This moves regexp building and filter caching to the `CustomFilter` class.

This does not change the functional behavior yet, but this changes how the
cache is built, doing per-custom_filter regexps so that filters can be matched
independently, while still offering caching.

* Perform server-side filtering and output result in REST API

* Fix numerous filters_changed events being sent when editing multiple keywords at once

* Add some tests

* Use the new API in the WebUI

- use client-side logic for filters we have fetched rules for.
  This is so that filter changes can be retroactively applied without
  reloading the UI.
- use server-side logic for filters we haven't fetched rules for yet
  (e.g. network error, or initial timeline loading)

* Minor optimizations and refactoring

* Perform server-side filtering on the streaming server

* Change the wording of filter action labels

* Fix issues pointed out by linter

* Change design of “Show anyway” link in accordence to review comments

* Drop “irreversible” filtering behavior

* Move /api/v2/filter_keywords to /api/v1/filters/keywords

* Rename `filter_results` attribute to `filtered`

* Rename REST::LegacyFilterSerializer to REST::V1::FilterSerializer

* Fix systemChannelId value in streaming server

* Simplify code by removing client-side filtering code

The simplifcation comes at a cost though: filters aren't retroactively
applied anymore.

app/javascript/mastodon/actions/filters.js

@@ -1,26 +0,0 @@
-import api from '../api';
-
-export const FILTERS_FETCH_REQUEST = 'FILTERS_FETCH_REQUEST';
-export const FILTERS_FETCH_SUCCESS = 'FILTERS_FETCH_SUCCESS';
-export const FILTERS_FETCH_FAIL    = 'FILTERS_FETCH_FAIL';
-
-export const fetchFilters = () => (dispatch, getState) => {
-  dispatch({
-    type: FILTERS_FETCH_REQUEST,
-    skipLoading: true,
-  });
-
-  api(getState)
-    .get('/api/v1/filters')
-    .then(({ data }) => dispatch({
-      type: FILTERS_FETCH_SUCCESS,
-      filters: data,
-      skipLoading: true,
-    }))
-    .catch(err => dispatch({
-      type: FILTERS_FETCH_FAIL,
-      err,
-      skipLoading: true,
-      skipAlert: true,
-    }));
-};

app/javascript/mastodon/actions/importer/index.js

@@ -5,6 +5,7 @@ export const ACCOUNTS_IMPORT = 'ACCOUNTS_IMPORT';
 export const STATUS_IMPORT   = 'STATUS_IMPORT';
 export const STATUSES_IMPORT = 'STATUSES_IMPORT';
 export const POLLS_IMPORT    = 'POLLS_IMPORT';
+export const FILTERS_IMPORT  = 'FILTERS_IMPORT';
 
 function pushUnique(array, object) {
   if (array.every(element => element.id !== object.id)) {
@@ -28,6 +29,10 @@ export function importStatuses(statuses) {
   return { type: STATUSES_IMPORT, statuses };
 }
 
+export function importFilters(filters) {
+  return { type: FILTERS_IMPORT, filters };
+}
+
 export function importPolls(polls) {
   return { type: POLLS_IMPORT, polls };
 }
@@ -61,11 +66,16 @@ export function importFetchedStatuses(statuses) {
     const accounts = [];
     const normalStatuses = [];
     const polls = [];
+    const filters = [];
 
     function processStatus(status) {
       pushUnique(normalStatuses, normalizeStatus(status, getState().getIn(['statuses', status.id])));
       pushUnique(accounts, status.account);
 
+      if (status.filtered) {
+        status.filtered.forEach(result => pushUnique(filters, result.filter));
+      }
+
       if (status.reblog && status.reblog.id) {
         processStatus(status.reblog);
       }
@@ -80,6 +90,7 @@ export function importFetchedStatuses(statuses) {
     dispatch(importPolls(polls));
     dispatch(importFetchedAccounts(accounts));
     dispatch(importStatuses(normalStatuses));
+    dispatch(importFilters(filters));
   };
 }
 

app/javascript/mastodon/actions/importer/normalizer.js

@@ -42,6 +42,14 @@ export function normalizeAccount(account) {
   return account;
 }
 
+export function normalizeFilterResult(result) {
+  const normalResult = { ...result };
+
+  normalResult.filter = normalResult.filter.id;
+
+  return normalResult;
+}
+
 export function normalizeStatus(status, normalOldStatus) {
   const normalStatus   = { ...status };
   normalStatus.account = status.account.id;
@@ -54,6 +62,10 @@ export function normalizeStatus(status, normalOldStatus) {
     normalStatus.poll = status.poll.id;
   }
 
+  if (status.filtered) {
+    normalStatus.filtered = status.filtered.map(normalizeFilterResult);
+  }
+
   // Only calculate these values when status first encountered and
   // when the underlying values change. Otherwise keep the ones
   // already in the reducer

app/javascript/mastodon/actions/notifications.js

@@ -12,10 +12,8 @@ import { saveSettings } from './settings';
 import { defineMessages } from 'react-intl';
 import { List as ImmutableList } from 'immutable';
 import { unescapeHTML } from '../utils/html';
-import { getFiltersRegex } from '../selectors';
 import { usePendingItems as preferPendingItems } from 'mastodon/initial_state';
 import compareId from 'mastodon/compare_id';
-import { searchTextFromRawStatus } from 'mastodon/actions/importer/normalizer';
 import { requestNotificationPermission } from '../utils/notifications';
 
 export const NOTIFICATIONS_UPDATE      = 'NOTIFICATIONS_UPDATE';
@@ -62,20 +60,17 @@ export function updateNotifications(notification, intlMessages, intlLocale) {
     const showInColumn = activeFilter === 'all' ? getState().getIn(['settings', 'notifications', 'shows', notification.type], true) : activeFilter === notification.type;
     const showAlert    = getState().getIn(['settings', 'notifications', 'alerts', notification.type], true);
     const playSound    = getState().getIn(['settings', 'notifications', 'sounds', notification.type], true);
-    const filters      = getFiltersRegex(getState(), { contextType: 'notifications' });
 
     let filtered = false;
 
-    if (['mention', 'status'].includes(notification.type)) {
-      const dropRegex   = filters[0];
-      const regex       = filters[1];
-      const searchIndex = searchTextFromRawStatus(notification.status);
+    if (['mention', 'status'].includes(notification.type) && notification.status.filtered) {
+      const filters = notification.status.filtered.filter(result => result.filter.context.includes('notifications'));
 
-      if (dropRegex && dropRegex.test(searchIndex)) {
+      if (filters.some(result => result.filter.filter_action === 'hide')) {
         return;
       }
 
-      filtered = regex && regex.test(searchIndex);
+      filtered = filters.length > 0;
     }
 
     if (['follow_request'].includes(notification.type)) {

app/javascript/mastodon/actions/streaming.js

@@ -21,7 +21,6 @@ import {
   updateReaction as updateAnnouncementsReaction,
   deleteAnnouncement,
 } from './announcements';
-import { fetchFilters } from './filters';
 import { getLocale } from '../locales';
 
 const { messages } = getLocale();
@@ -97,9 +96,6 @@ export const connectTimelineStream = (timelineId, channelName, params = {}, opti
         case 'conversation':
           dispatch(updateConversations(JSON.parse(data.payload)));
           break;
-        case 'filters_changed':
-          dispatch(fetchFilters());
-          break;
         case 'announcement':
           dispatch(updateAnnouncements(JSON.parse(data.payload)));
           break;