Add ability to filter individual posts (#18945)

* Add database table for status-specific filters

* Add REST endpoints, entities and attributes

* Show status filters in /filters interface

* Perform server-side filtering for individual posts filters

* Fix filtering on context mismatch

* Refactor `toServerSideType` by moving it to its own module

* Move loupe and delete icons to their own module

* Add ability to filter individual posts from WebUI

* Replace keyword list by warnings (expired, context mismatch)

* Refactor server-side filtering code

* Add tests

16 files changed, 611 insertions, 42 deletions

diff --git a/app/javascript/mastodon/actions/filters.js b/app/javascript/mastodon/actions/filters.js
new file mode 100644
index 000000000..76326802e
--- /dev/null
+++ b/app/javascript/mastodon/actions/filters.js
@@ -0,0 +1,93 @@
+import api from '../api';
+import { openModal } from './modal';
+
+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 FILTERS_STATUS_CREATE_REQUEST = 'FILTERS_STATUS_CREATE_REQUEST';
+export const FILTERS_STATUS_CREATE_SUCCESS = 'FILTERS_STATUS_CREATE_SUCCESS';
+export const FILTERS_STATUS_CREATE_FAIL    = 'FILTERS_STATUS_CREATE_FAIL';
+
+export const FILTERS_CREATE_REQUEST = 'FILTERS_CREATE_REQUEST';
+export const FILTERS_CREATE_SUCCESS = 'FILTERS_CREATE_SUCCESS';
+export const FILTERS_CREATE_FAIL    = 'FILTERS_CREATE_FAIL';
+
+export const initAddFilter = (status, { contextType }) => dispatch =>
+  dispatch(openModal('FILTER', {
+    statusId: status?.get('id'),
+    contextType: contextType,
+  }));
+
+export const fetchFilters = () => (dispatch, getState) => {
+  dispatch({
+    type: FILTERS_FETCH_REQUEST,
+    skipLoading: true,
+  });
+
+  api(getState)
+    .get('/api/v2/filters')
+    .then(({ data }) => dispatch({
+      type: FILTERS_FETCH_SUCCESS,
+      filters: data,
+      skipLoading: true,
+    }))
+    .catch(err => dispatch({
+      type: FILTERS_FETCH_FAIL,
+      err,
+      skipLoading: true,
+      skipAlert: true,
+    }));
+};
+
+export const createFilterStatus = (params, onSuccess, onFail) => (dispatch, getState) => {
+  dispatch(createFilterStatusRequest());
+
+  api(getState).post(`/api/v1/filters/${params.filter_id}/statuses`, params).then(response => {
+    dispatch(createFilterStatusSuccess(response.data));
+    if (onSuccess) onSuccess();
+  }).catch(error => {
+    dispatch(createFilterStatusFail(error));
+    if (onFail) onFail();
+  });
+};
+
+export const createFilterStatusRequest = () => ({
+  type: FILTERS_STATUS_CREATE_REQUEST,
+});
+
+export const createFilterStatusSuccess = filter_status => ({
+  type: FILTERS_STATUS_CREATE_SUCCESS,
+  filter_status,
+});
+
+export const createFilterStatusFail = error => ({
+  type: FILTERS_STATUS_CREATE_FAIL,
+  error,
+});
+
+export const createFilter = (params, onSuccess, onFail) => (dispatch, getState) => {
+  dispatch(createFilterRequest());
+
+  api(getState).post('/api/v2/filters', params).then(response => {
+    dispatch(createFilterSuccess(response.data));
+    if (onSuccess) onSuccess(response.data);
+  }).catch(error => {
+    dispatch(createFilterFail(error));
+    if (onFail) onFail();
+  });
+};
+
+export const createFilterRequest = () => ({
+  type: FILTERS_CREATE_REQUEST,
+});
+
+export const createFilterSuccess = filter => ({
+  type: FILTERS_CREATE_SUCCESS,
+  filter,
+});
+
+export const createFilterFail = error => ({
+  type: FILTERS_CREATE_FAIL,
+  error,
+});
diff --git a/app/javascript/mastodon/actions/statuses.js b/app/javascript/mastodon/actions/statuses.js
index adc24eabf..32a4f1f85 100644
--- a/app/javascript/mastodon/actions/statuses.js
+++ b/app/javascript/mastodon/actions/statuses.js
@@ -42,9 +42,9 @@ export function fetchStatusRequest(id, skipLoading) {
   };
 };
 
-export function fetchStatus(id) {
+export function fetchStatus(id, forceFetch = false) {
   return (dispatch, getState) => {
-    const skipLoading = getState().getIn(['statuses', id], null) !== null;
+    const skipLoading = !forceFetch && getState().getIn(['statuses', id], null) !== null;
 
     dispatch(fetchContext(id));
 
diff --git a/app/javascript/mastodon/components/status.js b/app/javascript/mastodon/components/status.js
index dee935a6c..d36311c67 100644
--- a/app/javascript/mastodon/components/status.js
+++ b/app/javascript/mastodon/components/status.js
@@ -80,6 +80,7 @@ class Status extends ImmutablePureComponent {
     onOpenMedia: PropTypes.func,
     onOpenVideo: PropTypes.func,
     onBlock: PropTypes.func,
+    onAddFilter: PropTypes.func,
     onEmbed: PropTypes.func,
     onHeightChange: PropTypes.func,
     onToggleHidden: PropTypes.func,
diff --git a/app/javascript/mastodon/components/status_action_bar.js b/app/javascript/mastodon/components/status_action_bar.js
index d44da482d..4b384e6e5 100644
--- a/app/javascript/mastodon/components/status_action_bar.js
+++ b/app/javascript/mastodon/components/status_action_bar.js
@@ -44,6 +44,7 @@ const messages = defineMessages({
   unblockDomain: { id: 'account.unblock_domain', defaultMessage: 'Unblock domain {domain}' },
   unmute: { id: 'account.unmute', defaultMessage: 'Unmute @{name}' },
   unblock: { id: 'account.unblock', defaultMessage: 'Unblock @{name}' },
+  filter: { id: 'status.filter', defaultMessage: 'Filter this post' },
 });
 
 const mapStateToProps = (state, { status }) => ({
@@ -80,6 +81,7 @@ class StatusActionBar extends ImmutablePureComponent {
     onPin: PropTypes.func,
     onBookmark: PropTypes.func,
     onFilter: PropTypes.func,
+    onAddFilter: PropTypes.func,
     withDismiss: PropTypes.bool,
     withCounters: PropTypes.bool,
     scrollKey: PropTypes.string,
@@ -211,8 +213,8 @@ class StatusActionBar extends ImmutablePureComponent {
     this.props.onMuteConversation(this.props.status);
   }
 
-  handleFilter = () => {
-    this.props.onFilter();
+  handleFilterClick = () => {
+    this.props.onAddFilter(this.props.status);
   }
 
   handleCopy = () => {
@@ -235,7 +237,7 @@ class StatusActionBar extends ImmutablePureComponent {
   }
 
 
-  handleFilterClick = () => {
+  handleHideClick = () => {
     this.props.onFilter();
   }
 
@@ -294,6 +296,12 @@ class StatusActionBar extends ImmutablePureComponent {
         menu.push({ text: intl.formatMessage(messages.block, { name: account.get('username') }), action: this.handleBlockClick });
       }
 
+      if (!this.props.onFilter) {
+        menu.push(null);
+        menu.push({ text: intl.formatMessage(messages.filter), action: this.handleFilterClick });
+        menu.push(null);
+      }
+
       menu.push({ text: intl.formatMessage(messages.report, { name: account.get('username') }), action: this.handleReport });
 
       if (account.get('acct') !== account.get('username')) {
@@ -343,7 +351,7 @@ class StatusActionBar extends ImmutablePureComponent {
     );
 
     const filterButton = this.props.onFilter && (
-      <IconButton className='status__action-bar-button' title={intl.formatMessage(messages.hide)} icon='eye' onClick={this.handleFilterClick} />
+      <IconButton className='status__action-bar-button' title={intl.formatMessage(messages.hide)} icon='eye' onClick={this.handleHideClick} />
     );
 
     return (
diff --git a/app/javascript/mastodon/containers/status_container.js b/app/javascript/mastodon/containers/status_container.js
index ef0aca13a..28698b082 100644
--- a/app/javascript/mastodon/containers/status_container.js
+++ b/app/javascript/mastodon/containers/status_container.js
@@ -34,6 +34,9 @@ import {
   blockDomain,
   unblockDomain,
 } from '../actions/domain_blocks';
+import {
+  initAddFilter,
+} from '../actions/filters';
 import { initMuteModal } from '../actions/mutes';
 import { initBlockModal } from '../actions/blocks';
 import { initBoostModal } from '../actions/boosts';
@@ -66,7 +69,7 @@ const makeMapStateToProps = () => {
   return mapStateToProps;
 };
 
-const mapDispatchToProps = (dispatch, { intl }) => ({
+const mapDispatchToProps = (dispatch, { intl, contextType }) => ({
 
   onReply (status, router) {
     dispatch((_, getState) => {
@@ -176,6 +179,10 @@ const mapDispatchToProps = (dispatch, { intl }) => ({
     dispatch(initReport(status.get('account'), status));
   },
 
+  onAddFilter (status) {
+    dispatch(initAddFilter(status, { contextType }));
+  },
+
   onMute (account) {
     dispatch(initMuteModal(account));
   },
diff --git a/app/javascript/mastodon/features/compose/components/language_dropdown.js b/app/javascript/mastodon/features/compose/components/language_dropdown.js
index d76490c77..0af3db7a4 100644
--- a/app/javascript/mastodon/features/compose/components/language_dropdown.js
+++ b/app/javascript/mastodon/features/compose/components/language_dropdown.js
@@ -8,6 +8,7 @@ import spring from 'react-motion/lib/spring';
 import { supportsPassiveEvents } from 'detect-passive-events';
 import classNames from 'classnames';
 import { languages as preloadedLanguages } from 'mastodon/initial_state';
+import { loupeIcon, deleteIcon } from 'mastodon/utils/icons';
 import fuzzysort from 'fuzzysort';
 
 const messages = defineMessages({
@@ -16,22 +17,6 @@ const messages = defineMessages({
   clear: { id: 'emoji_button.clear', defaultMessage: 'Clear' },
 });
 
-// Copied from emoji-mart for consistency with emoji picker and since
-// they don't export the icons in the package
-const icons = {
-  loupe: (
-    <svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' width='13' height='13'>
-      <path d='M12.9 14.32a8 8 0 1 1 1.41-1.41l5.35 5.33-1.42 1.42-5.33-5.34zM8 14A6 6 0 1 0 8 2a6 6 0 0 0 0 12z' />
-    </svg>
-  ),
-
-  delete: (
-    <svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' width='13' height='13'>
-      <path d='M10 8.586L2.929 1.515 1.515 2.929 8.586 10l-7.071 7.071 1.414 1.414L10 11.414l7.071 7.071 1.414-1.414L11.414 10l7.071-7.071-1.414-1.414L10 8.586z' />
-    </svg>
-  ),
-};
-
 const listenerOptions = supportsPassiveEvents ? { passive: true } : false;
 
 class LanguageDropdownMenu extends React.PureComponent {
@@ -242,7 +227,7 @@ class LanguageDropdownMenu extends React.PureComponent {
           <div className={`language-dropdown__dropdown ${placement}`} style={{ ...style, opacity: opacity, transform: mounted ? `scale(${scaleX}, ${scaleY})` : null }} ref={this.setRef}>
             <div className='emoji-mart-search'>
               <input type='search' value={searchValue} onChange={this.handleSearchChange} onKeyDown={this.handleSearchKeyDown} placeholder={intl.formatMessage(messages.search)} autoFocus />
-              <button className='emoji-mart-search-icon' disabled={!isSearching} aria-label={intl.formatMessage(messages.clear)} onClick={this.handleClear}>{!isSearching ? icons.loupe : icons.delete}</button>
+              <button className='emoji-mart-search-icon' disabled={!isSearching} aria-label={intl.formatMessage(messages.clear)} onClick={this.handleClear}>{!isSearching ? loupeIcon : deleteIcon}</button>
             </div>
 
             <div className='language-dropdown__dropdown__results emoji-mart-scroll' role='listbox' ref={this.setListRef}>
diff --git a/app/javascript/mastodon/features/filters/added_to_filter.js b/app/javascript/mastodon/features/filters/added_to_filter.js
new file mode 100644
index 000000000..3785eb3c5
--- /dev/null
+++ b/app/javascript/mastodon/features/filters/added_to_filter.js
@@ -0,0 +1,102 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import ImmutablePropTypes from 'react-immutable-proptypes';
+import { FormattedMessage } from 'react-intl';
+import { toServerSideType } from 'mastodon/utils/filters';
+import Button from 'mastodon/components/button';
+import { connect } from 'react-redux';
+
+const mapStateToProps = (state, { filterId }) => ({
+  filter: state.getIn(['filters', filterId]),
+});
+
+export default @connect(mapStateToProps)
+class AddedToFilter extends React.PureComponent {
+
+  static propTypes = {
+    onClose: PropTypes.func.isRequired,
+    contextType: PropTypes.string,
+    filter: ImmutablePropTypes.map.isRequired,
+    dispatch: PropTypes.func.isRequired,
+  };
+
+  handleCloseClick = () => {
+    const { onClose } = this.props;
+    onClose();
+  };
+
+  render () {
+    const { filter, contextType } = this.props;
+
+    let expiredMessage = null;
+    if (filter.get('expires_at') && filter.get('expires_at') < new Date()) {
+      expiredMessage = (
+        <React.Fragment>
+          <h4 className='report-dialog-modal__subtitle'><FormattedMessage id='filter_modal.added.expired_title' defaultMessage='Expired filter!' /></h4>
+          <p className='report-dialog-modal__lead'>
+            <FormattedMessage
+              id='filter_modal.added.expired_explanation'
+              defaultMessage='This filter category has expired, you will need to change the expiration date for it to apply.'
+            />
+          </p>
+        </React.Fragment>
+      );
+    }
+
+    let contextMismatchMessage = null;
+    if (contextType && !filter.get('context').includes(toServerSideType(contextType))) {
+      contextMismatchMessage = (
+        <React.Fragment>
+          <h4 className='report-dialog-modal__subtitle'><FormattedMessage id='filter_modal.added.context_mismatch_title' defaultMessage='Context mismatch!' /></h4>
+          <p className='report-dialog-modal__lead'>
+            <FormattedMessage
+              id='filter_modal.added.context_mismatch_explanation'
+              defaultMessage='This filter category does not apply to the context in which you have accessed this post. If you want the post to be filtered in this context too, you will have to edit the filter.'
+            />
+          </p>
+        </React.Fragment>
+      );
+    }
+
+    const settings_link = (
+      <a href={`/filters/${filter.get('id')}/edit`}>
+        <FormattedMessage
+          id='filter_modal.added.settings_link'
+          defaultMessage='settings page'
+        />
+      </a>
+    );
+
+    return (
+      <React.Fragment>
+        <h3 className='report-dialog-modal__title'><FormattedMessage id='filter_modal.added.title' defaultMessage='Filter added!' /></h3>
+        <p className='report-dialog-modal__lead'>
+          <FormattedMessage
+            id='filter_modal.added.short_explanation'
+            defaultMessage='This post has been added to the following filter category: {title}.'
+            values={{ title: filter.get('title') }}
+          />
+        </p>
+
+        {expiredMessage}
+        {contextMismatchMessage}
+
+        <h4 className='report-dialog-modal__subtitle'><FormattedMessage id='filter_modal.added.review_and_configure_title' defaultMessage='Filter settings' /></h4>
+        <p className='report-dialog-modal__lead'>
+          <FormattedMessage
+            id='filter_modal.added.review_and_configure'
+            defaultMessage='To review and further configure this filter category, go to the {settings_link}.'
+            values={{ settings_link }}
+          />
+        </p>
+
+        <div className='flex-spacer' />
+
+        <div className='report-dialog-modal__actions'>
+          <Button onClick={this.handleCloseClick}><FormattedMessage id='report.close' defaultMessage='Done' /></Button>
+        </div>
+      </React.Fragment>
+    );
+  }
+
+}
diff --git a/app/javascript/mastodon/features/filters/select_filter.js b/app/javascript/mastodon/features/filters/select_filter.js
new file mode 100644
index 000000000..b5b354529
--- /dev/null
+++ b/app/javascript/mastodon/features/filters/select_filter.js
@@ -0,0 +1,192 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import { connect } from 'react-redux';
+import { defineMessages, injectIntl, FormattedMessage } from 'react-intl';
+import { toServerSideType } from 'mastodon/utils/filters';
+import { loupeIcon, deleteIcon } from 'mastodon/utils/icons';
+import Icon from 'mastodon/components/icon';
+import fuzzysort from 'fuzzysort';
+
+const messages = defineMessages({
+  search: { id: 'filter_modal.select_filter.search', defaultMessage: 'Search or create' },
+  clear: { id: 'emoji_button.clear', defaultMessage: 'Clear' },
+});
+
+const mapStateToProps = (state, { contextType }) => ({
+  filters: Array.from(state.get('filters').values()).map((filter) => [
+    filter.get('id'),
+    filter.get('title'),
+    filter.get('keywords')?.map((keyword) => keyword.get('keyword')).join('\n'),
+    filter.get('expires_at') && filter.get('expires_at') < new Date(),
+    contextType && !filter.get('context').includes(toServerSideType(contextType)),
+  ]),
+});
+
+export default @connect(mapStateToProps)
+@injectIntl
+class SelectFilter extends React.PureComponent {
+
+  static propTypes = {
+    onSelectFilter: PropTypes.func.isRequired,
+    onNewFilter: PropTypes.func.isRequired,
+    filters: PropTypes.arrayOf(PropTypes.arrayOf(PropTypes.object)),
+    intl: PropTypes.object.isRequired,
+  };
+
+  state = {
+    searchValue: '',
+  };
+
+  search () {
+    const { filters } = this.props;
+    const { searchValue } = this.state;
+
+    if (searchValue === '') {
+      return filters;
+    }
+
+    return fuzzysort.go(searchValue, filters, {
+      keys: ['1', '2'],
+      limit: 5,
+      threshold: -10000,
+    }).map(result => result.obj);
+  }
+
+  renderItem = filter => {
+    let warning = null;
+    if (filter[3] || filter[4]) {
+      warning = (
+        <span className='language-dropdown__dropdown__results__item__common-name'>
+          (
+          {filter[3] && <FormattedMessage id='filter_modal.select_filter.expired' defaultMessage='expired' />}
+          {filter[3] && filter[4] && ', '}
+          {filter[4] && <FormattedMessage id='filter_modal.select_filter.context_mismatch' defaultMessage='does not apply to this context' />}
+          )
+        </span>
+      );
+    }
+
+    return (
+      <div key={filter[0]} role='button' tabIndex='0' data-index={filter[0]} className='language-dropdown__dropdown__results__item' onClick={this.handleItemClick} onKeyDown={this.handleKeyDown}>
+        <span className='language-dropdown__dropdown__results__item__native-name'>{filter[1]}</span> {warning}
+      </div>
+    );
+  }
+
+  renderCreateNew (name) {
+    return (
+      <div key='add-new-filter' role='button' tabIndex='0' className='language-dropdown__dropdown__results__item' onClick={this.handleNewFilterClick} onKeyDown={this.handleKeyDown}>
+        <Icon id='plus' fixedWidth /> <FormattedMessage id='filter_modal.select_filter.prompt_new' defaultMessage='New category: {name}' values={{ name }} />
+      </div>
+    );
+  }
+
+  handleSearchChange = ({ target }) => {
+    this.setState({ searchValue: target.value });
+  }
+
+  setListRef = c => {
+    this.listNode = c;
+  }
+
+  handleKeyDown = e => {
+    const index = Array.from(this.listNode.childNodes).findIndex(node => node === e.currentTarget);
+
+    let element = null;
+
+    switch(e.key) {
+    case ' ':
+    case 'Enter':
+      e.currentTarget.click();
+      break;
+    case 'ArrowDown':
+      element = this.listNode.childNodes[index + 1] || this.listNode.firstChild;
+      break;
+    case 'ArrowUp':
+      element = this.listNode.childNodes[index - 1] || this.listNode.lastChild;
+      break;
+    case 'Tab':
+      if (e.shiftKey) {
+        element = this.listNode.childNodes[index - 1] || this.listNode.lastChild;
+      } else {
+        element = this.listNode.childNodes[index + 1] || this.listNode.firstChild;
+      }
+      break;
+    case 'Home':
+      element = this.listNode.firstChild;
+      break;
+    case 'End':
+      element = this.listNode.lastChild;
+      break;
+    }
+
+    if (element) {
+      element.focus();
+      e.preventDefault();
+      e.stopPropagation();
+    }
+  }
+
+  handleSearchKeyDown = e => {
+    let element = null;
+
+    switch(e.key) {
+    case 'Tab':
+    case 'ArrowDown':
+      element = this.listNode.firstChild;
+
+      if (element) {
+        element.focus();
+        e.preventDefault();
+        e.stopPropagation();
+      }
+
+      break;
+    }
+  }
+
+  handleClear = () => {
+    this.setState({ searchValue: '' });
+  }
+
+  handleItemClick = e => {
+    const value = e.currentTarget.getAttribute('data-index');
+
+    e.preventDefault();
+
+    this.props.onSelectFilter(value);
+  }
+
+  handleNewFilterClick = e => {
+    e.preventDefault();
+
+    this.props.onNewFilter(this.state.searchValue);
+  };
+
+  render () {
+    const { intl } = this.props;
+
+    const { searchValue } = this.state;
+    const isSearching = searchValue !== '';
+    const results = this.search();
+
+    return (
+      <React.Fragment>
+        <h3 className='report-dialog-modal__title'><FormattedMessage id='filter_modal.select_filter.title' defaultMessage='Filter this post' /></h3>
+        <p className='report-dialog-modal__lead'><FormattedMessage id='filter_modal.select_filter.subtitle' defaultMessage='Use an existing category or create a new one' /></p>
+
+        <div className='emoji-mart-search'>
+          <input type='search' value={searchValue} onChange={this.handleSearchChange} onKeyDown={this.handleSearchKeyDown} placeholder={intl.formatMessage(messages.search)} autoFocus />
+          <button className='emoji-mart-search-icon' disabled={!isSearching} aria-label={intl.formatMessage(messages.clear)} onClick={this.handleClear}>{!isSearching ? loupeIcon : deleteIcon}</button>
+        </div>
+
+        <div className='language-dropdown__dropdown__results emoji-mart-scroll' role='listbox' ref={this.setListRef}>
+          {results.map(this.renderItem)}
+          {isSearching && this.renderCreateNew(searchValue) }
+        </div>
+
+      </React.Fragment>
+    );
+  }
+
+}
diff --git a/app/javascript/mastodon/features/ui/components/filter_modal.js b/app/javascript/mastodon/features/ui/components/filter_modal.js
new file mode 100644
index 000000000..376db961d
--- /dev/null
+++ b/app/javascript/mastodon/features/ui/components/filter_modal.js
@@ -0,0 +1,134 @@
+import React from 'react';
+import { connect } from 'react-redux';
+import { fetchStatus } from 'mastodon/actions/statuses';
+import { fetchFilters, createFilter, createFilterStatus } from 'mastodon/actions/filters';
+import PropTypes from 'prop-types';
+import { defineMessages, FormattedMessage, injectIntl } from 'react-intl';
+import ImmutablePureComponent from 'react-immutable-pure-component';
+import IconButton from 'mastodon/components/icon_button';
+import SelectFilter from 'mastodon/features/filters/select_filter';
+import AddedToFilter from 'mastodon/features/filters/added_to_filter';
+
+const messages = defineMessages({
+  close: { id: 'lightbox.close', defaultMessage: 'Close' },
+});
+
+export default @connect(undefined)
+@injectIntl
+class FilterModal extends ImmutablePureComponent {
+
+  static propTypes = {
+    statusId: PropTypes.string.isRequired,
+    contextType: PropTypes.string,
+    dispatch: PropTypes.func.isRequired,
+    intl: PropTypes.object.isRequired,
+  };
+
+  state = {
+    step: 'select',
+    filterId: null,
+    isSubmitting: false,
+    isSubmitted: false,
+  };
+
+  handleNewFilterSuccess = (result) => {
+    this.handleSelectFilter(result.id);
+  };
+
+  handleSuccess = () => {
+    const { dispatch, statusId } = this.props;
+    dispatch(fetchStatus(statusId, true));
+    this.setState({ isSubmitting: false, isSubmitted: true, step: 'submitted' });
+  };
+
+  handleFail = () => {
+    this.setState({ isSubmitting: false });
+  };
+
+  handleNextStep = step => {
+    this.setState({ step });
+  };
+
+  handleSelectFilter = (filterId) => {
+    const { dispatch, statusId } = this.props;
+
+    this.setState({ isSubmitting: true, filterId });
+
+    dispatch(createFilterStatus({
+      filter_id: filterId,
+      status_id: statusId,
+    }, this.handleSuccess, this.handleFail));
+  };
+
+  handleNewFilter = (title) => {
+    const { dispatch } = this.props;
+
+    this.setState({ isSubmitting: true });
+
+    dispatch(createFilter({
+      title,
+      context: ['home', 'notifications', 'public', 'thread', 'account'],
+      action: 'warn',
+    }, this.handleNewFilterSuccess, this.handleFail));
+  };
+
+  componentDidMount () {
+    const { dispatch } = this.props;
+
+    dispatch(fetchFilters());
+  }
+
+  render () {
+    const {
+      intl,
+      statusId,
+      contextType,
+      onClose,
+    } = this.props;
+
+    const {
+      step,
+      filterId,
+    } = this.state;
+
+    let stepComponent;
+
+    switch(step) {
+    case 'select':
+      stepComponent = (
+        <SelectFilter
+          contextType={contextType}
+          onSelectFilter={this.handleSelectFilter}
+          onNewFilter={this.handleNewFilter}
+        />
+      );
+      break;
+    case 'create':
+      stepComponent = null;
+      break;
+    case 'submitted':
+      stepComponent = (
+        <AddedToFilter
+          contextType={contextType}
+          filterId={filterId}
+          statusId={statusId}
+          onClose={onClose}
+        />
+      );
+    }
+
+    return (
+      <div className='modal-root__modal report-dialog-modal'>
+        <div className='report-modal__target'>
+          <IconButton className='report-modal__close' title={intl.formatMessage(messages.close)} icon='times' onClick={onClose} size={20} />
+          <FormattedMessage id='filter_modal.title.status' defaultMessage='Filter a post' />
+        </div>
+
+        <div className='report-dialog-modal__container'>
+          {stepComponent}
+        </div>
+      </div>
+    );
+  }
+
+}
diff --git a/app/javascript/mastodon/features/ui/components/modal_root.js b/app/javascript/mastodon/features/ui/components/modal_root.js
index 3fc235849..b2c30e079 100644
--- a/app/javascript/mastodon/features/ui/components/modal_root.js
+++ b/app/javascript/mastodon/features/ui/components/modal_root.js
@@ -20,6 +20,7 @@ import {
   ListEditor,
   ListAdder,
   CompareHistoryModal,
+  FilterModal,
 } from 'mastodon/features/ui/util/async-components';
 
 const MODAL_COMPONENTS = {
@@ -37,6 +38,7 @@ const MODAL_COMPONENTS = {
   'FOCAL_POINT': () => Promise.resolve({ default: FocalPointModal }),
   'LIST_ADDER': ListAdder,
   'COMPARE_HISTORY': CompareHistoryModal,
+  'FILTER': FilterModal,
 };
 
 export default class ModalRoot extends React.PureComponent {
diff --git a/app/javascript/mastodon/features/ui/util/async-components.js b/app/javascript/mastodon/features/ui/util/async-components.js
index 92c683e2f..29b06206a 100644
--- a/app/javascript/mastodon/features/ui/util/async-components.js
+++ b/app/javascript/mastodon/features/ui/util/async-components.js
@@ -161,3 +161,7 @@ export function CompareHistoryModal () {
 export function Explore () {
   return import(/* webpackChunkName: "features/explore" */'../../explore');
 }
+
+export function FilterModal () {
+  return import(/*webpackChunkName: "modals/filter_modal" */'../components/filter_modal');
+}
diff --git a/app/javascript/mastodon/reducers/filters.js b/app/javascript/mastodon/reducers/filters.js
index 14b704027..cc1d3349c 100644
--- a/app/javascript/mastodon/reducers/filters.js
+++ b/app/javascript/mastodon/reducers/filters.js
@@ -1,4 +1,5 @@
 import { FILTERS_IMPORT } from '../actions/importer';
+import { FILTERS_FETCH_SUCCESS, FILTERS_CREATE_SUCCESS } from '../actions/filters';
 import { Map as ImmutableMap, is, fromJS } from 'immutable';
 
 const normalizeFilter = (state, filter) => {
@@ -7,13 +8,17 @@ const normalizeFilter = (state, filter) => {
     title: filter.title,
     context: filter.context,
     filter_action: filter.filter_action,
+    keywords: filter.keywords,
     expires_at: filter.expires_at ? Date.parse(filter.expires_at) : null,
   });
 
   if (is(state.get(filter.id), normalizedFilter)) {
     return state;
   } else {
-    return state.set(filter.id, normalizedFilter);
+    // Do not overwrite keywords when receiving a partial filter
+    return state.update(filter.id, ImmutableMap(), (old) => (
+      old.mergeWith(((old_value, new_value) => (new_value === undefined ? old_value : new_value)), normalizedFilter)
+    ));
   }
 };
 
@@ -27,6 +32,10 @@ const normalizeFilters = (state, filters) => {
 
 export default function filters(state = ImmutableMap(), action) {
   switch(action.type) {
+  case FILTERS_CREATE_SUCCESS:
+    return normalizeFilter(state, action.filter);
+  case FILTERS_FETCH_SUCCESS:
+    //TODO: handle deleting obsolete filters
   case FILTERS_IMPORT:
     return normalizeFilters(state, action.filters);
   default:
diff --git a/app/javascript/mastodon/selectors/index.js b/app/javascript/mastodon/selectors/index.js
index 187e3306d..3dd7f4897 100644
--- a/app/javascript/mastodon/selectors/index.js
+++ b/app/javascript/mastodon/selectors/index.js
@@ -1,5 +1,6 @@
 import { createSelector } from 'reselect';
 import { List as ImmutableList, Map as ImmutableMap } from 'immutable';
+import { toServerSideType } from 'mastodon/utils/filters';
 import { me } from '../initial_state';
 
 const getAccountBase         = (state, id) => state.getIn(['accounts', id], null);
@@ -20,23 +21,6 @@ export const makeGetAccount = () => {
   });
 };
 
-const toServerSideType = columnType => {
-  switch (columnType) {
-  case 'home':
-  case 'notifications':
-  case 'public':
-  case 'thread':
-  case 'account':
-    return columnType;
-  default:
-    if (columnType.indexOf('list:') > -1) {
-      return 'home';
-    } else {
-      return 'public'; // community, account, hashtag
-    }
-  }
-};
-
 const getFilters = (state, { contextType }) => {
   if (!contextType) return null;
 
@@ -73,6 +57,7 @@ export const makeGetStatus = () => {
         if (filterResults.some((result) => filters.getIn([result.get('filter'), 'filter_action']) === 'hide')) {
           return null;
         }
+        filterResults = filterResults.filter(result => filters.has(result.get('filter')));
         if (!filterResults.isEmpty()) {
           filtered = filterResults.map(result => filters.getIn([result.get('filter'), 'title']));
         }
diff --git a/app/javascript/mastodon/utils/filters.js b/app/javascript/mastodon/utils/filters.js
new file mode 100644
index 000000000..97b433a99
--- /dev/null
+++ b/app/javascript/mastodon/utils/filters.js
@@ -0,0 +1,16 @@
+export const toServerSideType = columnType => {
+  switch (columnType) {
+  case 'home':
+  case 'notifications':
+  case 'public':
+  case 'thread':
+  case 'account':
+    return columnType;
+  default:
+    if (columnType.indexOf('list:') > -1) {
+      return 'home';
+    } else {
+      return 'public'; // community, account, hashtag
+    }
+  }
+};
diff --git a/app/javascript/mastodon/utils/icons.js b/app/javascript/mastodon/utils/icons.js
new file mode 100644
index 000000000..be566032e
--- /dev/null
+++ b/app/javascript/mastodon/utils/icons.js
@@ -0,0 +1,13 @@
+// Copied from emoji-mart for consistency with emoji picker and since
+// they don't export the icons in the package
+export const loupeIcon = (
+  <svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' width='13' height='13'>
+    <path d='M12.9 14.32a8 8 0 1 1 1.41-1.41l5.35 5.33-1.42 1.42-5.33-5.34zM8 14A6 6 0 1 0 8 2a6 6 0 0 0 0 12z' />
+  </svg>
+);
+
+export const deleteIcon = (
+  <svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' width='13' height='13'>
+    <path d='M10 8.586L2.929 1.515 1.515 2.929 8.586 10l-7.071 7.071 1.414 1.414L10 11.414l7.071 7.071 1.414-1.414L11.414 10l7.071-7.071-1.414-1.414L10 8.586z' />
+  </svg>
+);
diff --git a/app/javascript/styles/mastodon/components.scss b/app/javascript/styles/mastodon/components.scss
index a0a39812b..f5377a858 100644
--- a/app/javascript/styles/mastodon/components.scss
+++ b/app/javascript/styles/mastodon/components.scss
@@ -5233,6 +5233,16 @@ a.status-card.compact:hover {
     line-height: 22px;
     color: lighten($inverted-text-color, 16%);
     margin-bottom: 30px;
+
+    a {
+      text-decoration: none;
+      color: $inverted-text-color;
+      font-weight: 500;
+
+      &:hover {
+        text-decoration: underline;
+      }
+    }
   }
 
   &__actions {
@@ -5379,6 +5389,14 @@ a.status-card.compact:hover {
     background: transparent;
     margin: 15px 0;
   }
+
+  .emoji-mart-search {
+    padding-right: 10px;
+  }
+
+  .emoji-mart-search-icon {
+    right: 10px + 5px;
+  }
 }
 
 .report-modal__container {