Track frequently used emojis in web UI (#5275)

* Track frequently used emojis in web UI

* Persist emoji usage, but debounce commits to the settings API

* Fix #5144 - Add tooltips to picker

* Display only 2 lines of frequently used emojis

app/javascript/mastodon/actions/compose.js

@@ -1,6 +1,7 @@
 import api from '../api';
 import { throttle } from 'lodash';
 import { search as emojiSearch } from '../features/emoji/emoji_mart_search_light';
+import { useEmoji } from './emojis';
 
 import {
   updateTimeline,
@@ -305,6 +306,8 @@ export function selectComposeSuggestion(position, token, suggestion) {
     if (typeof suggestion === 'object' && suggestion.id) {
       completion    = suggestion.native || suggestion.colons;
       startPosition = position - 1;
+
+      dispatch(useEmoji(suggestion));
     } else {
       completion    = getState().getIn(['accounts', suggestion, 'acct']);
       startPosition = position;

app/javascript/mastodon/actions/emojis.js

@@ -0,0 +1,14 @@
+import { saveSettings } from './settings';
+
+export const EMOJI_USE = 'EMOJI_USE';
+
+export function useEmoji(emoji) {
+  return dispatch => {
+    dispatch({
+      type: EMOJI_USE,
+      emoji,
+    });
+
+    dispatch(saveSettings());
+  };
+};

app/javascript/mastodon/actions/settings.js

@@ -1,6 +1,8 @@
 import axios from 'axios';
+import { debounce } from 'lodash';
 
 export const SETTING_CHANGE = 'SETTING_CHANGE';
+export const SETTING_SAVE   = 'SETTING_SAVE';
 
 export function changeSetting(key, value) {
   return dispatch => {
@@ -14,10 +16,16 @@ export function changeSetting(key, value) {
   };
 };
 
+const debouncedSave = debounce((dispatch, getState) => {
+  if (getState().getIn(['settings', 'saved'])) {
+    return;
+  }
+
+  const data = getState().get('settings').filter((_, key) => key !== 'saved').toJS();
+
+  axios.put('/api/web/settings', { data }).then(() => dispatch({ type: SETTING_SAVE }));
+}, 5000, { trailing: true });
+
 export function saveSettings() {
-  return (_, getState) => {
-    axios.put('/api/web/settings', {
-      data: getState().get('settings').toJS(),
-    });
-  };
+  return (dispatch, getState) => debouncedSave(dispatch, getState);
 };