PLT-1378 Initial version of emoji reactions (#4520)

* Refactored emoji.json to support multiple aliases and emoji categories

* Added custom category to emoji.jsx and stabilized all fields

* Removed conflicting aliases for :mattermost: and :ca:

* fixup after store changes

* Added emoji reactions

* Removed reactions for an emoji when that emoji is deleted

* Fixed incorrect test case

* Renamed ReactionList to ReactionListView

* Fixed :+1: and :-1: not showing up as possible reactions

* Removed text emoticons from emoji reaction autocomplete

* Changed emoji reactions to be sorted by the order that they were first created

* Set a maximum number of listeners for the ReactionStore

* Removed unused code from Textbox component

* Fixed reaction permissions

* Changed error code when trying to modify reactions for another user

* Fixed merge conflicts

* Properly applied theme colours to reactions

* Fixed ESLint and gofmt errors

* Fixed ReactionListContainer to properly update when its post prop changes

* Removed unnecessary escape characters from reaction regexes

* Shared reaction message pattern between CreatePost and CreateComment

* Removed an unnecessary select query when saving a reaction

* Changed reactions route to be under /reactions

* Fixed copyright dates on newly added files

* Removed debug code that prevented all unit tests from being ran

* Cleaned up unnecessary code for reactions

* Renamed ReactionStore.List to ReactionStore.GetForPost

3 files changed, 176 insertions, 38 deletions

diff --git a/webapp/stores/emoji_store.jsx b/webapp/stores/emoji_store.jsx
index fd72b4636..3d9bf7875 100644
--- a/webapp/stores/emoji_store.jsx
+++ b/webapp/stores/emoji_store.jsx
@@ -5,12 +5,64 @@ import AppDispatcher from '../dispatcher/app_dispatcher.jsx';
 import Constants from 'utils/constants.jsx';
 import EventEmitter from 'events';
 
-import EmojiJson from 'utils/emoji.json';
+import * as Emoji from 'utils/emoji.jsx';
 
 const ActionTypes = Constants.ActionTypes;
 
 const CHANGE_EVENT = 'changed';
 
+// Wrap the contents of the store so that we don't need to construct an ES6 map where most of the content
+// (the system emojis) will never change. It provides the get/has functions of a map and an iterator so
+// that it can be used in for..of loops
+class EmojiMap {
+    constructor(customEmojis) {
+        this.customEmojis = customEmojis;
+
+        // Store customEmojis to an array so we can iterate it more easily
+        this.customEmojisArray = [...customEmojis];
+    }
+
+    has(name) {
+        return Emoji.EmojiIndicesByAlias.has(name) || this.customEmojis.has(name);
+    }
+
+    get(name) {
+        if (Emoji.EmojiIndicesByAlias.has(name)) {
+            return Emoji.Emojis[Emoji.EmojiIndicesByAlias.get(name)];
+        }
+
+        return this.customEmojis.get(name);
+    }
+
+    [Symbol.iterator]() {
+        const customEmojisArray = this.customEmojisArray;
+
+        return {
+            systemIndex: 0,
+            customIndex: 0,
+            next() {
+                if (this.systemIndex < Emoji.Emojis.length) {
+                    const emoji = Emoji.Emojis[this.systemIndex];
+
+                    this.systemIndex += 1;
+
+                    return {value: [emoji.aliases[0], emoji]};
+                }
+
+                if (this.customIndex < customEmojisArray.length) {
+                    const emoji = customEmojisArray[this.customIndex][1];
+
+                    this.customIndex += 1;
+
+                    return {value: [emoji.name, emoji]};
+                }
+
+                return {done: true};
+            }
+        };
+    }
+}
+
 class EmojiStore extends EventEmitter {
     constructor() {
         super();
@@ -19,18 +71,10 @@ class EmojiStore extends EventEmitter {
 
         this.setMaxListeners(600);
 
-        this.emojis = new Map(EmojiJson);
-        this.systemEmojis = new Map(EmojiJson);
-
-        this.unicodeEmojis = new Map();
-        for (const [, emoji] of this.systemEmojis) {
-            if (emoji.unicode) {
-                this.unicodeEmojis.set(emoji.unicode, emoji);
-            }
-        }
-
         this.receivedCustomEmojis = false;
         this.customEmojis = new Map();
+
+        this.map = new EmojiMap(this.customEmojis);
     }
 
     addChangeListener(callback) {
@@ -50,20 +94,19 @@ class EmojiStore extends EventEmitter {
     }
 
     setCustomEmojis(customEmojis) {
+        customEmojis.sort((a, b) => a.name[0].localeCompare(b.name[0]));
+
         this.customEmojis = new Map();
 
         for (const emoji of customEmojis) {
             this.addCustomEmoji(emoji);
         }
 
-        this.sortCustomEmojis();
-        this.updateEmojiMap();
+        this.map = new EmojiMap(this.customEmojis);
     }
 
     addCustomEmoji(emoji) {
         this.customEmojis.set(emoji.name, emoji);
-
-        // this doesn't update this.emojis, but it's only called by setCustomEmojis which does that afterwards
     }
 
     removeCustomEmoji(id) {
@@ -73,21 +116,10 @@ class EmojiStore extends EventEmitter {
                 break;
             }
         }
-
-        this.updateEmojiMap();
-    }
-
-    sortCustomEmojis() {
-        this.customEmojis = new Map([...this.customEmojis.entries()].sort((a, b) => a[0].localeCompare(b[0])));
-    }
-
-    updateEmojiMap() {
-        // add custom emojis to the map first so that they can't override system ones
-        this.emojis = new Map([...this.customEmojis, ...this.systemEmojis]);
     }
 
-    getSystemEmojis() {
-        return this.systemEmojis;
+    hasSystemEmoji(name) {
+        return Emoji.EmojiIndicesByAlias.has(name);
     }
 
     getCustomEmojiMap() {
@@ -95,24 +127,23 @@ class EmojiStore extends EventEmitter {
     }
 
     getEmojis() {
-        return this.emojis;
+        return this.map;
     }
 
     has(name) {
-        return this.emojis.has(name);
+        return this.map.has(name);
     }
 
     get(name) {
-        // prioritize system emojis so that custom ones can't override them
-        return this.emojis.get(name);
+        return this.map.get(name);
     }
 
     hasUnicode(codepoint) {
-        return this.unicodeEmojis.has(codepoint);
+        return Emoji.EmojiIndicesByUnicode.has(codepoint);
     }
 
     getUnicode(codepoint) {
-        return this.unicodeEmojis.get(codepoint);
+        return Emoji.Emojis[Emoji.EmojiIndicesByUnicode.get(codepoint)];
     }
 
     getEmojiImageUrl(emoji) {
@@ -121,7 +152,7 @@ class EmojiStore extends EventEmitter {
             return `/api/v3/emoji/${emoji.id}`;
         }
 
-        const filename = emoji.unicode || emoji.filename || emoji.name;
+        const filename = emoji.filename || emoji.aliases[0];
 
         return Constants.EMOJI_PATH + '/' + filename + '.png';
     }
diff --git a/webapp/stores/post_store.jsx b/webapp/stores/post_store.jsx
index fbe5cd457..5e8155c40 100644
--- a/webapp/stores/post_store.jsx
+++ b/webapp/stores/post_store.jsx
@@ -118,7 +118,15 @@ class PostStoreClass extends EventEmitter {
 
     getEarliestPost(id) {
         if (this.postsInfo.hasOwnProperty(id)) {
-            return this.postsInfo[id].postList.posts[this.postsInfo[id].postList.order[this.postsInfo[id].postList.order.length - 1]];
+            const postList = this.postsInfo[id].postList;
+
+            for (let i = postList.order.length - 1; i >= 0; i--) {
+                const postId = postList.order[i];
+
+                if (postList.posts[postId].state !== Constants.POST_DELETED) {
+                    return postList.posts[postId];
+                }
+            }
         }
 
         return null;
@@ -126,7 +134,13 @@ class PostStoreClass extends EventEmitter {
 
     getLatestPost(id) {
         if (this.postsInfo.hasOwnProperty(id)) {
-            return this.postsInfo[id].postList.posts[this.postsInfo[id].postList.order[0]];
+            const postList = this.postsInfo[id].postList;
+
+            for (const postId of postList.order) {
+                if (postList.posts[postId].state !== Constants.POST_DELETED) {
+                    return postList.posts[postId];
+                }
+            }
         }
 
         return null;
@@ -318,7 +332,8 @@ class PostStoreClass extends EventEmitter {
             // make sure to copy the post so that component state changes work properly
             postList.posts[post.id] = Object.assign({}, post, {
                 state: Constants.POST_DELETED,
-                file_ids: []
+                file_ids: [],
+                has_reactions: false
             });
         }
     }
diff --git a/webapp/stores/reaction_store.jsx b/webapp/stores/reaction_store.jsx
new file mode 100644
index 000000000..166569e3d
--- /dev/null
+++ b/webapp/stores/reaction_store.jsx
@@ -0,0 +1,92 @@
+// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+import AppDispatcher from '../dispatcher/app_dispatcher.jsx';
+import Constants from 'utils/constants.jsx';
+import EventEmitter from 'events';
+
+const ActionTypes = Constants.ActionTypes;
+
+const CHANGE_EVENT = 'changed';
+
+class ReactionStore extends EventEmitter {
+    constructor() {
+        super();
+
+        this.dispatchToken = AppDispatcher.register(this.handleEventPayload.bind(this));
+
+        this.reactions = new Map();
+
+        this.setMaxListeners(600);
+    }
+
+    addChangeListener(postId, callback) {
+        this.on(CHANGE_EVENT + postId, callback);
+    }
+
+    removeChangeListener(postId, callback) {
+        this.removeListener(CHANGE_EVENT + postId, callback);
+    }
+
+    emitChange(postId) {
+        this.emit(CHANGE_EVENT + postId, postId);
+    }
+
+    setReactions(postId, reactions) {
+        this.reactions.set(postId, reactions);
+    }
+
+    addReaction(postId, reaction) {
+        const reactions = [];
+
+        for (const existing of this.getReactions(postId)) {
+            // make sure not to add duplicates
+            if (existing.user_id !== reaction.user_id || existing.post_id !== reaction.post_id ||
+                existing.emoji_name !== reaction.emoji_name) {
+                reactions.push(existing);
+            }
+        }
+
+        reactions.push(reaction);
+
+        this.setReactions(postId, reactions);
+    }
+
+    removeReaction(postId, reaction) {
+        const reactions = [];
+
+        for (const existing of this.getReactions(postId)) {
+            if (existing.user_id !== reaction.user_id || existing.post_id !== reaction.post_id ||
+                existing.emoji_name !== reaction.emoji_name) {
+                reactions.push(existing);
+            }
+        }
+
+        this.setReactions(postId, reactions);
+    }
+
+    getReactions(postId) {
+        return this.reactions.get(postId) || [];
+    }
+
+    handleEventPayload(payload) {
+        const action = payload.action;
+
+        switch (action.type) {
+        case ActionTypes.RECEIVED_REACTIONS:
+            this.setReactions(action.postId, action.reactions);
+            this.emitChange(action.postId);
+            break;
+        case ActionTypes.ADDED_REACTION:
+            this.addReaction(action.postId, action.reaction);
+            this.emitChange(action.postId);
+            break;
+        case ActionTypes.REMOVED_REACTION:
+            this.removeReaction(action.postId, action.reaction);
+            this.emitChange(action.postId);
+            break;
+        }
+    }
+}
+
+export default new ReactionStore();
\ No newline at end of file