Message reactions backend

constants.json

@@ -1,4 +1,6 @@
 {
+	"NEW_EVENT_ADD_REACTION": "add_reaction",
+	"NEW_EVENT_REMOVE_REACTION": "remove_reaction",
 	"NEW_EVENT_CLOSE": "close",
 	"NEW_EVENT_CLOSED": "closed",
 	"NEW_EVENT_INACTIVE": "inactive",
@@ -20,6 +22,5 @@
 	"NEW_EVENT_READ_MESSAGE": "read_message",
 	"NEW_EVENT_ONLINE_STATUS": "online_status",
 	"NEW_EVENT_REQUEST_PUBLIC_KEY": "requestPublicKey",
-
 	"FIFTEEN_MINUTES": 900000
 }

server/index.js

@@ -50,6 +50,7 @@ const CloseChatHandler = require('./sockets/close');
 const stopSearch = require('./sockets/stopSearch');
 const onlineStatus = require('./sockets/onlineStatus');
 const requestPublicKeyHandler = require('./sockets/requestPublicKey');
+const ReactionsHandler = require('./sockets/reactions');
 
 app.use(express.json());
 app.use(cors());
@@ -66,6 +67,7 @@ io.on('connection', (socket) => {
    * This event is emitted once the user clicks on the Start button or
    * navigates to the /founduser route
    */
+  ReactionsHandler(socket);
   JoinHandler(io, socket);
   SendMessageHandler(socket);
   EditMessageHandler(socket);

server/migrations/addReactionsField.js

@@ -0,0 +1,49 @@
+require('dotenv').config();
+const mongoose = require('mongoose');
+const Message = require('../models/MessageModel');
+
+async function migrateMessages() {
+  console.log('Starting migration: Adding reactions field to messages');
+
+  try {
+    // Connect to MongoDB
+    await mongoose.connect(process.env.MongoDB_URL, {
+      useNewUrlParser: true,
+      useUnifiedTopology: true,
+    });
+
+    console.log('Connected to MongoDB');
+
+    // Find all messages that don't have the reactions field
+    const messages = await Message.find({ reactions: { $exists: false } });
+    console.log(`Found ${messages.length} messages to update`);
+
+    // Update messages in batches to avoid memory issues
+    const batchSize = 100;
+    let updated = 0;
+
+    for (let i = 0; i < messages.length; i += batchSize) {
+      const batch = messages.slice(i, i + batchSize);
+      const operations = batch.map(message => ({
+        updateOne: {
+          filter: { _id: message._id },
+          update: { $set: { reactions: new Map() } }
+        }
+      }));
+
+      await Message.bulkWrite(operations);
+      updated += batch.length;
+      console.log(`Updated ${updated}/${messages.length} messages`);
+    }
+
+    console.log('Migration completed successfully');
+  } catch (error) {
+    console.error('Migration failed:', error);
+  } finally {
+    await mongoose.disconnect();
+    console.log('Disconnected from MongoDB');
+  }
+}
+
+// Run the migration
+migrateMessages();

server/models/MessageModel.js

@@ -37,6 +37,11 @@ const MessageSchema = new Schema(
       type: Schema.Types.ObjectId,
       ref: 'Message',
     },
+    reactions: {
+      type: Map,
+      of: [String], // Array of user IDs who reacted with this emoji
+      default: () => new Map()  // Using a function to return a new Map instance
+    }
   },
   {
     timestamps: true,
@@ -54,11 +59,11 @@ const MessageSchema = new Schema(
             oldMessages: this.oldMessages,
             isRead: this.isRead,
             replyTo: this.replyTo?.toString() || null,
+            reactions: this.reactions ? Object.fromEntries(this.reactions) : {}
           };
         },
       },
     },
   }
 );
-
 module.exports = model('Message', MessageSchema);

server/package.json

@@ -11,7 +11,8 @@
     "test": "echo \"Error: no test specified\" && exit 1",
     "lint": "eslint --ext .js,.ts --ignore-path .gitignore --fix ./",
     "format": "prettier --write .",
-    "prepare": "cd .. && husky install server/.husky"
+    "prepare": "cd .. && husky install server/.husky",
+    "migrate:reactions": "node migrations/addReactionsField.js"
   },
   "repository": {
     "type": "git",

server/sockets/reactions.js

@@ -0,0 +1,76 @@
+const { 
+    NEW_EVENT_ADD_REACTION, 
+    NEW_EVENT_REMOVE_REACTION 
+  } = require('../../constants.json');
+  const { getActiveUser, addReaction, removeReaction } = require('../utils/lib');
+
+  module.exports = (socket) => {
+    // Handle adding a reaction
+    socket.on(
+      NEW_EVENT_ADD_REACTION,
+      async ({ messageId, chatId, emoji }, reactionAddedSuccessfully) => {
+        try {
+          const user = getActiveUser({
+            socketId: socket.id,
+          });
+
+          if (!user || !messageId || !chatId || !emoji) {
+            reactionAddedSuccessfully(false);
+            return;
+          }
+
+          const reactionAdded = await addReaction(chatId, messageId, emoji, user.id);
+
+          if (reactionAdded) {
+            // Broadcast the reaction to all users in the chat
+            socket.broadcast.to(chatId).emit(NEW_EVENT_ADD_REACTION, {
+              messageId,
+              chatId,
+              emoji,
+              userId: user.id
+            });
+          }
+
+          reactionAddedSuccessfully(reactionAdded);
+        } catch (error) {
+          console.error('Error adding reaction:', error);
+          reactionAddedSuccessfully(false);
+        }
+      }
+    );
+
+    // Handle removing a reaction
+    socket.on(
+      NEW_EVENT_REMOVE_REACTION,
+      async ({ messageId, chatId, emoji }, reactionRemovedSuccessfully) => {
+        try {
+          const user = getActiveUser({
+            socketId: socket.id,
+          });
+
+          if (!user || !messageId || !chatId || !emoji) {
+            reactionRemovedSuccessfully(false);
+            return;
+          }
+
+          const reactionRemoved = await removeReaction(chatId, messageId, emoji, user.id);
+
+          if (reactionRemoved) {
+            // Broadcast the reaction removal to all users in the chat
+            socket.broadcast.to(chatId).emit(NEW_EVENT_REMOVE_REACTION, {
+              messageId,
+              chatId,
+              emoji,
+              userId: user.id
+            });
+          }
+
+          reactionRemovedSuccessfully(reactionRemoved);
+        } catch (error) {
+          console.error('Error removing reaction:', error);
+          reactionRemovedSuccessfully(false);
+        }
+      }
+    );
+  };
+

server/utils/lib.js

@@ -546,6 +546,81 @@ async function isUserBlocked(users) {
     return timeSinceCreated <= FIFTEEN_MINUTES; // Check if within 15 minutes
 }
 
+
+/**
+ * Add a reaction to a message
+ * @param {string} chatId - The chat ID
+ * @param {string} messageId - The message ID
+ * @param {string} emoji - The emoji to add
+ * @param {string} userId - The user ID who reacted
+ * @returns {Promise<boolean>} - Whether the reaction was added
+ */
+async function addReaction(chatId, messageId, emoji, userId) {
+  if (!chats[chatId] || !chats[chatId].messages[messageId]) {
+    return false;
+  }
+
+  // Get the message from the database
+  const messageDoc = await Message.findById(messageId);
+  if (!messageDoc) {return false;}
+
+  // Add the reaction using the instance method
+  const reactionAdded = await messageDoc.addReaction(emoji, userId);
+
+  if (reactionAdded) {
+    // Update in-memory cache
+    const message = chats[chatId].messages[messageId];
+    if (!message.reactions) {
+      message.reactions = {};
+    }
+
+    if (!message.reactions[emoji]) {
+      message.reactions[emoji] = [];
+    }
+
+    if (!message.reactions[emoji].includes(userId)) {
+      message.reactions[emoji].push(userId);
+    }
+  }
+
+  return reactionAdded;
+}
+
+/**
+ * Remove a reaction from a message
+ * @param {string} chatId - The chat ID
+ * @param {string} messageId - The message ID
+ * @param {string} emoji - The emoji to remove
+ * @param {string} userId - The user ID who reacted
+ * @returns {Promise<boolean>} - Whether the reaction was removed
+ */
+async function removeReaction(chatId, messageId, emoji, userId) {
+  if (!chats[chatId] || !chats[chatId].messages[messageId]) {
+    return false;
+  }
+
+  // Get the message from the database
+  const messageDoc = await Message.findById(messageId);
+  if (!messageDoc) {return false;}
+
+  // Remove the reaction using the instance method
+  const reactionRemoved = await messageDoc.removeReaction(emoji, userId);
+
+  if (reactionRemoved) {
+    // Update in-memory cache
+    const message = chats[chatId].messages[messageId];
+    if (message.reactions && message.reactions[emoji]) {
+      message.reactions[emoji] = message.reactions[emoji].filter(id => id !== userId);
+
+      if (message.reactions[emoji].length === 0) {
+        delete message.reactions[emoji];
+      }
+    }
+  }
+
+  return reactionRemoved;
+}
+
 module.exports = {
   init,
   createChat,
@@ -567,5 +642,8 @@ module.exports = {
   seenMessage,
   blockUser,
   isUserBlocked,
-  isMessageEditableOrDeletable
+  isMessageEditableOrDeletable,
+  removeReaction,
+  addReaction,
+  addReaction,
 };