From d7d73179eedf8110d51c9a8a163a341b930fdb63 Mon Sep 17 00:00:00 2001
From: Louis Laureys <louis@laureys.me>
Date: Sun, 12 Sep 2021 22:15:39 +0200
Subject: [PATCH] Make thread counters work correctly

---
 lib/api/messages.js | 53 +++++++++++++++++++++++++++------------------
 1 file changed, 32 insertions(+), 21 deletions(-)

diff --git a/lib/api/messages.js b/lib/api/messages.js
index 13e107a..2869e4a 100644
--- a/lib/api/messages.js
+++ b/lib/api/messages.js
@@ -61,6 +61,35 @@ module.exports = (db, server, messageHandler, userHandler, storageHandler, setti
         });
     });
 
+    const addThreadCountersToMessageList = async (user, list) => {
+        const threadIdsToCount = list.map(message => message.thread);
+        const threadCounts = await db.database
+            .collection('messages')
+            .aggregate([
+                {
+                    $match: {
+                        user: new ObjectId(user),
+                        thread: { $in: threadIdsToCount }
+                    }
+                },
+                {
+                    $group: {
+                        _id: '$thread',
+                        count: {
+                            $sum: 1
+                        }
+                    }
+                }
+            ])
+            .toArray();
+
+        return list.map(message => {
+            const matchingThreadCount = threadCounts.find(thread => thread._id.toString() === message.thread.toString());
+            message.threadMessageCount = matchingThreadCount ? matchingThreadCount.count : undefined
+            return message
+        });
+    };
+
     const putMessageHandler = async (req, res, next) => {
         res.charSet('utf-8');
 
@@ -413,16 +442,7 @@ module.exports = (db, server, messageHandler, userHandler, storageHandler, setti
             }
 
             if (threadCounters) {
-                const threadIdsToFetch = listing.results.map(message => message.thread);
-                const threads = await db.database
-                    .collection('threads')
-                    .find({ _id: { $in: threadIdsToFetch } })
-                    .toArray();
-
-                listing.results = listing.results.map(message => ({
-                    ...message,
-                    threadEntity: threads.find(thread => thread._id.toString() === message.thread.toString())
-                }));
+                listing.results = await addThreadCountersToMessageList(user, listing.results);
             }
 
             let response = {
@@ -837,16 +857,7 @@ module.exports = (db, server, messageHandler, userHandler, storageHandler, setti
             }
 
             if (threadCounters) {
-                const threadIdsToFetch = listing.results.map(message => message.thread);
-                const threads = await db.database
-                    .collection('threads')
-                    .find({ _id: { $in: threadIdsToFetch } })
-                    .toArray();
-
-                listing.results = listing.results.map(message => ({
-                    ...message,
-                    threadEntity: threads.find(thread => thread._id.toString() === message.thread.toString())
-                }));
+                listing.results = await addThreadCountersToMessageList(user, listing.results);
             }
 
             let response = {
@@ -3169,7 +3180,7 @@ function formatMessageListing(messageData) {
         id: messageData.uid,
         mailbox: messageData.mailbox,
         thread: messageData.thread,
-        threadMessageCount: messageData.threadEntity?.ids?.length,
+        threadMessageCount: messageData.threadMessageCount,
         from: from && from[0],
         to,
         cc,