From 5b831fcc83135096df8085b707ca5b7fe3b668ba Mon Sep 17 00:00:00 2001
From: Christian Pauly <christian-pauly@posteo.de>
Date: Wed, 29 Jun 2022 14:41:50 +0200
Subject: [PATCH] refactor: Handle Ephemerals method

This makes sure that the handle
ephemerals method becomes fully
type and null safe, does not handle
maps directly anymore and stores
the corresponding fake m.read
room account data only once
per sync.
---
 lib/src/client.dart | 73 ++++++++++++++++++++++++++++-----------------
 1 file changed, 46 insertions(+), 27 deletions(-)

diff --git a/lib/src/client.dart b/lib/src/client.dart
index def88969..d8def7c9 100644
--- a/lib/src/client.dart
+++ b/lib/src/client.dart
@@ -1748,44 +1748,63 @@ class Client extends MatrixApi {
   }
 
   Future<void> _handleEphemerals(Room room, List<BasicRoomEvent> events) async {
+    var updateReceipts = false;
+    final receiptStateContent =
+        room.roomAccountData['m.receipt']?.content ?? {};
     for (final event in events) {
       await _handleRoomEvents(room, [event], EventUpdateType.ephemeral);
 
       // Receipt events are deltas between two states. We will create a
       // fake room account data event for this and store the difference
       // there.
-      if (event.type == 'm.receipt') {
-        final receiptStateContent =
-            room.roomAccountData['m.receipt']?.content ?? {};
-        for (final eventEntry in event.content.entries) {
-          final eventID = eventEntry.key;
-          if (event.content[eventID]['m.read'] != null) {
-            final Map<String, dynamic> userTimestampMap =
-                event.content[eventID]['m.read'];
-            for (final userTimestampMapEntry in userTimestampMap.entries) {
-              final mxid = userTimestampMapEntry.key;
+      if (event.type != 'm.receipt') continue;
+      updateReceipts = true;
+      for (final entry in event.content.entries) {
+        final eventId = entry.key;
+        final value = entry.value;
 
-              // Remove previous receipt event from this user
-              if (receiptStateContent[eventID] is Map<String, dynamic> &&
-                  receiptStateContent[eventID]['m.read']
-                      is Map<String, dynamic> &&
-                  receiptStateContent[eventID]['m.read'].containsKey(mxid)) {
-                receiptStateContent[eventID]['m.read'].remove(mxid);
-              }
-              if (userTimestampMap[mxid] is Map<String, dynamic> &&
-                  userTimestampMap[mxid].containsKey('ts')) {
-                receiptStateContent[mxid] = {
-                  'event_id': eventID,
-                  'ts': userTimestampMap[mxid]['ts'],
-                };
-              }
-            }
+        final userTimestampMap =
+            (value is Map ? Map<String, dynamic>.from(value) : null)
+                ?.tryGetMap<String, dynamic>('m.read');
+
+        if (userTimestampMap == null) continue;
+
+        for (final userTimestampMapEntry in userTimestampMap.entries) {
+          final mxid = userTimestampMapEntry.key;
+
+          // Remove previous receipt event from this user
+          if (receiptStateContent
+                  .tryGetMap<String, dynamic>(eventId)
+                  ?.tryGetMap<String, dynamic>('m.read')
+                  ?.containsKey(mxid) ??
+              false) {
+            receiptStateContent[eventId]['m.read'].remove(mxid);
+          }
+          if (userTimestampMap
+                  .tryGetMap<String, dynamic>(mxid)
+                  ?.containsKey('ts') ??
+              false) {
+            receiptStateContent[mxid] = {
+              'event_id': eventId,
+              'ts': userTimestampMap[mxid]['ts'],
+            };
           }
         }
-        event.content = receiptStateContent;
-        await _handleRoomEvents(room, [event], EventUpdateType.accountData);
       }
     }
+
+    if (updateReceipts) {
+      await _handleRoomEvents(
+          room,
+          [
+            BasicRoomEvent(
+              type: 'm.receipt',
+              roomId: room.id,
+              content: receiptStateContent,
+            )
+          ],
+          EventUpdateType.accountData);
+    }
   }
 
   Future<void> _handleRoomEvents(