Matrix: fetch previous messages when reaching the top

1 files changed, 85 insertions, 32 deletions

diff --git a/src/plugins/Matrix.cpp b/src/plugins/Matrix.cpp
index 2d4fd4a..529d42a 100644
--- a/src/plugins/Matrix.cpp
+++ b/src/plugins/Matrix.cpp
@@ -159,9 +159,37 @@ namespace QuickMedia {
         return PluginResult::OK;
     }
 
-    PluginResult Matrix::get_room_messages(const std::string &room_id, size_t start_index, BodyItems &result_items, size_t &num_new_messages) {
-        num_new_messages = 0;
+    static void room_messages_to_body_items(RoomData *room_data, Message *messages, size_t num_messages, BodyItems &result_items) {
+        // TODO: This prev_user_id should check previous message, otherwise if after a sync there is only 1 new message then it wont
+        // merge with the previous message. But for that to work then also have to send existing body items to this function,
+        // to get the body item to merge with
+        size_t prev_user_id = -1;
+        for(size_t i = 0; i < num_messages; ++i) {
+            const UserInfo &user_info = room_data->user_info[messages[i].user_id];
+            if(messages[i].user_id == prev_user_id && messages[i].url.empty()) {
+                assert(!result_items.empty());
+                result_items.back()->append_description("\n");
+                result_items.back()->append_description(messages[i].body);
+            } else {
+                auto body_item = std::make_unique<BodyItem>("");
+                body_item->set_author(user_info.display_name);
+                body_item->set_description(messages[i].body);
+                if(!messages[i].thumbnail_url.empty())
+                    body_item->thumbnail_url = messages[i].thumbnail_url;
+                else if(!messages[i].url.empty())
+                    body_item->thumbnail_url = messages[i].url;
+                else
+                    body_item->thumbnail_url = user_info.avatar_url;
+                // TODO: Show image thumbnail inline instead of url to image
+                body_item->url = messages[i].url;
+                result_items.push_back(std::move(body_item));
+                prev_user_id = messages[i].user_id;
+            }
+        }
+    }
 
+    // TODO: Merge common code with |get_new_room_messages|
+    PluginResult Matrix::get_all_synced_room_messages(const std::string &room_id, BodyItems &result_items) {
         auto room_it = room_data_by_id.find(room_id);
         if(room_it == room_data_by_id.end()) {
             fprintf(stderr, "Error: no such room: %s\n", room_id.c_str());
@@ -169,7 +197,7 @@ namespace QuickMedia {
         }
 
         if(!room_it->second->initial_fetch_finished) {
-            PluginResult result = load_initial_room_data(room_id, room_it->second.get());
+            PluginResult result = get_previous_room_messages(room_id, room_it->second.get());
             if(result == PluginResult::OK) {
                 room_it->second->initial_fetch_finished = true;
             } else {
@@ -178,36 +206,49 @@ namespace QuickMedia {
             }
         }
 
-        // This will happen if there are no new messages
-        if(start_index >= room_it->second->messages.size())
-            return PluginResult::OK;
+        room_messages_to_body_items(room_it->second.get(), room_it->second->messages.data(), room_it->second->messages.size(), result_items);
+        room_it->second->last_read_index = room_it->second->messages.size();
+        return PluginResult::OK;
+    }
 
-        num_new_messages = room_it->second->messages.size() - start_index;
+    PluginResult Matrix::get_new_room_messages(const std::string &room_id, BodyItems &result_items) {
+        auto room_it = room_data_by_id.find(room_id);
+        if(room_it == room_data_by_id.end()) {
+            fprintf(stderr, "Error: no such room: %s\n", room_id.c_str());
+            return PluginResult::ERR;
+        }
 
-        size_t prev_user_id = -1;
-        for(auto it = room_it->second->messages.begin() + start_index, end = room_it->second->messages.end(); it != end; ++it) {
-            const UserInfo &user_info = room_it->second->user_info[it->user_id];
-            if(it->user_id == prev_user_id && it->url.empty()) {
-                assert(!result_items.empty());
-                result_items.back()->append_description("\n");
-                result_items.back()->append_description(it->body);
+        if(!room_it->second->initial_fetch_finished) {
+            PluginResult result = get_previous_room_messages(room_id, room_it->second.get());
+            if(result == PluginResult::OK) {
+                room_it->second->initial_fetch_finished = true;
             } else {
-                auto body_item = std::make_unique<BodyItem>("");
-                body_item->set_author(user_info.display_name);
-                body_item->set_description(it->body);
-                if(!it->thumbnail_url.empty())
-                    body_item->thumbnail_url = it->thumbnail_url;
-                else if(!it->url.empty())
-                    body_item->thumbnail_url = it->url;
-                else
-                    body_item->thumbnail_url = user_info.avatar_url;
-                // TODO: Show image thumbnail inline instead of url to image
-                body_item->url = it->url;
-                result_items.push_back(std::move(body_item));
-                prev_user_id = it->user_id;
+                fprintf(stderr, "Initial sync failed for room: %s\n", room_id.c_str());
+                return result;
             }
         }
 
+        size_t num_new_messages = room_it->second->messages.size() - room_it->second->last_read_index;
+        room_messages_to_body_items(room_it->second.get(), room_it->second->messages.data() + room_it->second->last_read_index, num_new_messages, result_items);
+        room_it->second->last_read_index = room_it->second->messages.size();
+        return PluginResult::OK;
+    }
+
+    PluginResult Matrix::get_previous_room_messages(const std::string &room_id, BodyItems &result_items) {
+        auto room_it = room_data_by_id.find(room_id);
+        if(room_it == room_data_by_id.end()) {
+            fprintf(stderr, "Error: no such room: %s\n", room_id.c_str());
+            return PluginResult::ERR;
+        }
+        
+        size_t num_messages_before = room_it->second->messages.size();
+        PluginResult result = get_previous_room_messages(room_id, room_it->second.get());
+        if(result != PluginResult::OK)
+            return result;
+
+        size_t num_messages_after = room_it->second->messages.size();
+        size_t num_new_messages = num_messages_after - num_messages_before;
+        room_messages_to_body_items(room_it->second.get(), room_it->second->messages.data(), num_new_messages, result_items);
         return PluginResult::OK;
     }
 
@@ -270,10 +311,12 @@ namespace QuickMedia {
             if(!timeline_json.isObject())
                 continue;
 
-            // This may be non-existent if this is the first event in the room
-            const Json::Value &prev_batch_json = timeline_json["prev_batch"];
-            if(prev_batch_json.isString())
-                room_it->second->prev_batch = prev_batch_json.asString();
+            if(room_it->second->prev_batch.empty()) {
+                // This may be non-existent if this is the first event in the room
+                const Json::Value &prev_batch_json = timeline_json["prev_batch"];
+                if(prev_batch_json.isString())
+                    room_it->second->prev_batch = prev_batch_json.asString();
+            }
 
             const Json::Value &events_json = timeline_json["events"];
             events_add_user_info(events_json, room_it->second.get());
@@ -415,8 +458,11 @@ namespace QuickMedia {
             }
         }
 
+        // TODO: Loop and std::move instead? doesn't insert create copies?
         if(message_dir == MessageDirection::BEFORE) {
             room_data->messages.insert(room_data->messages.begin(), new_messages.rbegin(), new_messages.rend());
+            if(room_data->last_read_index != 0)
+                room_data->last_read_index += new_messages.size();
         } else if(message_dir == MessageDirection::AFTER) {
             room_data->messages.insert(room_data->messages.end(), new_messages.begin(), new_messages.end());
         }
@@ -500,7 +546,7 @@ namespace QuickMedia {
         }
     }
 
-    PluginResult Matrix::load_initial_room_data(const std::string &room_id, RoomData *room_data) {
+    PluginResult Matrix::get_previous_room_messages(const std::string &room_id, RoomData *room_data) {
         std::string from = room_data->prev_batch;
         if(from.empty()) {
             fprintf(stderr, "Info: missing previous batch for room: %s, using /sync next batch\n", room_id.c_str());
@@ -554,6 +600,13 @@ namespace QuickMedia {
         const Json::Value &chunk_json = json_root["chunk"];
         events_add_messages(chunk_json, room_data, MessageDirection::BEFORE);
 
+        const Json::Value &end_json = json_root["end"];
+        if(!end_json.isString()) {
+            fprintf(stderr, "Warning: matrix messages response is missing 'end', this could happen if we received the very first messages in the room\n");
+            return PluginResult::OK;
+        }
+
+        room_data->prev_batch = end_json.asString();
         return PluginResult::OK;
     }