Use single event model for all application events

20 files changed, 303 insertions, 354 deletions

diff --git a/src/main/java/com/juick/server/ActivityPubManager.java b/src/main/java/com/juick/server/ActivityPubManager.java
index c40bbb5c..2fa663eb 100644
--- a/src/main/java/com/juick/server/ActivityPubManager.java
+++ b/src/main/java/com/juick/server/ActivityPubManager.java
@@ -4,6 +4,7 @@ import com.juick.Message;
 import com.juick.Reaction;
 import com.juick.User;
 import com.juick.formatters.PlainTextFormatter;
+import com.juick.server.api.SystemActivity.ActivityType;
 import com.juick.server.api.activity.model.Context;
 import com.juick.server.api.activity.model.activities.Accept;
 import com.juick.server.api.activity.model.activities.Announce;
@@ -142,10 +143,10 @@ public class ActivityPubManager implements ActivityListener, NotificationListene
         List<String> segments = uriComponents.getPathSegments();
         if (segments.get(0).equals("n")) {
             String[] ids = segments.get(1).split("-", 2);
-            if (ids.length == 2 && Integer.valueOf(ids[1]) == 0) {
+            if (ids.length == 2 && Integer.parseInt(ids[1]) == 0) {
                 // only messages
                 logger.info("{} recommends {}", event.getActorUri(), Integer.valueOf(ids[0]));
-                messagesService.likeMessage(Integer.valueOf(ids[0]), 0, Reaction.LIKE, event.getActorUri());
+                messagesService.likeMessage(Integer.parseInt(ids[0]), 0, Reaction.LIKE, event.getActorUri());
             }
         }
     }
@@ -156,18 +157,27 @@ public class ActivityPubManager implements ActivityListener, NotificationListene
         List<String> segments = uriComponents.getPathSegments();
         if (segments.get(0).equals("n")) {
             String[] ids = segments.get(1).split("-", 2);
-            if (ids.length == 2 && Integer.valueOf(ids[1]) == 0) {
+            if (ids.length == 2 && Integer.parseInt(ids[1]) == 0) {
                 // only messages
                 logger.info("{} stop recommending {}", event.getActorUri(), Integer.valueOf(ids[0]));
-                messagesService.likeMessage(Integer.valueOf(ids[0]), 0, null, event.getActorUri());
+                messagesService.likeMessage(Integer.parseInt(ids[0]), 0, null, event.getActorUri());
             }
         }
     }
 
     @Override
-    public void processMessageEvent(MessageEvent messageEvent) {
-        Message msg = messageEvent.getMessage();
-        if (MessageUtils.isPM(msg)) {
+    public void processSystemEvent(SystemEvent systemEvent) {
+        ActivityType type = systemEvent.getActivity().getType();
+        if (type.equals(ActivityType.message)) {
+            processMessage(systemEvent.getActivity().getMessage());
+        } else if (type.equals(ActivityType.like)) {
+            if (systemEvent.getActivity().getFrom().equals(serviceUser)) {
+                processTop(systemEvent.getActivity().getMessage());
+            }
+        }
+    }
+    private void processMessage(Message msg) {
+        if (MessageUtils.isPM(msg) || msg.isService()) {
             return;
         }
         User user = msg.getUser();
@@ -323,28 +333,11 @@ public class ActivityPubManager implements ActivityListener, NotificationListene
     }
 
     @Override
-    public void processSubscribeEvent(SubscribeEvent subscribeEvent) {
-
-    }
-
-    @Override
-    public void processLikeEvent(LikeEvent likeEvent) {
-
-    }
-
-    @Override
     public void processPingEvent(PingEvent pingEvent) {
 
     }
 
-    @Override
-    public void processMessageReadEvent(MessageReadEvent messageReadEvent) {
-
-    }
-
-    @Override
-    public void processTopEvent(TopEvent topEvent) {
-        Message message = topEvent.getMessage();
+    private void processTop(Message message) {
         Note note = makeNote(message);
         Announce announce = new Announce();
         announce.setId(note.getId() + "#top");
diff --git a/src/main/java/com/juick/server/CommandsManager.java b/src/main/java/com/juick/server/CommandsManager.java
index b21ff81c..6fd88f07 100644
--- a/src/main/java/com/juick/server/CommandsManager.java
+++ b/src/main/java/com/juick/server/CommandsManager.java
@@ -23,6 +23,7 @@ import com.juick.User;
 import com.juick.formatters.PlainTextFormatter;
 import com.juick.model.CommandResult;
 import com.juick.model.TagStats;
+import com.juick.server.api.SystemActivity;
 import com.juick.server.helpers.annotation.UserCommand;
 import com.juick.server.util.HttpUtils;
 import com.juick.server.www.WebApp;
@@ -141,9 +142,12 @@ public class CommandsManager {
         msg.getUser().setAvatar(webApp.getAvatarUrl(msg.getUser()));
         subscriptionService.subscribeMessage(msg, user);
 
-        applicationEventPublisher.publishEvent(new MessageReadEvent(this, user, msg));
-        applicationEventPublisher.publishEvent(new MessageEvent(this, msg, subscriptionService.getSubscribedUsers(msg.getUser().getUid(), msg)));
-        return CommandResult.build(msg, "New message posted.\n#" + msg.getMid() + " https://juick.com/m/" + msg.getMid(), String.format("[New message](%s) posted", PlainTextFormatter.formatUrl(msg)));
+        applicationEventPublisher.publishEvent(new SystemEvent(this, SystemActivity.read(user, msg)));
+        applicationEventPublisher.publishEvent(new SystemEvent(this,
+                SystemActivity.message(user, msg, subscriptionService.getSubscribedUsers(msg.getUser().getUid(), msg))));
+        return CommandResult.build(msg,
+                "New message posted.\n#" + msg.getMid() + " https://juick.com/m/" + msg.getMid(),
+                String.format("[New message](%s) posted", PlainTextFormatter.formatUrl(msg)));
     }
 
     @UserCommand(pattern = "^ping$", patternFlags = Pattern.CASE_INSENSITIVE,
@@ -180,7 +184,8 @@ public class CommandsManager {
                     jmsg.setUser(user_from);
                     jmsg.setTo(user_to);
                     jmsg.setText(body);
-                    applicationEventPublisher.publishEvent(new MessageEvent(this, jmsg, Collections.singletonList(user_to)));
+                    applicationEventPublisher.publishEvent(new SystemEvent(this,
+                            SystemActivity.message(user_from, jmsg, Collections.singletonList(user_to))));
                     return CommandResult.fromString("Private message sent");
                 }
             }
@@ -314,9 +319,9 @@ public class CommandsManager {
                 MessagesService.RecommendStatus status = messagesService.recommendMessage(mid, user.getUid(), user.getUri().toASCIIString());
                 switch (status) {
                     case Added:
-                        applicationEventPublisher.publishEvent(new LikeEvent(this, user, msg.get(),
+                        applicationEventPublisher.publishEvent(new SystemEvent(this, SystemActivity.like(user, msg.get(),
                                 subscriptionService.getUsersSubscribedToUserRecommendations(
-                                        user.getUid(), msg.get())));
+                                        user.getUid(), msg.get()))));
                         return CommandResult.fromString("Message is added to your recommendations");
                     case Deleted:
                         return CommandResult.fromString("Message deleted from your recommendations.");
@@ -338,7 +343,8 @@ public class CommandsManager {
         if (subscribe) {
             if (subscriptionService.subscribeUser(user, toUser)) {
                 // TODO: already subscribed case
-                applicationEventPublisher.publishEvent(new SubscribeEvent(this, user, toUser));
+                applicationEventPublisher.publishEvent(new SystemEvent(this,
+                        SystemActivity.follow(user, Collections.singletonList(toUser))));
                 return CommandResult.fromString("Subscribed to @" + toUser.getName());
             }
         } else {
@@ -376,7 +382,7 @@ public class CommandsManager {
             if (subscribe) {
                 if (subscriptionService.subscribeMessage(msg.get(), user)) {
                     applicationEventPublisher.publishEvent(
-                            new MessageReadEvent(this, user, msg.get()));
+                            new SystemEvent(this, SystemActivity.read(user, msg.get())));
                     return CommandResult.fromString("Subscribed");
                 }
             } else {
@@ -429,10 +435,10 @@ public class CommandsManager {
             if (showReplies) {
                 List<com.juick.Message> replies = messagesService.getReplies(user, mid);
                 applicationEventPublisher.publishEvent(
-                        new MessageReadEvent(this, user, msg.get()));
+                        new SystemEvent(this, SystemActivity.read(user, msg.get())));
                 replies.add(0, msg.get());
-                return CommandResult.fromString(String.join("\n",
-                        replies.stream().map(PlainTextFormatter::formatPostSummary).collect(Collectors.toList())));
+                return CommandResult.fromString(replies.stream()
+                        .map(PlainTextFormatter::formatPostSummary).collect(Collectors.joining("\n")));
             }
             return CommandResult.fromString(PlainTextFormatter.formatPost(msg.get()));
         }
@@ -474,8 +480,8 @@ public class CommandsManager {
     }
     @UserCommand(pattern = "^D #(\\d+)(\\.|\\-|\\/)(\\d+)$", help = "D #1234/5 - Delete comment", patternFlags = Pattern.CASE_INSENSITIVE)
     public CommandResult commandDeleteReply(User user, URI attachment, String... args) {
-        int mid = Integer.valueOf(args[0]);
-        int rid = Integer.valueOf(args[2]);
+        int mid = Integer.parseInt(args[0]);
+        int rid = Integer.parseInt(args[2]);
         if (messagesService.deleteReply(user.getUid(), mid, rid)) {
             return CommandResult.fromString("Reply deleted");
         } else {
@@ -556,12 +562,15 @@ public class CommandsManager {
                     imagesService.saveImageWithPreviews(attachmentFName, fname);
                 }
                 applicationEventPublisher.publishEvent(
-                        new MessageReadEvent(this, user, msg.get()));
+                        new SystemEvent(this, SystemActivity.read(user, msg.get())));
                 Message original = messagesService.getMessage(mid).orElseThrow(IllegalStateException::new);
                 subscriptionService.subscribeMessage(original, user);
                 Message reply = messagesService.getReply(mid, newrid);
                 reply.getUser().setAvatar(webApp.getAvatarUrl(reply.getUser()));
-                applicationEventPublisher.publishEvent(new MessageEvent(this, reply, subscriptionService.getUsersSubscribedToComments(original, reply)));
+                applicationEventPublisher.publishEvent(
+                        new SystemEvent(this,
+                        SystemActivity.message(reply.getUser(), reply,
+                                subscriptionService.getUsersSubscribedToComments(original, reply))));
                 return CommandResult.build(reply, "Reply posted.\n#" + mid + "/" + newrid + " "
                                 + "https://juick.com/m/" + mid + "#" + newrid,
                         String.format("[Reply](%s) posted", PlainTextFormatter.formatUrl(reply)));
diff --git a/src/main/java/com/juick/server/EmailManager.java b/src/main/java/com/juick/server/EmailManager.java
index bd77d8d6..edff7b70 100644
--- a/src/main/java/com/juick/server/EmailManager.java
+++ b/src/main/java/com/juick/server/EmailManager.java
@@ -2,6 +2,7 @@ package com.juick.server;
 
 import com.juick.Message;
 import com.juick.User;
+import com.juick.server.api.SystemActivity;
 import com.juick.service.EmailService;
 import com.juick.service.MessagesService;
 import com.juick.service.UserService;
@@ -52,9 +53,15 @@ public class EmailManager implements NotificationListener {
     private PebbleEngine pebbleEngine;
 
     @Override
-    public void processMessageEvent(@Nonnull MessageEvent event) {
-        Message msg = event.getMessage();
-        List<User> subscribedUsers = event.getUsers();
+    public void processSystemEvent(@Nonnull SystemEvent systemEvent) {
+        var activity = systemEvent.getActivity();
+        var msg = activity.getMessage();
+        var subscribers = activity.getTo();
+        if (activity.getType().equals(SystemActivity.ActivityType.message)) {
+            processMessage(msg, subscribers);
+        }
+    }
+    private void processMessage(com.juick.Message msg, List<User> subscribedUsers) {
         if (msg.isService()) {
             return;
         }
@@ -78,30 +85,10 @@ public class EmailManager implements NotificationListener {
     }
 
     @Override
-    public void processSubscribeEvent(SubscribeEvent subscribeEvent) {
-
-    }
-
-    @Override
-    public void processLikeEvent(LikeEvent likeEvent) {
-
-    }
-
-    @Override
     public void processPingEvent(PingEvent pingEvent) {
 
     }
 
-    @Override
-    public void processMessageReadEvent(MessageReadEvent messageReadEvent) {
-
-    }
-
-    @Override
-    public void processTopEvent(TopEvent topEvent) {
-
-    }
-
     private void emailNotify(String email, String subject, Message msg) {
         Map<String, String> headers = new HashMap<>();
         if (!MessageUtils.isPM(msg)) {
diff --git a/src/main/java/com/juick/server/ServerManager.java b/src/main/java/com/juick/server/ServerManager.java
index 5b859125..ca69f7d8 100644
--- a/src/main/java/com/juick/server/ServerManager.java
+++ b/src/main/java/com/juick/server/ServerManager.java
@@ -21,6 +21,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.juick.Message;
 import com.juick.User;
 import com.juick.model.AnonymousUser;
+import com.juick.server.api.SystemActivity;
 import com.juick.service.MessagesService;
 import com.juick.service.SubscriptionService;
 import com.juick.service.UserService;
@@ -34,6 +35,7 @@ import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Component;
 import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;
 
+import javax.annotation.Nonnull;
 import javax.annotation.PostConstruct;
 import javax.inject.Inject;
 import java.util.ArrayList;
@@ -91,10 +93,30 @@ public class ServerManager implements NotificationListener {
     }
 
     @Override
-    public void processMessageEvent(MessageEvent event) {
-        com.juick.Message jmsg = event.getMessage();
-        List<User> subscribedUsers = ListUtils.union(event.getUsers(), Collections.singletonList(jmsg.getUser()));
+    public void processSystemEvent(@Nonnull SystemEvent systemEvent) {
+        var activity = systemEvent.getActivity();
+        var from = activity.getFrom();
+        var message = activity.getMessage();
+        var subscribers = activity.getTo();
+        if (activity.getType().equals(SystemActivity.ActivityType.message)) {
+            processMessage(from, message, subscribers);
+        } else if (activity.getType().equals(SystemActivity.ActivityType.like)) {
+            if (from.equals(serviceUser)) {
+                processTop(message);
+            }
+        }
+        try {
+            var eventHeader = Collections.singletonMap("X-Event-Version", "1.0");
+            emailManager.sendEmail("noreply@juick.com", serviceEmail, "New system event",
+                    jsonMapper.writeValueAsString(systemEvent), null, eventHeader);
+        } catch (JsonProcessingException e) {
+            logger.warn("JSON exception", e);
+        }
+    }
+    private void processMessage(User from, com.juick.Message jmsg, List<User> subscribers) {
+        List<User> subscribedUsers = ListUtils.union(subscribers, Collections.singletonList(jmsg.getUser()));
         if (jmsg.isService()) {
+            logger.info("Message read event from {} for {}", from.getUid(), jmsg.getMid());
             readEvent(jmsg, Collections.singletonList(serviceUser));
             return;
         }
@@ -111,21 +133,6 @@ public class ServerManager implements NotificationListener {
             onJuickMessageReply(jmsg, subscribedUsers);
         }
         messageEvent(jmsg, Collections.singletonList(serviceUser));
-        try {
-            emailManager.sendEmail("noreply@juick.com", serviceEmail, "New message", jsonMapper.writeValueAsString(jmsg), null, Collections.emptyMap());
-        } catch (JsonProcessingException e) {
-            logger.warn("JSON exception", e);
-        }
-    }
-
-    @Override
-    public void processSubscribeEvent(SubscribeEvent subscribeEvent) {
-
-    }
-
-    @Override
-    public void processLikeEvent(LikeEvent likeEvent) {
-
     }
 
     @Override
@@ -133,35 +140,19 @@ public class ServerManager implements NotificationListener {
 
     }
 
-    @Override
-    public void processMessageReadEvent(MessageReadEvent messageReadEvent) {
-        User user = messageReadEvent.getUser();
-        Message source = messageReadEvent.getMessage();
-
-        logger.info("Message read event from {} for {}", user.getUid(), source.getMid());
-        Message serviceMessage = new Message();
-        serviceMessage.setService(true);
-        serviceMessage.setUser(user);
-        serviceMessage.setMid(source.getMid());
-        serviceMessage.setUnread(false);
-        readEvent(serviceMessage, Arrays.asList(serviceUser, user));
-    }
-
-    @Override
-    public void processTopEvent(TopEvent topEvent) {
-        User topUser = topEvent.getMessage().getUser();
-        topEvent(topEvent.getMessage(), Arrays.asList(topUser, serviceUser));
+    private void processTop(Message msg) {
+        User topUser = msg.getUser();
+        topEvent(msg, Arrays.asList(topUser, serviceUser));
     }
-
-    public void topEvent(Message msg, List<User> subscribers){
+    private void topEvent(Message msg, List<User> subscribers){
         sendSseEvent(msg, "top", subscribers);
     }
 
-    public void readEvent(Message msg, List<User> subscribers){
+    private void readEvent(Message msg, List<User> subscribers){
         sendSseEvent(msg, "read", subscribers);
     }
 
-    public void messageEvent(Message msg, List<User> subscribers) {
+    private void messageEvent(Message msg, List<User> subscribers) {
         sendSseEvent(msg, "msg", subscribers);
     }
 
diff --git a/src/main/java/com/juick/server/TelegramBotManager.java b/src/main/java/com/juick/server/TelegramBotManager.java
index 9e53fbe1..7ca9e347 100644
--- a/src/main/java/com/juick/server/TelegramBotManager.java
+++ b/src/main/java/com/juick/server/TelegramBotManager.java
@@ -20,17 +20,14 @@ package com.juick.server;
 import com.juick.User;
 import com.juick.model.AnonymousUser;
 import com.juick.model.CommandResult;
+import com.juick.server.api.SystemActivity;
 import com.juick.server.util.HttpUtils;
 import com.juick.service.MessagesService;
 import com.juick.service.TelegramService;
 import com.juick.service.UserService;
-import com.juick.service.component.LikeEvent;
-import com.juick.service.component.MessageEvent;
-import com.juick.service.component.MessageReadEvent;
+import com.juick.service.component.SystemEvent;
 import com.juick.service.component.NotificationListener;
 import com.juick.service.component.PingEvent;
-import com.juick.service.component.SubscribeEvent;
-import com.juick.service.component.TopEvent;
 import com.juick.util.MessageUtils;
 import com.pengrad.telegrambot.Callback;
 import com.pengrad.telegrambot.TelegramBot;
@@ -370,7 +367,7 @@ public class TelegramBotManager implements NotificationListener {
                 User user = userService.getUserByUID(userId).orElseThrow(IllegalStateException::new);
                 userService.updateLastSeen(user);
                 applicationEventPublisher.publishEvent(
-                        new MessageReadEvent(this, user, source));
+                        new SystemEvent(this, SystemActivity.read(user, source)));
             }
         }
     }
@@ -394,9 +391,22 @@ public class TelegramBotManager implements NotificationListener {
     }
 
     @Override
-    public void processMessageEvent(MessageEvent messageEvent) {
-        com.juick.Message jmsg = messageEvent.getMessage();
-        List<User> subscribedUsers = messageEvent.getUsers();
+    public void processSystemEvent(SystemEvent systemEvent) {
+        var activity = systemEvent.getActivity();
+        var type = activity.getType();
+        if (type.equals(SystemActivity.ActivityType.message)) {
+            processMessage(activity.getMessage(), activity.getTo());
+        } else if (type.equals(SystemActivity.ActivityType.like)) {
+            if (systemEvent.getActivity().getFrom().getName().equals(serviceUser)) {
+                processTop(systemEvent.getActivity().getMessage());
+            } else {
+                processLike(activity.getFrom(), activity.getMessage(), activity.getTo());
+            }
+        } else if (type.equals(SystemActivity.ActivityType.follow)) {
+            processFollow(activity.getFrom(), activity.getTo());
+        }
+    }
+    private void processMessage(com.juick.Message jmsg, List<User> subscribedUsers) {
         if (jmsg.isService()) {
             return;
         }
@@ -422,12 +432,8 @@ public class TelegramBotManager implements NotificationListener {
         }
     }
 
-    @Override
-    public void processLikeEvent(LikeEvent likeEvent) {
-        User liker = likeEvent.getUser();
+    private void processLike(User liker, com.juick.Message message, List<User> subscribers) {
         if (!liker.getName().equals(serviceUser)) {
-            com.juick.Message message = likeEvent.getMessage();
-            List<User> subscribers = likeEvent.getSubscribers();
             logger.info("Like received in tg listener");
             if (!userService.isInBLAny(message.getUser().getUid(), liker.getUid())) {
                 telegramService.getTelegramIdentifiers(Collections.singletonList(message.getUser()))
@@ -445,24 +451,14 @@ public class TelegramBotManager implements NotificationListener {
 
     }
 
-    @Override
-    public void processMessageReadEvent(MessageReadEvent messageReadEvent) {
-
-    }
-
-    @Override
-    public void processTopEvent(TopEvent topEvent) {
-        com.juick.Message message = topEvent.getMessage();
+    private void processTop(com.juick.Message message) {
         telegramService.getTelegramIdentifiers(Collections.singletonList(message.getUser()))
                 .forEach(c -> telegramNotify(c, String.format("Your [post](%s) became popular!",
                         formatUrl(message)), new com.juick.Message()));
     }
 
-    @Override
-    public void processSubscribeEvent(SubscribeEvent subscribeEvent) {
-        User subscriber = subscribeEvent.getUser();
-        User target = subscribeEvent.getToUser();
-        telegramService.getTelegramIdentifiers(Collections.singletonList(target))
+    private void processFollow(User subscriber, List<User> target) {
+        telegramService.getTelegramIdentifiers(target)
                 .forEach(c -> telegramNotify(c, String.format("%s subscribed to your blog",
                         MessageUtils.getMarkdownUser(subscriber)), new com.juick.Message()));
     }
diff --git a/src/main/java/com/juick/server/TopManager.java b/src/main/java/com/juick/server/TopManager.java
index fe3d605d..ff7ae9fd 100644
--- a/src/main/java/com/juick/server/TopManager.java
+++ b/src/main/java/com/juick/server/TopManager.java
@@ -19,15 +19,21 @@ package com.juick.server;
 
 import com.juick.Message;
 import com.juick.Tag;
+import com.juick.User;
+import com.juick.server.api.SystemActivity;
 import com.juick.service.MessagesService;
-import com.juick.service.component.TopEvent;
+import com.juick.service.UserService;
+import com.juick.service.component.SystemEvent;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Component;
 
+import javax.annotation.PostConstruct;
 import javax.inject.Inject;
+import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -37,8 +43,20 @@ public class TopManager {
     @Inject
     private MessagesService messagesService;
     @Inject
+    private UserService userService;
+    @Inject
     private ApplicationEventPublisher applicationEventPublisher;
 
+    @Value("${service_user:juick}")
+    private String serviceUsername;
+
+    private User serviceUser;
+
+    @PostConstruct
+    public void init() {
+        serviceUser = userService.getUserByName(serviceUsername);
+    }
+
     @Scheduled(fixedRate = 3600000)
     public void updateTop() {
         messagesService.getPopularCandidates().forEach(m -> {
@@ -47,7 +65,8 @@ public class TopManager {
             messagesService.setMessagePopular(m, 1);
             List<String> tags = jmsg.getTags().stream().map(Tag::getName).map(String::toLowerCase).collect(Collectors.toList());
             if (!tags.contains("juick")) {
-                applicationEventPublisher.publishEvent(new TopEvent(this, jmsg));
+                applicationEventPublisher.publishEvent(new SystemEvent(this,
+                        SystemActivity.like(serviceUser, jmsg, Collections.emptyList())));
             }
         });
     }
diff --git a/src/main/java/com/juick/server/TwitterManager.java b/src/main/java/com/juick/server/TwitterManager.java
index d799bb17..0cb247fe 100644
--- a/src/main/java/com/juick/server/TwitterManager.java
+++ b/src/main/java/com/juick/server/TwitterManager.java
@@ -18,6 +18,7 @@ package com.juick.server;
 
 import com.juick.Message;
 import com.juick.User;
+import com.juick.server.api.SystemActivity;
 import com.juick.service.UserService;
 import com.juick.service.component.*;
 import com.juick.service.CrosspostService;
@@ -85,41 +86,32 @@ public class TwitterManager implements NotificationListener {
     }
 
     @Override
-    public void processMessageEvent(MessageEvent messageEvent) {
-        Message msg = messageEvent.getMessage();
-        if (MessageUtils.isPM(msg) || MessageUtils.isReply(msg) || msg.isService()) {
-            return;
-        }
-        if (StringUtils.isNotEmpty(crosspostService.getTwitterName(msg.getUser().getUid()))) {
-            if (msg.getTags().stream().noneMatch(t -> t.getName().equals("notwitter"))) {
-                twitterPost(msg);
+    public void processSystemEvent(SystemEvent systemEvent) {
+        var activity = systemEvent.getActivity();
+        var msg = activity.getMessage();
+        if (activity.getType().equals(SystemActivity.ActivityType.message)) {
+            if (MessageUtils.isPM(msg) || MessageUtils.isReply(msg) || msg.isService()) {
+                return;
+            }
+            if (StringUtils.isNotEmpty(crosspostService.getTwitterName(msg.getUser().getUid()))) {
+                if (msg.getTags().stream().noneMatch(t -> t.getName().equals("notwitter"))) {
+                    twitterPost(msg);
+                }
+            }
+        } else if (activity.getType().equals(SystemActivity.ActivityType.like)) {
+            if (activity.getFrom().getName().equals(serviceUsername)) {
+                processTop(msg);
             }
         }
     }
 
     @Override
-    public void processSubscribeEvent(SubscribeEvent subscribeEvent) {
-
-    }
-
-    @Override
-    public void processLikeEvent(LikeEvent likeEvent) {
-
-    }
-
-    @Override
     public void processPingEvent(PingEvent pingEvent) {
 
     }
 
-    @Override
-    public void processMessageReadEvent(MessageReadEvent messageReadEvent) {
-
-    }
-
-    @Override
-    public void processTopEvent(TopEvent topEvent) {
-        Message jmsg = SerializationUtils.clone(topEvent.getMessage());
+    private void processTop(com.juick.Message message) {
+        Message jmsg = SerializationUtils.clone(message);
         jmsg.setUser(serviceUser);
         twitterPost(jmsg);
     }
diff --git a/src/main/java/com/juick/server/XMPPManager.java b/src/main/java/com/juick/server/XMPPManager.java
index a41e6053..a0390507 100644
--- a/src/main/java/com/juick/server/XMPPManager.java
+++ b/src/main/java/com/juick/server/XMPPManager.java
@@ -20,6 +20,7 @@ package com.juick.server;
 import com.juick.User;
 import com.juick.formatters.PlainTextFormatter;
 import com.juick.model.CommandResult;
+import com.juick.server.api.SystemActivity;
 import com.juick.server.www.WebApp;
 import com.juick.server.xmpp.iq.MessageQuery;
 import com.juick.service.MessagesService;
@@ -337,9 +338,20 @@ public class XMPPManager implements NotificationListener {
     }
 
     @Override
-    public void processMessageEvent(MessageEvent event) {
-        com.juick.Message msg = event.getMessage();
-        List<User> subscribers = event.getUsers();
+    public void processSystemEvent(SystemEvent systemEvent) {
+        var activity = systemEvent.getActivity();
+        var type = activity.getType();
+        if (type.equals(SystemActivity.ActivityType.message)) {
+            processMessage(activity.getMessage(), activity.getTo());
+        } else if (type.equals(SystemActivity.ActivityType.like)) {
+            if (systemEvent.getActivity().getFrom().equals(serviceUser)) {
+                processTop(systemEvent.getActivity().getMessage());
+            } else {
+                processLike(activity.getFrom(), activity.getMessage(), activity.getTo());
+            }
+        }
+    }
+    private void processMessage(com.juick.Message msg, List<User> subscribers) {
         if (msg.isService()) {
             return;
         }
@@ -376,17 +388,7 @@ public class XMPPManager implements NotificationListener {
         return ClientMessage.from(reply);
     }
 
-    @Override
-    public void processSubscribeEvent(SubscribeEvent subscribeEvent) {
-
-    }
-
-    @Override
-    public void processLikeEvent(LikeEvent likeEvent) {
-        List<User> users = likeEvent.getSubscribers();
-        com.juick.Message jmsg = likeEvent.getMessage();
-        User liker = likeEvent.getUser();
-
+    public void processLike(User liker, com.juick.Message jmsg, List<User> users) {
         if (!userService.isInBLAny(jmsg.getUser().getUid(), liker.getUid())) {
             userService.getJIDsbyUID(jmsg.getUser().getUid()).forEach(authorJid -> {
                 Message xmppMessage = new Message();
@@ -454,14 +456,7 @@ public class XMPPManager implements NotificationListener {
                 });
     }
 
-    @Override
-    public void processMessageReadEvent(MessageReadEvent messageReadEvent) {
-
-    }
-
-    @Override
-    public void processTopEvent(TopEvent topEvent) {
-        com.juick.Message message = topEvent.getMessage();
+    public void processTop(com.juick.Message message) {
         try {
             commandsManager.processCommand(serviceUser, String.format("! #%d", message.getMid()), URI.create(StringUtils.EMPTY));
         } catch (Exception e) {
diff --git a/src/main/java/com/juick/server/api/Messages.java b/src/main/java/com/juick/server/api/Messages.java
index 3ac272f2..1c9e37ad 100644
--- a/src/main/java/com/juick/server/api/Messages.java
+++ b/src/main/java/com/juick/server/api/Messages.java
@@ -22,12 +22,12 @@ import com.juick.Tag;
 import com.juick.User;
 import com.juick.server.Utils;
 import com.juick.server.www.WebApp;
-import com.juick.service.component.MessageReadEvent;
 import com.juick.model.CommandResult;
 import com.juick.server.util.HttpBadRequestException;
 import com.juick.service.MessagesService;
 import com.juick.service.TagService;
 import com.juick.service.UserService;
+import com.juick.service.component.SystemEvent;
 import com.juick.service.security.annotation.Visitor;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.tuple.Pair;
@@ -192,7 +192,7 @@ public class Messages {
                 if (!visitor.isAnonymous()) {
                     userService.updateLastSeen(visitor);
                     applicationEventPublisher.publishEvent(
-                            new MessageReadEvent(this, visitor, msg));
+                            new SystemEvent(this, SystemActivity.read(visitor, msg)));
                 }
                 replies.add(0, msg);
                 return ResponseEntity.ok(replies);
@@ -209,7 +209,7 @@ public class Messages {
             Message msg = messagesService.getMessage(mid).orElseThrow(IllegalStateException::new);
             userService.updateLastSeen(visitor);
             applicationEventPublisher.publishEvent(
-                    new MessageReadEvent(this, visitor, msg));
+                    new SystemEvent(this, SystemActivity.read(visitor, msg)));
             return IOUtils.toByteArray(invisiblePixel.getInputStream());
         }
         throw new HttpBadRequestException();
diff --git a/src/main/java/com/juick/server/api/PM.java b/src/main/java/com/juick/server/api/PM.java
index b65841c0..4a408dce 100644
--- a/src/main/java/com/juick/server/api/PM.java
+++ b/src/main/java/com/juick/server/api/PM.java
@@ -28,7 +28,7 @@ import com.juick.server.util.WebUtils;
 import com.juick.server.www.WebApp;
 import com.juick.service.PMQueriesService;
 import com.juick.service.UserService;
-import com.juick.service.component.MessageEvent;
+import com.juick.service.component.SystemEvent;
 import com.juick.service.security.annotation.Visitor;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.http.MediaType;
@@ -97,7 +97,9 @@ public class PM {
             jmsg.setText(body);
             jmsg.setTo(userTo);
             jmsg.getUser().setAvatar(webApp.getAvatarUrl(jmsg.getUser()));
-            applicationEventPublisher.publishEvent(new MessageEvent(this, jmsg, Collections.singletonList(jmsg.getTo())));
+            applicationEventPublisher.publishEvent(
+                    new SystemEvent(this,
+                            SystemActivity.message(jmsg.getUser(), jmsg, Collections.singletonList(jmsg.getTo()))));
             return jmsg;
 
         }
diff --git a/src/main/java/com/juick/server/api/SystemActivity.java b/src/main/java/com/juick/server/api/SystemActivity.java
new file mode 100644
index 00000000..162374d1
--- /dev/null
+++ b/src/main/java/com/juick/server/api/SystemActivity.java
@@ -0,0 +1,88 @@
+package com.juick.server.api;
+
+import com.juick.Message;
+import com.juick.User;
+
+import java.util.List;
+
+public class SystemActivity {
+    public static SystemActivity like(User from, Message message, List<User> subscribers) {
+        var like = new SystemActivity();
+        like.setType(ActivityType.like);
+        like.setFrom(from);
+        like.setMessage(message);
+        like.setTo(subscribers);
+        return like;
+    }
+
+    public static SystemActivity message(User from, Message message, List<User> subscribers) {
+        var msg = new SystemActivity();
+        msg.setType(ActivityType.message);
+        msg.setFrom(from);
+        msg.setMessage(message);
+        msg.setTo(subscribers);
+        return msg;
+    }
+
+    public static SystemActivity read(User from, Message message) {
+        var read = new SystemActivity();
+        read.setType(ActivityType.message);
+        read.setFrom(from);
+        var msg = new Message();
+        msg.setMid(message.getMid());
+        msg.setService(true);
+        msg.setUnread(false);
+        read.setMessage(msg);
+        return read;
+    }
+
+    public static SystemActivity follow(User from, List<User> to) {
+        var follow = new SystemActivity();
+        follow.setFrom(from);
+        follow.setTo(to);
+        return follow;
+    }
+
+    public enum ActivityType {
+        message,
+        like,
+        follow
+    }
+
+    private ActivityType type;
+    private User from;
+    private List<User> to;
+    private Message message;
+
+    public ActivityType getType() {
+        return type;
+    }
+
+    public void setType(ActivityType type) {
+        this.type = type;
+    }
+
+    public User getFrom() {
+        return from;
+    }
+
+    public void setFrom(User from) {
+        this.from = from;
+    }
+
+    public List<User> getTo() {
+        return to;
+    }
+
+    public void setTo(List<User> to) {
+        this.to = to;
+    }
+
+    public Message getMessage() {
+        return message;
+    }
+
+    public void setMessage(Message message) {
+        this.message = message;
+    }
+}
diff --git a/src/main/java/com/juick/service/component/LikeEvent.java b/src/main/java/com/juick/service/component/LikeEvent.java
deleted file mode 100644
index 0d4df70c..00000000
--- a/src/main/java/com/juick/service/component/LikeEvent.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package com.juick.service.component;
-
-import com.juick.Message;
-import com.juick.User;
-import org.springframework.context.ApplicationEvent;
-
-import java.util.List;
-
-public class LikeEvent extends ApplicationEvent {
-    private User user;
-    private Message message;
-    private List<User> subscribers;
-    /**
-     * Create a new ApplicationEvent.
-     *
-     * @param source the object on which the event initially occurred (never {@code null})
-     */
-    public LikeEvent(Object source, User user, Message message, List<User> subscribers) {
-        super(source);
-        this.message = message;
-        this.user = user;
-        this.subscribers = subscribers;
-    }
-
-    public User getUser() {
-        return user;
-    }
-
-    public Message getMessage() {
-        return message;
-    }
-
-    public List<User> getSubscribers() {
-        return subscribers;
-    }
-}
diff --git a/src/main/java/com/juick/service/component/MessageEvent.java b/src/main/java/com/juick/service/component/MessageEvent.java
deleted file mode 100644
index 82911a58..00000000
--- a/src/main/java/com/juick/service/component/MessageEvent.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package com.juick.service.component;
-
-import com.juick.Message;
-import com.juick.User;
-import org.springframework.context.ApplicationEvent;
-
-import java.util.List;
-
-public class MessageEvent extends ApplicationEvent {
-    private Message message;
-    private List<User> users;
-    /**
-     * Create a new ApplicationEvent.
-     *
-     * @param source the object on which the event initially occurred (never {@code null})
-     * @param message app message
-     * @param interestedUsers users interested in notification
-     */
-    public MessageEvent(Object source, Message message, List<User> interestedUsers) {
-        super(source);
-        this.message = message;
-        this.users = interestedUsers;
-    }
-
-    public Message getMessage() {
-        return message;
-    }
-    public List<User> getUsers() {
-        return users;
-    }
-}
diff --git a/src/main/java/com/juick/service/component/MessageReadEvent.java b/src/main/java/com/juick/service/component/MessageReadEvent.java
deleted file mode 100644
index b2af4a08..00000000
--- a/src/main/java/com/juick/service/component/MessageReadEvent.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package com.juick.service.component;
-
-import com.juick.Message;
-import com.juick.User;
-import org.springframework.context.ApplicationEvent;
-
-import javax.annotation.Nonnull;
-
-public class MessageReadEvent extends ApplicationEvent {
-    private User user;
-    private Message message;
-    /**
-     * Create a new ApplicationEvent.
-     *
-     * @param source the object on which the event initially occurred (never {@code null})
-     */
-    public MessageReadEvent(Object source, @Nonnull User user, Message message) {
-        super(source);
-        this.user = user;
-        this.message = message;
-    }
-
-    public User getUser() {
-        return user;
-    }
-
-    public Message getMessage() {
-        return message;
-    }
-}
diff --git a/src/main/java/com/juick/service/component/NotificationListener.java b/src/main/java/com/juick/service/component/NotificationListener.java
index 38d0490a..7ca88de8 100644
--- a/src/main/java/com/juick/service/component/NotificationListener.java
+++ b/src/main/java/com/juick/service/component/NotificationListener.java
@@ -6,20 +6,8 @@ import org.springframework.scheduling.annotation.Async;
 public interface NotificationListener {
     @Async
     @EventListener
-    void processMessageEvent(MessageEvent messageEvent);
-    @Async
-    @EventListener
-    void processSubscribeEvent(SubscribeEvent subscribeEvent);
-    @Async
-    @EventListener
-    void processLikeEvent(LikeEvent likeEvent);
+    void processSystemEvent(SystemEvent systemEvent);
     @Async
     @EventListener
     void processPingEvent(PingEvent pingEvent);
-    @Async
-    @EventListener
-    void processMessageReadEvent(MessageReadEvent messageReadEvent);
-    @Async
-    @EventListener
-    void processTopEvent(TopEvent topEvent);
 }
diff --git a/src/main/java/com/juick/service/component/SubscribeEvent.java b/src/main/java/com/juick/service/component/SubscribeEvent.java
deleted file mode 100644
index 9b644f2f..00000000
--- a/src/main/java/com/juick/service/component/SubscribeEvent.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package com.juick.service.component;
-
-import com.juick.User;
-import org.springframework.context.ApplicationEvent;
-
-public class SubscribeEvent extends ApplicationEvent {
-    private User user;
-    private User toUser;
-    /**
-     * Create a new ApplicationEvent.
-     *
-     * @param source the object on which the event initially occurred (never {@code null})
-     */
-    public SubscribeEvent(Object source, User user, User toUser) {
-        super(source);
-        this.user = user;
-        this.toUser = toUser;
-    }
-
-    public User getUser() {
-        return user;
-    }
-
-    public User getToUser() {
-        return toUser;
-    }
-}
diff --git a/src/main/java/com/juick/service/component/SystemEvent.java b/src/main/java/com/juick/service/component/SystemEvent.java
new file mode 100644
index 00000000..11a10860
--- /dev/null
+++ b/src/main/java/com/juick/service/component/SystemEvent.java
@@ -0,0 +1,26 @@
+package com.juick.service.component;
+
+import com.juick.Message;
+import com.juick.User;
+import com.juick.server.api.SystemActivity;
+import org.springframework.context.ApplicationEvent;
+
+import java.util.List;
+
+public class SystemEvent extends ApplicationEvent {
+    private SystemActivity activity;
+    /**
+     * Create a new ApplicationEvent.
+     *
+     * @param source the object on which the event initially occurred (never {@code null})
+     * @param activity system activity
+     */
+    public SystemEvent(Object source, SystemActivity activity) {
+        super(source);
+        this.activity = activity;
+    }
+
+    public SystemActivity getActivity() {
+        return activity;
+    }
+}
diff --git a/src/main/java/com/juick/service/component/TopEvent.java b/src/main/java/com/juick/service/component/TopEvent.java
deleted file mode 100644
index b7e24957..00000000
--- a/src/main/java/com/juick/service/component/TopEvent.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package com.juick.service.component;
-
-import com.juick.Message;
-import org.springframework.context.ApplicationEvent;
-
-public class TopEvent extends ApplicationEvent {
-    private Message message;
-    /**
-     * Create a new ApplicationEvent.
-     *
-     * @param source the object on which the event initially occurred (never {@code null})
-     */
-    public TopEvent(Object source, Message message) {
-        super(source);
-        this.message = message;
-    }
-
-    public Message getMessage() {
-        return message;
-    }
-}
diff --git a/src/test/java/com/juick/server/MockNotificationListener.java b/src/test/java/com/juick/server/MockNotificationListener.java
index 4fc9a1d9..c3a929fd 100644
--- a/src/test/java/com/juick/server/MockNotificationListener.java
+++ b/src/test/java/com/juick/server/MockNotificationListener.java
@@ -1,13 +1,13 @@
 package com.juick.server;
 
-import com.juick.service.component.TopEvent;
+import com.juick.service.component.SystemEvent;
 import org.springframework.context.ApplicationListener;
 
 import javax.annotation.Nonnull;
 
-public class MockNotificationListener implements ApplicationListener<TopEvent> {
+public class MockNotificationListener implements ApplicationListener<SystemEvent> {
     @Override
-    public void onApplicationEvent(@Nonnull TopEvent event) {
+    public void onApplicationEvent(@Nonnull SystemEvent event) {
 
     }
 }
diff --git a/src/test/java/com/juick/server/tests/ServerTests.java b/src/test/java/com/juick/server/tests/ServerTests.java
index 901d1501..e5d39743 100644
--- a/src/test/java/com/juick/server/tests/ServerTests.java
+++ b/src/test/java/com/juick/server/tests/ServerTests.java
@@ -18,6 +18,7 @@
 package com.juick.server.tests;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -34,6 +35,7 @@ import com.juick.model.CommandResult;
 import com.juick.model.PrivateChats;
 import com.juick.model.TagStats;
 import com.juick.server.*;
+import com.juick.server.api.SystemActivity;
 import com.juick.server.api.Users;
 import com.juick.server.api.activity.Profile;
 import com.juick.server.api.activity.model.Context;
@@ -46,8 +48,7 @@ import com.juick.server.util.HttpUtils;
 import com.juick.server.util.ImageUtils;
 import com.juick.server.www.WebApp;
 import com.juick.service.*;
-import com.juick.service.component.MessageEvent;
-import com.juick.service.component.TopEvent;
+import com.juick.service.component.SystemEvent;
 import com.juick.test.util.MockUtils;
 import com.juick.util.DateFormattersHolder;
 import com.juick.util.MessageUtils;
@@ -1011,8 +1012,8 @@ public class ServerTests {
         assertThat(lastRead.apply(ugnich, mid), is(freefdrid));
         privacyQueriesService.blacklistUser(ugnich, freefd);
         int newfreefdrid = messagesService.createReply(mid, 0, freefd, "from ban", null);
-        serverManager.processMessageEvent(new MessageEvent(this, messagesService.getReply(mid, newfreefdrid),
-                Collections.emptyList()));
+        serverManager.processSystemEvent(new SystemEvent(this, SystemActivity.message(juick, messagesService.getReply(mid, newfreefdrid),
+                Collections.emptyList())));
         assertThat(userService.isReplyToBL(ugnich, messagesService.getReply(mid, newfreefdrid)), is(true));
         // TODO: test event listeners correctly
         Thread.sleep(2000L);
@@ -2159,16 +2160,16 @@ public class ServerTests {
     @MockBean
     private MockNotificationListener notificationListener;
     @Captor
-    protected ArgumentCaptor<TopEvent> topEventCaptor;
+    protected ArgumentCaptor<SystemEvent> topEventCaptor;
     @Test
     public void topEventShouldNotLossUser() {
         Message topMessage = MockUtils.mockMessage(1000, ugnich, "top message");
         topMessage.setTo(AnonymousUser.INSTANCE);
-        TopEvent event = new TopEvent(this, topMessage);
+        SystemEvent event = new SystemEvent(this, SystemActivity.like(juick, topMessage, Collections.emptyList()));
         applicationEventPublisher.publishEvent(event);
         Mockito.verify(notificationListener, Mockito.times(1)).onApplicationEvent(topEventCaptor.capture());
-        TopEvent receivedEvent = topEventCaptor.getValue();
-        assertThat(receivedEvent.getMessage().getUser(), is(ugnich));
+        SystemEvent receivedEvent = topEventCaptor.getValue();
+        assertThat(receivedEvent.getActivity().getMessage().getUser(), is(ugnich));
     }
     @Test
     public void tagStatsSpec() throws Exception {
@@ -2221,4 +2222,11 @@ public class ServerTests {
         var authorResult = commandsManager.processCommand(ugnich, String.format("#%d PEOPLE", mid), emptyUri);
         assertThat(authorResult.getNewMessage().isPresent(), is(true));
     }
+    @Test
+    public void activitySerializationTest() throws JsonProcessingException {
+        var freefd = MockUtils.mockUser(10, "freefd", "secret");
+        var like = SystemActivity.like(MockUtils.mockUser(1, "ugnich", "secret"),
+                MockUtils.mockMessage(1, freefd, "txt"), Collections.singletonList(freefd));
+        var likeStr = jsonMapper.writeValueAsString(like);
+    }
 }