server: refactoring

3 files changed, 571 insertions, 0 deletions

diff --git a/juick-common/src/main/java/com/juick/server/CommandsManager.java b/juick-common/src/main/java/com/juick/server/CommandsManager.java
new file mode 100644
index 00000000..9bde0884
--- /dev/null
+++ b/juick-common/src/main/java/com/juick/server/CommandsManager.java
@@ -0,0 +1,493 @@
+/*
+ * Copyright (C) 2008-2017, Juick
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.juick.server;
+
+import com.juick.Message;
+import com.juick.Tag;
+import com.juick.User;
+import com.juick.formatters.PlainTextFormatter;
+import com.juick.server.component.LikeEvent;
+import com.juick.server.component.MessageEvent;
+import com.juick.server.component.PingEvent;
+import com.juick.server.component.SubscribeEvent;
+import com.juick.server.helpers.CommandResult;
+import com.juick.server.helpers.TagStats;
+import com.juick.server.helpers.annotation.UserCommand;
+import com.juick.server.util.HttpUtils;
+import com.juick.server.util.ImageUtils;
+import com.juick.server.util.TagUtils;
+import com.juick.service.*;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.math.NumberUtils;
+import org.apache.commons.lang3.reflect.MethodUtils;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.stereotype.Component;
+import rocks.xmpp.addr.Jid;
+
+import javax.annotation.Nonnull;
+import javax.inject.Inject;
+import java.lang.reflect.Method;
+import java.net.URI;
+import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+/**
+ *
+ * @author ugnich
+ */
+@Component
+public class CommandsManager {
+    @Inject
+    private MessagesService messagesService;
+    @Inject
+    private UserService userService;
+    @Inject
+    private TagService tagService;
+    @Inject
+    private PMQueriesService pmQueriesService;
+    @Inject
+    private ShowQueriesService showQueriesService;
+    @Inject
+    private PrivacyQueriesService privacyQueriesService;
+    @Inject
+    private SubscriptionService subscriptionService;
+    @Value("${upload_tmp_dir:#{systemEnvironment['TEMP'] ?: '/tmp'}}")
+    private String tmpDir;
+    @Value("${img_path:#{systemEnvironment['TEMP'] ?: '/tmp'}}")
+    private String imgDir;
+    @Inject
+    private ApplicationEventPublisher applicationEventPublisher;
+
+    public CommandResult processCommand(User user, Jid from, String input, @Nonnull URI attachment) throws Exception {
+        Optional<Method> cmd = MethodUtils.getMethodsListWithAnnotation(getClass(), UserCommand.class).stream()
+                .filter(m -> Pattern.compile(m.getAnnotation(UserCommand.class).pattern(),
+                        m.getAnnotation(UserCommand.class).patternFlags()).matcher(input).matches())
+                .findFirst();
+        if (cmd.isPresent()) {
+            Matcher matcher = Pattern.compile(cmd.get().getAnnotation(UserCommand.class).pattern(),
+                    cmd.get().getAnnotation(UserCommand.class).patternFlags()).matcher(input);
+            List<String> groups = new ArrayList<>();
+            while (matcher.find()) {
+                for (int i = 1; i <= matcher.groupCount(); i++) {
+                    groups.add(matcher.group(i));
+                }
+            }
+            return (CommandResult) getClass().getMethod(cmd.get().getName(), User.class, Jid.class, URI.class, String[].class)
+                    .invoke(this, user, from, attachment, groups.toArray(new String[groups.size()]));
+        }
+        // new message
+        List<Tag> tags = tagService.fromString(input, false);
+        String body = input.substring(TagUtils.toString(tags).length());
+        String attachmentType = StringUtils.isNotEmpty(attachment.toString()) ? attachment.toString().substring(attachment.toString().length() - 3) : null;
+        int mid = messagesService.createMessage(user.getUid(), body, attachmentType, tags);
+        subscriptionService.subscribeMessage(mid, user.getUid());
+        if (StringUtils.isNotEmpty(attachmentType)) {
+            String attachmentFName = attachment.getScheme().equals("juick") ? attachment.getHost()
+                    : HttpUtils.downloadImage(attachment.toURL(), tmpDir).getHost();
+            String fname = String.format("%d.%s", mid, attachmentType);
+            ImageUtils.saveImageWithPreviews(attachmentFName, fname, tmpDir, imgDir);
+        }
+        com.juick.Message msg = messagesService.getMessage(mid);
+        applicationEventPublisher.publishEvent(new MessageEvent(this, msg));
+        return CommandResult.fromMessage(msg, StringUtils.EMPTY);
+    }
+
+    @UserCommand(pattern = "^ping$", patternFlags = Pattern.CASE_INSENSITIVE,
+            help = "PING - returns you a PONG")
+    public CommandResult commandPing(User user, Jid from, URI attachment, String[] input) {
+        applicationEventPublisher.publishEvent(new PingEvent(this, user));
+        return CommandResult.fromString("PONG");
+    }
+
+    @UserCommand(pattern = "^help$", patternFlags = Pattern.CASE_INSENSITIVE,
+            help = "HELP - returns this help message")
+    public CommandResult commandHelp(User user, Jid from, URI attachment, String[] input) {
+        return CommandResult.fromString(Arrays.stream(getClass().getDeclaredMethods())
+                .filter(m -> m.isAnnotationPresent(UserCommand.class))
+                .map(m -> m.getAnnotation(UserCommand.class).help())
+                .collect(Collectors.joining("\n")));
+    }
+
+    @UserCommand(pattern = "^login$", patternFlags = Pattern.CASE_INSENSITIVE,
+            help = "LOGIN - log in to Juick website")
+    public CommandResult commandLogin(User user_from, Jid from, URI attachment, String[] input) {
+        return CommandResult.fromString("http://juick.com/login?hash=" + userService.getHashByUID(user_from.getUid()));
+    }
+    @UserCommand(pattern = "^\\@(\\S+)\\s+([\\s\\S]+)$", help = "@username message - send PM to username")
+    public CommandResult commandPM(User user_from, Jid from, URI attachment, String... arguments) {
+        String body = arguments[1];
+
+        User user_to = userService.getUserByName(arguments[0]);
+
+        if (user_to.getUid() > 0) {
+            if (!userService.isInBLAny(user_to.getUid(), user_from.getUid())) {
+                if (pmQueriesService.createPM(user_from.getUid(), user_to.getUid(), body)) {
+                    com.juick.Message jmsg = new com.juick.Message();
+                    jmsg.setUser(user_from);
+                    jmsg.setTo(user_to);
+                    jmsg.setText(body);
+                    applicationEventPublisher.publishEvent(new MessageEvent(this, jmsg));
+                    return CommandResult.fromString("Private message sent");
+                }
+            }
+        }
+        return CommandResult.fromString("Error");
+    }
+    @UserCommand(pattern = "^bl$", patternFlags = Pattern.CASE_INSENSITIVE,
+            help = "BL - Show your blacklist")
+    public CommandResult commandBLShow(User user_from, Jid from, URI attachment, String... arguments) {
+        List<User> blusers = userService.getUserBLUsers(user_from.getUid());
+        List<String> bltags = tagService.getUserBLTags(user_from.getUid());
+
+        String txt = StringUtils.EMPTY;
+        if (bltags.size() > 0) {
+            for (String bltag : bltags) {
+                txt += "*" + bltag + "\n";
+            }
+
+            if (blusers.size() > 0) {
+                txt += "\n";
+            }
+        }
+        if (blusers.size() > 0) {
+            for (User bluser : blusers) {
+                txt += "@" + bluser.getName() + "\n";
+            }
+        }
+        if (txt.isEmpty()) {
+            txt = "You don't have any users or tags in your blacklist.";
+        }
+
+        return CommandResult.fromString(txt);
+    }
+
+    @UserCommand(pattern = "^#\\+$", help = "#+ - Show last Juick messages")
+    public CommandResult commandLast(User user_from, Jid from, URI attachment, String... arguments) {
+        return CommandResult.fromString("Last messages:\n"
+                + printMessages(messagesService.getAll(user_from.getUid(), 0), true));
+    }
+
+    @UserCommand(pattern = "@", help = "@ - Show recommendations and popular personal blogs")
+    public CommandResult commandUsers(User user_from, Jid from, URI attachment, String... arguments) {
+        StringBuilder msg = new StringBuilder();
+        msg.append("Recommended blogs");
+        List<String> recommendedUsers = showQueriesService.getRecommendedUsers(user_from);
+        if (recommendedUsers.size() > 0) {
+            for (String user : recommendedUsers) {
+                msg.append("\n@").append(user);
+            }
+        } else {
+            msg.append("\nNo recommendations now. Subscribe to more blogs. ;)");
+        }
+        msg.append("\n\nTop 10 personal blogs:");
+        List<String> topUsers = showQueriesService.getTopUsers();
+        if (topUsers.size() > 0) {
+            for (String user : topUsers) {
+                msg.append("\n@").append(user);
+            }
+        } else {
+            msg.append("\nNo top users. Empty DB? ;)");
+        }
+        return CommandResult.fromString(msg.toString());
+    }
+    @UserCommand(pattern = "^bl\\s+@([^\\s\\n\\+]+)", patternFlags = Pattern.CASE_INSENSITIVE,
+            help = "BL @username - add @username to your blacklist")
+    public CommandResult blacklistUser(User user_from, Jid from, URI attachment, String... arguments) {
+        User blUser = userService.getUserByName(arguments[0]);
+        if (blUser != null) {
+            PrivacyQueriesService.PrivacyResult result = privacyQueriesService.blacklistUser(user_from, blUser);
+            if (result == PrivacyQueriesService.PrivacyResult.Added) {
+                return CommandResult.fromString("User added to your blacklist");
+            } else {
+                return CommandResult.fromString("User removed from your blacklist");
+            }
+        }
+        return CommandResult.fromString("User not found");
+    }
+    @UserCommand(pattern = "^bl\\s\\*(\\S+)$", patternFlags = Pattern.CASE_INSENSITIVE,
+            help = "BL *tag - add *tag to your blacklist")
+    public CommandResult blacklistTag(User user_from, Jid from, URI attachment, String... arguments) {
+        User blUser = userService.getUserByName(arguments[0]);
+        if (blUser != null) {
+            Tag tag = tagService.getTag(arguments[0], false);
+            if (tag != null) {
+                PrivacyQueriesService.PrivacyResult result = privacyQueriesService.blacklistTag(user_from, tag);
+                if (result == PrivacyQueriesService.PrivacyResult.Added) {
+                    return CommandResult.fromString("Tag added to your blacklist");
+                } else {
+                    return CommandResult.fromString("Tag removed from your blacklist");
+                }
+            }
+        }
+        return CommandResult.fromString("Tag not found");
+    }
+    @UserCommand(pattern = "\\*", help = "* - Show your tags")
+    public CommandResult commandTags(User currentUser, Jid from, URI attachment, String... args) {
+        List<TagStats> tags = tagService.getUserTagStats(currentUser.getUid());
+        String msg = "Your tags: (tag - messages)\n" +
+                tags.stream()
+                        .map(t -> String.format("\n*%s - %d", t.getTag().getName(), t.getUsageCount())).collect(Collectors.joining());
+        return CommandResult.fromString(msg);
+    }
+    @UserCommand(pattern = "S", help = "S - Show your subscriptions")
+    public CommandResult commandSubscriptions(User currentUser, Jid from, URI attachment, String... args) {
+        List<User> friends = userService.getUserFriends(currentUser.getUid());
+        List<String> tags = subscriptionService.getSubscribedTags(currentUser);
+        String msg = friends.size() > 0 ? "You are subscribed to users:" + friends.stream().map(u -> "\n@" + u.getName())
+                .collect(Collectors.joining())
+                : "You are not subscribed to any user.";
+        msg += tags.size() > 0 ? "\nYou are subscribed to tags:" + tags.stream().map(t -> "\n*" + t)
+                .collect(Collectors.joining())
+                : "\nYou are not subscribed to any tag.";
+        return CommandResult.fromString(msg);
+    }
+    @UserCommand(pattern = "!", help = "! - Show your favorite messages")
+    public CommandResult commandFavorites(User currentUser, Jid from, URI attachment, String... args) {
+        List<Integer> mids = messagesService.getUserRecommendations(currentUser.getUid(), 0);
+        if (mids.size() > 0) {
+            return CommandResult.fromString("Favorite messages: \n" + printMessages(mids, false));
+        }
+        return CommandResult.fromString("No favorite messages, try to \"like\" something ;)");
+    }
+    @UserCommand(pattern = "^\\!\\s+#(\\d+)", help = "! #12345 - recommend message")
+    public CommandResult commandRecommend(User user, Jid from, URI attachment, String... arguments) {
+        int mid = NumberUtils.toInt(arguments[0], 0);
+        if (mid > 0) {
+            com.juick.Message msg = messagesService.getMessage(mid);
+            if (msg != null) {
+                if (msg.getUser() == user) {
+                    return CommandResult.fromString("You can't recommend your own messages.");
+                }
+                MessagesService.RecommendStatus status = messagesService.recommendMessage(mid, user.getUid());
+                switch (status) {
+                    case Added:
+                        applicationEventPublisher.publishEvent(new LikeEvent(this, user, msg));
+                        return CommandResult.fromString("Message is added to your recommendations");
+                    case Deleted:
+                        return CommandResult.fromString("Message deleted from your recommendations.");
+                }
+            }
+            return CommandResult.fromString("Message not found");
+        }
+        return CommandResult.fromString("Message not found");
+    }
+    // TODO: target notification
+    @UserCommand(pattern = "^(s|u)\\s+\\@(\\S+)$", help = "S @username - subscribe to user" +
+            "\nU @username - unsubscribe from user", patternFlags = Pattern.CASE_INSENSITIVE)
+    public CommandResult commandSubscribeUser(User user, Jid from, URI attachment, String... args) {
+        boolean subscribe = args[0].equalsIgnoreCase("s");
+        User toUser = userService.getUserByName(args[1]);
+        if (subscribe) {
+            if (subscriptionService.subscribeUser(user, toUser)) {
+                // TODO: already subscribed case
+                applicationEventPublisher.publishEvent(new SubscribeEvent(this, user, toUser));
+                return CommandResult.fromString("Subscribed to @" + toUser.getName());
+            }
+        } else {
+            if (subscriptionService.unSubscribeUser(user, toUser)) {
+                return CommandResult.fromString("Unsubscribed from @" + toUser.getName());
+            }
+            return CommandResult.fromString("You was not subscribed to @" + toUser.getName());
+        }
+        return CommandResult.fromString("Error");
+    }
+    @UserCommand(pattern = "^(s|u)\\s+\\*(\\S+)$", help = "S *tag - subscribe to tag" +
+            "\nU *tag - unsubscribe from tag", patternFlags = Pattern.CASE_INSENSITIVE)
+    public CommandResult commandSubscribeTag(User user, Jid from, URI attachment, String... args) {
+        boolean subscribe = args[0].equalsIgnoreCase("s");
+        Tag tag = tagService.getTag(args[1], true);
+        if (subscribe) {
+            if (subscriptionService.subscribeTag(user, tag)) {
+                return CommandResult.fromString("Subscribed");
+            }
+        } else {
+            if (subscriptionService.unSubscribeTag(user, tag)) {
+                return CommandResult.fromString("Unsubscribed from " + tag.getName());
+            }
+            return CommandResult.fromString("You was not subscribed to " + tag.getName());
+        }
+        return CommandResult.fromString("Error");
+    }
+    @UserCommand(pattern = "^(s|u)\\s+#(\\d+)$", help = "S #1234 - subscribe to comments" +
+            "\nU #1234 - unsubscribe from comments", patternFlags = Pattern.CASE_INSENSITIVE)
+    public CommandResult commandSubscribeMessage(User user, Jid from, URI attachment, String... args) {
+        boolean subscribe = args[0].equalsIgnoreCase("s");
+        int mid = NumberUtils.toInt(args[1], 0);
+        if (messagesService.getMessage(mid) != null) {
+            if (subscribe) {
+                if (subscriptionService.subscribeMessage(mid, user.getUid())) {
+                    return CommandResult.fromString("Subscribed");
+                }
+            } else {
+                if (subscriptionService.unSubscribeMessage(mid, user.getUid())) {
+                    return CommandResult.fromString("Unsubscribed from #" + mid);
+                }
+                return CommandResult.fromString("You was not subscribed to #" + mid);
+            }
+        }
+        return CommandResult.fromString("Error");
+    }
+    @UserCommand(pattern = "^(on|off)$", patternFlags = Pattern.CASE_INSENSITIVE,
+            help = "ON/OFF - Enable/disable subscriptions delivery")
+    public CommandResult commandOnOff(User user, Jid from, URI attachment, String[] input) {
+        UserService.ActiveStatus newStatus;
+        String retValUpdated;
+        if (input[0].toLowerCase().equals("on")) {
+            newStatus = UserService.ActiveStatus.Active;
+            retValUpdated = "Notifications are activated for " + from.asBareJid().toEscapedString();
+        } else {
+            newStatus = UserService.ActiveStatus.Inactive;
+            retValUpdated = "Notifications are disabled for " + from.asBareJid().toEscapedString();
+        }
+
+        if (userService.setActiveStatusForJID(from.asBareJid().toEscapedString(), newStatus)) {
+            return CommandResult.fromString(retValUpdated);
+        } else {
+            return CommandResult.fromString(String.format("Subscriptions status for %s was not changed", from.toEscapedString()));
+        }
+    }
+    @UserCommand(pattern = "^\\@([^\\s\\n\\+]+)(\\+?)$",
+            help = "@username+ - Show user's info and last 20 messages")
+    public CommandResult commandUser(User user, Jid from, URI attachment, String... arguments) {
+        User blogUser = userService.getUserByName(arguments[0]);
+        int page = arguments[1].length();
+        if (blogUser.getUid() > 0) {
+            List<Integer> mids = messagesService.getUserBlog(blogUser.getUid(), 0, 0);
+            return CommandResult.fromString(String.format("Last messages from @%s:\n%s", arguments[0],
+                    printMessages(mids, false)));
+        }
+        return CommandResult.fromString("User not found");
+    }
+    @UserCommand(pattern = "^#(\\d+)(\\+?)$", help = "#1234 - Show message (#1234+ - message with replies)")
+    public CommandResult commandShow(User user, Jid from, URI attachment, String... arguments) {
+        boolean showReplies = arguments[1].length() > 0;
+        int mid = NumberUtils.toInt(arguments[0], 0);
+        if (mid == 0) {
+            return CommandResult.fromString("Error");
+        }
+        com.juick.Message msg = messagesService.getMessage(mid);
+        if (msg != null) {
+            if (showReplies) {
+                List<com.juick.Message> replies = messagesService.getReplies(mid);
+                replies.add(0, msg);
+                return CommandResult.fromString(String.join("\n",
+                        replies.stream().map(PlainTextFormatter::formatPostSummary).collect(Collectors.toList())));
+            }
+            return CommandResult.fromString(PlainTextFormatter.formatPost(msg));
+        }
+        return CommandResult.fromString("Message not found");
+    }
+    @UserCommand(pattern = "^#(\\d+)\\/(\\d+)$", help = "#1234/5 - Show reply")
+    public CommandResult commandShowReply(User user, Jid from, URI attachment, String... arguments) {
+        int mid = NumberUtils.toInt(arguments[0], 0);
+        int rid = NumberUtils.toInt(arguments[1], 0);
+        com.juick.Message reply = messagesService.getReply(mid, rid);
+        if (reply != null) {
+            return CommandResult.fromString(PlainTextFormatter.formatPost(reply));
+        }
+        return CommandResult.fromString("Reply not found");
+    }
+    @UserCommand(pattern = "^\\*(\\S+)(\\+?)$", help = "*tag - Show last messages with tag")
+    public CommandResult commandShowTag(User user, Jid from, URI attachment, String... arguments) {
+        Tag tag = tagService.getTag(arguments[0], false);
+        if (tag != null) {
+            // TODO: synonims
+            List<Integer> mids = messagesService.getTag(tag.TID, user.getUid(), 0, 10);
+            return CommandResult.fromString("Last messages with *" + tag.getName() + ":\n" + printMessages(mids, true));
+        }
+        return CommandResult.fromString("Tag not found");
+    }
+    @UserCommand(pattern = "^D #(\\d+)$", help = "D #1234 - Delete post", patternFlags = Pattern.CASE_INSENSITIVE)
+    public CommandResult commandDeletePost(User user, Jid from, URI attachment, String... args) {
+        int mid = Integer.valueOf(args[0]);
+        if (messagesService.deleteMessage(user.getUid(), mid)) {
+            return CommandResult.fromString("Message deleted");
+        }
+        return CommandResult.fromString("This is not your message");
+    }
+    @UserCommand(pattern = "^D #(\\d+)(\\.|\\-|\\/)(\\d+)$", help = "D #1234/5 - Delete comment", patternFlags = Pattern.CASE_INSENSITIVE)
+    public CommandResult commandDeleteReply(User user, Jid from, URI attachment, String... args) {
+        int mid = Integer.valueOf(args[0]);
+        int rid = Integer.valueOf(args[2]);
+        if (messagesService.deleteReply(user.getUid(), mid, rid)) {
+            return CommandResult.fromString("Reply deleted");
+        } else {
+            return CommandResult.fromString("This is not your reply");
+        }
+    }
+    @UserCommand(pattern = "^(D L|DL|D LAST)$", help = "D L - Delete last message", patternFlags = Pattern.CASE_INSENSITIVE)
+    public CommandResult commandDeleteLast(User user, Jid from, URI attachment, String... args) {
+        return CommandResult.fromString("Temporarily unavailable");
+    }
+    @UserCommand(pattern = "^\\?\\s+\\@([a-zA-Z0-9\\-\\.\\@]+)\\s+([\\s\\S]+)$", help = "? @user string - search in user messages")
+    public CommandResult commandSearch(User user, Jid from, URI attachment, String... args) {
+        return CommandResult.fromString("Temporarily unavailable");
+    }
+    @UserCommand(pattern = "^\\?\\s+([\\s\\S]+)$", help = "? string - search in all messages")
+    public CommandResult commandSearchAll(User user, Jid from, URI attachment, String... args) {
+        return CommandResult.fromString("Temporarily unavailable");
+    }
+    @UserCommand(pattern = "^(#+)$", help = "# - Show last messages from your feed (## - second page, ...)")
+    public CommandResult commandMyFeed(User user, Jid from, URI attachment, String... arguments) {
+        // number of # is the page count
+        int page = arguments[0].length() - 1;
+        List<Integer> mids = messagesService.getMyFeed(user.getUid(), page, false);
+        if (mids.size() > 0) {
+            return CommandResult.fromString("Your feed: \n" + printMessages(mids, true));
+        }
+        return CommandResult.fromString("Your feed is empty");
+    }
+    @UserCommand(pattern = "^(#|\\.)(\\d+)((\\.|\\-|\\/)(\\d+))?\\s([\\s\\S]+)?",
+            help = "#1234 *tag *tag2 - edit tags\n#1234 text - reply to message")
+    public CommandResult EditOrReply(User user, Jid from, @Nonnull URI attachment, String... args) throws Exception {
+        int mid = NumberUtils.toInt(args[1]);
+        int rid = NumberUtils.toInt(args[4], 0);
+        String txt = StringUtils.defaultString(args[5]);
+        List<Tag> messageTags = tagService.fromString(txt, true);
+        if (messageTags.size() > 0) {
+            if (user.getUid() != messagesService.getMessageAuthor(mid).getUid()) {
+                return CommandResult.fromString("It is not your message");
+            }
+            tagService.updateTags(mid, messageTags);
+            return CommandResult.fromString("Tags are updated");
+        } else {
+            String attachmentStr = attachment.toString();
+            String attachmentType = StringUtils.isNotEmpty(attachmentStr) ? attachmentStr.substring(attachmentStr.length() - 3) : null;
+            int newrid = messagesService.createReply(mid, rid, user.getUid(), txt, attachmentType);
+            if (StringUtils.isNotEmpty(attachmentType)) {
+                String attachmentFName = attachment.getScheme().equals("juick") ? attachment.getHost()
+                        : HttpUtils.downloadImage(attachment.toURL(), tmpDir).getHost();
+                String fname = String.format("%d-%d.%s", mid, newrid, attachmentType);
+                ImageUtils.saveImageWithPreviews(attachmentFName, fname, tmpDir, imgDir);
+            }
+            Message reply = messagesService.getReply(mid, newrid);
+            applicationEventPublisher.publishEvent(new MessageEvent(this, reply));
+            return CommandResult.fromMessage(reply,"Reply posted.\n#" + mid + "/" + newrid + " "
+                    + "https://juick.com/" + mid + "#" + newrid);
+        }
+    }
+
+    String printMessages(List<Integer> mids, boolean crop) {
+        return messagesService.getMessages(mids).stream()
+                .sorted(Collections.reverseOrder())
+                .map(PlainTextFormatter::formatPostSummary).collect(Collectors.joining("\n\n"));
+    }
+}
diff --git a/juick-common/src/main/java/com/juick/server/helpers/CommandResult.java b/juick-common/src/main/java/com/juick/server/helpers/CommandResult.java
new file mode 100644
index 00000000..29244115
--- /dev/null
+++ b/juick-common/src/main/java/com/juick/server/helpers/CommandResult.java
@@ -0,0 +1,28 @@
+package com.juick.server.helpers;
+
+import com.juick.Message;
+
+public class CommandResult {
+    private String text;
+    private Message newMessage;
+
+    public String getText() {
+        return text;
+    }
+
+    public Message getNewMessage() {
+        return newMessage;
+    }
+    public static CommandResult fromMessage(Message newMessage, String text) {
+        CommandResult result = new CommandResult();
+        result.newMessage = newMessage;
+        result.text = text;
+        return result;
+    }
+    public static CommandResult fromString(String text) {
+        CommandResult result = new CommandResult();
+        result.text = text;
+        return result;
+    }
+
+}
diff --git a/juick-common/src/main/java/com/juick/server/helpers/annotation/UserCommand.java b/juick-common/src/main/java/com/juick/server/helpers/annotation/UserCommand.java
new file mode 100644
index 00000000..4f07001c
--- /dev/null
+++ b/juick-common/src/main/java/com/juick/server/helpers/annotation/UserCommand.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2008-2017, Juick
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.juick.server.helpers.annotation;
+
+import org.apache.commons.lang3.StringUtils;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Created by oxpa on 22.03.16.
+ */
+@Target({ElementType.TYPE, ElementType.METHOD})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface UserCommand {
+    /**
+     *
+     * @return a command pattern
+     */
+    String pattern() default StringUtils.EMPTY;
+
+    /**
+     *
+     * @return pattern flags
+     */
+    int patternFlags() default 0;
+
+    /**
+     *
+     * @return a string used in HELP command output. Basically, only 1 string
+     */
+    String help() default StringUtils.EMPTY;
+}