Start implementing activity log feature

31 files changed, 903 insertions, 265 deletions

diff --git a/spark-bukkit/build.gradle b/spark-bukkit/build.gradle
index e8c6721..836e389 100644
--- a/spark-bukkit/build.gradle
+++ b/spark-bukkit/build.gradle
@@ -1,6 +1,8 @@
 dependencies {
     compile project(':spark-common')
-    compile 'net.kyori:text-adapter-bukkit:1.0.3'
+    compile('net.kyori:text-adapter-bukkit:1.0.3') {
+        exclude(module: 'text')
+    }
     compileOnly 'org.spigotmc:spigot-api:1.12.2-R0.1-SNAPSHOT'
 }
 
diff --git a/spark-bukkit/src/main/java/me/lucko/spark/bukkit/BukkitCommandSender.java b/spark-bukkit/src/main/java/me/lucko/spark/bukkit/BukkitCommandSender.java
new file mode 100644
index 0000000..dacea76
--- /dev/null
+++ b/spark-bukkit/src/main/java/me/lucko/spark/bukkit/BukkitCommandSender.java
@@ -0,0 +1,61 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.bukkit;
+
+import me.lucko.spark.common.CommandSender;
+import net.kyori.text.Component;
+import net.kyori.text.adapter.bukkit.TextAdapter;
+
+public class BukkitCommandSender implements CommandSender {
+    private final org.bukkit.command.CommandSender sender;
+
+    public BukkitCommandSender(org.bukkit.command.CommandSender sender) {
+        this.sender = sender;
+    }
+
+    @Override
+    public String getName() {
+        return this.sender.getName();
+    }
+
+    @Override
+    public void sendMessage(Component message) {
+        TextAdapter.sendComponent(this.sender, message);
+    }
+
+    @Override
+    public boolean hasPermission(String permission) {
+        return this.sender.hasPermission(permission);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        BukkitCommandSender that = (BukkitCommandSender) o;
+        return this.sender.equals(that.sender);
+    }
+
+    @Override
+    public int hashCode() {
+        return this.sender.hashCode();
+    }
+}
diff --git a/spark-bukkit/src/main/java/me/lucko/spark/bukkit/SparkBukkitPlugin.java b/spark-bukkit/src/main/java/me/lucko/spark/bukkit/SparkBukkitPlugin.java
index 15c725d..ee85c70 100644
--- a/spark-bukkit/src/main/java/me/lucko/spark/bukkit/SparkBukkitPlugin.java
+++ b/spark-bukkit/src/main/java/me/lucko/spark/bukkit/SparkBukkitPlugin.java
@@ -20,29 +20,27 @@
 
 package me.lucko.spark.bukkit;
 
+import me.lucko.spark.common.CommandSender;
 import me.lucko.spark.common.SparkPlatform;
 import me.lucko.spark.common.SparkPlugin;
 import me.lucko.spark.common.command.CommandResponseHandler;
 import me.lucko.spark.common.monitor.tick.TpsCalculator;
 import me.lucko.spark.common.sampler.ThreadDumper;
 import me.lucko.spark.common.sampler.TickCounter;
-import net.kyori.text.Component;
 import net.kyori.text.TextComponent;
-import net.kyori.text.adapter.bukkit.TextAdapter;
 import org.bukkit.ChatColor;
 import org.bukkit.command.Command;
-import org.bukkit.command.CommandSender;
 import org.bukkit.plugin.java.JavaPlugin;
 
 import java.nio.file.Path;
-import java.util.Collections;
-import java.util.HashSet;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
 
-public class SparkBukkitPlugin extends JavaPlugin implements SparkPlugin<CommandSender> {
+public class SparkBukkitPlugin extends JavaPlugin implements SparkPlugin {
 
-    private final SparkPlatform<CommandSender> platform = new SparkPlatform<>(this);
+    private final SparkPlatform platform = new SparkPlatform(this);
 
     @Override
     public void onEnable() {
@@ -56,7 +54,7 @@ public class SparkBukkitPlugin extends JavaPlugin implements SparkPlugin<Command
                     return true;
                 }
 
-                CommandResponseHandler<CommandSender> resp = new CommandResponseHandler<>(this.platform, sender);
+                CommandResponseHandler resp = new CommandResponseHandler(this.platform, new BukkitCommandSender(sender));
                 TpsCalculator tpsCalculator = this.platform.getTpsCalculator();
                 resp.replyPrefixed(TextComponent.of("TPS from last 5s, 10s, 1m, 5m, 15m:"));
                 resp.replyPrefixed(TextComponent.builder(" ").append(tpsCalculator.toFormattedComponent()).build());
@@ -71,22 +69,14 @@ public class SparkBukkitPlugin extends JavaPlugin implements SparkPlugin<Command
     }
 
     @Override
-    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
-        if (!sender.hasPermission("spark")) {
-            sender.sendMessage(ChatColor.RED + "You do not have permission to use this command.");
-            return true;
-        }
-
-        this.platform.executeCommand(sender, args);
+    public boolean onCommand(org.bukkit.command.CommandSender sender, Command command, String label, String[] args) {
+        this.platform.executeCommand(new BukkitCommandSender(sender), args);
         return true;
     }
 
     @Override
-    public List<String> onTabComplete(CommandSender sender, Command command, String alias, String[] args) {
-        if (!sender.hasPermission("spark")) {
-            return Collections.emptyList();
-        }
-        return this.platform.tabCompleteCommand(sender, args);
+    public List<String> onTabComplete(org.bukkit.command.CommandSender sender, Command command, String alias, String[] args) {
+        return this.platform.tabCompleteCommand(new BukkitCommandSender(sender), args);
     }
 
     @Override
@@ -106,15 +96,10 @@ public class SparkBukkitPlugin extends JavaPlugin implements SparkPlugin<Command
 
     @Override
     public Set<CommandSender> getSendersWithPermission(String permission) {
-        Set<CommandSender> senders = new HashSet<>(getServer().getOnlinePlayers());
+        List<org.bukkit.command.CommandSender> senders = new LinkedList<>(getServer().getOnlinePlayers());
         senders.removeIf(sender -> !sender.hasPermission(permission));
         senders.add(getServer().getConsoleSender());
-        return senders;
-    }
-
-    @Override
-    public void sendMessage(CommandSender sender, Component message) {
-        TextAdapter.sendComponent(sender, message);
+        return senders.stream().map(BukkitCommandSender::new).collect(Collectors.toSet());
     }
 
     @Override
diff --git a/spark-bungeecord/build.gradle b/spark-bungeecord/build.gradle
index 55dcb4e..5ee50d7 100644
--- a/spark-bungeecord/build.gradle
+++ b/spark-bungeecord/build.gradle
@@ -1,6 +1,8 @@
 dependencies {
     compile project(':spark-common')
-    compile 'net.kyori:text-adapter-bungeecord:1.0.3'
+    compile('net.kyori:text-adapter-bungeecord:1.0.3') {
+        exclude(module: 'text')
+    }
     compileOnly 'net.md-5:bungeecord-api:1.12-SNAPSHOT'
 }
 
diff --git a/spark-bungeecord/src/main/java/me/lucko/spark/bungeecord/BungeeCordCommandSender.java b/spark-bungeecord/src/main/java/me/lucko/spark/bungeecord/BungeeCordCommandSender.java
new file mode 100644
index 0000000..d3a831c
--- /dev/null
+++ b/spark-bungeecord/src/main/java/me/lucko/spark/bungeecord/BungeeCordCommandSender.java
@@ -0,0 +1,61 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.bungeecord;
+
+import me.lucko.spark.common.CommandSender;
+import net.kyori.text.Component;
+import net.kyori.text.adapter.bungeecord.TextAdapter;
+
+public class BungeeCordCommandSender implements CommandSender {
+    private final net.md_5.bungee.api.CommandSender sender;
+
+    public BungeeCordCommandSender(net.md_5.bungee.api.CommandSender sender) {
+        this.sender = sender;
+    }
+
+    @Override
+    public String getName() {
+        return this.sender.getName();
+    }
+
+    @Override
+    public void sendMessage(Component message) {
+        TextAdapter.sendComponent(this.sender, message);
+    }
+
+    @Override
+    public boolean hasPermission(String permission) {
+        return this.sender.hasPermission(permission);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        BungeeCordCommandSender that = (BungeeCordCommandSender) o;
+        return this.sender.equals(that.sender);
+    }
+
+    @Override
+    public int hashCode() {
+        return this.sender.hashCode();
+    }
+}
diff --git a/spark-bungeecord/src/main/java/me/lucko/spark/bungeecord/SparkBungeeCordPlugin.java b/spark-bungeecord/src/main/java/me/lucko/spark/bungeecord/SparkBungeeCordPlugin.java
index ba2ee99..193ae06 100644
--- a/spark-bungeecord/src/main/java/me/lucko/spark/bungeecord/SparkBungeeCordPlugin.java
+++ b/spark-bungeecord/src/main/java/me/lucko/spark/bungeecord/SparkBungeeCordPlugin.java
@@ -20,27 +20,24 @@
 
 package me.lucko.spark.bungeecord;
 
+import me.lucko.spark.common.CommandSender;
 import me.lucko.spark.common.SparkPlatform;
 import me.lucko.spark.common.SparkPlugin;
 import me.lucko.spark.common.sampler.ThreadDumper;
 import me.lucko.spark.common.sampler.TickCounter;
-import net.kyori.text.Component;
-import net.kyori.text.adapter.bungeecord.TextAdapter;
-import net.md_5.bungee.api.ChatColor;
-import net.md_5.bungee.api.CommandSender;
-import net.md_5.bungee.api.chat.TextComponent;
 import net.md_5.bungee.api.plugin.Command;
 import net.md_5.bungee.api.plugin.Plugin;
 import net.md_5.bungee.api.plugin.TabExecutor;
 
 import java.nio.file.Path;
-import java.util.Collections;
-import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
 
-public class SparkBungeeCordPlugin extends Plugin implements SparkPlugin<CommandSender> {
+public class SparkBungeeCordPlugin extends Plugin implements SparkPlugin {
 
-    private final SparkPlatform<CommandSender> platform = new SparkPlatform<>(this);
+    private final SparkPlatform platform = new SparkPlatform(this);
 
     @Override
     public void onEnable() {
@@ -70,15 +67,10 @@ public class SparkBungeeCordPlugin extends Plugin implements SparkPlugin<Command
 
     @Override
     public Set<CommandSender> getSendersWithPermission(String permission) {
-        Set<CommandSender> senders = new HashSet<>(getProxy().getPlayers());
+        List<net.md_5.bungee.api.CommandSender> senders = new LinkedList<>(getProxy().getPlayers());
         senders.removeIf(sender -> !sender.hasPermission(permission));
         senders.add(getProxy().getConsole());
-        return senders;
-    }
-
-    @Override
-    public void sendMessage(CommandSender sender, Component message) {
-        TextAdapter.sendComponent(sender, message);
+        return senders.stream().map(BungeeCordCommandSender::new).collect(Collectors.toSet());
     }
 
     @Override
@@ -105,23 +97,13 @@ public class SparkBungeeCordPlugin extends Plugin implements SparkPlugin<Command
         }
 
         @Override
-        public void execute(CommandSender sender, String[] args) {
-            if (!sender.hasPermission("spark")) {
-                TextComponent msg = new TextComponent("You do not have permission to use this command.");
-                msg.setColor(ChatColor.RED);
-                sender.sendMessage(msg);
-                return;
-            }
-
-            this.plugin.platform.executeCommand(sender, args);
+        public void execute(net.md_5.bungee.api.CommandSender sender, String[] args) {
+            this.plugin.platform.executeCommand(new BungeeCordCommandSender(sender), args);
         }
 
         @Override
-        public Iterable<String> onTabComplete(CommandSender sender, String[] args) {
-            if (!sender.hasPermission("spark")) {
-                return Collections.emptyList();
-            }
-            return this.plugin.platform.tabCompleteCommand(sender, args);
+        public Iterable<String> onTabComplete(net.md_5.bungee.api.CommandSender sender, String[] args) {
+            return this.plugin.platform.tabCompleteCommand(new BungeeCordCommandSender(sender), args);
         }
     }
 }
diff --git a/spark-common/build.gradle b/spark-common/build.gradle
index a8b95c6..8a9ee16 100644
--- a/spark-common/build.gradle
+++ b/spark-common/build.gradle
@@ -1,7 +1,16 @@
 dependencies {
     compile 'com.squareup.okhttp3:okhttp:3.14.1'
     compile 'com.squareup.okio:okio:1.17.3'
-    compile 'net.kyori:text-api:2.0.0'
+    compile('net.kyori:text-api:2.0.0') {
+        exclude(module: 'checker-qual')
+    }
+    compile('net.kyori:text-serializer-gson:2.0.0') {
+        exclude(module: 'text-api')
+        exclude(module: 'gson')
+    }
+    compile('net.kyori:text-serializer-legacy:2.0.0') {
+        exclude(module: 'text-api')
+    }
     compileOnly 'com.google.code.gson:gson:2.7'
     compileOnly 'com.google.guava:guava:19.0'
 }
diff --git a/spark-common/src/main/java/me/lucko/spark/common/ActivityLog.java b/spark-common/src/main/java/me/lucko/spark/common/ActivityLog.java
new file mode 100644
index 0000000..4b5e942
--- /dev/null
+++ b/spark-common/src/main/java/me/lucko/spark/common/ActivityLog.java
@@ -0,0 +1,195 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.common;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import com.google.gson.JsonPrimitive;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+public class ActivityLog {
+
+    private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create();
+    private static final JsonParser PARSER = new JsonParser();
+
+    private final Path file;
+
+    private final List<Activity> log = new LinkedList<>();
+    private final Object[] mutex = new Object[0];
+
+    public ActivityLog(Path file) {
+        this.file = file;
+    }
+
+    public void addToLog(Activity activity) {
+        synchronized (this.mutex) {
+            this.log.add(activity);
+        }
+        save();
+    }
+
+    public List<Activity> getLog() {
+        synchronized (this.mutex) {
+            return new LinkedList<>(this.log);
+        }
+    }
+
+    public void save() {
+        JsonArray array = new JsonArray();
+        synchronized (this.mutex) {
+            for (Activity activity : this.log) {
+                if (!activity.shouldExpire()) {
+                    array.add(activity.serialize());
+                }
+            }
+        }
+
+        try {
+            Files.createDirectories(this.file.getParent());
+        } catch (IOException e) {
+            // ignore
+        }
+
+        try (BufferedWriter writer = Files.newBufferedWriter(this.file, StandardCharsets.UTF_8)) {
+            GSON.toJson(array, writer);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void load() {
+        if (!Files.exists(this.file)) {
+            synchronized (this.mutex) {
+                this.log.clear();
+                return;
+            }
+        }
+
+        JsonArray array;
+        try (BufferedReader reader = Files.newBufferedReader(this.file, StandardCharsets.UTF_8)) {
+            array = PARSER.parse(reader).getAsJsonArray();
+        } catch (IOException e) {
+            e.printStackTrace();
+            return;
+        }
+
+        boolean save = false;
+
+        synchronized (this.mutex) {
+            this.log.clear();
+            for (JsonElement element : array) {
+                try {
+                    Activity activity = Activity.deserialize(element);
+                    if (activity.shouldExpire()) {
+                        save = true;
+                    }
+                    this.log.add(activity);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+
+        if (save) {
+            try {
+                save();
+            } catch (Exception e) {
+                // ignore
+            }
+        }
+    }
+
+    public static final class Activity {
+        private final String user;
+        private final long time;
+        private final String type;
+        private final String url;
+
+        public Activity(String user, long time, String type, String url) {
+            this.user = user;
+            this.time = time;
+            this.type = type;
+            this.url = url;
+        }
+
+        public String getUser() {
+            return this.user;
+        }
+
+        public long getTime() {
+            return this.time;
+        }
+
+        public String getType() {
+            return this.type;
+        }
+
+        public String getUrl() {
+            return this.url;
+        }
+
+        public boolean shouldExpire() {
+            return (System.currentTimeMillis() - this.time) > TimeUnit.DAYS.toMillis(7);
+        }
+
+        public JsonObject serialize() {
+            JsonObject object = new JsonObject();
+
+            JsonObject user = new JsonObject();
+            user.add("name", new JsonPrimitive(this.user));
+            object.add("user", user);
+
+            object.add("time", new JsonPrimitive(this.time));
+            object.add("type", new JsonPrimitive(this.type));
+
+            JsonObject data = new JsonObject();
+            data.add("url", new JsonPrimitive(this.url));
+            object.add("data", data);
+
+            return object;
+        }
+
+        public static Activity deserialize(JsonElement element) {
+            JsonObject object = element.getAsJsonObject();
+
+            String user = object.get("user").getAsJsonObject().get("name").getAsJsonPrimitive().getAsString();
+            long time = object.get("time").getAsJsonPrimitive().getAsLong();
+            String type = object.get("type").getAsJsonPrimitive().getAsString();
+            String url = object.get("data").getAsJsonObject().get("url").getAsJsonPrimitive().getAsString();
+
+            return new Activity(user, time, type, url);
+        }
+    }
+
+}
diff --git a/spark-common/src/main/java/me/lucko/spark/common/CommandSender.java b/spark-common/src/main/java/me/lucko/spark/common/CommandSender.java
new file mode 100644
index 0000000..9d2ecc0
--- /dev/null
+++ b/spark-common/src/main/java/me/lucko/spark/common/CommandSender.java
@@ -0,0 +1,33 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.common;
+
+import net.kyori.text.Component;
+
+public interface CommandSender {
+
+    String getName();
+
+    void sendMessage(Component message);
+
+    boolean hasPermission(String permission);
+
+}
diff --git a/spark-common/src/main/java/me/lucko/spark/common/SparkPlatform.java b/spark-common/src/main/java/me/lucko/spark/common/SparkPlatform.java
index 6b3eb21..d05d9e8 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/SparkPlatform.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/SparkPlatform.java
@@ -24,6 +24,7 @@ import com.google.common.collect.ImmutableList;
 import me.lucko.spark.common.command.Arguments;
 import me.lucko.spark.common.command.Command;
 import me.lucko.spark.common.command.CommandResponseHandler;
+import me.lucko.spark.common.command.modules.ActivityLogModule;
 import me.lucko.spark.common.command.modules.HealthModule;
 import me.lucko.spark.common.command.modules.MemoryModule;
 import me.lucko.spark.common.command.modules.SamplerModule;
@@ -35,6 +36,7 @@ import me.lucko.spark.common.sampler.TickCounter;
 import me.lucko.spark.common.util.BytebinClient;
 import net.kyori.text.Component;
 import net.kyori.text.TextComponent;
+import net.kyori.text.event.ClickEvent;
 import net.kyori.text.format.TextColor;
 import net.kyori.text.format.TextDecoration;
 import okhttp3.OkHttpClient;
@@ -47,10 +49,8 @@ import java.util.stream.Collectors;
 
 /**
  * Abstract spark implementation used by all platforms.
- *
- * @param <S> the sender (e.g. CommandSender) type used by the platform
  */
-public class SparkPlatform<S> {
+public class SparkPlatform {
 
     /** The URL of the viewer frontend */
     public static final String VIEWER_URL = "https://sparkprofiler.github.io/#";
@@ -59,22 +59,26 @@ public class SparkPlatform<S> {
     /** The bytebin instance used by the platform */
     public static final BytebinClient BYTEBIN_CLIENT = new BytebinClient(OK_HTTP_CLIENT, "https://bytebin.lucko.me/", "spark-plugin");
 
-    private final List<Command<S>> commands;
-    private final SparkPlugin<S> plugin;
-
+    private final SparkPlugin plugin;
+    private final List<Command> commands;
+    private final ActivityLog activityLog;
     private final TickCounter tickCounter;
     private final TpsCalculator tpsCalculator;
 
-    public SparkPlatform(SparkPlugin<S> plugin) {
+    public SparkPlatform(SparkPlugin plugin) {
         this.plugin = plugin;
 
-        ImmutableList.Builder<Command<S>> commandsBuilder = ImmutableList.builder();
-        new SamplerModule<S>().registerCommands(commandsBuilder::add);
-        new HealthModule<S>().registerCommands(commandsBuilder::add);
-        new TickMonitoringModule<S>().registerCommands(commandsBuilder::add);
-        new MemoryModule<S>().registerCommands(commandsBuilder::add);
+        ImmutableList.Builder<Command> commandsBuilder = ImmutableList.builder();
+        new SamplerModule().registerCommands(commandsBuilder::add);
+        new HealthModule().registerCommands(commandsBuilder::add);
+        new TickMonitoringModule().registerCommands(commandsBuilder::add);
+        new MemoryModule().registerCommands(commandsBuilder::add);
+        new ActivityLogModule().registerCommands(commandsBuilder::add);
         this.commands = commandsBuilder.build();
 
+        this.activityLog = new ActivityLog(plugin.getPluginFolder().resolve("activity.json"));
+        this.activityLog.load();
+
         this.tickCounter = plugin.createTickCounter();
         this.tpsCalculator = this.tickCounter != null ? new TpsCalculator() : null;
     }
@@ -92,10 +96,14 @@ public class SparkPlatform<S> {
         }
     }
 
-    public SparkPlugin<S> getPlugin() {
+    public SparkPlugin getPlugin() {
         return this.plugin;
     }
 
+    public ActivityLog getActivityLog() {
+        return this.activityLog;
+    }
+
     public TickCounter getTickCounter() {
         return this.tickCounter;
     }
@@ -104,17 +112,39 @@ public class SparkPlatform<S> {
         return this.tpsCalculator;
     }
 
-    public void executeCommand(S sender, String[] args) {
-        CommandResponseHandler<S> resp = new CommandResponseHandler<>(this, sender);
+    public void executeCommand(CommandSender sender, String[] args) {
+        CommandResponseHandler resp = new CommandResponseHandler(this, sender);
+
+        if (!sender.hasPermission("spark")) {
+            resp.replyPrefixed(TextComponent.of("You do not have permission to use this command.", TextColor.RED));
+            return;
+        }
+
         if (args.length == 0) {
-            sendUsage(resp);
+            resp.replyPrefixed(TextComponent.builder("")
+                    .append(TextComponent.of("spark", TextColor.WHITE))
+                    .append(Component.space())
+                    .append(TextComponent.of("v" + getPlugin().getVersion(), TextColor.GRAY))
+                    .build()
+            );
+            resp.replyPrefixed(TextComponent.builder("").color(TextColor.GRAY)
+                    .append(TextComponent.of("Use "))
+                    .append(TextComponent.builder("/" + getPlugin().getLabel() + " help")
+                            .color(TextColor.WHITE)
+                            .decoration(TextDecoration.UNDERLINED, true)
+                            .clickEvent(new ClickEvent(ClickEvent.Action.RUN_COMMAND, getPlugin().getLabel() + " help"))
+                            .build()
+                    )
+                    .append(TextComponent.of(" to view usage information."))
+                    .build()
+            );
             return;
         }
 
         ArrayList<String> rawArgs = new ArrayList<>(Arrays.asList(args));
         String alias = rawArgs.remove(0).toLowerCase();
 
-        for (Command<S> command : this.commands) {
+        for (Command command : this.commands) {
             if (command.aliases().contains(alias)) {
                 try {
                     command.executor().execute(this, sender, resp, new Arguments(rawArgs));
@@ -129,7 +159,11 @@ public class SparkPlatform<S> {
         sendUsage(resp);
     }
 
-    public List<String> tabCompleteCommand(S sender, String[] args) {
+    public List<String> tabCompleteCommand(CommandSender sender, String[] args) {
+        if (!sender.hasPermission("spark")) {
+            return Collections.emptyList();
+        }
+
         List<String> arguments = new ArrayList<>(Arrays.asList(args));
 
         if (args.length <= 1) {
@@ -140,7 +174,7 @@ public class SparkPlatform<S> {
         }
 
         String alias = arguments.remove(0);
-        for (Command<S> command : this.commands) {
+        for (Command command : this.commands) {
             if (command.aliases().contains(alias)) {
                 return command.tabCompleter().completions(this, sender, arguments);
             }
@@ -149,18 +183,20 @@ public class SparkPlatform<S> {
         return Collections.emptyList();
     }
 
-    private void sendUsage(CommandResponseHandler<S> sender) {
-        sender.replyPrefixed(TextComponent.builder()
+    private void sendUsage(CommandResponseHandler sender) {
+        sender.replyPrefixed(TextComponent.builder("")
                 .append(TextComponent.of("spark", TextColor.WHITE))
                 .append(Component.space())
                 .append(TextComponent.of("v" + getPlugin().getVersion(), TextColor.GRAY))
                 .build()
         );
-        for (Command<S> command : this.commands) {
-            sender.reply(TextComponent.builder()
+        for (Command command : this.commands) {
+            String usage = getPlugin().getLabel() + " " + command.aliases().get(0);
+            ClickEvent clickEvent = new ClickEvent(ClickEvent.Action.SUGGEST_COMMAND, usage);
+            sender.reply(TextComponent.builder("")
                     .append(TextComponent.builder(">").color(TextColor.GOLD).decoration(TextDecoration.BOLD, true).build())
                     .append(Component.space())
-                    .append(TextComponent.of("/" + getPlugin().getLabel() + " " + command.aliases().get(0), TextColor.GRAY))
+                    .append(TextComponent.builder("/" + usage).color(TextColor.GRAY).clickEvent(clickEvent).build())
                     .build()
             );
             for (Command.ArgumentInfo arg : command.arguments()) {
diff --git a/spark-common/src/main/java/me/lucko/spark/common/SparkPlugin.java b/spark-common/src/main/java/me/lucko/spark/common/SparkPlugin.java
index 19eb3d3..175fda5 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/SparkPlugin.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/SparkPlugin.java
@@ -22,12 +22,11 @@ package me.lucko.spark.common;
 
 import me.lucko.spark.common.sampler.ThreadDumper;
 import me.lucko.spark.common.sampler.TickCounter;
-import net.kyori.text.Component;
 
 import java.nio.file.Path;
 import java.util.Set;
 
-public interface SparkPlugin<S> {
+public interface SparkPlugin {
 
     String getVersion();
 
@@ -35,9 +34,7 @@ public interface SparkPlugin<S> {
 
     String getLabel();
 
-    Set<S> getSendersWithPermission(String permission);
-
-    void sendMessage(S sender, Component message);
+    Set<CommandSender> getSendersWithPermission(String permission);
 
     void runAsync(Runnable r);
 
diff --git a/spark-common/src/main/java/me/lucko/spark/common/command/Command.java b/spark-common/src/main/java/me/lucko/spark/common/command/Command.java
index c9f6551..ab95cb6 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/command/Command.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/command/Command.java
@@ -21,24 +21,25 @@
 package me.lucko.spark.common.command;
 
 import com.google.common.collect.ImmutableList;
+import me.lucko.spark.common.CommandSender;
 import me.lucko.spark.common.SparkPlatform;
 
 import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 
-public class Command<S> {
+public class Command {
 
-    public static <S> Builder<S> builder() {
-        return new Builder<>();
+    public static Builder builder() {
+        return new Builder();
     }
 
     private final List<String> aliases;
     private final List<ArgumentInfo> arguments;
-    private final Executor<S> executor;
-    private final TabCompleter<S> tabCompleter;
+    private final Executor executor;
+    private final TabCompleter tabCompleter;
 
-    private Command(List<String> aliases, List<ArgumentInfo> arguments, Executor<S> executor, TabCompleter<S> tabCompleter) {
+    private Command(List<String> aliases, List<ArgumentInfo> arguments, Executor executor, TabCompleter tabCompleter) {
         this.aliases = aliases;
         this.arguments = arguments;
         this.executor = executor;
@@ -53,45 +54,45 @@ public class Command<S> {
         return this.arguments;
     }
 
-    public Executor<S> executor() {
+    public Executor executor() {
         return this.executor;
     }
 
-    public TabCompleter<S> tabCompleter() {
+    public TabCompleter tabCompleter() {
         return this.tabCompleter;
     }
 
-    public static final class Builder<S> {
+    public static final class Builder {
         private final ImmutableList.Builder<String> aliases = ImmutableList.builder();
         private final ImmutableList.Builder<ArgumentInfo> arguments = ImmutableList.builder();
-        private Executor<S> executor = null;
-        private TabCompleter<S> tabCompleter = null;
+        private Executor executor = null;
+        private TabCompleter tabCompleter = null;
 
         Builder() {
 
         }
 
-        public Builder<S> aliases(String... aliases) {
+        public Builder aliases(String... aliases) {
             this.aliases.add(aliases);
             return this;
         }
 
-        public Builder<S> argumentUsage(String argumentName, String parameterDescription) {
+        public Builder argumentUsage(String argumentName, String parameterDescription) {
             this.arguments.add(new ArgumentInfo(argumentName, parameterDescription));
             return this;
         }
 
-        public Builder<S> executor(Executor<S> executor) {
+        public Builder executor(Executor executor) {
             this.executor = Objects.requireNonNull(executor, "executor");
             return this;
         }
 
-        public Builder<S> tabCompleter(TabCompleter<S> tabCompleter) {
+        public Builder tabCompleter(TabCompleter tabCompleter) {
             this.tabCompleter = Objects.requireNonNull(tabCompleter, "tabCompleter");
             return this;
         }
 
-        public Command<S> build() {
+        public Command build() {
             List<String> aliases = this.aliases.build();
             if (aliases.isEmpty()) {
                 throw new IllegalStateException("No aliases defined");
@@ -102,22 +103,22 @@ public class Command<S> {
             if (this.tabCompleter == null) {
                 this.tabCompleter = TabCompleter.empty();
             }
-            return new Command<>(aliases, this.arguments.build(), this.executor, this.tabCompleter);
+            return new Command(aliases, this.arguments.build(), this.executor, this.tabCompleter);
         }
     }
 
     @FunctionalInterface
-    public interface Executor<S> {
-        void execute(SparkPlatform<S> platform, S sender, CommandResponseHandler resp, Arguments arguments);
+    public interface Executor {
+        void execute(SparkPlatform platform, CommandSender sender, CommandResponseHandler resp, Arguments arguments);
     }
 
     @FunctionalInterface
-    public interface TabCompleter<S> {
-        static <S> TabCompleter<S> empty() {
+    public interface TabCompleter {
+        static <S> TabCompleter empty() {
             return (platform, sender, arguments) -> Collections.emptyList();
         }
 
-        List<String> completions(SparkPlatform<S> platform, S sender, List<String> arguments);
+        List<String> completions(SparkPlatform platform, CommandSender sender, List<String> arguments);
     }
 
     public static final class ArgumentInfo {
diff --git a/spark-common/src/main/java/me/lucko/spark/common/command/CommandModule.java b/spark-common/src/main/java/me/lucko/spark/common/command/CommandModule.java
index f195ef2..76c24b3 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/command/CommandModule.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/command/CommandModule.java
@@ -22,8 +22,8 @@ package me.lucko.spark.common.command;
 
 import java.util.function.Consumer;
 
-public interface CommandModule<S> {
+public interface CommandModule {
 
-    void registerCommands(Consumer<Command<S>> consumer);
+    void registerCommands(Consumer<Command> consumer);
 
 }
diff --git a/spark-common/src/main/java/me/lucko/spark/common/command/CommandResponseHandler.java b/spark-common/src/main/java/me/lucko/spark/common/command/CommandResponseHandler.java
index 94e1946..d31d1cf 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/command/CommandResponseHandler.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/command/CommandResponseHandler.java
@@ -20,50 +20,50 @@
 
 package me.lucko.spark.common.command;
 
+import me.lucko.spark.common.CommandSender;
 import me.lucko.spark.common.SparkPlatform;
 import net.kyori.text.Component;
 import net.kyori.text.TextComponent;
-import net.kyori.text.event.ClickEvent;
 import net.kyori.text.format.TextColor;
 import net.kyori.text.format.TextDecoration;
 
 import java.util.Set;
 import java.util.function.Consumer;
 
-public class CommandResponseHandler<S> {
+public class CommandResponseHandler {
 
     /** The prefix used in all messages "&8[&e&l⚡&8] &7" */
-    private static final TextComponent PREFIX = TextComponent.builder().color(TextColor.GRAY)
+    private static final TextComponent PREFIX = TextComponent.builder("").color(TextColor.GRAY)
             .append(TextComponent.of("[", TextColor.DARK_GRAY))
             .append(TextComponent.builder("⚡").color(TextColor.YELLOW).decoration(TextDecoration.BOLD, TextDecoration.State.TRUE).build())
             .append(TextComponent.of("]", TextColor.DARK_GRAY))
             .append(TextComponent.of(" "))
             .build();
 
-    private final SparkPlatform<S> platform;
-    private final S sender;
+    private final SparkPlatform platform;
+    private final CommandSender sender;
 
-    public CommandResponseHandler(SparkPlatform<S> platform, S sender) {
+    public CommandResponseHandler(SparkPlatform platform, CommandSender sender) {
         this.platform = platform;
         this.sender = sender;
     }
 
-    public S sender() {
+    public CommandSender sender() {
         return this.sender;
     }
 
-    public void allSenders(Consumer<? super S> action) {
-        Set<S> senders = this.platform.getPlugin().getSendersWithPermission("spark");
+    public void allSenders(Consumer<? super CommandSender> action) {
+        Set<CommandSender> senders = this.platform.getPlugin().getSendersWithPermission("spark");
         senders.add(this.sender);
         senders.forEach(action);
     }
 
     public void reply(Component message) {
-        this.platform.getPlugin().sendMessage(this.sender, message);
+        this.sender.sendMessage(message);
     }
 
     public void broadcast(Component message) {
-        allSenders(sender -> this.platform.getPlugin().sendMessage(sender, message));
+        allSenders(sender -> sender.sendMessage(message));
     }
 
     public void replyPrefixed(Component message) {
diff --git a/spark-common/src/main/java/me/lucko/spark/common/command/modules/ActivityLogModule.java b/spark-common/src/main/java/me/lucko/spark/common/command/modules/ActivityLogModule.java
new file mode 100644
index 0000000..ad6b3e8
--- /dev/null
+++ b/spark-common/src/main/java/me/lucko/spark/common/command/modules/ActivityLogModule.java
@@ -0,0 +1,120 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.common.command.modules;
+
+import me.lucko.spark.common.ActivityLog;
+import me.lucko.spark.common.command.Command;
+import me.lucko.spark.common.command.CommandModule;
+import net.kyori.text.Component;
+import net.kyori.text.TextComponent;
+import net.kyori.text.event.ClickEvent;
+import net.kyori.text.format.TextColor;
+import net.kyori.text.format.TextDecoration;
+
+import java.util.List;
+import java.util.function.Consumer;
+
+public class ActivityLogModule implements CommandModule {
+
+    @Override
+    public void registerCommands(Consumer<Command> consumer) {
+        consumer.accept(Command.builder()
+                .aliases("activity", "activitylog", "log")
+                .executor((platform, sender, resp, arguments) -> {
+                    List<ActivityLog.Activity> log = platform.getActivityLog().getLog();
+                    log.removeIf(ActivityLog.Activity::shouldExpire);
+
+                    if (log.isEmpty()) {
+                        resp.replyPrefixed(TextComponent.of("There are no entries present in the log."));
+                        return;
+                    }
+
+                    resp.replyPrefixed(TextComponent.of("Showing recent spark activity...", TextColor.GOLD));
+
+                    int count = 0;
+                    for (ActivityLog.Activity activity : log) {
+                        count++;
+
+                        resp.replyPrefixed(TextComponent.builder("")
+                                .append(TextComponent.builder(">").color(TextColor.DARK_GRAY).decoration(TextDecoration.BOLD, true).build())
+                                .append(Component.space())
+                                .append(TextComponent.of("#" + count, TextColor.WHITE))
+                                .append(TextComponent.of(" - ", TextColor.DARK_GRAY))
+                                .append(TextComponent.of(activity.getType(), TextColor.YELLOW))
+                                .append(TextComponent.of(" - ", TextColor.DARK_GRAY))
+                                .append(TextComponent.of(formatDateDiff(activity.getTime()), TextColor.GRAY))
+                                .build()
+                        );
+                        resp.replyPrefixed(TextComponent.builder("  ")
+                                .append(TextComponent.of("Created by: ", TextColor.GRAY))
+                                .append(TextComponent.of(activity.getUser(), TextColor.WHITE))
+                                .build()
+                        );
+                        resp.replyPrefixed(TextComponent.builder("  ")
+                                .append(TextComponent.of("Link: ", TextColor.GRAY))
+                                .append(TextComponent.builder(activity.getUrl())
+                                        .color(TextColor.WHITE)
+                                        .decoration(TextDecoration.UNDERLINED, true)
+                                        .clickEvent(new ClickEvent(ClickEvent.Action.OPEN_URL, activity.getUrl()))
+                                        .build()
+                                )
+                                .build()
+                        );
+                        resp.reply(Component.space());
+                    }
+                })
+                .tabCompleter(Command.TabCompleter.empty())
+                .build()
+        );
+    }
+
+    private static String formatDateDiff(long time) {
+        long seconds = (System.currentTimeMillis() - time) / 1000;
+
+        if (seconds <= 0) {
+            return "now";
+        }
+
+        long minute = seconds / 60;
+        seconds = seconds % 60;
+        long hour = minute / 60;
+        minute = minute % 60;
+        long day = hour / 24;
+        hour = hour % 24;
+
+        StringBuilder sb = new StringBuilder();
+        if (day != 0) {
+            sb.append(day).append("d ");
+        }
+        if (hour != 0) {
+            sb.append(hour).append("h ");
+        }
+        if (minute != 0) {
+            sb.append(minute).append("m ");
+        }
+        if (seconds != 0) {
+            sb.append(seconds).append("s");
+        }
+
+        return sb.toString().trim() + " ago";
+    }
+
+}
diff --git a/spark-common/src/main/java/me/lucko/spark/common/command/modules/HealthModule.java b/spark-common/src/main/java/me/lucko/spark/common/command/modules/HealthModule.java
index 097d264..83f9006 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/command/modules/HealthModule.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/command/modules/HealthModule.java
@@ -44,11 +44,11 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Consumer;
 
-public class HealthModule<S> implements CommandModule<S> {
+public class HealthModule implements CommandModule {
 
     @Override
-    public void registerCommands(Consumer<Command<S>> consumer) {
-        consumer.accept(Command.<S>builder()
+    public void registerCommands(Consumer<Command> consumer) {
+        consumer.accept(Command.builder()
                 .aliases("tps")
                 .executor((platform, sender, resp, arguments) -> {
                     TpsCalculator tpsCalculator = platform.getTpsCalculator();
@@ -63,7 +63,7 @@ public class HealthModule<S> implements CommandModule<S> {
                 .build()
         );
 
-        consumer.accept(Command.<S>builder()
+        consumer.accept(Command.builder()
                 .aliases("healthreport", "health", "ht")
                 .argumentUsage("memory", null)
                 .executor((platform, sender, resp, arguments) -> {
@@ -74,7 +74,7 @@ public class HealthModule<S> implements CommandModule<S> {
 
                         TpsCalculator tpsCalculator = platform.getTpsCalculator();
                         if (tpsCalculator != null) {
-                            report.add(TextComponent.builder()
+                            report.add(TextComponent.builder("")
                                     .append(TextComponent.builder(">").color(TextColor.DARK_GRAY).decoration(TextDecoration.BOLD, true).build())
                                     .append(Component.space())
                                     .append(TextComponent.of("TPS from last 5s, 10s, 1m, 5m, 15m:", TextColor.GOLD))
@@ -86,7 +86,7 @@ public class HealthModule<S> implements CommandModule<S> {
 
                         MemoryMXBean memoryMXBean = ManagementFactory.getMemoryMXBean();
                         MemoryUsage heapUsage = memoryMXBean.getHeapMemoryUsage();
-                        report.add(TextComponent.builder()
+                        report.add(TextComponent.builder("")
                                 .append(TextComponent.builder(">").color(TextColor.DARK_GRAY).decoration(TextDecoration.BOLD, true).build())
                                 .append(Component.space())
                                 .append(TextComponent.of("Memory usage:", TextColor.GOLD))
@@ -109,7 +109,7 @@ public class HealthModule<S> implements CommandModule<S> {
 
                         if (arguments.boolFlag("memory")) {
                             MemoryUsage nonHeapUsage = memoryMXBean.getNonHeapMemoryUsage();
-                            report.add(TextComponent.builder()
+                            report.add(TextComponent.builder("")
                                     .append(TextComponent.builder(">").color(TextColor.DARK_GRAY).decoration(TextDecoration.BOLD, true).build())
                                     .append(Component.space())
                                     .append(TextComponent.of("Non-heap memory usage:", TextColor.GOLD))
@@ -134,7 +134,7 @@ public class HealthModule<S> implements CommandModule<S> {
                                     usage = new MemoryUsage(usage.getInit(), usage.getUsed(), usage.getCommitted(), usage.getCommitted());
                                 }
 
-                                report.add(TextComponent.builder()
+                                report.add(TextComponent.builder("")
                                         .append(TextComponent.builder(">").color(TextColor.DARK_GRAY).decoration(TextDecoration.BOLD, true).build())
                                         .append(Component.space())
                                         .append(TextComponent.of(memoryPool.getName() + " pool usage:", TextColor.GOLD))
@@ -172,7 +172,7 @@ public class HealthModule<S> implements CommandModule<S> {
                         double processCpuLoad = CpuMonitor.getProcessCpuLoad();
 
                         if (systemCpuLoad >= 0 || processCpuLoad >= 0) {
-                            report.add(TextComponent.builder()
+                            report.add(TextComponent.builder("")
                                     .append(TextComponent.builder(">").color(TextColor.DARK_GRAY).decoration(TextDecoration.BOLD, true).build())
                                     .append(Component.space())
                                     .append(TextComponent.of("CPU usage:", TextColor.GOLD))
@@ -203,7 +203,7 @@ public class HealthModule<S> implements CommandModule<S> {
                             FileStore fileStore = Files.getFileStore(Paths.get("."));
                             long totalSpace = fileStore.getTotalSpace();
                             long usedSpace = totalSpace - fileStore.getUsableSpace();
-                            report.add(TextComponent.builder()
+                            report.add(TextComponent.builder("")
                                     .append(TextComponent.builder(">").color(TextColor.DARK_GRAY).decoration(TextDecoration.BOLD, true).build())
                                     .append(Component.space())
                                     .append(TextComponent.of("Disk usage:", TextColor.GOLD))
@@ -227,7 +227,7 @@ public class HealthModule<S> implements CommandModule<S> {
                             e.printStackTrace();
                         }
 
-                        TextComponent.Builder builder = TextComponent.builder();
+                        TextComponent.Builder builder = TextComponent.builder("");
                         report.forEach(line -> builder.append(line).append(Component.newline()));
                         resp.reply(builder.build());
                     });
@@ -259,7 +259,7 @@ public class HealthModule<S> implements CommandModule<S> {
             line.append(TextComponent.of(Strings.repeat(" ", (length - committedChars))));
         }
 
-        return TextComponent.builder()
+        return TextComponent.builder("")
                 .append(TextComponent.of("[", TextColor.DARK_GRAY))
                 .append(line.build())
                 .append(TextComponent.of("]", TextColor.DARK_GRAY))
@@ -293,7 +293,7 @@ public class HealthModule<S> implements CommandModule<S> {
             line.append(TextComponent.of(Strings.repeat(" ", (length - committedChars))));
         }
 
-        return TextComponent.builder()
+        return TextComponent.builder("")
                 .append(TextComponent.of("[", TextColor.DARK_GRAY))
                 .append(line.build())
                 .append(TextComponent.of("]", TextColor.DARK_GRAY))
@@ -303,7 +303,7 @@ public class HealthModule<S> implements CommandModule<S> {
     private static TextComponent generateCpuUsageDiagram(double usage, int length) {
         int usedChars = (int) ((usage * length));
         String line = Strings.repeat("/", usedChars) + Strings.repeat(" ", length - usedChars);
-        return TextComponent.builder()
+        return TextComponent.builder("")
                 .append(TextComponent.of("[", TextColor.DARK_GRAY))
                 .append(TextComponent.of(line, TextColor.GRAY))
                 .append(TextComponent.of("]", TextColor.DARK_GRAY))
@@ -313,7 +313,7 @@ public class HealthModule<S> implements CommandModule<S> {
     private static TextComponent generateDiskUsageDiagram(double used, double max, int length) {
         int usedChars = (int) ((used * length) / max);
         String line = Strings.repeat("/", usedChars) + Strings.repeat(" ", length - usedChars);
-        return TextComponent.builder()
+        return TextComponent.builder("")
                 .append(TextComponent.of("[", TextColor.DARK_GRAY))
                 .append(TextComponent.of(line, TextColor.GRAY))
                 .append(TextComponent.of("]", TextColor.DARK_GRAY))
diff --git a/spark-common/src/main/java/me/lucko/spark/common/command/modules/MemoryModule.java b/spark-common/src/main/java/me/lucko/spark/common/command/modules/MemoryModule.java
index e2d817d..b65db78 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/command/modules/MemoryModule.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/command/modules/MemoryModule.java
@@ -20,6 +20,7 @@
 
 package me.lucko.spark.common.command.modules;
 
+import me.lucko.spark.common.ActivityLog;
 import me.lucko.spark.common.SparkPlatform;
 import me.lucko.spark.common.command.Command;
 import me.lucko.spark.common.command.CommandModule;
@@ -38,12 +39,12 @@ import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.function.Consumer;
 
-public class MemoryModule<S> implements CommandModule<S> {
+public class MemoryModule implements CommandModule {
     private static final MediaType JSON_TYPE = MediaType.parse("application/json; charset=utf-8");
 
     @Override
-    public void registerCommands(Consumer<Command<S>> consumer) {
-        consumer.accept(Command.<S>builder()
+    public void registerCommands(Consumer<Command> consumer) {
+        consumer.accept(Command.builder()
                 .aliases("heapsummary")
                 .argumentUsage("run-gc-before", null)
                 .executor((platform, sender, resp, arguments) -> {
@@ -75,6 +76,8 @@ public class MemoryModule<S> implements CommandModule<S> {
                                     .clickEvent(new ClickEvent(ClickEvent.Action.OPEN_URL, url))
                                     .build()
                             );
+
+                            platform.getActivityLog().addToLog(new ActivityLog.Activity(sender.getName(), System.currentTimeMillis(), "Heap dump summary", url));
                         } catch (IOException e) {
                             resp.broadcastPrefixed(TextComponent.of("An error occurred whilst uploading the data.", TextColor.RED));
                             e.printStackTrace();
@@ -85,7 +88,7 @@ public class MemoryModule<S> implements CommandModule<S> {
                 .build()
         );
 
-        consumer.accept(Command.<S>builder()
+        consumer.accept(Command.builder()
                 .aliases("heapdump")
                 .argumentUsage("run-gc-before", null)
                 .argumentUsage("include-non-live", null)
diff --git a/spark-common/src/main/java/me/lucko/spark/common/command/modules/SamplerModule.java b/spark-common/src/main/java/me/lucko/spark/common/command/modules/SamplerModule.java
index e450b0b..fb1bc72 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/command/modules/SamplerModule.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/command/modules/SamplerModule.java
@@ -20,6 +20,7 @@
 
 package me.lucko.spark.common.command.modules;
 
+import me.lucko.spark.common.ActivityLog;
 import me.lucko.spark.common.SparkPlatform;
 import me.lucko.spark.common.command.Command;
 import me.lucko.spark.common.command.CommandModule;
@@ -46,7 +47,7 @@ import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
 
-public class SamplerModule<S> implements CommandModule<S> {
+public class SamplerModule implements CommandModule {
     private static final MediaType JSON_TYPE = MediaType.parse("application/json; charset=utf-8");
 
     /** Guards {@link #activeSampler} */
@@ -55,8 +56,8 @@ public class SamplerModule<S> implements CommandModule<S> {
     private Sampler activeSampler = null;
 
     @Override
-    public void registerCommands(Consumer<Command<S>> consumer) {
-        consumer.accept(Command.<S>builder()
+    public void registerCommands(Consumer<Command> consumer) {
+        consumer.accept(Command.builder()
                 .aliases("sampler")
                 .argumentUsage("info", null)
                 .argumentUsage("stop", null)
@@ -246,7 +247,7 @@ public class SamplerModule<S> implements CommandModule<S> {
         );
     }
 
-    private void handleUpload(SparkPlatform<S> platform, CommandResponseHandler<S> resp, Sampler sampler) {
+    private void handleUpload(SparkPlatform platform, CommandResponseHandler resp, Sampler sampler) {
         platform.getPlugin().runAsync(() -> {
             byte[] output = sampler.formCompressedDataPayload();
             try {
@@ -259,6 +260,8 @@ public class SamplerModule<S> implements CommandModule<S> {
                         .clickEvent(new ClickEvent(ClickEvent.Action.OPEN_URL, url))
                         .build()
                 );
+
+                platform.getActivityLog().addToLog(new ActivityLog.Activity(resp.sender().getName(), System.currentTimeMillis(), "Sampler", url));
             } catch (IOException e) {
                 resp.broadcastPrefixed(TextComponent.of("An error occurred whilst uploading the results.", TextColor.RED));
                 e.printStackTrace();
diff --git a/spark-common/src/main/java/me/lucko/spark/common/command/modules/TickMonitoringModule.java b/spark-common/src/main/java/me/lucko/spark/common/command/modules/TickMonitoringModule.java
index 3b26018..cbcf557 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/command/modules/TickMonitoringModule.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/command/modules/TickMonitoringModule.java
@@ -32,14 +32,14 @@ import net.kyori.text.format.TextColor;
 
 import java.util.function.Consumer;
 
-public class TickMonitoringModule<S> implements CommandModule<S> {
+public class TickMonitoringModule implements CommandModule {
 
     /** The tick monitor instance currently running, if any */
     private ReportingTickMonitor activeTickMonitor = null;
 
     @Override
-    public void registerCommands(Consumer<Command<S>> consumer) {
-        consumer.accept(Command.<S>builder()
+    public void registerCommands(Consumer<Command> consumer) {
+        consumer.accept(Command.builder()
                 .aliases("tickmonitoring")
                 .argumentUsage("threshold", "percentage increase")
                 .argumentUsage("without-gc", null)
@@ -71,9 +71,9 @@ public class TickMonitoringModule<S> implements CommandModule<S> {
     }
 
     private class ReportingTickMonitor extends TickMonitor {
-        private final CommandResponseHandler<S> resp;
+        private final CommandResponseHandler resp;
 
-        ReportingTickMonitor(CommandResponseHandler<S> resp, TickCounter tickCounter, int percentageChangeThreshold, boolean monitorGc) {
+        ReportingTickMonitor(CommandResponseHandler resp, TickCounter tickCounter, int percentageChangeThreshold, boolean monitorGc) {
             super(tickCounter, percentageChangeThreshold, monitorGc);
             this.resp = resp;
         }
diff --git a/spark-common/src/main/java/me/lucko/spark/common/monitor/tick/TickMonitor.java b/spark-common/src/main/java/me/lucko/spark/common/monitor/tick/TickMonitor.java
index 3d91368..5e1ec54 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/monitor/tick/TickMonitor.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/monitor/tick/TickMonitor.java
@@ -21,14 +21,12 @@
 package me.lucko.spark.common.monitor.tick;
 
 import com.sun.management.GarbageCollectionNotificationInfo;
-import com.sun.org.apache.regexp.internal.RE;
 import me.lucko.spark.common.monitor.memory.GarbageCollectionMonitor;
 import me.lucko.spark.common.sampler.TickCounter;
 import net.kyori.text.Component;
 import net.kyori.text.TextComponent;
 import net.kyori.text.format.TextColor;
 
-import java.awt.*;
 import java.text.DecimalFormat;
 import java.util.DoubleSummaryStatistics;
 
@@ -96,7 +94,7 @@ public abstract class TickMonitor implements TickCounter.TickTask, GarbageCollec
             // move onto the next state
             if (this.averageTickTime.getCount() >= 120) {
                 sendMessage(TextComponent.of("Analysis is now complete.", TextColor.GOLD));
-                sendMessage(TextComponent.builder().color(TextColor.GRAY)
+                sendMessage(TextComponent.builder("").color(TextColor.GRAY)
                         .append(TextComponent.of(">", TextColor.WHITE))
                         .append(Component.space())
                         .append(TextComponent.of("Max: "))
@@ -104,7 +102,7 @@ public abstract class TickMonitor implements TickCounter.TickTask, GarbageCollec
                         .append(TextComponent.of("ms"))
                         .build()
                 );
-                sendMessage(TextComponent.builder().color(TextColor.GRAY)
+                sendMessage(TextComponent.builder("").color(TextColor.GRAY)
                         .append(TextComponent.of(">", TextColor.WHITE))
                         .append(Component.space())
                         .append(TextComponent.of("Min: "))
@@ -112,7 +110,7 @@ public abstract class TickMonitor implements TickCounter.TickTask, GarbageCollec
                         .append(TextComponent.of("ms"))
                         .build()
                 );
-                sendMessage(TextComponent.builder().color(TextColor.GRAY)
+                sendMessage(TextComponent.builder("").color(TextColor.GRAY)
                         .append(TextComponent.of(">", TextColor.WHITE))
                         .append(Component.space())
                         .append(TextComponent.of("Avg: "))
@@ -136,7 +134,7 @@ public abstract class TickMonitor implements TickCounter.TickTask, GarbageCollec
 
             double percentageChange = (increase * 100d) / this.avg;
             if (percentageChange > this.percentageChangeThreshold) {
-                sendMessage(TextComponent.builder().color(TextColor.GRAY)
+                sendMessage(TextComponent.builder("").color(TextColor.GRAY)
                         .append(TextComponent.of("Tick "))
                         .append(TextComponent.of("#" + counter.getCurrentTick(), TextColor.DARK_GRAY))
                         .append(TextComponent.of(" lasted "))
@@ -166,7 +164,7 @@ public abstract class TickMonitor implements TickCounter.TickTask, GarbageCollec
             gcType = "Old Gen GC";
         }
 
-        sendMessage(TextComponent.builder().color(TextColor.GRAY)
+        sendMessage(TextComponent.builder("").color(TextColor.GRAY)
                 .append(TextComponent.of("Tick "))
                 .append(TextComponent.of("#" + this.tickCounter.getCurrentTick(), TextColor.DARK_GRAY))
                 .append(TextComponent.of(" included "))
diff --git a/spark-common/src/main/java/me/lucko/spark/common/monitor/tick/TpsCalculator.java b/spark-common/src/main/java/me/lucko/spark/common/monitor/tick/TpsCalculator.java
index 90a7b78..2278e0c 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/monitor/tick/TpsCalculator.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/monitor/tick/TpsCalculator.java
@@ -103,7 +103,7 @@ public class TpsCalculator implements TickCounter.TickTask {
     }
 
     public TextComponent toFormattedComponent() {
-        return TextComponent.builder()
+        return TextComponent.builder("")
                 .append(format(this.tps5S.getAverage())).append(TextComponent.of(", "))
                 .append(format(this.tps10S.getAverage())).append(TextComponent.of(", "))
                 .append(format(this.tps1M.getAverage())).append(TextComponent.of(", "))
diff --git a/spark-forge/build.gradle b/spark-forge/build.gradle
index a8c31cb..140612d 100644
--- a/spark-forge/build.gradle
+++ b/spark-forge/build.gradle
@@ -34,12 +34,6 @@ processResources {
 
 dependencies {
     compile project(':spark-common')
-
-    compile 'net.kyori:text:1.11-1.6.4', {
-        exclude(module: 'checker-qual')
-        exclude(module: 'guava')
-        exclude(module: 'gson')
-    }
 }
 
 shadowJar {
diff --git a/spark-forge/src/main/java/me/lucko/spark/forge/ForgeClientSparkPlugin.java b/spark-forge/src/main/java/me/lucko/spark/forge/ForgeClientSparkPlugin.java
index b214308..ec6a0fc 100644
--- a/spark-forge/src/main/java/me/lucko/spark/forge/ForgeClientSparkPlugin.java
+++ b/spark-forge/src/main/java/me/lucko/spark/forge/ForgeClientSparkPlugin.java
@@ -20,10 +20,10 @@
 
 package me.lucko.spark.forge;
 
+import me.lucko.spark.common.CommandSender;
 import me.lucko.spark.common.sampler.TickCounter;
 import net.minecraft.client.Minecraft;
 import net.minecraft.command.ICommandSender;
-import net.minecraft.server.MinecraftServer;
 import net.minecraftforge.client.ClientCommandHandler;
 import net.minecraftforge.fml.common.gameevent.TickEvent;
 
@@ -43,8 +43,13 @@ public class ForgeClientSparkPlugin extends ForgeSparkPlugin {
     }
 
     @Override
-    public Set<ICommandSender> getSendersWithPermission(String permission) {
-        return new HashSet<>(Collections.singleton(Minecraft.getMinecraft().player));
+    boolean hasPermission(ICommandSender sender, String permission) {
+        return true;
+    }
+
+    @Override
+    public Set<CommandSender> getSendersWithPermission(String permission) {
+        return new HashSet<>(Collections.singleton(new ForgeCommandSender(Minecraft.getMinecraft().player, this)));
     }
 
     @Override
@@ -66,9 +71,4 @@ public class ForgeClientSparkPlugin extends ForgeSparkPlugin {
     public List<String> getAliases() {
         return Collections.singletonList("sparkclient");
     }
-
-    @Override
-    public boolean checkPermission(MinecraftServer server, ICommandSender sender) {
-        return true;
-    }
 }
diff --git a/spark-forge/src/main/java/me/lucko/spark/forge/ForgeCommandSender.java b/spark-forge/src/main/java/me/lucko/spark/forge/ForgeCommandSender.java
new file mode 100644
index 0000000..4b71d86
--- /dev/null
+++ b/spark-forge/src/main/java/me/lucko/spark/forge/ForgeCommandSender.java
@@ -0,0 +1,66 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.forge;
+
+import me.lucko.spark.common.CommandSender;
+import net.kyori.text.Component;
+import net.kyori.text.serializer.gson.GsonComponentSerializer;
+import net.minecraft.command.ICommandSender;
+import net.minecraft.util.text.ITextComponent;
+
+public class ForgeCommandSender implements CommandSender {
+    private final ICommandSender sender;
+    private final ForgeSparkPlugin plugin;
+
+    public ForgeCommandSender(ICommandSender sender, ForgeSparkPlugin plugin) {
+        this.sender = sender;
+        this.plugin = plugin;
+    }
+
+    @Override
+    public String getName() {
+        return this.sender.getName();
+    }
+
+    @Override
+    public void sendMessage(Component message) {
+        ITextComponent component = ITextComponent.Serializer.jsonToComponent(GsonComponentSerializer.INSTANCE.serialize(message));
+        this.sender.sendMessage(component);
+    }
+
+    @Override
+    public boolean hasPermission(String permission) {
+        return this.plugin.hasPermission(this.sender, permission);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ForgeCommandSender that = (ForgeCommandSender) o;
+        return this.sender.equals(that.sender);
+    }
+
+    @Override
+    public int hashCode() {
+        return this.sender.hashCode();
+    }
+}
diff --git a/spark-forge/src/main/java/me/lucko/spark/forge/ForgeServerSparkPlugin.java b/spark-forge/src/main/java/me/lucko/spark/forge/ForgeServerSparkPlugin.java
index 167aa94..ba56f44 100644
--- a/spark-forge/src/main/java/me/lucko/spark/forge/ForgeServerSparkPlugin.java
+++ b/spark-forge/src/main/java/me/lucko/spark/forge/ForgeServerSparkPlugin.java
@@ -20,6 +20,7 @@
 
 package me.lucko.spark.forge;
 
+import me.lucko.spark.common.CommandSender;
 import me.lucko.spark.common.sampler.TickCounter;
 import net.minecraft.command.ICommandSender;
 import net.minecraft.server.MinecraftServer;
@@ -27,9 +28,10 @@ import net.minecraftforge.fml.common.FMLCommonHandler;
 import net.minecraftforge.fml.common.gameevent.TickEvent;
 
 import java.util.Collections;
-import java.util.HashSet;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 public class ForgeServerSparkPlugin extends ForgeSparkPlugin {
     public ForgeServerSparkPlugin(SparkForgeMod mod) {
@@ -37,12 +39,17 @@ public class ForgeServerSparkPlugin extends ForgeSparkPlugin {
     }
 
     @Override
-    public Set<ICommandSender> getSendersWithPermission(String permission) {
+    boolean hasPermission(ICommandSender sender, String permission) {
+        return sender.canUseCommand(4, permission);
+    }
+
+    @Override
+    public Set<CommandSender> getSendersWithPermission(String permission) {
         MinecraftServer mcServer = FMLCommonHandler.instance().getMinecraftServerInstance();
-        Set<ICommandSender> senders = new HashSet<>(mcServer.getPlayerList().getPlayers());
+        List<ICommandSender> senders = new LinkedList<>(mcServer.getPlayerList().getPlayers());
         senders.removeIf(sender -> !sender.canUseCommand(4, permission));
         senders.add(mcServer);
-        return senders;
+        return senders.stream().map(sender -> new ForgeCommandSender(sender, this)).collect(Collectors.toSet());
     }
 
     @Override
@@ -64,9 +71,4 @@ public class ForgeServerSparkPlugin extends ForgeSparkPlugin {
     public List<String> getAliases() {
         return Collections.emptyList();
     }
-
-    @Override
-    public boolean checkPermission(MinecraftServer server, ICommandSender sender) {
-        return sender.canUseCommand(4, "spark");
-    }
 }
diff --git a/spark-forge/src/main/java/me/lucko/spark/forge/ForgeSparkPlugin.java b/spark-forge/src/main/java/me/lucko/spark/forge/ForgeSparkPlugin.java
index 7298793..039a7de 100644
--- a/spark-forge/src/main/java/me/lucko/spark/forge/ForgeSparkPlugin.java
+++ b/spark-forge/src/main/java/me/lucko/spark/forge/ForgeSparkPlugin.java
@@ -24,43 +24,36 @@ import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import me.lucko.spark.common.SparkPlatform;
 import me.lucko.spark.common.SparkPlugin;
 import me.lucko.spark.common.sampler.ThreadDumper;
-import net.kyori.text.Component;
-import net.kyori.text.TextComponent;
-import net.kyori.text.serializer.ComponentSerializers;
 import net.minecraft.command.ICommand;
 import net.minecraft.command.ICommandSender;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.text.ITextComponent;
-import net.minecraft.util.text.Style;
-import net.minecraft.util.text.TextComponentString;
-import net.minecraft.util.text.TextFormatting;
-import net.minecraft.util.text.event.ClickEvent;
 import net.minecraftforge.fml.common.Mod;
 
 import javax.annotation.Nullable;
 import java.nio.file.Path;
-import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 
 @SuppressWarnings("NullableProblems")
-public abstract class ForgeSparkPlugin implements SparkPlugin<ICommandSender>, ICommand {
+public abstract class ForgeSparkPlugin implements SparkPlugin, ICommand {
 
     private final SparkForgeMod mod;
     private final ScheduledExecutorService scheduler;
-    private final SparkPlatform<ICommandSender> platform;
+    private final SparkPlatform platform;
 
     protected ForgeSparkPlugin(SparkForgeMod mod) {
         this.mod = mod;
         this.scheduler = Executors.newSingleThreadScheduledExecutor(
                 new ThreadFactoryBuilder().setNameFormat("spark-forge-async-worker").build()
         );
-        this.platform = new SparkPlatform<>(this);
+        this.platform = new SparkPlatform(this);
         this.platform.enable();
     }
 
+    abstract boolean hasPermission(ICommandSender sender, String permission);
+
     @Override
     public String getVersion() {
         return SparkForgeMod.class.getAnnotation(Mod.class).version();
@@ -72,12 +65,6 @@ public abstract class ForgeSparkPlugin implements SparkPlugin<ICommandSender>, I
     }
 
     @Override
-    public void sendMessage(ICommandSender sender, Component message) {
-        ITextComponent component = ITextComponent.Serializer.jsonToComponent(ComponentSerializers.JSON.serialize(message));
-        sender.sendMessage(component);
-    }
-
-    @Override
     public void runAsync(Runnable r) {
         this.scheduler.execute(r);
     }
@@ -96,25 +83,17 @@ public abstract class ForgeSparkPlugin implements SparkPlugin<ICommandSender>, I
 
     @Override
     public void execute(MinecraftServer server, ICommandSender sender, String[] args) {
-        if (!checkPermission(server, sender)) {
-            TextComponentString msg = new TextComponentString("You do not have permission to use this command.");
-            Style style = msg.getStyle();
-            style.setColor(TextFormatting.GRAY);
-            msg.setStyle(style);
-
-            sender.sendMessage(msg);
-            return;
-        }
-
-        this.platform.executeCommand(sender, args);
+        this.platform.executeCommand(new ForgeCommandSender(sender, this), args);
     }
 
     @Override
     public List<String> getTabCompletions(MinecraftServer server, ICommandSender sender, String[] args, @Nullable BlockPos blockPos) {
-        if (!checkPermission(server, sender)) {
-            return Collections.emptyList();
-        }
-        return this.platform.tabCompleteCommand(sender, args);
+        return this.platform.tabCompleteCommand(new ForgeCommandSender(sender, this), args);
+    }
+
+    @Override
+    public boolean checkPermission(MinecraftServer minecraftServer, ICommandSender sender) {
+        return hasPermission(sender, "spark");
     }
 
     @Override
diff --git a/spark-sponge/build.gradle b/spark-sponge/build.gradle
index dee1aac..3fd93e2 100644
--- a/spark-sponge/build.gradle
+++ b/spark-sponge/build.gradle
@@ -4,7 +4,9 @@ plugins {
 
 dependencies {
     compile project(':spark-common')
-    compile 'net.kyori:text-adapter-spongeapi:1.0.3'
+    compile('net.kyori:text-adapter-spongeapi:1.0.3') {
+        exclude(module: 'text')
+    }
     compileOnly 'org.spongepowered:spongeapi:7.1.0'
     annotationProcessor 'org.spongepowered:spongeapi:7.1.0'
 }
diff --git a/spark-sponge/src/main/java/me/lucko/spark/sponge/SparkSpongePlugin.java b/spark-sponge/src/main/java/me/lucko/spark/sponge/SparkSpongePlugin.java
index c0727ac..537bfea 100644
--- a/spark-sponge/src/main/java/me/lucko/spark/sponge/SparkSpongePlugin.java
+++ b/spark-sponge/src/main/java/me/lucko/spark/sponge/SparkSpongePlugin.java
@@ -21,12 +21,11 @@
 package me.lucko.spark.sponge;
 
 import com.google.inject.Inject;
+import me.lucko.spark.common.CommandSender;
 import me.lucko.spark.common.SparkPlatform;
 import me.lucko.spark.common.SparkPlugin;
 import me.lucko.spark.common.sampler.ThreadDumper;
 import me.lucko.spark.common.sampler.TickCounter;
-import net.kyori.text.Component;
-import net.kyori.text.adapter.spongeapi.TextAdapter;
 import org.spongepowered.api.Game;
 import org.spongepowered.api.command.CommandCallable;
 import org.spongepowered.api.command.CommandResult;
@@ -40,21 +39,16 @@ import org.spongepowered.api.plugin.Plugin;
 import org.spongepowered.api.scheduler.AsynchronousExecutor;
 import org.spongepowered.api.scheduler.SpongeExecutorService;
 import org.spongepowered.api.text.Text;
-import org.spongepowered.api.text.action.TextActions;
-import org.spongepowered.api.text.format.TextColors;
-import org.spongepowered.api.text.serializer.TextSerializers;
 import org.spongepowered.api.world.Location;
 import org.spongepowered.api.world.World;
 
 import javax.annotation.Nullable;
-import java.net.MalformedURLException;
-import java.net.URL;
 import java.nio.file.Path;
-import java.util.Collections;
-import java.util.HashSet;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 @Plugin(
         id = "spark",
@@ -67,13 +61,13 @@ import java.util.Set;
                 @Dependency(id = "spongeapi")
         }
 )
-public class SparkSpongePlugin implements SparkPlugin<CommandSource> {
+public class SparkSpongePlugin implements SparkPlugin {
 
     private final Game game;
     private final Path configDirectory;
     private final SpongeExecutorService asyncExecutor;
 
-    private final SparkPlatform<CommandSource> platform = new SparkPlatform<>(this);
+    private final SparkPlatform platform = new SparkPlatform(this);
 
     @Inject
     public SparkSpongePlugin(Game game, @ConfigDir(sharedRoot = false) Path configDirectory, @AsynchronousExecutor SpongeExecutorService asyncExecutor) {
@@ -109,16 +103,11 @@ public class SparkSpongePlugin implements SparkPlugin<CommandSource> {
     }
 
     @Override
-    public Set<CommandSource> getSendersWithPermission(String permission) {
-        Set<CommandSource> senders = new HashSet<>(this.game.getServer().getOnlinePlayers());
+    public Set<CommandSender> getSendersWithPermission(String permission) {
+        List<CommandSource> senders = new LinkedList<>(this.game.getServer().getOnlinePlayers());
         senders.removeIf(sender -> !sender.hasPermission(permission));
         senders.add(this.game.getServer().getConsole());
-        return senders;
-    }
-
-    @Override
-    public void sendMessage(CommandSource sender, Component message) {
-        TextAdapter.sendComponent(sender, message);
+        return senders.stream().map(SpongeCommandSender::new).collect(Collectors.toSet());
     }
 
     @Override
@@ -145,18 +134,13 @@ public class SparkSpongePlugin implements SparkPlugin<CommandSource> {
 
         @Override
         public CommandResult process(CommandSource source, String arguments) {
-            if (!testPermission(source)) {
-                source.sendMessage(Text.builder("You do not have permission to use this command.").color(TextColors.RED).build());
-                return CommandResult.empty();
-            }
-
-            this.plugin.platform.executeCommand(source, arguments.split(" "));
+            this.plugin.platform.executeCommand(new SpongeCommandSender(source), arguments.split(" "));
             return CommandResult.empty();
         }
 
         @Override
         public List<String> getSuggestions(CommandSource source, String arguments, @Nullable Location<World> targetPosition) {
-            return Collections.emptyList();
+            return this.plugin.platform.tabCompleteCommand(new SpongeCommandSender(source), arguments.split(" "));
         }
 
         @Override
diff --git a/spark-sponge/src/main/java/me/lucko/spark/sponge/SpongeCommandSender.java b/spark-sponge/src/main/java/me/lucko/spark/sponge/SpongeCommandSender.java
new file mode 100644
index 0000000..5b434fc
--- /dev/null
+++ b/spark-sponge/src/main/java/me/lucko/spark/sponge/SpongeCommandSender.java
@@ -0,0 +1,62 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.sponge;
+
+import me.lucko.spark.common.CommandSender;
+import net.kyori.text.Component;
+import net.kyori.text.adapter.spongeapi.TextAdapter;
+import org.spongepowered.api.command.CommandSource;
+
+public class SpongeCommandSender implements CommandSender {
+    private final CommandSource source;
+
+    public SpongeCommandSender(CommandSource source) {
+        this.source = source;
+    }
+
+    @Override
+    public String getName() {
+        return this.source.getName();
+    }
+
+    @Override
+    public void sendMessage(Component message) {
+        TextAdapter.sendComponent(this.source, message);
+    }
+
+    @Override
+    public boolean hasPermission(String permission) {
+        return this.source.hasPermission(permission);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        SpongeCommandSender that = (SpongeCommandSender) o;
+        return this.source.equals(that.source);
+    }
+
+    @Override
+    public int hashCode() {
+        return this.source.hashCode();
+    }
+}
diff --git a/spark-velocity/src/main/java/me/lucko/spark/velocity/SparkVelocityPlugin.java b/spark-velocity/src/main/java/me/lucko/spark/velocity/SparkVelocityPlugin.java
index c1c2f2d..4a5f500 100644
--- a/spark-velocity/src/main/java/me/lucko/spark/velocity/SparkVelocityPlugin.java
+++ b/spark-velocity/src/main/java/me/lucko/spark/velocity/SparkVelocityPlugin.java
@@ -30,21 +30,19 @@ import com.velocitypowered.api.event.proxy.ProxyShutdownEvent;
 import com.velocitypowered.api.plugin.Plugin;
 import com.velocitypowered.api.plugin.annotation.DataDirectory;
 import com.velocitypowered.api.proxy.ProxyServer;
+import me.lucko.spark.common.CommandSender;
 import me.lucko.spark.common.SparkPlatform;
 import me.lucko.spark.common.SparkPlugin;
 import me.lucko.spark.common.sampler.ThreadDumper;
 import me.lucko.spark.common.sampler.TickCounter;
-import net.kyori.text.Component;
-import net.kyori.text.TextComponent;
-import net.kyori.text.event.ClickEvent;
-import net.kyori.text.format.TextColor;
-import net.kyori.text.serializer.ComponentSerializers;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.optional.qual.MaybePresent;
 
 import java.nio.file.Path;
-import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 @Plugin(
         id = "spark",
@@ -53,9 +51,9 @@ import java.util.Set;
         description = "@desc@",
         authors = {"Luck", "sk89q"}
 )
-public class SparkVelocityPlugin implements SparkPlugin<CommandSource>, Command {
+public class SparkVelocityPlugin implements SparkPlugin, Command {
 
-    private final SparkPlatform<CommandSource> platform = new SparkPlatform<>(this);
+    private final SparkPlatform platform = new SparkPlatform(this);
 
     private final ProxyServer proxy;
     private final Path configDirectory;
@@ -79,13 +77,12 @@ public class SparkVelocityPlugin implements SparkPlugin<CommandSource>, Command
 
     @Override
     public void execute(@MaybePresent CommandSource sender, @NonNull @MaybePresent String[] args) {
-        if (!sender.hasPermission("spark")) {
-            TextComponent msg = TextComponent.builder("You do not have permission to use this command.").color(TextColor.RED).build();
-            sender.sendMessage(msg);
-            return;
-        }
+        this.platform.executeCommand(new VelocityCommandSender(sender), args);
+    }
 
-        this.platform.executeCommand(sender, args);
+    @Override
+    public @MaybePresent List<String> suggest(@MaybePresent CommandSource sender, @NonNull @MaybePresent String[] currentArgs) {
+        return this.platform.tabCompleteCommand(new VelocityCommandSender(sender), currentArgs);
     }
 
     @Override
@@ -104,16 +101,11 @@ public class SparkVelocityPlugin implements SparkPlugin<CommandSource>, Command
     }
 
     @Override
-    public Set<CommandSource> getSendersWithPermission(String permission) {
-        Set<CommandSource> senders = new HashSet<>(this.proxy.getAllPlayers());
+    public Set<CommandSender> getSendersWithPermission(String permission) {
+        List<CommandSource> senders = new LinkedList<>(this.proxy.getAllPlayers());
         senders.removeIf(sender -> !sender.hasPermission(permission));
         senders.add(this.proxy.getConsoleCommandSource());
-        return senders;
-    }
-
-    @Override
-    public void sendMessage(CommandSource sender, Component message) {
-        sender.sendMessage(message);
+        return senders.stream().map(VelocityCommandSender::new).collect(Collectors.toSet());
     }
 
     @Override
diff --git a/spark-velocity/src/main/java/me/lucko/spark/velocity/VelocityCommandSender.java b/spark-velocity/src/main/java/me/lucko/spark/velocity/VelocityCommandSender.java
new file mode 100644
index 0000000..1cad493
--- /dev/null
+++ b/spark-velocity/src/main/java/me/lucko/spark/velocity/VelocityCommandSender.java
@@ -0,0 +1,69 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.velocity;
+
+import com.velocitypowered.api.command.CommandSource;
+import com.velocitypowered.api.proxy.ConsoleCommandSource;
+import com.velocitypowered.api.proxy.Player;
+import me.lucko.spark.common.CommandSender;
+import net.kyori.text.Component;
+
+public class VelocityCommandSender implements CommandSender {
+    private final CommandSource source;
+
+    public VelocityCommandSender(CommandSource source) {
+        this.source = source;
+    }
+
+    @Override
+    public String getName() {
+        if (this.source instanceof Player) {
+            return ((Player) this.source).getUsername();
+        } else if (this.source instanceof ConsoleCommandSource) {
+            return "Console";
+        } else {
+            return "unknown:" + this.source.getClass().getSimpleName();
+        }
+    }
+
+    @Override
+    public void sendMessage(Component message) {
+        this.source.sendMessage(message);
+    }
+
+    @Override
+    public boolean hasPermission(String permission) {
+        return this.source.hasPermission(permission);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        VelocityCommandSender that = (VelocityCommandSender) o;
+        return this.source.equals(that.source);
+    }
+
+    @Override
+    public int hashCode() {
+        return this.source.hashCode();
+    }
+}