Offline player fetching improvements (#117)

Author: EpicPlayerA10

bungee/src/main/java/eu/kennytv/maintenance/bungee/MaintenanceBungeePlugin.java

@@ -61,8 +61,8 @@
 import java.util.List;
 import java.util.Set;
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
-import java.util.function.Consumer;
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 
@@ -176,28 +176,26 @@ public Task startMaintenanceRunnable(final Runnable runnable) {
     }
 
     @Override
-    public void getOfflinePlayer(final String name, final Consumer<@Nullable SenderInfo> consumer) {
+    public CompletableFuture<@Nullable SenderInfo> getOfflinePlayer(final String name) {
         final ProxiedPlayer player = getProxy().getPlayer(name);
         if (player != null) {
-            consumer.accept(new BungeeSenderInfo(player));
-            return;
+            return CompletableFuture.completedFuture(new BungeeSenderInfo(player));
         }
 
-        getProxy().getScheduler().runAsync(plugin, () -> {
+        return CompletableFuture.supplyAsync(() -> {
             try {
                 final ProfileLookup profile = doUUIDLookup(name);
-                consumer.accept(new ProxyOfflineSenderInfo(profile.getUuid(), profile.getName()));
-            } catch (final IOException e) {
-                e.printStackTrace();
-                consumer.accept(null);
+                return new ProxyOfflineSenderInfo(profile.getUuid(), profile.getName());
+            } catch (IOException e) {
+                throw new RuntimeException(e);
             }
         });
     }
 
     @Override
-    public void getOfflinePlayer(final UUID uuid, final Consumer<@Nullable SenderInfo> consumer) {
+    public CompletableFuture<@Nullable SenderInfo> getOfflinePlayer(final UUID uuid) {
         final ProxiedPlayer player = getProxy().getPlayer(uuid);
-        consumer.accept(player != null ? new BungeeSenderInfo(player) : null);
+        return CompletableFuture.completedFuture(player != null ? new BungeeSenderInfo(player) : null);
     }
 
     @Override

core-proxy/src/main/java/eu/kennytv/maintenance/core/proxy/MaintenanceProxyPlugin.java

@@ -28,16 +28,19 @@
 import eu.kennytv.maintenance.core.proxy.runnable.SingleMaintenanceScheduleRunnable;
 import eu.kennytv.maintenance.core.proxy.util.ProfileLookup;
 import eu.kennytv.maintenance.core.runnable.MaintenanceRunnableBase;
+import eu.kennytv.maintenance.core.util.RateLimitedException;
 import eu.kennytv.maintenance.core.util.SenderInfo;
 import eu.kennytv.maintenance.core.util.ServerType;
 import eu.kennytv.maintenance.core.util.Task;
+import org.jetbrains.annotations.Blocking;
 import org.jetbrains.annotations.Nullable;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
 import java.net.URL;
-import java.net.URLConnection;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -187,9 +190,66 @@ protected void kickPlayers() {
         kickPlayersFromProxy();
     }
 
+    @Blocking
+    @Nullable
     protected ProfileLookup doUUIDLookup(final String name) throws IOException {
+        ProfileLookup profileLookup;
+        try {
+            profileLookup = doUUIDLookupMojangAPI(name);
+        } catch (RateLimitedException e) {
+            // Use fallback API if rate limit is reached
+            profileLookup = doUUIDLookupAshconAPI(name);
+        }
+
+        if (settingsProxy.isFallbackToOfflineUUID() && profileLookup == null) {
+            // Use offline uuid
+            return new ProfileLookup(UUID.nameUUIDFromBytes(("OfflinePlayer:" + name).getBytes(StandardCharsets.UTF_8)), name);
+        }
+
+        return profileLookup;
+    }
+
+    /**
+     * Official Mojang API
+     */
+    @Nullable
+    private ProfileLookup doUUIDLookupMojangAPI(final String name) throws IOException {
+        final URL url = new URL("https://api.mojang.com/users/profiles/minecraft/" + name);
+        final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+        connection.setRequestMethod("GET");
+
+        int status = connection.getResponseCode();
+        if (status == 429) {
+            throw new RateLimitedException();
+        }
+        if (status == 404) {
+            // Return null if profile not found
+            return null;
+        }
+
+        try (final InputStream in = connection.getInputStream()) {
+            final String output = CharStreams.toString(new InputStreamReader(in));
+            final JsonObject json = GSON.fromJson(output, JsonObject.class);
+
+            final UUID uuid = fromStringUUIDWithoutDashes(json.getAsJsonPrimitive("id").getAsString());
+            final String username = json.getAsJsonPrimitive("name").getAsString();
+            return new ProfileLookup(uuid, username);
+        }
+    }
+
+    /**
+     * Fallback API (Ashcon API)
+     */
+    @Nullable
+    private ProfileLookup doUUIDLookupAshconAPI(final String name) throws IOException {
         final URL url = new URL("https://api.ashcon.app/mojang/v2/user/" + name);
-        final URLConnection connection = url.openConnection();
+        final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+
+        if (connection.getResponseCode() == 403) {
+            // Return null if profile not found
+            return null;
+        }
+
         try (final InputStream in = connection.getInputStream()) {
             final String output = CharStreams.toString(new InputStreamReader(in));
             final JsonObject json = GSON.fromJson(output, JsonObject.class);
@@ -200,6 +260,14 @@ protected ProfileLookup doUUIDLookup(final String name) throws IOException {
         }
     }
 
+    private UUID fromStringUUIDWithoutDashes(String undashedUUID) {
+        return UUID.fromString(
+            undashedUUID.substring(0, 8) + "-" + undashedUUID.substring(8, 12) + "-" +
+            undashedUUID.substring(12, 16) + "-" + undashedUUID.substring(16, 20) + "-" +
+            undashedUUID.substring(20, 32)
+        );
+    }
+
     public SettingsProxy getSettingsProxy() {
         return settingsProxy;
     }

core-proxy/src/main/java/eu/kennytv/maintenance/core/proxy/SettingsProxy.java

@@ -39,6 +39,7 @@ public final class SettingsProxy extends Settings {
     private Set<String> maintenanceServers;
     private List<String> fallbackServers;
     private String waitingServer;
+    private boolean fallbackToOfflineUUID;
 
     private Map<String, List<String>> commandsOnMaintenanceEnable;
     private Map<String, List<String>> commandsOnMaintenanceDisable;
@@ -103,6 +104,7 @@ protected void loadExtraSettings() {
         if (waitingServer.isEmpty() || waitingServer.equalsIgnoreCase("none")) {
             waitingServer = null;
         }
+        fallbackToOfflineUUID = config.getBoolean("fallback-to-offline-uuid", false);
 
         commandsOnMaintenanceEnable = new HashMap<>();
         final ConfigSection enableCommandsSection = config.getSection("commands-on-single-maintenance-enable");
@@ -279,6 +281,10 @@ public String getWaitingServer() {
         return waitingServer;
     }
 
+    public boolean isFallbackToOfflineUUID() {
+        return fallbackToOfflineUUID;
+    }
+
     public List<String> getCommandsOnMaintenanceEnable(final Server server) {
         final List<String> enableCommands = commandsOnMaintenanceEnable.getOrDefault("all", new ArrayList<>());
         final List<String> serverEnableCommands = commandsOnMaintenanceEnable.get(server.getName().toLowerCase(Locale.ROOT));

core/src/main/java/eu/kennytv/maintenance/core/MaintenancePlugin.java

@@ -57,8 +57,8 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
-import java.util.function.Consumer;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -447,9 +447,9 @@ protected String getPluginFolder() {
      *
      * @param name name of the player
      */
-    public abstract void getOfflinePlayer(String name, Consumer<@Nullable SenderInfo> consumer);
+    public abstract CompletableFuture<@Nullable SenderInfo> getOfflinePlayer(String name);
 
-    public abstract void getOfflinePlayer(UUID uuid, Consumer<@Nullable SenderInfo> consumer);
+    public abstract CompletableFuture<@Nullable SenderInfo> getOfflinePlayer(UUID uuid);
 
     public abstract File getDataFolder();
 

core/src/main/java/eu/kennytv/maintenance/core/Settings.java

@@ -41,8 +41,8 @@
 
 public class Settings implements eu.kennytv.maintenance.api.Settings {
     public static final String NEW_LINE_REPLACEMENT = "<br>";
-    private static final int CONFIG_VERSION = 7;
-    private static final int LANGUAGE_VERSION = 1;
+    private static final int CONFIG_VERSION = 8;
+    private static final int LANGUAGE_VERSION = 2;
     private static final Random RANDOM = new Random();
     protected final MaintenancePlugin plugin;
     private final Map<UUID, String> whitelistedPlayers = new HashMap<>();

core/src/main/java/eu/kennytv/maintenance/core/command/subcommand/WhitelistAddCommand.java

@@ -25,6 +25,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.UUID;
+import java.util.logging.Level;
 
 public final class WhitelistAddCommand extends CommandInfo {
 
@@ -64,7 +65,13 @@ public List<String> getTabCompletion(final SenderInfo sender, final String[] arg
     }
 
     private void addPlayerToWhitelist(final SenderInfo sender, final String name) {
-        plugin.getOfflinePlayer(name, selected -> {
+        plugin.getOfflinePlayer(name).whenComplete((selected, ex) -> {
+            if (ex != null) {
+                plugin.getLogger().log(Level.SEVERE, "Error while fetching offline player", ex);
+                sender.send(getMessage("offlinePlayerFetchError"));
+                return;
+            }
+
             if (selected == null) {
                 sender.send(getMessage("playerNotOnline"));
                 return;
@@ -75,7 +82,13 @@ private void addPlayerToWhitelist(final SenderInfo sender, final String name) {
     }
 
     private void addPlayerToWhitelist(final SenderInfo sender, final UUID uuid) {
-        plugin.getOfflinePlayer(uuid, selected -> {
+        plugin.getOfflinePlayer(uuid).whenComplete((selected, ex) -> {
+            if (ex != null) {
+                plugin.getLogger().log(Level.SEVERE, "Error while fetching offline player", ex);
+                sender.send(getMessage("offlinePlayerFetchError"));
+                return;
+            }
+
             if (selected == null) {
                 sender.send(getMessage("playerNotFoundUuid"));
                 return;

core/src/main/java/eu/kennytv/maintenance/core/command/subcommand/WhitelistRemoveCommand.java

@@ -50,16 +50,17 @@ public List<String> getTabCompletion(final SenderInfo sender, final String[] arg
         if (args.length != 2) return Collections.emptyList();
 
         final List<String> list = new ArrayList<>();
+        String matchNameLowerCase = args[1].toLowerCase();
         for (final String name : getSettings().getWhitelistedPlayers().values()) {
-            if (name.toLowerCase().startsWith(args[1])) {
+            if (name.toLowerCase().startsWith(matchNameLowerCase)) {
                 list.add(name);
             }
         }
         return list;
     }
 
     private void removePlayerFromWhitelist(final SenderInfo sender, final String name) {
-        plugin.getOfflinePlayer(name, selected -> {
+        plugin.getOfflinePlayer(name).whenComplete((selected, ex) -> {
             if (selected == null) {
                 if (getSettings().removeWhitelistedPlayer(name)) {
                     sender.send(getMessage("whitelistRemoved", "%PLAYER%", name));
@@ -74,7 +75,7 @@ private void removePlayerFromWhitelist(final SenderInfo sender, final String nam
     }
 
     private void removePlayerFromWhitelist(final SenderInfo sender, final UUID uuid) {
-        plugin.getOfflinePlayer(uuid, selected -> {
+        plugin.getOfflinePlayer(uuid).whenComplete((selected, ex) -> {
             if (selected == null) {
                 removePlayerFromWhitelist(sender, uuid, uuid.toString());
             } else {

core/src/main/java/eu/kennytv/maintenance/core/util/RateLimitedException.java

@@ -0,0 +1,9 @@
+package eu.kennytv.maintenance.core.util;
+
+import java.io.IOException;
+
+/**
+ * Exception thrown when an API rate limit is reached.
+ */
+public class RateLimitedException extends IOException {
+}

core/src/main/resources/config.yml

@@ -82,6 +82,9 @@ send-join-notification: false
 # ... I don't know why you would want that, but you can disable it. :p
 kick-online-players: true
 
+# When fetched player does not exist then fallback to offline uuid. Only works on proxies like Velocity or BungeeCord
+fallback-to-offline-uuid: false
+
 # Changes the language of command feedback/messages.
 # If you find missing translations or want to contribute a new language file, you are very welcome to message me on Spigot or my Discord server! :)
 # Currently available are: en (English), de (German), fr (French), pt (Portuguese), es (Spanish), ru (Russian), zh (Chinese), it (Italian),
@@ -123,4 +126,4 @@ timer-broadcast-for-seconds: [1200, 900, 600, 300, 120, 60, 30, 20, 10, 5, 4, 3,
 update-checks: true
 
 # Used for autoupdating the config, do not change this value.
-config-version: 7
+config-version: 8

core/src/main/resources/language-en.yml

@@ -44,6 +44,7 @@ whitelistEmpty: "<prefix><red>The maintenance whitelist is empty! Use <yellow>/m
 playerNotFound: "<prefix><red>No player with this name has played on this server before."
 playerNotFoundUuid: "<prefix><red>No player with that uuid could be found."
 playerNotOnline: "<prefix><red>There is no player online with that name."
+offlinePlayerFetchError: "<prefix><red>There was an error while fetching offline player. Please try again later."
 invalidUuid: "<prefix><red>Invalid uuid format!"
 #Messages for the Bungee/Velocity part, you can ignore them if you use the plugin on Spigot/Sponge
 sentToWaitingServer: "<prefix><red>You have been sent to a waiting server!"
@@ -100,4 +101,4 @@ helpSingleScheduleTimer: "<gold>/maintenance scheduletimer [server] <timer minut
 helpSingleToggle: "<gold>/maintenance <on/off> [server] <gray>(Enables/disables maintenance mode)"
 helpStatus: "<gold>/maintenance status <gray>(Lists all proxied servers, that are currently under maintenance)"
 #Used for autoupdating the language file, do not change this value.
-language-version: 1
+language-version: 2