Added Whitelist checks

build.gradle

@@ -24,7 +24,7 @@ repositories {
 dependencies {
     compileOnly "io.papermc.paper:paper-api:1.19.4-R0.1-SNAPSHOT"
     compileOnly 'org.geysermc.floodgate:api:2.2.2-SNAPSHOT'
-    implementation 'com.squareup.okhttp3:okhttp:4.11.0'
+    compileOnly 'org.apache.httpcomponents:httpclient:4.5.14'
 }
 
 def targetJavaVersion = 17

src/main/java/eu/mhsl/craftattack/spawn/appliances/whitelist/LoginException.java

@@ -0,0 +1,18 @@
+package eu.mhsl.craftattack.spawn.appliances.whitelist;
+
+import java.util.UUID;
+
+public class LoginException extends Exception {
+    public String title;
+    public String error;
+    public UUID user;
+    public String solution;
+
+    public LoginException(String title, String error, UUID user, String solution) {
+        super(error);
+        this.title = title;
+        this.error = error;
+        this.user = user;
+        this.solution = solution;
+    }
+}

src/main/java/eu/mhsl/craftattack/spawn/appliances/whitelist/PlayerJoinListener.java

@@ -1,12 +1,27 @@
 package eu.mhsl.craftattack.spawn.appliances.whitelist;
 
 import eu.mhsl.craftattack.spawn.appliance.ApplianceListener;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.NamedTextColor;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.player.AsyncPlayerPreLoginEvent;
 
 public class PlayerJoinListener extends ApplianceListener<Whitelist> {
     @EventHandler
     public void preLoginEvent(AsyncPlayerPreLoginEvent preLoginEvent) {
-
+        try {
+            getAppliance().login(preLoginEvent);
+        } catch (LoginException e) {
+            preLoginEvent.disallow(
+                    AsyncPlayerPreLoginEvent.Result.KICK_WHITELIST,
+                    Component.text()
+                            .appendNewline().appendNewline()
+                            .append(Component.text(e.title, NamedTextColor.DARK_RED)).appendNewline()
+                            .append(Component.text(e.error, NamedTextColor.RED)).appendNewline().appendNewline()
+                            .append(Component.text(e.solution, NamedTextColor.GRAY)).appendNewline().appendNewline()
+                            .append(Component.text(e.user.toString(), NamedTextColor.DARK_GRAY)).appendNewline()
+                            .build()
+            );
+        }
     }
 }

src/main/java/eu/mhsl/craftattack/spawn/appliances/whitelist/Whitelist.java

@@ -1,13 +1,83 @@
 package eu.mhsl.craftattack.spawn.appliances.whitelist;
 
+import com.google.gson.Gson;
 import eu.mhsl.craftattack.spawn.appliance.Appliance;
+import org.apache.http.client.utils.URIBuilder;
 import org.bukkit.event.Listener;
+import org.bukkit.event.player.AsyncPlayerPreLoginEvent;
 import org.jetbrains.annotations.NotNull;
 
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
 import java.util.List;
+import java.util.Objects;
+import java.util.UUID;
 
 public class Whitelist extends Appliance {
+    private record UserData(UUID uuid, String username, String firstname, String lastname) {}
 
+    private final URI apiEndpoint = URI.create(Objects.requireNonNull(localConfig().getString("api")));
+
+    public Whitelist() {
+        super("whitelist");
+    }
+
+    public void login(AsyncPlayerPreLoginEvent login) throws LoginException {
+        try {
+            UserData data = this.fetchUserData(login.getUniqueId());
+
+            if(!data.username.equalsIgnoreCase(login.getName()))
+                throw new LoginException(
+                        "Nutzername geändert",
+                        String.format("Der Name '%s' stimmt nicht mit '%s' überein.", data.username, login.getName()),
+                        login.getUniqueId(),
+                        "Bitte kontaktiere einen Admin, um Deine Anmeldedaten zu aktualisieren!"
+                );
+
+        } catch (LoginException e) {
+            throw e;
+        } catch (Exception e) {
+            throw new LoginException(
+                    "Interner Serverfehler",
+                    "Deine Zugangsdaten konnten nicht abgerufen werden.",
+                    login.getUniqueId(),
+                    "Versuche es später erneut oder kontaktiere einen Admin!"
+            );
+        }
+    }
+
+    private UserData fetchUserData(UUID uuid) throws LoginException {
+        URIBuilder uriBuilder = new URIBuilder(apiEndpoint);
+        uriBuilder.addParameter("uuid", uuid.toString());
+
+        try {
+            HttpClient client = HttpClient.newHttpClient();
+            HttpRequest httpRequest = HttpRequest.newBuilder()
+                    .uri(uriBuilder.build())
+                    .header("Content-Type", "application/json")
+                    .GET()
+                    .build();
+
+            HttpResponse<String> httpResponse = client.send(httpRequest, HttpResponse.BodyHandlers.ofString());
+
+            if(httpResponse.statusCode() == 400)
+                throw new LoginException(
+                        "Nicht angemeldet",
+                        "Du bist derzeit nicht als Teilnehmer des CraftAttack-Projektes registriert!",
+                        uuid,
+                        "Melde Dich bei einem Admin für eine nachträgliche Anmeldung."
+                );
+
+            return new Gson().fromJson(httpResponse.body(), UserData.class);
+
+        } catch (IOException | InterruptedException | URISyntaxException e) {
+            throw new RuntimeException(e);
+        }
+    }
 
     @Override
     protected @NotNull List<Listener> eventHandlers() {

src/main/resources/config.yml

@@ -21,7 +21,7 @@ countdown:
   worldborder-after: 0
 
 report:
-  api: https://mhsl.eu/craftattack/report
+  api: https://mhsl.eu/craftattack/api/report
 
 event:
   api: http://10.20.6.5:8080/
@@ -43,3 +43,6 @@ help:
 
 playerLimit:
   maxPlayers: 0
+
+whitelist:
+  api: https://mhsl.eu/craftattack/api/user