Adding `forceOfflineUuids` option, some minor fixes

src/main/java/org/samo_lego/simpleauth/SimpleAuth.java

@@ -36,7 +36,7 @@ import static org.samo_lego.simpleauth.utils.SimpleLogger.logInfo;
 
 public class SimpleAuth implements DedicatedServerModInitializer {
 
-    public static SimpleAuthDatabase DB = new SimpleAuthDatabase();
+    public static final SimpleAuthDatabase DB = new SimpleAuthDatabase();
 
 	public static final ExecutorService THREADPOOL = Executors.newCachedThreadPool();
 
@@ -45,19 +45,19 @@ public class SimpleAuth implements DedicatedServerModInitializer {
 	 * It's cleared on server stop in order to save some interactions with database during runtime.
 	 * Stores their data as {@link org.samo_lego.simpleauth.storage.PlayerCache PlayerCache} object.
 	 */
-	public static HashMap<String, PlayerCache> playerCacheMap = new HashMap<>();
+	public static final HashMap<String, PlayerCache> playerCacheMap = new HashMap<>();
 
 	/**
 	 * HashSet of player names that have Mojang accounts.
 	 * If player is saved in here, they will be treated as online-mode ones.
 	 */
-	public static HashSet<String> mojangAccountNamesCache = new HashSet<>();
+	public static final HashSet<String> mojangAccountNamesCache = new HashSet<>();
 
 	// Getting game directory
 	public static final Path gameDirectory = FabricLoader.getInstance().getGameDir();
 
 	// Server properties
-	public static Properties serverProp = new Properties();
+	public static final Properties serverProp = new Properties();
 
 	/**
 	 * Config of the SimpleAuth mod.

src/main/java/org/samo_lego/simpleauth/commands/LogoutCommand.java

@@ -23,7 +23,7 @@ public class LogoutCommand {
     private static int logout(ServerCommandSource serverCommandSource) throws CommandSyntaxException {
         ServerPlayerEntity player = serverCommandSource.getPlayer();
 
-        if(mojangAccountNamesCache.contains(player.getGameProfile().getName().toLowerCase())) {
+        if(!mojangAccountNamesCache.contains(player.getGameProfile().getName().toLowerCase())) {
             ((PlayerAuth) player).setAuthenticated(false);
             player.sendMessage(new LiteralText(config.lang.successfulLogout), false);
         }

src/main/java/org/samo_lego/simpleauth/mixin/MixinPlayerAdvancementTracker.java

@@ -30,7 +30,6 @@ public class MixinPlayerAdvancementTracker {
 
     @Inject(method = "load(Lnet/minecraft/server/ServerAdvancementLoader;)V",  at = @At("HEAD"))
     private void startMigratingOfflineAdvancements(ServerAdvancementLoader advancementLoader, CallbackInfo ci) {
-        System.out.println(this.advancementFile.isFile());
         if(config.experimental.premiumAutologin && ((PlayerAuth) this.owner).isUsingMojangAccount() && !this.advancementFile.isFile()) {
             // Migrate
             String playername = owner.getGameProfile().getName().toLowerCase();

src/main/java/org/samo_lego/simpleauth/mixin/MixinServerLoginNetworkHandler.java

@@ -21,13 +21,15 @@ import static org.samo_lego.simpleauth.SimpleAuth.*;
 import static org.samo_lego.simpleauth.utils.SimpleLogger.logError;
 
 @Mixin(ServerLoginNetworkHandler.class)
-public class MixinServerLoginNetworkHandler {
+public abstract class MixinServerLoginNetworkHandler {
 
     @Shadow
     private GameProfile profile;
     @Shadow
     private int loginTicks;
 
+    @Shadow protected abstract GameProfile toOfflineProfile(GameProfile profile);
+
     /**
      * Fake state of current player.
      */
@@ -49,6 +51,13 @@ public class MixinServerLoginNetworkHandler {
         }
     }
 
+    @Inject(method = "acceptPlayer()V", at = @At("HEAD"))
+    private void acceptPlayer(CallbackInfo ci) {
+        if(config.experimental.forceoOfflineUuids) {
+            this.profile = this.toOfflineProfile(this.profile);
+        }
+    }
+
     /**
      * Checks whether the player has purchased an account.
      * If so, server is presented as online, and continues as in normal-online mode.

src/main/java/org/samo_lego/simpleauth/storage/AuthConfig.java

@@ -25,6 +25,7 @@ import java.nio.charset.StandardCharsets;
 
 import static org.samo_lego.simpleauth.SimpleAuth.serverProp;
 import static org.samo_lego.simpleauth.utils.SimpleLogger.logError;
+import static org.samo_lego.simpleauth.utils.SimpleLogger.logInfo;
 
 public class AuthConfig {
     private static final Gson gson = new GsonBuilder()
@@ -230,9 +231,15 @@ public class AuthConfig {
                     new InputStreamReader(new FileInputStream(file), StandardCharsets.UTF_8)
             )) {
                 config = gson.fromJson(fileReader, AuthConfig.class);
-                if(config.experimental.premiumAutologin && !Boolean.parseBoolean(serverProp.getProperty("online-mode"))) {
-                    logError("You cannot use server in offline mode and premiumAutologin! Disabling the latter.");
-                    config.experimental.premiumAutologin = false;
+                if(!Boolean.parseBoolean(serverProp.getProperty("online-mode"))) {
+                    if(config.experimental.forceoOfflineUuids) {
+                        logInfo("Server is in offline mode, forceoOfflineUuids option is irrelevant. Setting it to false.");
+                        config.experimental.forceoOfflineUuids = false;
+                    }
+                    if(config.experimental.premiumAutologin) {
+                        logError("You cannot use server in offline mode and premiumAutologin! Disabling the latter.");
+                        config.experimental.premiumAutologin = false;
+                    }
                 }
             } catch (IOException e) {
                 throw new RuntimeException("[SimpleAuth] Problem occurred when trying to load config: ", e);

src/main/java/org/samo_lego/simpleauth/storage/PlayerCache.java

@@ -60,7 +60,7 @@ public class PlayerCache {
         public float pitch;
     }
 
-    public PlayerCache.LastLocation lastLocation = new PlayerCache.LastLocation();
+    public final PlayerCache.LastLocation lastLocation = new PlayerCache.LastLocation();
 
 
     private static final Gson gson = new Gson();

src/main/java/org/samo_lego/simpleauth/storage/SimpleAuthDatabase.java

@@ -64,6 +64,7 @@ public class SimpleAuthDatabase {
      * @param data data to put inside database
      * @return true if operation was successful, otherwise false
      */
+    @Deprecated
     public boolean registerUser(String uuid, String data) {
         try {
             if(!this.isUserRegistered(uuid)) {
@@ -111,6 +112,7 @@ public class SimpleAuthDatabase {
      * @param uuid uuid of the player to update data for
      * @param data data to put inside database
      */
+    @Deprecated
     public void updateUserData(String uuid, String data) {
         try {
             levelDBStore.put(bytes("UUID:" + uuid), bytes("data:" + data));

src/main/java/org/samo_lego/simpleauth/utils/AuthHelper.java

@@ -1,10 +1,5 @@
 package org.samo_lego.simpleauth.utils;
 
-import com.google.gson.JsonElement;
-import com.google.gson.JsonNull;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonParser;
-import org.samo_lego.simpleauth.SimpleAuth;
 import org.samo_lego.simpleauth.utils.hashing.HasherArgon2;
 import org.samo_lego.simpleauth.utils.hashing.HasherBCrypt;
 
@@ -12,9 +7,6 @@ import static org.samo_lego.simpleauth.SimpleAuth.config;
 import static org.samo_lego.simpleauth.SimpleAuth.playerCacheMap;
 
 public class AuthHelper {
-    // Json parser
-    private static final JsonParser parser = new JsonParser();
-
     /**
      * Checks password of user
      *