Auto-migrate player data (#23)

gradle.properties

@@ -10,7 +10,7 @@ loader_version=0.10.1+build.209
 fabric_version=0.24.0+build.411-1.16
 
 # Mod Properties
-mod_version = 1.6.2
+mod_version = 1.6.3
 maven_group = org.samo_lego
 archives_base_name = simpleauth
 

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

@@ -50,15 +50,15 @@ public class SimpleAuth implements DedicatedServerModInitializer {
 	 */
 	public static HashSet<String> mojangAccountNamesCache = new HashSet<>();
 
-	public static HashSet<String> accountStatusCache = new HashSet<>();
-
 	// Getting game directory
 	public static final Path gameDirectory = FabricLoader.getInstance().getGameDir();
 
 	// Server properties
 	public static Properties serverProp = new Properties();
 
-	// Mod config
+	/**
+	 * Config of the SimpleAuth mod.
+	 */
 	public static AuthConfig config;
 
 	@Override

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

@@ -7,6 +7,7 @@
 import net.minecraft.text.TranslatableText;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
@@ -30,6 +31,7 @@ public class MixinServerLoginNetworkHandler {
     /**
      * Fake state of current player.
      */
+    @Unique
     private boolean acceptCrackedPlayer = false;
 
     /**

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

@@ -0,0 +1,88 @@
+package org.samo_lego.simpleauth.mixin;
+
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtIo;
+import net.minecraft.world.WorldSaveHandler;
+import org.apache.logging.log4j.Logger;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.ModifyVariable;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+import org.spongepowered.asm.mixin.injection.callback.LocalCapture;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+import static org.samo_lego.simpleauth.SimpleAuth.config;
+import static org.samo_lego.simpleauth.SimpleAuth.mojangAccountNamesCache;
+
+@Mixin(WorldSaveHandler.class)
+public class MixinWorldSaveHandler {
+
+    @Final
+    @Shadow
+    private File playerDataDir;
+
+    @Unique
+    private boolean fileExists;
+
+    @Final
+    @Shadow
+    private static Logger LOGGER;
+
+    /**
+     * Saves whether player save file exists.
+     *
+     * @param playerEntity
+     * @param cir
+     * @param compoundTag
+     * @param file
+     */
+    @Inject(
+            method = "loadPlayerData(Lnet/minecraft/entity/player/PlayerEntity;)Lnet/minecraft/nbt/CompoundTag;",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Ljava/io/File;exists()Z"
+            ),
+            locals = LocalCapture.CAPTURE_FAILHARD
+    )
+    private void fileExists(PlayerEntity playerEntity, CallbackInfoReturnable<CompoundTag> cir, CompoundTag compoundTag, File file) {
+        // @ModifyVariable cannot capture locals
+        this.fileExists = file.exists();
+    }
+
+    /**
+     * Loads offline-uuid player data to compoundTag in order to migrate from offline to online.
+     *
+     * @param compoundTag null compound tag.
+     * @param player player who might need migration of datd.
+     * @return compoundTag containing migrated data.
+     */
+    @ModifyVariable(
+            method = "loadPlayerData(Lnet/minecraft/entity/player/PlayerEntity;)Lnet/minecraft/nbt/CompoundTag;",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Ljava/io/File;exists()Z"
+            )
+    )
+    private CompoundTag migratePlayerData(CompoundTag compoundTag, PlayerEntity player) {
+        // Checking for offline player data only if online doesn't exist yet
+        if(config.experimental.premiumAutologin && mojangAccountNamesCache.contains(player.getGameProfile().getName()) && !this.fileExists) {
+            File file = new File(this.playerDataDir, PlayerEntity.getOfflinePlayerUuid(player.getGameProfile().getName()) + ".dat");
+            if (file.exists() && file.isFile())
+                try {
+                    compoundTag = NbtIo.readCompressed(new FileInputStream(file));
+                }
+                catch (IOException e) {
+                    LOGGER.warn("Failed to load player data for {}", player.getGameProfile().getName());
+                }
+        }
+        return compoundTag;
+    }
+}

src/main/resources/mixins.simpleauth.json

@@ -8,7 +8,8 @@
     "MixinPlayerManager",
     "MixinServerLoginNetworkHandler",
     "MixinServerPlayNetworkHandler",
-    "MixinSlot"
+    "MixinSlot",
+    "MixinWorldSaveHandler"
   ],
   "injectors": {
     "defaultRequire": 1