Migrating advancements (#23)

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

@@ -0,0 +1,47 @@
+package org.samo_lego.simpleauth.mixin;
+
+import net.minecraft.advancement.PlayerAdvancementTracker;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.server.ServerAdvancementLoader;
+import net.minecraft.server.network.ServerPlayerEntity;
+import org.samo_lego.simpleauth.utils.PlayerAuth;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.io.File;
+
+import static org.samo_lego.simpleauth.SimpleAuth.config;
+
+@Mixin(PlayerAdvancementTracker.class)
+public class MixinPlayerAdvancementTracker {
+
+    @Mutable
+    @Shadow
+    @Final
+    private File advancementFile;
+
+    @Shadow
+    private ServerPlayerEntity owner;
+
+    @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();
+            this.advancementFile = new File(this.advancementFile.getParent(), PlayerEntity.getOfflinePlayerUuid(playername).toString() + ".json");
+        }
+    }
+
+    @Inject(method = "load(Lnet/minecraft/server/ServerAdvancementLoader;)V",  at = @At("TAIL"))
+    private void endMigratingOfflineAdvancements(ServerAdvancementLoader advancementLoader, CallbackInfo ci) {
+        if(config.experimental.premiumAutologin && ((PlayerAuth) this.owner).isUsingMojangAccount()) {
+            this.advancementFile = new File(this.advancementFile.getParent(), owner.getUuid() + ".json");
+        }
+    }
+}

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

@@ -30,7 +30,6 @@ public abstract class MixinPlayerManager {
         PlayerLeaveServerCallback.EVENT.invoker().onPlayerLeave(serverPlayerEntity);
     }
 
-    // Method for kicking player for
     @Inject(method = "checkCanJoin(Ljava/net/SocketAddress;Lcom/mojang/authlib/GameProfile;)Lnet/minecraft/text/Text;", at = @At("HEAD"), cancellable = true)
     private void checkCanJoin(SocketAddress socketAddress, GameProfile profile, CallbackInfoReturnable<Text> cir) {
         // Getting the player that is trying to join the server

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

@@ -192,8 +192,23 @@ public class AuthConfig {
          * Whether players who have a valid session should skip the authentication process.
          * You have to set online-mode to true in server.properties!
          * (cracked players will still be able to enter, but they'll need to login)
+         *
+         * This protects premium usernames from being stolen, since cracked players
+         * with name that is found in Mojang database, are kicked.
          */
         public boolean premiumAutologin = false;
+        /**
+         * Whether to modify player uuids to offline style.
+         * Note: this should be used only if you had your server
+         * running in offline mode and you made the switch to use
+         * AuthConfig#premiumAutoLogin AND your players already
+         * have e.g. villager discounts, which are based on uuid.
+         * Other things (advancements, playerdata) are migrated
+         * automatically, so think before enabling this. In case
+         * an online-mode player changes username, they'll loose all
+         * their stuff, unless you migrate it manually.
+         */
+        public boolean forceoOfflineUuids = false;
     }
 
     public MainConfig main = new MainConfig();

src/main/resources/mixins.simpleauth.json

@@ -4,6 +4,7 @@
   "compatibilityLevel": "JAVA_8",
   "mixins": [],
   "server": [
+    "MixinPlayerAdvancementTracker",
     "MixinPlayerEntity",
     "MixinPlayerManager",
     "MixinServerLoginNetworkHandler",