the_big_one/src/main/java/jesse/keeblarcraft/EventMgr/DimensionLoadingEvent.java

package jesse.keeblarcraft.EventMgr;

import java.util.HashMap;
import java.util.Map.Entry;

import jesse.keeblarcraft.ConfigMgr.ConfigManager;
import jesse.keeblarcraft.Utils.ChatUtil;
import jesse.keeblarcraft.Utils.ChatUtil.CONSOLE_COLOR;
import jesse.keeblarcraft.world.dimension.ModDimensions;
import net.minecraft.entity.player.PlayerInventory;
import net.minecraft.nbt.NbtElement;
import net.minecraft.nbt.NbtList;
import net.minecraft.server.network.ServerPlayerEntity;
import net.minecraft.server.world.ServerWorld;
import net.minecraft.text.Text;

public class DimensionLoadingEvent {
    private static DimensionLoadingEvent static_inst;

    public static DimensionLoadingEvent GetInstance() {
        if (static_inst == null) {
            static_inst = new DimensionLoadingEvent();
        }

        return static_inst;
    }

    private static class InventoryWrapper {
        public HashMap<String, NbtList> inventories = new HashMap<String, NbtList>();
    }

    private static InventoryWrapper iw = new InventoryWrapper();

    private static String CONFIG_LOCATION = "misc/dim_loading_cached_inventories/";
    ConfigManager config = new ConfigManager();

    public DimensionLoadingEvent() {
        // read config
        iw.inventories = config.ReadAllNbtListFromDirectory(CONFIG_LOCATION, NbtElement.COMPOUND_TYPE);
    }

    // TODO: In the future when the attribute system is more complete this will need to filter a whitelist of items
    // from the that system + story mode because some items will be able to transcend dimensions!
    public void HandleWorldMove(ServerPlayerEntity player, ServerWorld origin, ServerWorld destination) {
        System.out.println("World move event called!");

        // Player is ENTERING the custom dimension; strip their inventory!
        if (destination.getDimensionEntry().matchesKey(ModDimensions.KEEBLAR_DIM_TYPE) && (!iw.inventories.containsKey(player.getUuidAsString()))) {
            // Make sure player is in map. For now we only care about storing OVERWORLD inventory. We DO NOT care about
            // the dimension inventory!
            // if (!iw.inventories.containsKey(player.getUuidAsString())) {
                // Copy the nbt into the list
                NbtList inventoryNbt = new NbtList();
                player.getInventory().writeNbt(inventoryNbt);

                iw.inventories.put(player.getUuidAsString(), inventoryNbt);
                player.getInventory().clear();
            // }
        // Player is LEAVING the custom dimension. Give them their stuff back
        } else if (origin.getDimensionEntry().matchesKey(ModDimensions.KEEBLAR_DIM_TYPE) && iw.inventories.containsKey(player.getUuidAsString())) {
            // if (iw.inventories.containsKey(player.getUuidAsString())) {
                player.getInventory().readNbt(iw.inventories.get(player.getUuidAsString()));
                iw.inventories.remove(player.getUuidAsString());
            // }
        }

        FlashConfig();
    }

    // Call on server close before we lose the volatile memory
    public void SaveInventories() {
        System.out.println("Call to save inventories. Flashing IW.Inventories with size " + iw.inventories.size());
        FlashConfig();
    }

    public void CheckPlayer(ServerPlayerEntity player) {
        // Check the players logged in world. If they are logging into the overworld - we need to see if they are in our
        // map and give them the inventory back
        if ((!player.getWorld().getDimensionEntry().matchesKey(ModDimensions.KEEBLAR_DIM_TYPE)) && iw.inventories.containsKey(player.getUuidAsString())) {
            // We need to store the contents of the nbt into a regular inventory and magical chest and give it back to the player
            player.sendMessage(Text.of("[IMPORTANT]: It appears you have a saved inventory of items on the server! You can claim it with /magic-inventory claim"));
        }
    }

    // Fetches an inventory from this list. Use MagicInventory to store it along the transfer way!
    public NbtList GetInventory(String uuid) {
        NbtList nbt = iw.inventories.get(uuid);
        iw.inventories.remove(uuid);
        return nbt;
    }

    public void FlashConfig() {
        try {
            // config.WriteToJsonFile(CONFIG_LOCATION, iw);
            // First, ensure list is size > 0
            for (Entry<String, NbtList> list : iw.inventories.entrySet()) {
                if (list.getValue().size() > 0) {
                    config.WriteNbtListToFile(CONFIG_LOCATION + list.getKey() + ".nbt", list.getKey(), list.getValue());
                }
            }
        } catch (Exception e) {
            System.out.println(ChatUtil.ColoredString("Could not flash dimension loading configuration file", CONSOLE_COLOR.RED));
        }
    }
}