Twine/src/main/java/com/thebrokenrail/twine/item/BackpackItem.java

package com.thebrokenrail.twine.item;

import com.thebrokenrail.twine.Twine;
import com.thebrokenrail.twine.component.StageDataComponent;
import net.fabricmc.fabric.api.container.ContainerProviderRegistry;
import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.inventory.Inventories;
import net.minecraft.inventory.Inventory;
import net.minecraft.item.DyeableItem;
import net.minecraft.item.Item;
import net.minecraft.item.ItemGroup;
import net.minecraft.item.ItemStack;
import net.minecraft.server.world.ServerWorld;
import net.minecraft.text.LiteralText;
import net.minecraft.util.ActionResult;
import net.minecraft.util.Hand;
import net.minecraft.util.TypedActionResult;
import net.minecraft.util.collection.DefaultedList;
import net.minecraft.util.math.ChunkPos;
import net.minecraft.world.World;

public class BackpackItem extends Item implements DyeableItem {
    public static class ItemInventory implements Inventory {
        private final int size;
        private final ItemStack stack;
        private final Hand hand;
        private final DefaultedList<ItemStack> inv;

        public ItemInventory(int size, ItemStack stack, Hand hand) {
            this.size = size;
            this.stack = stack;
            this.hand = hand;
            inv = getInv();
        }

        public ItemStack getHolder() {
            return stack;
        }

        private DefaultedList<ItemStack> getInv() {
            DefaultedList<ItemStack> list = DefaultedList.ofSize(size, ItemStack.EMPTY);
            Inventories.fromTag(stack.getOrCreateTag(), list);
            return list;
        }

        private void setInv(DefaultedList<ItemStack> list) {
            Inventories.toTag(stack.getOrCreateTag(), list);
        }

        @Override
        public int size() {
            return size;
        }

        @Override
        public boolean isEmpty() {
            for (ItemStack item : inv) {
                if (item != ItemStack.EMPTY) {
                    return false;
                }
            }
            return true;
        }

        @Override
        public ItemStack getStack(int slot) {
            return inv.get(slot);
        }

        @Override
        public ItemStack removeStack(int slot, int amount) {
            return inv.get(slot).split(amount);
        }

        @Override
        public ItemStack removeStack(int slot) {
            ItemStack item = inv.get(slot);
            return item.split(item.getCount());
        }

        @Override
        public void setStack(int slot, ItemStack stack) {
            inv.set(slot, stack);
        }

        @Override
        public void markDirty() {
            setInv(inv);
        }

        @Override
        public boolean canPlayerUse(PlayerEntity player) {
            return player.getStackInHand(hand) == stack;
        }

        @Override
        public void clear() {
            for (int i = 0; i < size; i++) {
                inv.set(i, ItemStack.EMPTY);
            }
        }
    }

    private final boolean large;

    public BackpackItem(boolean large) {
        super(new Settings().maxCount(1).group(Twine.ITEM_GROUP));
        this.large = large;
    }

    @Override
    public TypedActionResult<ItemStack> use(World world, PlayerEntity user, Hand hand) {
        ItemStack stack = user.getStackInHand(hand);
        if (!world.isClient()) {
            ContainerProviderRegistry.INSTANCE.openContainer(Twine.BACKPACK_SCREEN, user, buf -> {
                buf.writeBoolean(large);
                buf.writeEnumConstant(hand);
            });

            StageDataComponent component = StageDataComponent.getFromWorld((ServerWorld) world);
            ChunkPos chunkPos = new ChunkPos(user.getBlockPos());

            int stage = component.findStageOfChunk(chunkPos);
            user.sendMessage(new LiteralText("Global Stage: " + stage), false);

            StageDataComponent.StageData[] personalData = component.getData(user.getUuid());
            int personalStage = StageDataComponent.findStageOfChunk(chunkPos, personalData);
            user.sendMessage(new LiteralText("Personal Stage: " + personalStage), false);
            user.sendMessage(new LiteralText("Personal Center Chunk X: " + personalData[personalStage].x + " Personal Center Chunk Z: " + personalData[personalStage].z), false);
            user.sendMessage(new LiteralText("Time To Personal Stage Increase: " + (Twine.STAGE_TIME - personalData[personalStage].time) + " Ticks"), false);
        }
        return new TypedActionResult<>(ActionResult.CONSUME, stack);
    }
}