CombinedInventoryProxy.php

<?php
 
/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */
 
declare(strict_types=1);
 
namespace pocketmine\inventory;
 
use pocketmine\item\Item;
use pocketmine\item\VanillaItems;
use pocketmine\player\InventoryWindow;
use function array_fill_keys;
use function array_keys;
use function array_map;
use function array_merge;
use function count;
use function spl_object_id;
 
final class CombinedInventoryProxy extends BaseInventory{
 
    private readonly int $size;
 
    private array $backingInventories = [];
    private array $slotToInventoryMap = [];
    private array $inventoryToOffsetMap = [];
 
    private InventoryListener $backingInventoryListener;
    private bool $modifyingBackingInventory = false;
 
    public function __construct(
        array $backingInventories
    ){
        parent::__construct();
        foreach($backingInventories as $backingInventory){
            $this->backingInventories[spl_object_id($backingInventory)] = $backingInventory;
        }
        $combinedSize = 0;
        foreach($this->backingInventories as $inventory){
            $size = $inventory->getSize();
 
            $this->inventoryToOffsetMap[spl_object_id($inventory)] = $combinedSize;
            for($slot = 0; $slot < $size; $slot++){
                $this->slotToInventoryMap[$combinedSize + $slot] = $inventory;
            }
 
            $combinedSize += $size;
        }
        $this->size = $combinedSize;
 
        $weakThis = \WeakReference::create($this);
        $this->backingInventoryListener = new CallbackInventoryListener(
            static fn(Inventory $inventory, int $slot, Item $oldItem) => $weakThis->get()?->onBackingSlotChange($inventory, $slot, $oldItem),
            static fn(Inventory $inventory, array $oldContents) => $weakThis->get()?->onBackingContentChange($inventory, $oldContents)
        );
        foreach($this->backingInventories as $inventory){
            $inventory->getListeners()->add($this->backingInventoryListener);
        }
    }
 
    private function onBackingSlotChange(Inventory $inventory, int $slot, Item $oldItem) : void{
        if($this->modifyingBackingInventory){
            return;
        }
 
        $offset = $this->inventoryToOffsetMap[spl_object_id($inventory)];
        $this->onSlotChange($offset + $slot, $oldItem);
    }
 
    private function onBackingContentChange(Inventory $inventory, array $oldContents) : void{
        if($this->modifyingBackingInventory){
            return;
        }
 
        if(count($this->backingInventories) === 1){
            $this->onContentChange($oldContents);
        }else{
            $offset = $this->inventoryToOffsetMap[spl_object_id($inventory)];
            for($slot = 0, $limit = $inventory->getSize(); $slot < $limit; $slot++){
                $this->onSlotChange($offset + $slot, $oldContents[$slot] ?? VanillaItems::AIR());
            }
        }
    }
 
    public function __destruct(){
        foreach($this->backingInventories as $inventory){
            $inventory->getListeners()->remove($this->backingInventoryListener);
        }
    }
 
    private function getInventory(int $slot) : array{
        $inventory = $this->slotToInventoryMap[$slot] ?? throw new \InvalidArgumentException("Invalid combined inventory slot $slot");
        $actualSlot = $slot - $this->inventoryToOffsetMap[spl_object_id($inventory)];
        return [$inventory, $actualSlot];
    }
 
    protected function internalSetItem(int $index, Item $item) : void{
        [$inventory, $actualSlot] = $this->getInventory($index);
 
        //Make sure our backing listener doesn't dispatch double updates to our own listeners
        $this->modifyingBackingInventory = true;
        try{
            $inventory->setItem($actualSlot, $item);
        }finally{
            $this->modifyingBackingInventory = false;
        }
    }
 
    protected function internalSetContents(array $items) : void{
        $contentsByInventory = array_fill_keys(array_keys($this->backingInventories), []);
        foreach($items as $i => $item){
            [$inventory, $actualSlot] = $this->getInventory($i);
            $contentsByInventory[spl_object_id($inventory)][$actualSlot] = $item;
        }
        foreach($contentsByInventory as $splObjectId => $backingInventoryContents){
            $backingInventory = $this->backingInventories[$splObjectId];
 
            //Make sure our backing listener doesn't dispatch double updates to our own listeners
            $this->modifyingBackingInventory = true;
            try{
                $backingInventory->setContents($backingInventoryContents);
            }finally{
                $this->modifyingBackingInventory = false;
            }
        }
    }
 
    public function getSize() : int{
        return $this->size;
    }
 
    public function getItem(int $index) : Item{
        [$inventory, $actualSlot] = $this->getInventory($index);
        return $inventory->getItem($actualSlot);
    }
 
    public function getContents(bool $includeEmpty = false) : array{
        $result = [];
        foreach($this->backingInventories as $inventory){
            $offset = $this->inventoryToOffsetMap[spl_object_id($inventory)];
            foreach($inventory->getContents($includeEmpty) as $i => $item){
                $result[$offset + $i] = $item;
            }
        }
 
        return $result;
    }
 
    public function getMatchingItemCount(int $slot, Item $test, bool $checkTags) : int{
        [$inventory, $actualSlot] = $this->getInventory($slot);
        return $inventory->getMatchingItemCount($actualSlot, $test, $checkTags);
    }
 
    public function isSlotEmpty(int $index) : bool{
        [$inventory, $actualSlot] = $this->getInventory($index);
        return $inventory->isSlotEmpty($actualSlot);
    }
 
    public function onOpen(InventoryWindow $window) : void{
        foreach($this->backingInventories as $inventory){
            $inventory->onOpen($window);
        }
    }
 
    public function onClose(InventoryWindow $window) : void{
        foreach($this->backingInventories as $inventory){
            $inventory->onClose($window);
        }
    }
 
    public function removeAllWindows() : void{
        foreach($this->backingInventories as $inventory){
            $inventory->removeAllWindows();
        }
    }
 
    public function getViewers() : array{
        return array_merge(...array_map(fn(Inventory $inventory) => $inventory->getViewers(), $this->backingInventories));
    }
}