From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: lexikiq <noellekiq@gmail.com>
Date: Fri, 18 Jun 2021 03:18:47 -0400
Subject: [PATCH] Add UnsafeValues#canPlaceItemOn


diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
index 64c50c52c11214740de7903e5592b8b6b2c170b3..be2739875ba1ba1a973c4a45c7e6a6996f0daf31 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
@@ -618,6 +618,55 @@ public final class CraftMagicNumbers implements UnsafeValues {
     }
     // Paper end
 
+    // Parchment start
+    @Override
+    public java.util.concurrent.CompletableFuture<Boolean> canPlaceItemOn(ItemStack item, gg.projecteden.parchment.OptionalHumanEntity player, org.bukkit.block.Block block, org.bukkit.block.BlockFace face) {
+        org.apache.commons.lang3.Validate.notNull(item, "item");
+        org.apache.commons.lang3.Validate.notNull(block, "block");
+        org.apache.commons.lang3.Validate.notNull(face, "face");
+        org.bukkit.entity.HumanEntity human = player == null ? null : player.getPlayer();
+        java.util.concurrent.CompletableFuture<Boolean> future = new java.util.concurrent.CompletableFuture<>();
+        if (block.getType().isEmpty() || block.isLiquid() || (block.getType() == Material.LIGHT && item.getType() != Material.LIGHT)) {
+            future.complete(false);
+            return future;
+        } else if (!face.isCartesian()) {
+            throw new IllegalArgumentException("face must be cartesian");
+        }
+
+
+        net.minecraft.world.entity.player.Player nmsPlayer = human == null ? null : ((org.bukkit.craftbukkit.entity.CraftHumanEntity) human).getHandle();
+        org.bukkit.craftbukkit.block.CraftBlock cBlock = (org.bukkit.craftbukkit.block.CraftBlock) block;
+        org.bukkit.craftbukkit.block.CraftBlock relativeBlock = (org.bukkit.craftbukkit.block.CraftBlock) block.getRelative(face);
+        if (!relativeBlock.isReplaceable()) {
+            future.complete(false);
+            return future;
+        }
+
+        org.bukkit.Location playerLoc = human != null ? human.getLocation() : relativeBlock.getLocation();
+        net.minecraft.core.Direction dir = net.minecraft.core.Direction.valueOf(face.name());
+        net.minecraft.world.item.ItemStack nmsStack = CraftItemStack.asNMSCopy(item);
+        Item nmsItem = nmsStack.getItem();
+        if (!(nmsItem instanceof net.minecraft.world.item.BlockItem blockItem)) {
+            future.complete(false);
+            return future;
+        }
+
+        net.minecraft.world.item.context.BlockPlaceContext context = new net.minecraft.world.item.context.BlockPlaceContext(new net.minecraft.world.item.context.UseOnContext(cBlock.getCraftWorld().getHandle(), nmsPlayer, net.minecraft.world.InteractionHand.MAIN_HAND, nmsStack, new net.minecraft.world.phys.BlockHitResult(CraftVector.toNMS(playerLoc.toVector()), dir, cBlock.getPosition(), false)));
+        context = blockItem.updatePlacementContext(context);
+        if (context == null) {
+            future.complete(false);
+            return future;
+        }
+        BlockState blockState = blockItem.getBlock().getStateForPlacement(context);
+        if (blockState == null) {
+            future.complete(false);
+            return future;
+        }
+        final net.minecraft.world.item.context.BlockPlaceContext ctx = context;
+        return future.completeAsync(() -> blockItem.canPlace(ctx, blockState), io.papermc.paper.util.MCUtil.MAIN_EXECUTOR);
+    }
+    // Parchment end
+
     /**
      * This helper class represents the different NBT Tags.
      * <p>