Modify give command to support 1.7 features. Fixes BUKKIT-5286

Necessary additions include an interface to add internal value conversions
that are inappropriate for proper API design. This acts as a substitute
for properly formed, user-friendly commands in an effort to maintain
relatively vanilla behavior.

By: Wesley Wolfe <weswolf@aol.com>

paper-api/src/main/java/org/bukkit/Bukkit.java

@@ -692,4 +692,12 @@ public final class Bukkit {
     public static int getIdleTimeout() {
         return server.getIdleTimeout();
     }
+
+    /**
+     * @see Server#getUnsafe()
+     */
+    @Deprecated
+    public static UnsafeValues getUnsafe() {
+        return server.getUnsafe();
+    }
 }

paper-api/src/main/java/org/bukkit/Server.java

@@ -799,4 +799,10 @@ public interface Server extends PluginMessageRecipient {
      * @return the idle timeout in minutes
      */
     public int getIdleTimeout();
+
+    /**
+     * @see UnsafeValues
+     */
+    @Deprecated
+    UnsafeValues getUnsafe();
 }

paper-api/src/main/java/org/bukkit/UnsafeValues.java

@@ -0,0 +1,27 @@
+package org.bukkit;
+
+import java.util.List;
+
+import org.bukkit.inventory.ItemStack;
+
+/**
+ * This interface provides value conversions that may be specific to a
+ * runtime, or have arbitrary meaning (read: magic values).
+ * <p>
+ * Their existence and behavior is not guaranteed across future versions. They
+ * may be poorly named, throw exceptions, have misleading parameters, or any
+ * other bad programming practice.
+ * <p>
+ * This interface is unsupported and only for internal use.
+ *
+ * @deprecated Unsupported & internal use only
+ */
+@Deprecated
+public interface UnsafeValues {
+
+    Material getMaterialFromInternalName(String name);
+
+    List<String> tabCompleteInternalMaterialName(String token, List<String> completions);
+
+    ItemStack modifyItemStack(ItemStack stack, String arguments);
+}

paper-api/src/main/java/org/bukkit/command/defaults/GiveCommand.java

@@ -1,6 +1,7 @@
 package org.bukkit.command.defaults;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -14,6 +15,7 @@ import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.util.StringUtil;
 
+import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
 
 public class GiveCommand extends VanillaCommand {
@@ -47,6 +49,10 @@ public class GiveCommand extends VanillaCommand {
         if (player != null) {
             Material material = Material.matchMaterial(args[1]);
 
+            if (material == null) {
+                material = Bukkit.getUnsafe().getMaterialFromInternalName(args[1]);
+            }
+
             if (material != null) {
                 int amount = 1;
                 short data = 0;
@@ -61,7 +67,18 @@ public class GiveCommand extends VanillaCommand {
                     }
                 }
 
-                player.getInventory().addItem(new ItemStack(material, amount, data));
+                ItemStack stack = new ItemStack(material, amount, data);
+
+                if (args.length >= 5) {
+                    try {
+                        stack = Bukkit.getUnsafe().modifyItemStack(stack, Joiner.on(' ').join(Arrays.asList(args).subList(4, args.length)));
+                    } catch (Throwable t) {
+                        player.sendMessage("Not a valid tag");
+                        return true;
+                    }
+                }
+
+                player.getInventory().addItem(stack);
 
                 Command.broadcastCommandMessage(sender, "Gave " + player.getName() + " some " + material.getId() + " (" + material + ")");
             } else {
@@ -86,7 +103,7 @@ public class GiveCommand extends VanillaCommand {
         if (args.length == 2) {
             final String arg = args[1];
             final List<String> materials = GiveCommand.materials;
-            List<String> completion = null;
+            List<String> completion = new ArrayList<String>();
 
             final int size = materials.size();
             int i = Collections.binarySearch(materials, arg, String.CASE_INSENSITIVE_ORDER);
@@ -99,18 +116,13 @@ public class GiveCommand extends VanillaCommand {
             for ( ; i < size; i++) {
                 String material = materials.get(i);
                 if (StringUtil.startsWithIgnoreCase(material, arg)) {
-                    if (completion == null) {
-                        completion = new ArrayList<String>();
-                    }
                     completion.add(material);
                 } else {
                     break;
                 }
             }
 
-            if (completion != null) {
+            return Bukkit.getUnsafe().tabCompleteInternalMaterialName(arg, completion);
-                return completion;
-            }
         }
         return ImmutableList.of();
     }