[WIP] ItemExpression: Like regexes for ItemStacks

.gitignore

@@ -3,3 +3,8 @@
 .classpath
 .project
 .settings/**
+
+/.idea/
+/*.iml
+/*.ipr
+/*.iws

pom.xml

@@ -72,24 +72,6 @@
 					</execution>
 				</executions>
 			</plugin>
-			<plugin>
-				<groupId>org.apache.maven.plugins</groupId>
-				<artifactId>maven-checkstyle-plugin</artifactId>
-				<version>2.17</version>
-				<configuration>
-					<configLocation>https://build.devotedmc.com/job/Style-guide-master/lastSuccessfulBuild/artifact/src/main/resources/devoted_checks.xml</configLocation>
-					<consoleOutput>true</consoleOutput>
-				</configuration>
-				<executions>
-					<execution>
-						<id>checkstyle</id>
-						<goals>
-							<goal>checkstyle</goal>
-						</goals>
-						<phase>prepare-package</phase>
-					</execution>
-				</executions>
-			</plugin>
 		</plugins>
 
 		<resources>

src/main/java/vg/civcraft/mc/civmodcore/CivModCorePlugin.java

@@ -1,5 +1,8 @@
 package vg.civcraft.mc.civmodcore;
 
+import vg.civcraft.mc.civmodcore.itemHandling.itemExpression.TestItemSolvingCommand;
+import vg.civcraft.mc.civmodcore.itemHandling.itemExpression.TestMatchingCommand;
+
 /**
  * The sole purpose of this class is to make Spigot recognize this library as a plugin and automatically load the
  * classes onto the classpath for us.
@@ -15,6 +18,9 @@ public void onEnable() {
 		super.onEnable();
 		// needed for some of the apis
 		instance = this;
+
+		getCommand("testitemsolving").setExecutor(new TestItemSolvingCommand());
+		getCommand("testitemmatching").setExecutor(new TestMatchingCommand());
 	}
 
 	public static CivModCorePlugin getInstance() {

src/main/java/vg/civcraft/mc/civmodcore/itemHandling/ItemMap.java

@@ -1,13 +1,11 @@
 package vg.civcraft.mc.civmodcore.itemHandling;
 
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 import java.util.Map.Entry;
-import java.util.Set;
+import java.util.function.Predicate;
 import java.util.logging.Logger;
+
+import com.google.common.collect.Lists;
 import net.minecraft.server.v1_13_R2.NBTTagCompound;
 import net.minecraft.server.v1_13_R2.NBTTagList;
 import org.bukkit.Bukkit;
@@ -18,6 +16,7 @@
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.PlayerInventory;
+import vg.civcraft.mc.civmodcore.itemHandling.itemExpression.ItemExpression;
 
 /**
  * Allows the storage and comparison of itemstacks while ignoring their maximum possible stack sizes. This offers
@@ -562,6 +561,48 @@ public boolean removeSafelyFrom(Inventory i) {
 		return true;
 	}
 
+	/**
+	 * Matches a number of ItemExpression on this ItemMap, trying to match each ItemExpression to a ItemStack 1:1.
+	 *
+	 * This works similar to, but not exactly like ItemMap.getEntries().steam().allMatch().
+	 *
+	 * For example, if this is an ItemMap of a diamond sword and a stack of dirt, passing this function a
+	 * ItemExpression that matches any sword will return true, but passing it a collection of
+	 * ItemExpressions [Matches diamond sword, Matches any sword] will return false, because it can't match each
+	 * ItemExpression to an ItemStack.
+	 * @param itemExpressions The collection of ItemExpression that will match over this ItemMap.
+	 * @return true if all if all of the ItemExpressions matched an item in this ItemMap in a 1:1 fashion, otherwise false.
+	 */
+	public boolean itemExpressionsMatchItems(Collection<ItemExpression> itemExpressions) {
+		// clone so we can remove elements as needed.
+		ArrayList<ItemExpression> itemExpressions1 = new ArrayList<>(itemExpressions);
+		ItemMap clone = clone();
+
+		// The list is reversed so we can remove the current ItemExpression without shifting over the list.
+		for (ItemExpression e : Lists.reverse(itemExpressions1)) {
+			Predicate<Entry<ItemStack, Integer>> iePredicate = e.getMatchesItemMapPredicate(clone);
+			boolean matched = false;
+
+			for (Entry<ItemStack, Integer> entry : clone.getEntrySet()) {
+				if (iePredicate.test(entry)) {
+					// Make sure that each ItemExpression can match one ItemStack,
+					// and that each ItemStack can only be matched by one ItemExpression
+					clone.removeItemStack(entry.getKey());
+					itemExpressions1.remove(e);
+					matched = true;
+					break;
+				}
+			}
+
+			if (!matched) {
+				// slight optimization to return early instead of needing to check every single ItemExpression
+				return false;
+			}
+		}
+
+		return itemExpressions1.isEmpty();
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (o instanceof ItemMap) {