Added NBT tag selector. Added selector syntax validator.

1 files changed, 180 insertions, 0 deletions

diff --git a/src/main/java/com/anthonyhilyard/iceberg/util/Selectors.java b/src/main/java/com/anthonyhilyard/iceberg/util/Selectors.java
index 65a2ebd..6f450f1 100644
--- a/src/main/java/com/anthonyhilyard/iceberg/util/Selectors.java
+++ b/src/main/java/com/anthonyhilyard/iceberg/util/Selectors.java
@@ -4,9 +4,14 @@ import net.minecraft.world.item.ItemStack;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.function.BiPredicate;
+
 import java.util.List;
 
 import net.minecraft.client.Minecraft;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NumericTag;
+import net.minecraft.nbt.Tag;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.chat.TextColor;
 import net.minecraft.resources.ResourceLocation;
@@ -23,13 +28,109 @@ public class Selectors
 		put("epic", Rarity.EPIC);
 	}};
 
+	private static Map<String, BiPredicate<Tag, String>> nbtComparators = new HashMap<String, BiPredicate<Tag, String>>() {{
+		put("=",  (tag, value) -> tag.getAsString().contentEquals(value));
+
+		put("!=", (tag, value) -> !tag.getAsString().contentEquals(value));
+
+		put(">",  (tag, value) -> {
+			try
+			{
+				double parsedValue = Double.valueOf(value);
+				if (tag instanceof NumericTag)
+				{
+					return ((NumericTag)tag).getAsDouble() > parsedValue;
+				}
+				else
+				{
+					return false;
+				}
+			}
+			catch (Exception e)
+			{
+				return false;
+			}
+		});
+
+		put("<",  (tag, value) -> {
+			try
+			{
+				double parsedValue = Double.valueOf(value);
+				if (tag instanceof NumericTag)
+				{
+					return ((NumericTag)tag).getAsDouble() < parsedValue;
+				}
+				else
+				{
+					return false;
+				}
+			}
+			catch (Exception e)
+			{
+				return false;
+			}
+		});
+	}};
+
+	/**
+	 * Returns true if this selector is syntactically valid.
+	 * @param value The selector.
+	 * @return True if the selector syntax is valid, false otherwise.
+	 */
+	public static boolean validateSelector(String value)
+	{
+		// This is a tag, which should be a resource location.
+		if (value.startsWith("$"))
+		{
+			return ResourceLocation.isValidResourceLocation(value.substring(1));
+		}
+		// Mod IDs need to conform to this regex: ^[a-z][a-z0-9_-]{1,63}$
+		else if (value.startsWith("@"))
+		{
+			return value.substring(1).matches("^[a-z][a-z0-9_-]{1,63}$");
+		}
+		// If this is a rarity, make sure it's a valid one.
+		else if (value.startsWith("!"))
+		{
+			return rarities.keySet().contains(value.substring(1).toLowerCase());
+		}
+		// If this is a hex color, ensure it's in a valid format.
+		else if (value.startsWith("#"))
+		{
+			return TextColor.parseColor(value) != null;
+		}
+		// Text matches are always considered valid.
+		else if (value.startsWith("%") || value.startsWith("^"))
+		{
+			return true;
+		}
+		// Any text is valid for NBT tag selectors.
+		else if (value.startsWith("&"))
+		{
+			return true;
+		}
+		// Otherwise it's an item, so just make sure it's a value resource location.
+		else
+		{
+			return value == null || value == "" || ResourceLocation.isValidResourceLocation(value);
+		}
+	}
+
+	/**
+	 * Returns true if the given item is matched by the given selector.
+	 * @param item An ItemStack instance of an item to check.
+	 * @param selector A selector string to check against.
+	 * @return True if the item matches, false otherwise.
+	 */
 	public static boolean itemMatches(ItemStack item, String selector)
 	{
 		String itemResourceLocation = item.getItem().getRegistryName().toString();
+		// Item ID
 		if (selector.equals(itemResourceLocation) || selector.equals(itemResourceLocation.replace("minecraft:", "")))
 		{
 			return true;
 		}
+		// Item name color
 		else if (selector.startsWith("#"))
 		{
 			TextColor entryColor = TextColor.parseColor(selector);
@@ -38,6 +139,7 @@ public class Selectors
 				return true;
 			}
 		}
+		// Vanilla rarity
 		else if (selector.startsWith("!"))
 		{
 			if (item.getRarity() == rarities.get(selector.substring(1)))
@@ -45,6 +147,7 @@ public class Selectors
 				return true;
 			}
 		}
+		// Mod ID
 		else if (selector.startsWith("@"))
 		{
 			if (itemResourceLocation.startsWith(selector.substring(1) + ":"))
@@ -52,6 +155,7 @@ public class Selectors
 				return true;
 			}
 		}
+		// Item tag
 		else if (selector.startsWith("$"))
 		{
 			if (ItemTags.getAllTags().getTagOrEmpty(new ResourceLocation(selector.substring(1))).getValues().contains(item.getItem()))
@@ -59,6 +163,7 @@ public class Selectors
 				return true;
 			}
 		}
+		// Item display name
 		else if (selector.startsWith("%"))
 		{
 			if (item.getDisplayName().getString().contains(selector.substring(1)))
@@ -66,6 +171,7 @@ public class Selectors
 				return true;
 			}
 		}
+		// Tooltip text
 		else if (selector.startsWith("^"))
 		{
 			Minecraft mc = Minecraft.getInstance();
@@ -82,7 +188,81 @@ public class Selectors
 				return true;
 			}
 		}
+		// NBT tag
+		else if (selector.startsWith("&"))
+		{
+			String tagName = selector.substring(1);
+			String tagValue = null;
+			BiPredicate<Tag, String> valueChecker = null;
+
+			// This implementation means tag names containing and comparator strings can't be compared.
+			// Hopefully this isn't common.
+			for (String comparator : nbtComparators.keySet())
+			{
+				if (tagName.contains(comparator))
+				{
+					valueChecker = nbtComparators.get(comparator);
+					String[] components = tagName.split(comparator);
+					tagName = components[0];
+					if (components.length > 1)
+					{
+						tagValue = components[1];
+					}
+					break;
+				}
+			}
+
+			// Look for a tag matching the given name.
+			Tag matchedTag = getSubtag(item.getTag(), tagName);
+			if (matchedTag != null)
+			{
+				// A tag value of null means that we are just looking for the presence of this tag.
+				if (tagValue == null)
+				{
+					return true;
+				}
+				// Otherwise, we will use the provided comparator.
+				else
+				{
+					if (valueChecker != null)
+					{
+						return valueChecker.test(matchedTag, tagValue);
+					}
+				}
+			}
+		}
 
 		return false;
 	}
+
+	/**
+	 * Retrieves the first inner tag with the given key, or null if there is no match.
+	 */
+	private static Tag getSubtag(CompoundTag tag, String key)
+	{
+		if (tag == null)
+		{
+			return null;
+		}
+
+		if (tag.contains(key))
+		{
+			return tag.get(key);
+		}
+		else
+		{
+			for (String innerKey : tag.getAllKeys())
+			{
+				if (tag.getTagType(innerKey) == Tag.TAG_COMPOUND)
+				{
+					Tag innerTag = getSubtag(tag.getCompound(innerKey), key);
+					if (innerTag != null)
+					{
+						return innerTag;
+					}
+				}
+			}
+			return null;
+		}
+	}
 }
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