DamageValues.java

package org.shininet.bukkit.itemrenamer.configuration;

import java.util.Deque;
import java.util.List;

import com.google.common.collect.Range;
import com.google.common.collect.Ranges;

/**
 * Can represent a range of damage values, or one of the two special types.
 * 
 * @author Kristian
 */
public class DamageValues {
	public static final DamageValues ALL = new DamageValues((byte) -1);
	public static final DamageValues OTHER = new DamageValues((byte) -2);

	private final Range<Integer> range;
	
	/**
	 * Construct a special damage value that is not otherwise legal.
	 * @param key - special damage value.
	 */
	private DamageValues(byte key) {
		this.range = Ranges.singleton((int) key);
	}
	
	public DamageValues(int value) {
		this(value, value);
	}

	public DamageValues(int minimumValue, int maximumValue) {
		validateValue(minimumValue, "minimumValue");
		validateValue(maximumValue, "maximumValue");
		
		this.range = Ranges.closed(minimumValue, maximumValue);
	}
	
	private void validateValue(int value, String name) {
		if (value < 0)
			throw new IllegalArgumentException("Value " + name + " cannot be less than zero (" + value + ")");
		if (value > Short.MAX_VALUE)
			throw new IllegalArgumentException("Value " + name + " cannot be greater than SHORT.MAX_VALUE (" + value + ")");
	}

	public Range<Integer> getRange() {
		return range;
	}
	
	/**
	 * Parse a given argument list to a damage value.
	 * @param arguments - the argument list.
	 * @return The parsed damage value.
	 * @throws IllegalArgumentException If we were unable to find a constant or integer range.
 	 */
	public static DamageValues parse(Deque<String> arguments) {
		if (arguments.isEmpty())
			throw new IllegalArgumentException("Must specify a damage value.");
		
		String clean = arguments.peekFirst().trim();
		
		if (clean.equalsIgnoreCase("ALL")) {
			arguments.pollFirst();
			return ALL;
		} else if (clean.equalsIgnoreCase("OTHER")) {
			arguments.pollFirst();
			return OTHER;
		} else {
			List<Integer> range = ConfigParsers.getIntegers(arguments, 2, Ranges.closed(0, (int) Short.MAX_VALUE));
			
			if (range.size() == 1)
				return new DamageValues(range.get(0));
			else if (range.size() == 2)
				return new DamageValues(range.get(0), range.get(1));
			else
				throw new IllegalArgumentException("No integer range or value found.");
		}
	}
	
	@Override
	public String toString() {
		if (this == ALL)
			return "ALL";
		else if (this == OTHER)
			return "OTHER";
		else
			return range.toString();
	}
}