package lu.jpt.csparqlproject.util;

import java.util.HashMap;
import java.util.Map;

/**
 * This is a small helper class which will be used on some occasions
 * to make output easier to read by providing a method to replace known
 * uris in (tuple) strings with their known prefix.
 */
public class PrefixManager {

	/**
	 * Key is the uri, value is its prefix
	 */
	private Map<String, String> prefixTable;
	
	
	public PrefixManager() {
		this.prefixTable = new HashMap<String, String>();
	}
	
	/**
	 * Register a known prefix with its corresponding uri
	 * @param prefix
	 * @param uri
	 */
	public void registerPrefix(String prefix, String uri) {
		this.prefixTable.put(uri, prefix);
	}
	
	/**
	 * Replace all uris within a tuple with their know prefix
	 * This is not efficient, but that is not the point
	 * @param tuple as a string
	 * @return shortened tuple string
	 */
	public String applyPrefix(String tuple) {
		for (Map.Entry<String, String> entry : this.prefixTable.entrySet()) {
			tuple = tuple.replace(entry.getKey(), entry.getValue() + ":");
		}
		return tuple;
	}
	
}