package org.xmlfield.core.internal;
   
   import static org.apache.commons.lang.StringUtils.substringAfter;
   import static org.apache.commons.lang.StringUtils.substringBetween;
   
   import java.util.HashMap;
   import java.util.Iterator;
   import java.util.Map;
   import java.util.Map.Entry;
  
  import org.xmlfield.annotations.Namespaces;
  
  /**
   * Namespaces container class.
   * 
   * @author PGMY03781
   * @author Nicolas Richeton
   * 
   */
  public class NamespaceMap implements
  		Iterable<Map.Entry<String, String>> {
  
  	private final Map<String, String> prefixesURIs = new HashMap<String, String>();
  	private String stringValue = "";
  
  	NamespaceMap(final Namespaces namespaces) {
  		this(namespaces == null ? new String[0] : namespaces.value());
  	}
  
  	public NamespaceMap(final String... namespaces) {
  		if (namespaces != null) {
  			for (final String n : namespaces) {
  				final String prefix = substringBetween(n, ":", "=");
  
  				if (prefix == null) {
  
  					throw new IllegalArgumentException(
  							"Illegal namespace prefix for XPath expressions: "
  									+ n);
  				}
  
  				final String uri = substringAfter(n, "=").replace("\"", "");
  				prefixesURIs.put(prefix, uri);
  			}
  			updateToString();
  		}
  	}
  
  	void addNamespaces(final NamespaceMap nMap) {
  		if (nMap != null) {
  			prefixesURIs.putAll(nMap.prefixesURIs);
  			updateToString();
  		}
  	}
  
  	public String get(String prefix) {
  		return prefixesURIs.get(prefix);
  	}
  
  	public Map<String, String> getPrefixesURIs() {
  		return prefixesURIs;
  	}
  
  	public boolean isEmpty() {
  		return prefixesURIs.isEmpty();
  	}
  
  	@Override
  	public Iterator<Entry<String, String>> iterator() {
  		return prefixesURIs.entrySet().iterator();
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see java.lang.Object#toString()
  	 */
  	@Override
  	public String toString() {
  		return stringValue;
  
  	}
  
  	/**
  	 * Updates toString representation. The representation is stored
  	 * internally to speed up toString, as the value will not change in most
  	 * cases after creation.
  	 */
  	private void updateToString() {
  		if (!prefixesURIs.isEmpty()) {
  			StringBuilder builder = new StringBuilder();
  			for (Entry<String, String> entry : this) {
  				builder.append(entry.getKey());
  				builder.append(":");
  				builder.append(entry.getValue());
  				builder.append(",");
  			}
  			stringValue = builder.toString();
  		}
 	}
 
 }