/*
 * To change this template, choose Tools | Templates and open the template in
 * the editor.
 */

package it.gotoandplay.smartfoxclient.util;

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

/*
 * 
 * @author Lapo
 */
public class Entities {
	private static final Map <Character, String> ascTab = new HashMap <Character, String> ();
	private static final Map <String, String> ascTabRev = new HashMap <String, String> ();
	private static final Map <String, String> hexTable = new HashMap <String, String> ();

	static {
		ascTab.put ('>', "&gt;");
		ascTab.put ('<', "&lt;");
		ascTab.put ('&', "&amp;");
		ascTab.put ('\'', "&apos;");
		ascTab.put ('"', "&quot;");

		ascTabRev.put ("&gt;", ">");
		ascTabRev.put ("&lt;", "<");
		ascTabRev.put ("&amp;", "&");
		ascTabRev.put ("&apos;", "'");
		ascTabRev.put ("&quot;", "\"");

		/*
		 * int count = 0; for (String key : new String[]{"0", "1", "2", "3",
		 * "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"}) {
		 * hexTable.put(key, String.valueOf(count++)); }
		 */
	}

	public static String decodeEntities (final String st) {
		final StringBuilder sb = new StringBuilder ();

		int i = 0;
		char chi;

		StringBuilder entity;

		while (i < st.length ()) {
			final char ch = st.charAt (i);

			if (ch == '&') {
				entity = new StringBuilder ("&");

				do {
					i++ ;
					chi = st.charAt (i);
					entity.append (chi);
				} while (chi != ';' && i < st.length ());

				final String convertedEntity = ascTabRev.get (entity
						.toString ());

				if (convertedEntity != null) {
					sb.append (convertedEntity);
				}

			} else {
				sb.append (ch);
			}

			i++ ;
		}

		return sb.toString ();
	}

	public static String encodeEntities (final String st) {
		final StringBuilder sb = new StringBuilder ();
		// char codes < 32 are ignored except for tab,lf,cr

		for (int i = 0; i < st.length (); i++ ) {
			final char ch = st.charAt (i);

			if (ch == 9 || ch == 10 || ch == 13) {
				sb.append (ch);
			} else if (ch >= 32 && ch <= 126) {
				final String entity = ascTab.get (new Character (ch));

				if (entity != null) {
					sb.append (entity);
				} else {
					sb.append (ch);
				}
			} else {
				sb.append (ch);
			}
		}

		return sb.toString ();
	}

}