package eu.siacs.conversations.generator;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import android.util.Base64;

public abstract class AbstractGenerator {
	public final String[] FEATURES = { "urn:xmpp:jingle:1",
			"urn:xmpp:jingle:apps:file-transfer:3",
			"urn:xmpp:jingle:transports:s5b:1",
			"urn:xmpp:jingle:transports:ibb:1",
			"urn:xmpp:receipts",
			"urn:xmpp:chat-markers:0",
			"http://jabber.org/protocol/muc",
			"jabber:x:conference",
			"http://jabber.org/protocol/caps",
			"http://jabber.org/protocol/disco#info"};
	//public final String[] FEATURES = { "http://jabber.org/protocol/muc","http://jabber.org/protocol/disco#info", "http://jabber.org/protocol/disco#items", "http://jabber.org/protocol/caps" };
	
	//public final String IDENTITY_NAME = "Exodus 0.9.1";
	//public final String IDENTITY_TYPE = "pc";
	
	
	public final String IDENTITY_NAME = "Conversations 0.5";
	public final String IDENTITY_TYPE = "phone";
	
	public String getCapHash() {
		StringBuilder s = new StringBuilder();
		s.append("client/"+IDENTITY_TYPE+"//"+IDENTITY_NAME+"<");
		MessageDigest md = null;
	    try {
	        md = MessageDigest.getInstance("SHA-1");
	    }
	    catch(NoSuchAlgorithmException e) {
	        return null;
	    }
	    List<String> features = Arrays.asList(FEATURES);
		Collections.sort(features);
		for(String feature : features) {
			s.append(feature+"<");
	    }
		byte[] sha1 = md.digest(s.toString().getBytes());
	    return new String(Base64.encode(sha1, Base64.DEFAULT));
	}
}