/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.harmony.auth.internal.kerberos.v5;

import java.io.IOException;
import java.math.BigInteger;
import java.util.Arrays;
import java.util.List;
import java.util.StringTokenizer;

import org.apache.harmony.security.asn1.ASN1Explicit;
import org.apache.harmony.security.asn1.ASN1Integer;
import org.apache.harmony.security.asn1.ASN1Sequence;
import org.apache.harmony.security.asn1.ASN1SequenceOf;
import org.apache.harmony.security.asn1.ASN1StringType;
import org.apache.harmony.security.asn1.ASN1Type;
import org.apache.harmony.security.asn1.BerInputStream;

/**
 * Kerberos PrincipalName type.
 * 
 * @see http://www.ietf.org/rfc/rfc4120.txt
 */
public class PrincipalName {

	public static final int NT_UNKNOWN = 0;

	public static final int NT_PRINCIPAL = 1;

	public static final int NT_SRV_INST = 2;

	public static final int NT_SRV_HST = 3;

	public static final int NT_SRV_XHST = 4;

	public static final int NT_UID = 5;

	public static final int NT_X500_PRINCIPAL = 6;

	public static final int NT_SMTP_NAME = 7;

	public static final int NT_ENTERPRISE = 10;

	public static PrincipalName instanceOf(byte[] enc) throws IOException {
		return (PrincipalName) ASN1.decode(enc);
	}

	private final int type;

	private final String name[];

	// PrincipalName ::= SEQUENCE {
	// name-type [0] Int32,
	// name-string [1] SEQUENCE OF KerberosString
	// }
	static final ASN1Sequence ASN1 = new ASN1Sequence(new ASN1Type[] {
			new ASN1Explicit(0, ASN1Integer.getInstance()),
			new ASN1Explicit(1,
					new ASN1SequenceOf(ASN1StringType.GENERALSTRING)), }) {

		@Override
		protected Object getDecodedObject(BerInputStream in) throws IOException {

			final Object[] values = (Object[]) in.content;

			final int type = ASN1Integer.toIntValue(values[0]);

			// TODO: list to array conversion should be done by framework
			final List<?> list = (List<?>) values[1];
			final String[] name = list.toArray(new String[list.size()]);
			return new PrincipalName(type, name);
		}

		@Override
		protected void getValues(Object object, Object[] values) {

			final PrincipalName name = (PrincipalName) object;

			values[0] = BigInteger.valueOf(name.getType()).toByteArray();

			values[1] = Arrays.asList(name.getName());
		}
	};

	public PrincipalName(int type, String str) {
		this.type = type;

		// FIXME: ignores escaped '/','@' chars
		if (str.indexOf('/') == -1) {
			// there is only one component in principal name
			name = new String[] { str };
		} else {
			final StringTokenizer strTknzr = new StringTokenizer(str, "/"); //$NON-NLS-1$
			name = new String[strTknzr.countTokens()];
			for (int i = 0; i < name.length; i++) {
				name[i] = strTknzr.nextToken();
			}
		}
	}

	public PrincipalName(int type, String[] name) {
		this.type = type;
		this.name = name;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		}

		if (!(obj instanceof PrincipalName)) {
			return false;
		}

		final PrincipalName that = (PrincipalName) obj;

		return type == that.type && Arrays.equals(that.name, name);
	}

	public String getCanonicalName() {
		final StringBuilder buf = new StringBuilder();
		for (int i = 0; i < (name.length - 1); i++) {
			buf.append(name[i]);
			buf.append('/');
		}
		// append last name element
		buf.append(name[name.length - 1]);

		return buf.toString();
	}

	public byte[] getEncoded() {
		return ASN1.encode(this);
	}

	public String[] getName() {
		return name;
	}

	public int getType() {
		return type;
	}

	@Override
	public int hashCode() {
		return type + Arrays.hashCode(name);
	}

	@Override
	public String toString() {
		final StringBuilder buf = new StringBuilder("Name: "); //$NON-NLS-1$

		for (int i = 0; i < (name.length - 1); i++) {
			buf.append(name[i]);
			buf.append('/');
		}
		buf.append(name[name.length - 1]);
		buf.append(", type: "); //$NON-NLS-1$
		buf.append(type);

		return buf.toString();
	}
}