/*
 * 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.hadoop.hbase.security.token;

import com.google.protobuf.ByteString;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.protobuf.generated.AuthenticationProtos;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.token.TokenIdentifier;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

/**
 * Represents the identity information stored in an HBase authentication token.
 */
@InterfaceAudience.Private
public class AuthenticationTokenIdentifier extends TokenIdentifier {
  public static final Text AUTH_TOKEN_TYPE = new Text("HBASE_AUTH_TOKEN");

  protected String username;
  protected int keyId;
  protected long issueDate;
  protected long expirationDate;
  protected long sequenceNumber;

  public AuthenticationTokenIdentifier() {
  }

  public AuthenticationTokenIdentifier(String username) {
    this.username = username;
  }

  public AuthenticationTokenIdentifier(String username, int keyId,
      long issueDate, long expirationDate) {
    this.username = username;
    this.keyId = keyId;
    this.issueDate = issueDate;
    this.expirationDate = expirationDate;
  }

  @Override
  public Text getKind() {
    return AUTH_TOKEN_TYPE;
  }

  @Override
  public UserGroupInformation getUser() {
    if (username == null || "".equals(username)) {
      return null;
    }
    return UserGroupInformation.createRemoteUser(username);
  }

  public String getUsername() {
    return username;
  }

  void setUsername(String name) {
    this.username = name;
  }

  public int getKeyId() {
    return keyId;
  }

  void setKeyId(int id) {
    this.keyId = id;
  }

  public long getIssueDate() {
    return issueDate;
  }

  void setIssueDate(long timestamp) {
    this.issueDate = timestamp;
  }

  public long getExpirationDate() {
    return expirationDate;
  }

  void setExpirationDate(long timestamp) {
    this.expirationDate = timestamp;
  }

  public long getSequenceNumber() {
    return sequenceNumber;
  }

  void setSequenceNumber(long seq) {
    this.sequenceNumber = seq;
  }

  public byte[] toBytes() {
    AuthenticationProtos.TokenIdentifier.Builder builder =
        AuthenticationProtos.TokenIdentifier.newBuilder();
    builder.setKind(AuthenticationProtos.TokenIdentifier.Kind.HBASE_AUTH_TOKEN);
    if (username != null) {
      builder.setUsername(ByteString.copyFromUtf8(username));
    }
    builder.setIssueDate(issueDate)
        .setExpirationDate(expirationDate)
        .setKeyId(keyId)
        .setSequenceNumber(sequenceNumber);
    return builder.build().toByteArray();
  }

  @Override
  public void write(DataOutput out) throws IOException {
    byte[] pbBytes = toBytes();
    out.writeInt(pbBytes.length);
    out.write(pbBytes);
  }

  @Override
  public void readFields(DataInput in) throws IOException {
    int len = in.readInt();
    byte[] inBytes = new byte[len];
    in.readFully(inBytes);
    AuthenticationProtos.TokenIdentifier identifier =
        AuthenticationProtos.TokenIdentifier.newBuilder().mergeFrom(inBytes).build();
    // sanity check on type
    if (!identifier.hasKind() ||
        identifier.getKind() != AuthenticationProtos.TokenIdentifier.Kind.HBASE_AUTH_TOKEN) {
      throw new IOException("Invalid TokenIdentifier kind from input "+identifier.getKind());
    }

    // copy the field values
    if (identifier.hasUsername()) {
      username = identifier.getUsername().toStringUtf8();
    }
    if (identifier.hasKeyId()) {
      keyId = identifier.getKeyId();
    }
    if (identifier.hasIssueDate()) {
      issueDate = identifier.getIssueDate();
    }
    if (identifier.hasExpirationDate()) {
      expirationDate = identifier.getExpirationDate();
    }
    if (identifier.hasSequenceNumber()) {
      sequenceNumber = identifier.getSequenceNumber();
    }
  }

  @Override
  public boolean equals(Object other) {
    if (other == null) {
      return false;
    }
    if (other instanceof AuthenticationTokenIdentifier) {
      AuthenticationTokenIdentifier ident = (AuthenticationTokenIdentifier)other;
      return sequenceNumber == ident.getSequenceNumber()
          && keyId == ident.getKeyId()
          && issueDate == ident.getIssueDate()
          && expirationDate == ident.getExpirationDate()
          && (username == null ? ident.getUsername() == null :
              username.equals(ident.getUsername()));
    }
    return false;
  }

  @Override
  public int hashCode() {
    return (int)sequenceNumber;
  }
}