/*
 * 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.io.crypto.tls;

import java.util.Objects;

/**
 * Base class for instances of {@link KeyStoreLoader} which load the key/trust stores from files on
 * a filesystem.
 * <p/>
 * This file has been copied from the Apache ZooKeeper project.
 * @see <a href=
 *      "https://github.com/apache/zookeeper/blob/c74658d398cdc1d207aa296cb6e20de00faec03e/zookeeper-server/src/main/java/org/apache/zookeeper/common/FileKeyStoreLoader.java">Base
 *      revision</a>
 */
abstract class FileKeyStoreLoader implements KeyStoreLoader {
  final String keyStorePath;
  final String trustStorePath;
  final char[] keyStorePassword;
  final char[] trustStorePassword;

  FileKeyStoreLoader(String keyStorePath, String trustStorePath, char[] keyStorePassword,
    char[] trustStorePassword) {
    this.keyStorePath = keyStorePath;
    this.trustStorePath = trustStorePath;
    this.keyStorePassword = keyStorePassword;
    this.trustStorePassword = trustStorePassword;
  }

  /**
   * Base class for builder pattern used by subclasses.
   * @param <T> the subtype of FileKeyStoreLoader created by the Builder.
   */
  static abstract class Builder<T extends FileKeyStoreLoader> {
    String keyStorePath;
    String trustStorePath;
    char[] keyStorePassword;
    char[] trustStorePassword;

    Builder() {
    }

    Builder<T> setKeyStorePath(String keyStorePath) {
      this.keyStorePath = Objects.requireNonNull(keyStorePath);
      return this;
    }

    Builder<T> setTrustStorePath(String trustStorePath) {
      this.trustStorePath = Objects.requireNonNull(trustStorePath);
      return this;
    }

    Builder<T> setKeyStorePassword(char[] keyStorePassword) {
      this.keyStorePassword = Objects.requireNonNull(keyStorePassword);
      return this;
    }

    Builder<T> setTrustStorePassword(char[] trustStorePassword) {
      this.trustStorePassword = Objects.requireNonNull(trustStorePassword);
      return this;
    }

    abstract T build();
  }
}
