/*
    * 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.eclipse.aether.generator.gnupg.loaders;
  
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.nio.charset.StandardCharsets;
  
  import org.bouncycastle.util.encoders.Hex;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.generator.gnupg.GnupgSignatureArtifactGeneratorFactory;
  import org.eclipse.aether.util.ConfigUtils;
  import org.eclipse.sisu.Priority;
  
  import static org.eclipse.aether.generator.gnupg.GnupgConfigurationKeys.RESOLVER_GPG_KEY;
  import static org.eclipse.aether.generator.gnupg.GnupgConfigurationKeys.RESOLVER_GPG_KEY_FINGERPRINT;
  import static org.eclipse.aether.generator.gnupg.GnupgConfigurationKeys.RESOLVER_GPG_KEY_PASS;
  
  /**
   * Loader that looks for environment variables.
   */
  @Singleton
  @Named(GpgEnvLoader.NAME)
  @Priority(30)
  @SuppressWarnings("checkstyle:magicnumber")
  public final class GpgEnvLoader implements GnupgSignatureArtifactGeneratorFactory.Loader {
      public static final String NAME = "env";
  
      @Override
      public byte[] loadKeyRingMaterial(RepositorySystemSession session) {
          String keyMaterial = ConfigUtils.getString(session, null, "env." + RESOLVER_GPG_KEY);
          if (keyMaterial != null) {
              return keyMaterial.getBytes(StandardCharsets.UTF_8);
          }
          return null;
      }
  
      @Override
      public byte[] loadKeyFingerprint(RepositorySystemSession session) {
          String keyFingerprint = ConfigUtils.getString(session, null, "env." + RESOLVER_GPG_KEY_FINGERPRINT);
          if (keyFingerprint != null) {
              if (keyFingerprint.trim().length() == 40) {
                  return Hex.decode(keyFingerprint);
              } else {
                  throw new IllegalArgumentException(
                          "Key fingerprint configuration is wrong (hex encoded, 40 characters)");
              }
          }
          return null;
      }
  
      @Override
      public char[] loadPassword(RepositorySystemSession session, byte[] fingerprint) {
          String keyPassword = ConfigUtils.getString(session, null, "env." + RESOLVER_GPG_KEY_PASS);
          if (keyPassword != null) {
              return keyPassword.toCharArray();
          }
          return null;
      }
  }