/*
    * 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.maven.api.services;
  
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.Optional;
  
  import org.apache.maven.api.Session;
  import org.apache.maven.api.annotations.Experimental;
  import org.apache.maven.api.annotations.Immutable;
  import org.apache.maven.api.annotations.Nonnull;
  import org.apache.maven.api.annotations.NotThreadSafe;
  import org.apache.maven.api.annotations.Nullable;
  
  import static org.apache.maven.api.services.BaseRequest.nonNull;
  
  /**
   * Collects settings that control the building of effective settings.
   */
  @Experimental
  @Immutable
  public interface SettingsBuilderRequest {
  
      @Nonnull
      Session getSession();
  
      /**
       * Gets the global settings source.
       *
       * @return the global settings source or {@code null} if none
       */
      @Nonnull
      Optional<Source> getGlobalSettingsSource();
  
      /**
       * Gets the project settings source.
       *
       * @return the project settings source or {@code null} if none
       */
      @Nonnull
      Optional<Source> getProjectSettingsSource();
  
      /**
       * Gets the user settings source.
       *
       * @return the user settings source or {@code null} if none
       */
      @Nonnull
      Optional<Source> getUserSettingsSource();
  
      @Nonnull
      static SettingsBuilderRequest build(
              @Nonnull Session session, @Nonnull Source globalSettingsSource, @Nonnull Source userSettingsSource) {
          return build(session, globalSettingsSource, null, userSettingsSource);
      }
  
      @Nonnull
      static SettingsBuilderRequest build(
              @Nonnull Session session, @Nonnull Path globalSettingsPath, @Nonnull Path userSettingsPath) {
          return build(session, Source.fromPath(globalSettingsPath), null, Source.fromPath(userSettingsPath));
      }
  
      @Nonnull
      static SettingsBuilderRequest build(
              @Nonnull Session session,
              @Nullable Source globalSettingsSource,
              @Nullable Source projectSettingsSource,
              @Nullable Source userSettingsSource) {
          return builder()
                  .session(nonNull(session, "session cannot be null"))
                  .globalSettingsSource(globalSettingsSource)
                  .projectSettingsSource(projectSettingsSource)
                  .userSettingsSource(userSettingsSource)
                  .build();
      }
  
      @Nonnull
      static SettingsBuilderRequest build(
              @Nonnull Session session,
              @Nullable Path globalSettingsPath,
              @Nullable Path projectSettingsPath,
              @Nullable Path userSettingsPath) {
         return builder()
                 .session(nonNull(session, "session cannot be null"))
                 .globalSettingsSource(
                         globalSettingsPath != null && Files.exists(globalSettingsPath)
                                 ? Source.fromPath(globalSettingsPath)
                                 : null)
                 .projectSettingsSource(
                         projectSettingsPath != null && Files.exists(projectSettingsPath)
                                 ? Source.fromPath(projectSettingsPath)
                                 : null)
                 .userSettingsSource(
                         userSettingsPath != null && Files.exists(userSettingsPath)
                                 ? Source.fromPath(userSettingsPath)
                                 : null)
                 .build();
     }
 
     @Nonnull
     static SettingsBuilderRequestBuilder builder() {
         return new SettingsBuilderRequestBuilder();
     }
 
     @NotThreadSafe
     class SettingsBuilderRequestBuilder {
         Session session;
         Source globalSettingsSource;
         Source projectSettingsSource;
         Source userSettingsSource;
 
         public SettingsBuilderRequestBuilder session(Session session) {
             this.session = session;
             return this;
         }
 
         public SettingsBuilderRequestBuilder globalSettingsSource(Source globalSettingsSource) {
             this.globalSettingsSource = globalSettingsSource;
             return this;
         }
 
         public SettingsBuilderRequestBuilder projectSettingsSource(Source projectSettingsSource) {
             this.projectSettingsSource = projectSettingsSource;
             return this;
         }
 
         public SettingsBuilderRequestBuilder userSettingsSource(Source userSettingsSource) {
             this.userSettingsSource = userSettingsSource;
             return this;
         }
 
         public SettingsBuilderRequest build() {
             return new DefaultSettingsBuilderRequest(
                     session, globalSettingsSource, projectSettingsSource, userSettingsSource);
         }
 
         private static class DefaultSettingsBuilderRequest extends BaseRequest implements SettingsBuilderRequest {
             private final Source globalSettingsSource;
             private final Source projectSettingsSource;
             private final Source userSettingsSource;
 
             @SuppressWarnings("checkstyle:ParameterNumber")
             DefaultSettingsBuilderRequest(
                     @Nonnull Session session,
                     @Nullable Source globalSettingsSource,
                     @Nullable Source projectSettingsSource,
                     @Nullable Source userSettingsSource) {
                 super(session);
                 this.globalSettingsSource = globalSettingsSource;
                 this.projectSettingsSource = projectSettingsSource;
                 this.userSettingsSource = userSettingsSource;
             }
 
             @Nonnull
             @Override
             public Optional<Source> getGlobalSettingsSource() {
                 return Optional.ofNullable(globalSettingsSource);
             }
 
             @Nonnull
             @Override
             public Optional<Source> getProjectSettingsSource() {
                 return Optional.ofNullable(projectSettingsSource);
             }
 
             @Nonnull
             @Override
             public Optional<Source> getUserSettingsSource() {
                 return Optional.ofNullable(userSettingsSource);
             }
         }
     }
 }