/**
    * This file Copyright (c) 2015-2016 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.config.registry;
  
  import static info.magnolia.cms.util.ExceptionUtil.exceptionToWords;
  import static info.magnolia.config.registry.DefinitionProvider.Problem.SeverityType.SEVERE;
  import static java.util.stream.Collectors.toList;
  
  import info.magnolia.config.registry.DefinitionProvider.Problem;
  import info.magnolia.config.registry.decoration.DefinitionDecorator;
  import info.magnolia.transformer.TransformationResult;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  
  import com.google.common.collect.ImmutableList;
  
  /**
   * A builder that allows to construct a {@link info.magnolia.config.registry.DefinitionProvider}s progressively,
   * without nesting try/catch blocks.
   *
   * @see #newBuilder()
   *
   * @param <T> the type the built provider will provide
   */
  public class DefinitionProviderBuilder<T> {
      public static <T> DefinitionProviderBuilder<T> newBuilder() {
          return new DefinitionProviderBuilder<>();
      }
  
      private DefinitionMetadata metadata;
      private DefinitionRawView rawView;
      private T definition;
      private List<Problem> problems = new ArrayList<>();
      private List<DefinitionDecorator<T>> decorators = Collections.emptyList();
      private List<String> errorMessages = new ArrayList<>();
      private long lastModified = -1;
  
      private DefinitionProviderBuilder() {
      }
  
      public DefinitionProviderBuilder<T> metadata(DefinitionMetadata metadata) {
          this.metadata = metadata;
          return this;
      }
  
      public DefinitionProviderBuilder<T> metadata(DefinitionMetadataBuilder metadata) {
          this.metadata = metadata.build();
          return this;
      }
  
      public DefinitionProviderBuilder<T> rawView(DefinitionRawView rawView) {
          this.rawView = rawView;
          return this;
      }
  
      public DefinitionProviderBuilder<T> definition(T definition) {
          this.definition = definition;
          return this;
      }
  
      public DefinitionProviderBuilder<T> addProblem(Problem problem) {
          this.problems.add(problem);
          return this;
      }
  
     public DefinitionProviderBuilder<T> decorators(List<DefinitionDecorator<T>> decorators) {
         this.decorators = decorators;
         return this;
     }
 
     /**
      * @deprecated since 5.5 - use {@link #addProblem(Problem)} instead.
      */
     @Deprecated
     public DefinitionProviderBuilder<T> addErrorMessage(String errorMessage) {
         this.errorMessages.add(errorMessage);
         return this;
     }
 
     public DefinitionProviderBuilder<T> withLastModifed(long lastModified) {
         this.lastModified = lastModified;
         return this;
     }
 
     public DefinitionProvider<T> buildFromTransformationResult(TransformationResult<T> transformationResult) {
         try {
             transformationResult.getProblems().forEach(transformationProblem -> addProblem(
                     Problem
                             .fromTransformationProblem(transformationProblem)
                             .withType(Problem.DefaultTypes.RESOLUTION)
                             .withTitle("Source data processing problem")
                             .withDetails(transformationProblem.getMessage())
                             .build()));
 
             definition(transformationResult.get());
         } catch (Exception e) {
             final String errorMessage = exceptionToWords(e);
             addProblem(
                     Problem
                             .severe()
                             .withDetails(errorMessage)
                             .withType(Problem.DefaultTypes.RESOLUTION)
                             .withTitle("Source data processing failed with un-expected exception")
                             .build());
         }
 
         return build();
     }
 
     public DefinitionProvider<T> build() {
         return new DefinitionProviderImpl<>(
                 this.metadata,
                 this.rawView,
                 this.definition,
                 ImmutableList.<String>builder()
                         .addAll(this.errorMessages)
                         .addAll(this.problems.stream()
                                 .map(problem -> problem.getTitle() + problem.getDetails())
                                 .collect(toList()))
                         .build(),
                 this.problems,
                 this.lastModified > 0 ? lastModified : System.currentTimeMillis(),
                 decorators
         );
     }
 
     /**
      * Implementation of DefinitionProviderBuilder.
      */
     static class DefinitionProviderImpl<T> implements DefinitionProvider<T> {
         private final List<Problem> problems;
         private final DefinitionMetadata metadata;
         private final DefinitionRawView rawView;
         private final T definition;
         private final List<String> errorMessages;
         private final boolean valid;
         private final long lastModified;
         private final List<DefinitionDecorator<T>> decorators;
 
         protected DefinitionProviderImpl(DefinitionMetadata metadata, DefinitionRawView rawView, T definition, List<String> errorMessages) {
             this(metadata, rawView, definition, errorMessages, Collections.emptyList(), System.currentTimeMillis(), Collections.emptyList());
         }
 
         protected DefinitionProviderImpl(DefinitionMetadata metadata, DefinitionRawView rawView, T definition, List<String> errorMessages, List<Problem> problems, long lastModified, List<DefinitionDecorator<T>> decorators) {
             this.metadata = metadata;
             this.rawView = rawView;
             this.definition = definition;
             this.errorMessages = errorMessages;
             this.problems = problems;
             this.lastModified = lastModified;
             this.decorators = decorators;
             this.valid = metadata != null &&
                     rawView != null &&
                     definition != null &&
                     !this.problems.stream()
                             .filter(p -> p.getSeverityType() == SEVERE)
                             .findFirst()
                             .isPresent();
         }
 
         @Override
         public Collection<Problem> getProblems() {
             return problems;
         }
 
         @Override
         public List<DefinitionDecorator<T>> getDecorators() {
             return decorators;
         }
 
         @Override
         public DefinitionMetadata getMetadata() {
             return metadata;
         }
 
         @Override
         public DefinitionRawView getRaw() {
             return rawView;
         }
 
         @Override
         public T get() {
             if (!valid) {
                 throw new Registry.InvalidDefinitionException(metadata.getReferenceId());
             }
             return definition;
         }
 
         @Override
         public boolean isValid() {
             return valid;
         }
 
         @Override
         public List<String> getErrorMessages() {
             return errorMessages;
         }
 
         @Override
         public long getLastModified() {
             return lastModified;
         }
     }
 }