package fr.ifremer.quadrige3.core.dao.technical.gson;
   
   /*-
    * #%L
    * Quadrige3 Core :: Quadrige3 Core Shared
    * $Id:$
    * $HeadURL:$
    * %%
    * Copyright (C) 2017 Ifremer
   * %%
   * This program is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Affero General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU Affero General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   * #L%
   */
  
  import com.google.common.base.Charsets;
  import com.google.common.collect.Multimap;
  import com.google.gson.Gson;
  import com.google.gson.GsonBuilder;
  import com.google.gson.JsonIOException;
  import com.google.gson.JsonSyntaxException;
  import fr.ifremer.quadrige3.core.exception.QuadrigeTechnicalException;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.Reader;
  import java.io.Writer;
  import java.lang.reflect.Type;
  import java.nio.file.Files;
  import java.util.Date;
  import java.util.Map;
  import java.util.TimeZone;
  
  import static org.nuiton.i18n.I18n.t;
  
  /**
   * <p>Gson utility class.</p>
   */
  public class Gsons {
  
      /**
       * Constant <code>DATE_PATTERN="yyyy-MM-dd'T'HH:mm:ss.SSSX"</code>
       * With timezone and milliseconds
       */
      static final String DATE_PATTERN = "yyyy-MM-dd'T'HH:mm:ss.SSSX";
  
      /**
       * <p>newBuilder.</p>
       *
       * @return a {@link com.google.gson.GsonBuilder} object.
       */
      public static GsonBuilder newBuilder(TimeZone timezone) {
          return new GsonBuilder()
                  // make sure date will be serialized
                  .setDateFormat(DATE_PATTERN)
                  // Register special case for Timestamp - mantis #36465
                  .registerTypeHierarchyAdapter(Date.class, new DateTypeAdapter(DATE_PATTERN, timezone))
                  // Register Multimap adapter
                  .registerTypeAdapter(Multimap.class, new MultimapTypeAdapter());
      }
  
      /**
       * <p>newBuilder.</p>
       *
       * @return a {@link com.google.gson.GsonBuilder} object.
       */
      public static GsonBuilder newBuilder() {
          return newBuilder(TimeZone.getDefault());
      }
  
      /**
       * <p>deserializeFile.</p>
       *
       * @param file  a {@link java.io.File} object.
       * @param clazz a {@link java.lang.Class} object.
       * @param <T>   a T object.
       * @return a T object.
       */
      public static <T> T deserializeFile(File file, Class<T> clazz) {
  
          return deserializeFile(file, clazz, null);
      }
  
      public static <T> T deserializeFile(File file, Class<T> clazz, Map<Type, Object> additionalTypeAdapter) {
  
          T result;
          if (!file.exists() || !file.isFile()) {
              return null;
          }
 
         try (Reader reader = Files.newBufferedReader(file.toPath(), Charsets.UTF_8)) {
 
             GsonBuilder gsonBuilder = newBuilder();
             if (additionalTypeAdapter != null) {
                 for (Type type : additionalTypeAdapter.keySet()) {
                     gsonBuilder.registerTypeAdapter(type, additionalTypeAdapter.get(type));
                 }
             }
             result = gsonBuilder.create().fromJson(reader, clazz);
 
         } catch (IOException | JsonSyntaxException | JsonIOException ex) {
             throw new QuadrigeTechnicalException(t("quadrige3.error.read.file", file.getAbsolutePath(), ex.getMessage()), ex);
         }
 
         return result;
     }
 
     public static void serializeToFile(Object object, File file) {
 
         try (Writer writer = Files.newBufferedWriter(file.toPath(), Charsets.UTF_8)) {
 
             Gson gson = newBuilder().enableComplexMapKeySerialization().create();
             gson.toJson(object, writer);
 
         } catch (IOException | JsonIOException ex) {
             throw new QuadrigeTechnicalException(t("quadrige3.error.write.file", file.getAbsolutePath(), ex.getMessage()), ex);
         }
     }
 }