package fr.ifremer.quadrige3.synchro.server.technical;
   
   /*-
    * #%L
    * Quadrige3 Core :: Quadrige3 Synchro server
    * $Id:$
    * $HeadURL:$
    * %%
    * 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.gson.Gson;
  import fr.ifremer.quadrige3.core.dao.technical.Files;
  import fr.ifremer.quadrige3.core.exception.QuadrigeTechnicalException;
  import org.apache.commons.io.FilenameUtils;
  import org.apache.commons.lang3.builder.ToStringBuilder;
  import org.apache.commons.lang3.builder.ToStringStyle;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.http.HttpResponse;
  import org.springframework.util.MimeTypeUtils;
  import org.springframework.web.multipart.MultipartFile;
  
  import javax.servlet.http.HttpServletResponse;
  import java.io.*;
  import java.lang.reflect.Type;
  import java.nio.charset.StandardCharsets;
  
  public class ServletUtils {
  
      private static final Log log = LogFactory.getLog(ServletUtils.class);
  
      public static void copyFile(MultipartFile source, File target) throws IOException {
          try (OutputStream os = new BufferedOutputStream(new FileOutputStream(target, false));
               InputStream is = new BufferedInputStream(source.getInputStream())) {
  
              Files.copyStream(is, os);
          }
      }
  
      public static void copyFileToResponse(File file, HttpServletResponse response) {
          // Set mime type
          String contentType = MimeTypeUtils.APPLICATION_OCTET_STREAM.getType();
          if (FilenameUtils.isExtension(file.getName(), "properties")) {
              contentType = MimeTypeUtils.TEXT_PLAIN.getType();
          }
          response.setContentType(contentType);
  
          // Set length
          response.setContentLengthLong(file.length());
  
          // set headers for the response
          String headerKey = "Content-Disposition";
          String headerValue = String.format("attachment; filename=\"%s\"", file.getName());
          response.setHeader(headerKey, headerValue);
  
          try (OutputStream os = response.getOutputStream();
               InputStream is = new BufferedInputStream(new FileInputStream(file))) {
              Files.copyStream(is, os);
          } catch (IOException e) {
              throw new QuadrigeTechnicalException("Error while writing file content to response", e);
          }
      }
      
      /* -- Internal methods -- */
  
      protected static Object parseResponse(HttpResponse response, Gson gson, Class<?> ResultClass) throws IOException {
          Object result;
          
          boolean stringOutput = ResultClass.equals(String.class);
          
          // If trace enable, log the response before parsing
          if (stringOutput) {
              try (InputStream content = response.getEntity().getContent()) {
                  String stringContent = getContentAsString(content);
                  if (log.isDebugEnabled()) {
                      log.debug("Parsing response:\n" + stringContent);
                  }
                  return stringContent;
              }
          }
          
          // trace not enable
          else {
             try (InputStream content = response.getEntity().getContent()) {
                 Reader reader = new InputStreamReader(content, StandardCharsets.UTF_8);
                 result = gson.fromJson(reader, ResultClass);
             }
         }
         
 
         if (result == null) {
             throw new QuadrigeTechnicalException("emptyResponse");
         }
 
         if (log.isTraceEnabled()) {
             log.trace("response: " + ToStringBuilder.reflectionToString(result, ToStringStyle.SHORT_PREFIX_STYLE));
         }
 
         return result;
     }
 
     protected static <T> T parseResponse(HttpResponse response, Gson gson, Type typeOfT) throws IOException {
         T result;
 
         try (InputStream content = response.getEntity().getContent()) {
             Reader reader = new InputStreamReader(content, StandardCharsets.UTF_8);
             result = gson.fromJson(reader, typeOfT);
         }
 
         if (result == null) {
             throw new QuadrigeTechnicalException("emptyResponse");
         }
 
         if (log.isTraceEnabled()) {
             log.trace("response: " + ToStringBuilder.reflectionToString(result, ToStringStyle.SHORT_PREFIX_STYLE));
         }
 
         return result;
     }
 
     private static String getContentAsString(InputStream content) throws IOException {
         Reader reader = new InputStreamReader(content, StandardCharsets.UTF_8);
         StringBuilder result = new StringBuilder();
         char[] buf = new char[64];
         int len;
         while((len = reader.read(buf)) != -1) {
             result.append(buf, 0, len);
         }
         return result.toString();
     }
     
 
 
 }