/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe 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 General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.datamodel.niofs;
  
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.nio.file.FileSystemNotFoundException;
  import java.nio.file.InvalidPathException;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.nio.file.spi.FileSystemProvider;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Objects;
  
  import org.apache.logging.log4j.LogManager;
  import org.mycore.common.config.MCRConfiguration2;
  
  /**
   * @author Thomas Scheffler (yagee)
   *
   */
  final class MCRPaths {
  
      static final String DEFAULT_SCHEME_PROPERTY = "MCR.NIO.DefaultScheme";
  
      static List<FileSystemProvider> webAppProvider = new ArrayList<>(4);
  
      private MCRPaths() {
      }
  
      static URI getURI(String owner, String path) throws URISyntaxException {
          String scheme = getDefaultScheme();
          return getURI(scheme, owner, path);
      }
  
      private static String getDefaultScheme() {
          return MCRConfiguration2.getString(DEFAULT_SCHEME_PROPERTY).orElse("ifs2");
      }
  
      static URI getURI(String scheme, String owner, String path) throws URISyntaxException {
          boolean needSeperator = Objects.requireNonNull(path, "No 'path' specified.").isEmpty()
              || path.charAt(0) != MCRAbstractFileSystem.SEPARATOR;
          String aPath = needSeperator ? (MCRAbstractFileSystem.SEPARATOR_STRING + path) : path;
          String finalPath = MCRAbstractFileSystem.SEPARATOR_STRING
              + Objects.requireNonNull(owner, "No 'owner' specified.") + ":" + aPath;
          return new URI(Objects.requireNonNull(scheme, "No 'scheme' specified."), null, finalPath, null);
      }
  
      static Path getPath(String owner, String path) {
          String scheme = getDefaultScheme();
          return getPath(scheme, owner, path);
      }
  
      static Path getPath(String scheme, String owner, String path) {
          URI uri;
          try {
              uri = getURI(scheme, owner, path);
              LogManager.getLogger(MCRPaths.class).debug("Generated path URI:{}", uri);
          } catch (URISyntaxException e) {
              throw new InvalidPathException(path, "URI syntax error (" + e.getMessage() + ") for path");
          }
          try {
              return Paths.get(uri);
          } catch (FileSystemNotFoundException e) {
              for (FileSystemProvider provider : webAppProvider) {
                  if (provider.getScheme().equals(uri.getScheme())) {
                      return provider.getPath(uri);
                  }
              }
              throw e;
          }
      }
  
      static void addFileSystemProvider(FileSystemProvider provider) {
          webAppProvider.add(provider);
      }
  }