/*
    * Copyright 2019 LINE Corporation
    *
    * LINE Corporation 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:
    *
    *   https://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 com.linecorp.centraldogma.server.internal.storage.repository;
  
  import static com.linecorp.centraldogma.server.mirror.MirrorUtil.normalizePath;
  
  import java.io.UnsupportedEncodingException;
  import java.net.URI;
  import java.net.URLDecoder;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /**
   * A utility class for creating a mirroring task.
   */
  public final class MirrorUtil {
  
      /**
       * Splits the specified 'remoteUri' into:
       * - the actual remote repository URI
       * - the path in the remote repository
       * - the branch name.
       *
       * <p>e.g. git+ssh://foo.com/bar.git/some-path#master is split into:
       * - remoteRepoUri: git+ssh://foo.com/bar.git
       * - remotePath:    /some-path/
       * - remoteBranch:  master
       *
       * <p>e.g. dogma://foo.com/bar/qux.dogma is split into:
       * - remoteRepoUri: dogma://foo.com/bar/qux.dogma
       * - remotePath:    / (default)
       * - remoteBranch:  {@code defaultBranch}
       */
      public static String[] split(URI remoteUri, String suffix) {
          final String host = remoteUri.getHost();
          if (host == null && !remoteUri.getScheme().endsWith("+file")) {
              throw new IllegalArgumentException("no host in remoteUri: " + remoteUri);
          }
  
          final String path = remoteUri.getRawPath();
          if (path == null) {
              throw new IllegalArgumentException("no path in remoteUri: " + remoteUri);
          }
  
          final Matcher matcher = Pattern.compile("^(.*?\\." + suffix + ")(?:$|/)").matcher(path);
          if (!matcher.find()) {
              throw new IllegalArgumentException("no '." + suffix + "' in remoteUri path: " + remoteUri);
          }
  
          final String newRemoteUri;
          final int port = remoteUri.getPort();
          if (host != null) {
              if (port > 0) {
                  newRemoteUri = remoteUri.getScheme() + "://" + host + ':' + port +
                                 matcher.group(1);
              } else {
                  newRemoteUri = remoteUri.getScheme() + "://" + host + matcher.group(1);
              }
          } else {
              newRemoteUri = remoteUri.getScheme() + "://" + matcher.group(1);
          }
  
          final String remotePath;
          try {
              String decoded = URLDecoder.decode(path.substring(matcher.group(1).length()), "UTF-8");
              decoded = normalizePath(decoded);
  
              remotePath = decoded;
          } catch (UnsupportedEncodingException e) {
              throw new Error(e);
          }
  
          final String remoteBranch = remoteUri.getFragment();
  
          return new String[] { newRemoteUri, remotePath, remoteBranch };
      }
  
      private MirrorUtil() {}
  }