/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF 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
    *
   *   http://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 org.apache.maven.resolver.internal.ant.tasks;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.List;
  import java.util.TreeSet;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.tools.ant.BuildException;
  import org.eclipse.aether.artifact.Artifact;
  
  /**
   * Represents the layout type for a Maven repository.
   * <p>
   * This is an Ant {@code DataType} used to configure the repository layout in tasks such as
   * {@code <repository>}. It determines how artifact coordinates are translated into paths
   * when accessing the repository.
   * </p>
   *
   * <h2>Supported Layouts:</h2>
   * <ul>
   *   <li><strong>default</strong> – the standard Maven 2+ repository layout (recommended)</li>
   * </ul>
   * Since default is currently the default layout (and no other types are currently supported), it is safe to omit this.
   * <h2>Usage Example:</h2>
   * <pre>{@code
   * <repositories>
   *   <repository id="central" url="https://repo.maven.apache.org/maven2">
   *      <layout>default</layout>
   *   </repository>
   * </repositories>
   * }</pre>
   *
   * <p>
   * This type is typically used as a nested element inside {@code <repository>} definitions.
   * </p>
   *
   * @see org.apache.maven.resolver.internal.ant.types.RemoteRepository
   */
  class Layout {
  
      public static final String GID = "{groupId}";
  
      public static final String GID_DIRS = "{groupIdDirs}";
  
      public static final String AID = "{artifactId}";
  
      public static final String VER = "{version}";
  
      public static final String BVER = "{baseVersion}";
  
      public static final String EXT = "{extension}";
  
      public static final String CLS = "{classifier}";
  
      private final String[] tokens;
  
      Layout(String layout) throws BuildException {
          Collection<String> valid = new HashSet<>(Arrays.asList(GID, GID_DIRS, AID, VER, BVER, EXT, CLS));
          List<String> tokens = new ArrayList<>();
          Matcher m = Pattern.compile("(\\{[^}]*\\})|([^{]+)").matcher(layout);
          while (m.find()) {
              if (m.group(1) != null && !valid.contains(m.group(1))) {
                  throw new BuildException("Invalid variable '" + m.group() + "' in layout, supported variables are "
                          + new TreeSet<String>(valid));
              }
              tokens.add(m.group());
          }
          this.tokens = tokens.toArray(new String[0]);
      }
  
      public String getPath(Artifact artifact) {
          StringBuilder buffer = new StringBuilder(128);
  
          for (int i = 0; i < tokens.length; i++) {
              String token = tokens[i];
              if (GID.equals(token)) {
                  buffer.append(artifact.getGroupId());
             } else if (GID_DIRS.equals(token)) {
                 buffer.append(artifact.getGroupId().replace('.', '/'));
             } else if (AID.equals(token)) {
                 buffer.append(artifact.getArtifactId());
             } else if (VER.equals(token)) {
                 buffer.append(artifact.getVersion());
             } else if (BVER.equals(token)) {
                 buffer.append(artifact.getBaseVersion());
             } else if (CLS.equals(token)) {
                 if (artifact.getClassifier().length() <= 0) {
                     if (i > 0) {
                         String lt = tokens[i - 1];
                         if (!lt.isEmpty() && "-_".indexOf(lt.charAt(lt.length() - 1)) >= 0) {
                             buffer.setLength(buffer.length() - 1);
                         }
                     }
                 } else {
                     buffer.append(artifact.getClassifier());
                 }
             } else if (EXT.equals(token)) {
                 buffer.append(artifact.getExtension());
             } else {
                 buffer.append(token);
             }
         }
 
         return buffer.toString();
     }
 }