/*
    * 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.wrapper;
  
  import java.net.URI;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  
  /**
   * @author Hans Dockter
   */
  public class PathAssembler {
      public static final String MAVEN_USER_HOME_STRING = "MAVEN_USER_HOME";
  
      public static final String PROJECT_STRING = "PROJECT";
  
      private Path mavenUserHome;
  
      public PathAssembler() {}
  
      public PathAssembler(Path mavenUserHome) {
          this.mavenUserHome = mavenUserHome;
      }
  
      /**
       * Determines the local locations for the distribution to use given the supplied configuration.
       *
       * @param configuration a wrapper configuration
       * @return the local distribution
       */
      public LocalDistribution getDistribution(WrapperConfiguration configuration) {
          String baseName = getBaseName(configuration.getDistribution());
          String distName = removeExtension(baseName);
          Path rootDirName = rootDirName(distName, configuration);
          Path distDir = getBaseDir(configuration.getDistributionBase())
                  .resolve(configuration.getDistributionPath())
                  .resolve(rootDirName);
          Path distZip = getBaseDir(configuration.getZipBase())
                  .resolve(configuration.getZipPath())
                  .resolve(rootDirName)
                  .resolve(baseName);
          return new LocalDistribution(distDir, distZip);
      }
  
      private Path rootDirName(String distName, WrapperConfiguration configuration) {
          String urlHash = getHash(configuration.getDistribution());
          return Paths.get(distName, urlHash);
      }
  
      private String getHash(URI path) {
          return Integer.toHexString(path.hashCode());
      }
  
      private String removeExtension(String name) {
          int dot = name.lastIndexOf(".");
          return dot > 0 ? name.substring(0, dot) : name;
      }
  
      private String getBaseName(URI distUrl) {
          return Paths.get(distUrl.getPath()).getFileName().toString();
      }
  
      private Path getBaseDir(String base) {
          if (MAVEN_USER_HOME_STRING.equals(base)) {
              return mavenUserHome;
          } else if (PROJECT_STRING.equals(base)) {
              return Paths.get(System.getProperty("user.dir"));
          } else {
              throw new RuntimeException("Base: " + base + " is unknown");
          }
      }
  
      /**
       * Local distribution
       */
      public static class LocalDistribution {
          private final Path distZip;
  
          private final Path distDir;
  
          public LocalDistribution(Path distDir, Path distZip) {
              this.distDir = distDir;
              this.distZip = distZip;
         }
 
         /**
          * Returns the location to install the distribution into.
          *
          * @return the location to install the distribution into
          */
         public Path getDistributionDir() {
             return distDir;
         }
 
         /**
          * Returns the location to install the distribution ZIP file to.
          *
          * @return the location to install the distribution ZIP file to
          */
         public Path getZipFile() {
             return distZip;
         }
     }
 }