/*
    * 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.eclipse.aether.internal.test.util;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.io.StringReader;
  import java.net.URL;
  import java.nio.charset.StandardCharsets;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.artifact.DefaultArtifact;
  import org.eclipse.aether.graph.Dependency;
  import org.eclipse.aether.graph.Exclusion;
  import org.eclipse.aether.repository.RemoteRepository;
  
  /**
   * @see IniArtifactDescriptorReader
   */
  class IniArtifactDataReader {
  
      private final String prefix;
  
      /**
       * Constructs a data reader with the given prefix.
       *
       * @param prefix the prefix to use for loading resources from the classpath
       */
      IniArtifactDataReader(String prefix) {
          this.prefix = prefix;
      }
  
      /**
       * Load an artifact description from the classpath and parse it.
       */
      ArtifactDescription parse(String resource) throws IOException {
          URL res = this.getClass().getClassLoader().getResource(prefix + resource);
  
          if (res == null) {
              throw new IOException("cannot find resource: " + resource);
          }
          return parse(res);
      }
  
      /**
       * Open the given URL and parse it.
       */
      private ArtifactDescription parse(URL res) throws IOException {
          return parse(new InputStreamReader(res.openStream(), StandardCharsets.UTF_8));
      }
  
      /**
       * Parse the given String.
       */
      ArtifactDescription parseLiteral(String description) throws IOException {
          StringReader reader = new StringReader(description);
          return parse(reader);
      }
  
      private enum State {
          NONE,
          RELOCATION,
          DEPENDENCIES,
          MANAGEDDEPENDENCIES,
          REPOSITORIES
      }
  
      private ArtifactDescription parse(Reader reader) throws IOException {
          String line = null;
  
          State state = State.NONE;
  
          Map<State, List<String>> sections = new HashMap<>();
  
          BufferedReader in = null;
         try {
             in = new BufferedReader(reader);
             while ((line = in.readLine()) != null) {
 
                 line = cutComment(line);
                 if (isEmpty(line)) {
                     continue;
                 }
 
                 if (line.startsWith("[")) {
                     try {
                         String name = line.substring(1, line.length() - 1);
                         name = name.replace("-", "").toUpperCase(Locale.ENGLISH);
                         state = State.valueOf(name);
                         sections.put(state, new ArrayList<>());
                     } catch (IllegalArgumentException e) {
                         throw new IOException("unknown section: " + line);
                     }
                 } else {
                     List<String> lines = sections.get(state);
                     if (lines == null) {
                         throw new IOException("missing section: " + line);
                     }
                     lines.add(line.trim());
                 }
             }
 
             in.close();
             in = null;
         } finally {
             try {
                 if (in != null) {
                     in.close();
                 }
             } catch (final IOException e) {
                 // Suppressed due to an exception already thrown in the try block.
             }
         }
 
         Artifact relocation = relocation(sections.get(State.RELOCATION));
         List<Dependency> dependencies = dependencies(sections.get(State.DEPENDENCIES), false);
         List<Dependency> managedDependencies = dependencies(sections.get(State.MANAGEDDEPENDENCIES), true);
         List<RemoteRepository> repositories = repositories(sections.get(State.REPOSITORIES));
 
         return new ArtifactDescription(relocation, dependencies, managedDependencies, repositories);
     }
 
     private List<RemoteRepository> repositories(List<String> list) {
         ArrayList<RemoteRepository> ret = new ArrayList<>();
         if (list == null) {
             return ret;
         }
         for (String coords : list) {
             String[] split = coords.split(":", 3);
             String id = split[0];
             String type = split[1];
             String url = split[2];
 
             ret.add(new RemoteRepository.Builder(id, type, url).build());
         }
         return ret;
     }
 
     private List<Dependency> dependencies(List<String> list, boolean managed) {
         List<Dependency> ret = new ArrayList<>();
         if (list == null) {
             return ret;
         }
 
         Collection<Exclusion> exclusions = new ArrayList<>();
 
         Boolean optional = null;
         Artifact artifact = null;
         String scope = null;
 
         for (String coords : list) {
             if (coords.startsWith("-")) {
                 coords = coords.substring(1);
                 String[] split = coords.split(":");
                 exclusions.add(new Exclusion(split[0], split[1], "*", "*"));
             } else {
                 if (artifact != null) {
                     // commit dependency
                     Dependency dep = new Dependency(artifact, scope, optional, exclusions);
                     ret.add(dep);
 
                     exclusions = new ArrayList<>();
                 }
 
                 ArtifactDefinition def = new ArtifactDefinition(coords);
 
                 optional = managed ? def.getOptional() : Boolean.valueOf(Boolean.TRUE.equals(def.getOptional()));
 
                 scope = "".equals(def.getScope()) && !managed ? "compile" : def.getScope();
 
                 artifact = new DefaultArtifact(
                         def.getGroupId(), def.getArtifactId(), "", def.getExtension(), def.getVersion());
             }
         }
         if (artifact != null) {
             // commit dependency
             Dependency dep = new Dependency(artifact, scope, optional, exclusions);
             ret.add(dep);
         }
 
         return ret;
     }
 
     private Artifact relocation(List<String> list) {
         if (list == null || list.isEmpty()) {
             return null;
         }
         String coords = list.get(0);
         ArtifactDefinition def = new ArtifactDefinition(coords);
         return new DefaultArtifact(def.getGroupId(), def.getArtifactId(), "", def.getExtension(), def.getVersion());
     }
 
     private static boolean isEmpty(String line) {
         return line == null || line.isEmpty();
     }
 
     private static String cutComment(String line) {
         int idx = line.indexOf('#');
 
         if (idx != -1) {
             line = line.substring(0, idx);
         }
 
         return line;
     }
 }