/*
    * 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.impl.scope;
  
  import java.util.Collection;
  import java.util.Objects;
  
  import org.eclipse.aether.collection.DependencyCollectionContext;
  import org.eclipse.aether.collection.DependencySelector;
  import org.eclipse.aether.graph.Dependency;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * A dependency selector that filters transitive dependencies based on their scope. It is configurable from which level
   * applies, as it depend on "as project" and "as dependency" use cases.
   * <p>
   * <em>Important note:</em> equals/hashCode must factor in starting state, as instances of this class
   * (potentially differentially configured) are used now in session, but are kept in a set.
   * <p>
   * <em>Note:</em> This filter does not assume any relationships between the scopes.
   * In particular, the filter is not aware of scopes that logically include other scopes.
   *
   * @see Dependency#getScope()
   */
  public final class ScopeDependencySelector implements DependencySelector {
      /**
       * This enables "legacy" mode (proper): in Resolver 1.x "transitive" state depended on the presence or
       * absence of the root node.
       */
      public static ScopeDependencySelector legacy(Collection<String> included, Collection<String> excluded) {
          return new ScopeDependencySelector(
                  Objects.hash(true, 0, 1, Integer.MAX_VALUE, included, excluded),
                  true,
                  0,
                  1,
                  Integer.MAX_VALUE,
                  included,
                  excluded);
      }
  
      /**
       * Selects dependencies by scope always (from root).
       */
      public static ScopeDependencySelector fromRoot(Collection<String> included, Collection<String> excluded) {
          return from(1, included, excluded);
      }
  
      /**
       * Selects dependencies by scope starting from direct dependencies.
       */
      public static ScopeDependencySelector fromDirect(Collection<String> included, Collection<String> excluded) {
          return from(2, included, excluded);
      }
  
      /**
       * Selects dependencies by scope starting from given depth (1=root, 2=direct, 3=transitives of direct ones...).
       */
      public static ScopeDependencySelector from(
              int applyFrom, Collection<String> included, Collection<String> excluded) {
          return fromTo(applyFrom, Integer.MAX_VALUE, included, excluded);
      }
  
      /**
       * Selects dependencies by scope starting from given depth (1=root, 2=direct, 3=transitives of direct ones...) to
       * given depth.
       */
      public static ScopeDependencySelector fromTo(
              int applyFrom, int applyTo, Collection<String> included, Collection<String> excluded) {
          if (applyFrom < 1) {
              throw new IllegalArgumentException("applyFrom must be non-zero and positive");
          }
          if (applyFrom > applyTo) {
              throw new IllegalArgumentException("applyTo must be greater or equal than applyFrom");
          }
          return new ScopeDependencySelector(
                  Objects.hash(false, 0, applyFrom, applyTo, included, excluded),
                  false,
                  0,
                  applyFrom,
                  applyTo,
                  included,
                  excluded);
     }
 
     private final int seed;
     private final boolean shiftIfRootNull;
     private final int depth;
     private final int applyFrom;
     private final int applyTo;
     private final Collection<String> included;
     private final Collection<String> excluded;
 
     private ScopeDependencySelector(
             int seed,
             boolean shiftIfRootNull,
             int depth,
             int applyFrom,
             int applyTo,
             Collection<String> included,
             Collection<String> excluded) {
         this.seed = seed;
         this.shiftIfRootNull = shiftIfRootNull;
         this.depth = depth;
         this.applyFrom = applyFrom;
         this.applyTo = applyTo;
         this.included = included;
         this.excluded = excluded;
     }
 
     @Override
     public boolean selectDependency(Dependency dependency) {
         requireNonNull(dependency, "dependency cannot be null");
         if (depth < applyFrom || depth > applyTo) {
             return true;
         }
 
         String scope = dependency.getScope();
         return (included == null || included.contains(scope)) && (excluded == null || !excluded.contains(scope));
     }
 
     @Override
     public DependencySelector deriveChildSelector(DependencyCollectionContext context) {
         requireNonNull(context, "context cannot be null");
         if (depth == 0 && shiftIfRootNull && context.getDependency() == null) {
             return new ScopeDependencySelector(
                     seed, shiftIfRootNull, depth + 1, applyFrom + 1, applyTo, included, excluded);
         }
         if (depth >= applyFrom && depth != applyTo) {
             return this;
         }
         return new ScopeDependencySelector(seed, shiftIfRootNull, depth + 1, applyFrom, applyTo, included, excluded);
     }
 
     @Override
     public boolean equals(Object obj) {
         if (this == obj) {
             return true;
         } else if (null == obj || !getClass().equals(obj.getClass())) {
             return false;
         }
 
         ScopeDependencySelector that = (ScopeDependencySelector) obj;
         return seed == that.seed
                 && shiftIfRootNull == that.shiftIfRootNull
                 && depth == that.depth
                 && applyFrom == that.applyFrom
                 && applyTo == that.applyTo
                 && Objects.equals(included, that.included)
                 && Objects.equals(excluded, that.excluded);
     }
 
     @Override
     public int hashCode() {
         int hash = 17;
         hash = hash * 31 + seed;
         hash = hash * 31 + (shiftIfRootNull ? 0 : 1);
         hash = hash * 31 + depth;
         hash = hash * 31 + applyFrom;
         hash = hash * 31 + applyTo;
         hash = hash * 31 + (included != null ? included.hashCode() : 0);
         hash = hash * 31 + (excluded != null ? excluded.hashCode() : 0);
         return hash;
     }
 
     @Override
     public String toString() {
         return String.format(
                 "%s(included: %s, excluded: %s, applied: %s)",
                 getClass().getSimpleName(), included, excluded, depth >= applyFrom);
     }
 }