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/*
 * Copyright DataStax, Inc.
 *
 * Licensed 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 com.datastax.oss.driver.internal.querybuilder;

import com.datastax.oss.driver.shaded.guava.common.collect.ImmutableList;
import com.datastax.oss.driver.shaded.guava.common.collect.ImmutableMap;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.Map;
import java.util.function.Function;

public class ImmutableCollections {

  @NonNull
  public static  ImmutableList append(@NonNull ImmutableList list, @NonNull T newElement) {
    return ImmutableList.builder().addAll(list).add(newElement).build();
  }

  @NonNull
  public static  ImmutableList concat(
      @NonNull ImmutableList list1, @NonNull Iterable list2) {
    return ImmutableList.builder().addAll(list1).addAll(list2).build();
  }

  @NonNull
  public static  ImmutableList modifyLast(
      @NonNull ImmutableList list, @NonNull Function change) {
    ImmutableList.Builder builder = ImmutableList.builder();
    int size = list.size();
    for (int i = 0; i < size - 1; i++) {
      builder.add(list.get(i));
    }
    builder.add(change.apply(list.get(size - 1)));
    return builder.build();
  }

  /**
   * If the existing map has an entry with the new key, that old entry will be removed, but the new
   * entry will appear last in the iteration order of the resulting map. Example:
   *
   * {@code
   * append({a=>1, b=>2, c=>3}, a, 4) == {b=>2, c=>3, a=>4}
   * }
   */
  @NonNull
  public static  ImmutableMap append(
      @NonNull ImmutableMap map, @NonNull K newKey, @NonNull V newValue) {
    ImmutableMap.Builder builder = ImmutableMap.builder();
    for (Map.Entry entry : map.entrySet()) {
      if (!entry.getKey().equals(newKey)) {
        builder.put(entry);
      }
    }
    builder.put(newKey, newValue);
    return builder.build();
  }

  /**
   * If the existing map has entries that collide with the new map, those old entries will be
   * removed, but the new entries will appear at their new position in the iteration order of the
   * resulting map. Example:
   *
   * {@code
   * concat({a=>1, b=>2, c=>3}, {c=>4, a=>5}) == {b=>2, c=>4, a=>5}
   * }
   */
  @NonNull
  public static  ImmutableMap concat(
      @NonNull ImmutableMap map1, @NonNull Map map2) {
    ImmutableMap.Builder builder = ImmutableMap.builder();
    for (Map.Entry entry : map1.entrySet()) {
      if (!map2.containsKey(entry.getKey())) {
        builder.put(entry);
      }
    }
    builder.putAll(map2);
    return builder.build();
  }
}