/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2014 wcm.io
    * %%
    * 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.
   * #L%
   */
  package io.wcm.handler.url.suffix;
  
  import static io.wcm.handler.url.suffix.impl.UrlSuffixUtil.splitSuffix;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.function.Predicate;
  
  import org.apache.sling.api.SlingHttpServletRequest;
  import org.jetbrains.annotations.NotNull;
  import org.osgi.annotation.versioning.ProviderType;
  
  /**
   * Implementation of {@link SuffixStateKeepingStrategy} that calls a Filter for each suffix part from the
   * current request to decide if it should be kept when constructing a new suffix.
   */
  @ProviderType
  public final class FilteringSuffixStateStrategy implements SuffixStateKeepingStrategy {
  
    private final Predicate<String> suffixPartFilter;
  
    /**
     * @param suffixPartFilter the {@link Predicate} that defines which suffix parts are allowed
     */
    public FilteringSuffixStateStrategy(Predicate<String> suffixPartFilter) {
      this.suffixPartFilter = suffixPartFilter;
    }
  
    @Override
    public @NotNull List<String> getSuffixPartsToKeep(@NotNull SlingHttpServletRequest request) {
  
      // get and split suffix parts from the current request
      String existingSuffix = request.getRequestPathInfo().getSuffix();
      String[] suffixPartArray = splitSuffix(existingSuffix);
  
      // iterate over all these suffix parts and gather those that should be kept
      List<String> suffixPartsToKeep = new ArrayList<>();
      for (int i = 0; i < suffixPartArray.length; i++) {
        String nextPart = suffixPartArray[i];
  
        // for each part: check filter if it should be inc
        if (suffixPartFilter == null || suffixPartFilter.test(nextPart)) {
          suffixPartsToKeep.add(nextPart);
        }
      }
  
      return suffixPartsToKeep;
    }
  
  }