/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2021 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.maven.plugins.slinginitialcontenttransform.contentparser;
  
  import java.util.Map;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.commons.lang3.StringUtils;
  import org.apache.sling.contentparser.api.ContentHandler;
  
  import io.wcm.tooling.commons.contentpackagebuilder.element.ContentElement;
  import io.wcm.tooling.commons.contentpackagebuilder.element.ContentElementImpl;
  
  /**
   * {@link ContentHandler} implementation that produces a tree of {@link ContentElement} items.
   */
  final class ContentElementHandler implements ContentHandler {
  
    private ContentElement root;
  
    @SuppressWarnings("java:S5998") // paths are assumed to be safe
    private static final Pattern PATH_PATTERN = Pattern.compile("^((/[^/]+)*)(/([^/]+))$");
  
    @Override
    public void resource(String path, Map<String, Object> properties) {
      if (StringUtils.equals(path, "/")) {
        root = new ContentElementImpl(null, properties);
      }
      else {
        if (root == null) {
          throw new IllegalStateException("Root resource not set.");
        }
        Matcher matcher = PATH_PATTERN.matcher(path);
        if (!matcher.matches()) {
          throw new IllegalStateException("Unexpected path:" + path);
        }
        String relativeParentPath = StringUtils.stripStart(matcher.group(1), "/");
        String name = matcher.group(4);
        ContentElement parent;
        if (StringUtils.isEmpty(relativeParentPath)) {
          parent = root;
        }
        else {
          parent = root.getChild(relativeParentPath);
        }
        if (parent == null) {
          throw new IllegalStateException("Parent '" + relativeParentPath + "' does not exist.");
        }
        parent.getChildren().put(name, new ContentElementImpl(name, properties));
      }
    }
  
    public ContentElement getRoot() {
      return root;
    }
  
  }