/*
    * Copyright 2024 Bloomreach B.V. (https://www.bloomreach.com)
    *
    * 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 org.onehippo.forge.content.exim.repository.jaxrs.util;
  
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.LinkedHashSet;
  import java.util.Set;
  
  import javax.jcr.Node;
  import javax.jcr.NodeIterator;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  import javax.jcr.query.Query;
  import javax.jcr.query.QueryResult;
  
  import org.apache.commons.lang3.StringUtils;
  import org.onehippo.forge.content.exim.core.util.HippoNodeUtils;
  import org.onehippo.forge.content.exim.repository.jaxrs.param.ExecutionParams;
  import org.onehippo.forge.content.exim.repository.jaxrs.param.QueriesAndPaths;
  import org.onehippo.forge.content.exim.repository.jaxrs.param.Result;
  import org.onehippo.forge.content.exim.repository.jaxrs.param.ResultItem;
  
  /**
   * Utility to collect {@link ResultItem}s based on various conditions.
   */
  public class ResultItemSetCollector {
  
      private ResultItemSetCollector() {
      }
  
      /**
       * Collect {@link ResultItem}s from the given {@code params} by picking nodes from the given paths or querying
       * nodes from the given queries.
       * @param session JCR session
       * @param params ExecutionParams instance
       * @return collected {@link ResultItem}s
       * @throws RepositoryException if repository exception occurs
       */
      public static Result collectItemsFromExecutionParams(final Session session, final ExecutionParams params)
              throws RepositoryException {
          Result result = new Result();
  
          QueriesAndPaths binaries = params.getBinaries();
  
          if (binaries != null) {
              Set<String> binaryPathsCache = new LinkedHashSet<>();
              fillResultItemsForNodePaths(session, binaries.getPaths(), true, binaryPathsCache, result);
              fillResultItemsFromQueries(session, binaries.getQueries(), true, binaryPathsCache, result);
          }
  
          QueriesAndPaths documents = params.getDocuments();
  
          if (documents != null) {
              Set<String> documentPathsCache = new LinkedHashSet<>();
              fillResultItemsForNodePaths(session, documents.getPaths(), false, documentPathsCache, result);
              fillResultItemsFromQueries(session, documents.getQueries(), false, documentPathsCache, result);
          }
  
          return result;
      }
  
      /**
       * Collect nodes from {@code nodePaths} with validations and fill {@link ResultItem} instances in {@code resultOut}.
       * @param session JCR session
       * @param nodePaths document or binary node paths to validate
       * @param binary flag whether the node paths are for binary content or not
       * @param pathsCache node path cache set, which can be useful if you want to avoid putting the same items multiple times.
       *                   This can be null.
       * @param resultOut {@link Result} instance
       * @throws RepositoryException if repository exception occurs
       */
      public static void fillResultItemsForNodePaths(Session session, Collection<String> nodePaths,
              boolean binary, Set<String> pathsCache, Result resultOut) throws RepositoryException {
          if (pathsCache == null) {
              pathsCache = new HashSet<>();
          }
  
          for (String path : nodePaths) {
              if ((binary && !HippoNodeUtils.isBinaryPath(path)) || (!binary && !HippoNodeUtils.isDocumentPath(path))) {
                  continue;
              }
  
              if (!session.nodeExists(path)) {
                  continue;
              }
 
             Node handle = HippoNodeUtils.getHippoDocumentHandle(session.getNode(path));
 
             if (handle == null) {
                 continue;
             }
 
             String handlePath = handle.getPath();
 
             if (pathsCache.contains(handlePath)) {
                 continue;
             }
 
             Node firstVariant = HippoNodeUtils.getFirstVariantNode(handle);
 
             if (firstVariant == null) {
                 continue;
             }
 
             pathsCache.add(handlePath);
             ResultItem item = new ResultItem(handlePath, firstVariant.getPrimaryNodeType().getName());
             resultOut.addItem(item);
         }
     }
 
     /**
      * Collect nodes by executing the {@code queries} with validations and fill {@link ResultItem} instances in
      * {@code resultOut}.
      * @param session JCR session
      * @param queries JCR query statements for documents or binaries
      * @param binary flag whether the node paths are for binary content or not
      * @param pathsCache node path cache set, which can be useful if you want to avoid putting the same items multiple times.
      *                   This can be null.
      * @param resultOut {@link Result} instance
      * @throws RepositoryException if repository exception occurs
      */
     public static void fillResultItemsFromQueries(Session session, Collection<String> queries,
             boolean binary, Set<String> pathsCache, Result resultOut) throws RepositoryException {
         for (String query : queries) {
             if (StringUtils.isBlank(query)) {
                 continue;
             }
 
             if (!StringUtils.startsWith(query, "/") || StringUtils.startsWithIgnoreCase(query, "select")) {
                 continue;
             }
 
             final String language = (StringUtils.startsWithIgnoreCase(query, "select")) ? Query.SQL : Query.XPATH;
             Query jcrQuery = session.getWorkspace().getQueryManager().createQuery(query, language);
             QueryResult queryResult = jcrQuery.execute();
 
             for (NodeIterator nodeIt = queryResult.getNodes(); nodeIt.hasNext();) {
                 Node node = nodeIt.nextNode();
 
                 if (node == null) {
                     continue;
                 }
 
                 String nodePath = node.getPath();
 
                 if ((binary && !HippoNodeUtils.isBinaryPath(nodePath)) || (!binary && !HippoNodeUtils.isDocumentPath(nodePath))) {
                     continue;
                 }
 
                 Node handle = HippoNodeUtils.getHippoDocumentHandle(node);
 
                 if (handle == null) {
                     continue;
                 }
 
                 String handlePath = handle.getPath();
 
                 if (pathsCache.contains(handlePath)) {
                     continue;
                 }
 
                 Node firstVariant = HippoNodeUtils.getFirstVariantNode(handle);
 
                 if (firstVariant == null) {
                     continue;
                 }
 
                 pathsCache.add(handlePath);
                 ResultItem item = new ResultItem(handlePath, firstVariant.getPrimaryNodeType().getName());
                 resultOut.addItem(item);
             }
         }
     }
 }