/*
    * #%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.wcm.parsys.componentinfo.impl;
  
  import static io.wcm.wcm.parsys.ParsysNameConstants.NN_PARSYS_CONFIG;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Set;
  import java.util.regex.Pattern;
  
  import org.apache.commons.lang3.ArrayUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.jackrabbit.util.Text;
  import org.apache.sling.api.resource.Resource;
  import org.apache.sling.api.resource.ResourceResolver;
  import org.apache.sling.api.resource.ValueMap;
  import org.jetbrains.annotations.NotNull;
  
  import com.day.cq.commons.jcr.JcrConstants;
  
  import io.wcm.wcm.parsys.componentinfo.ParsysConfig;
  
  /**
   * Reads paragraph system configuration from page component resource type definition in repository.
   * TODO: add caching for resolved parsys config from resource?
   */
  final class ResourceParsysConfigProvider {
  
    private static final String NN_PATHS = "paths";
    private static final String PN_PATH = "path";
    private static final String PN_PATTERN = "pattern";
    private static final String PN_ALLOWEDCHILDREN = "allowedChildren";
    private static final String PN_DENIEDDCHILDREN = "deniedChildren";
    private static final String PN_ALLOWEDPARENTS = "allowedParents";
    private static final String PN_PARENTANCESTORLEVEL = "parentAncestorLevel";
    private static final String PN_INHERIT = "inherit";
  
    private final List<ParsysConfig> pathDefs;
  
    /**
     * @param pageComponentResource Page component resource
     */
    ResourceParsysConfigProvider(Resource pageComponentResource) {
      this.pathDefs = getPathDefs(pageComponentResource);
    }
  
    private static List<ParsysConfig> getPathDefs(Resource pageComponentResource) {
      List<ParsysConfig> pathDefs = new ArrayList<>();
  
      ResourceResolver resourceResolver = pageComponentResource.getResourceResolver();
      Resource pathsResource = resourceResolver.getResource(pageComponentResource, "./" + NN_PARSYS_CONFIG + "/" + NN_PATHS);
      if (pathsResource != null) {
        Iterator<Resource> pathDefResources = resourceResolver.listChildren(pathsResource);
        while (pathDefResources.hasNext()) {
          Resource pathDefResource = pathDefResources.next();
          pathDefs.add(new PathDef(pathDefResource, pageComponentResource.getResourceType()));
        }
      }
  
      return pathDefs;
    }
  
    /**
     * @return All path definitions
     */
    public List<ParsysConfig> getPathDefs() {
      return this.pathDefs;
    }
  
    /**
     * Paragraph System configuration path definition.
     */
    private static class PathDef implements ParsysConfig {
  
      private final String pageComponentPath;
      private final Pattern pathPattern;
      private final Set<String> allowedChildren;
      private final Set<String> deniedChildren;
      private final Set<String> allowedParents;
      private final int parentAncestorLevel;
     private final boolean inheritFromSuperType;
 
     /**
      * @param pathDefResource Path definition resource
      * @param pageComponentPath resource type of page component
      */
     PathDef(Resource pathDefResource, String pageComponentPath) {
       this.pageComponentPath = pageComponentPath;
       ValueMap pathDefProps = pathDefResource.getValueMap();
 
       // resolve path/path pattern
       String path = pathDefProps.get(PN_PATH, String.class);
       String patternString = pathDefProps.get(PN_PATTERN, String.class);
       if (StringUtils.isNotEmpty(patternString)) {
         this.pathPattern = Pattern.compile(patternString);
       }
       else if (StringUtils.isNotBlank(path)) {
         this.pathPattern = Pattern.compile("^" + Pattern.quote(path) + "$");
       }
       else {
         String name = Text.getName(pathDefResource.getPath());
         this.pathPattern = Pattern.compile("^" + Pattern.quote(JcrConstants.JCR_CONTENT + "/" + name) + "$");
       }
 
       // get allowed children/denied children/parents
       this.allowedChildren = Set.of(pathDefProps.get(PN_ALLOWEDCHILDREN, ArrayUtils.EMPTY_STRING_ARRAY));
       this.deniedChildren = Set.of(pathDefProps.get(PN_DENIEDDCHILDREN, ArrayUtils.EMPTY_STRING_ARRAY));
       this.allowedParents = Set.of(pathDefProps.get(PN_ALLOWEDPARENTS, ArrayUtils.EMPTY_STRING_ARRAY));
 
       // ancestor level
       this.parentAncestorLevel = pathDefProps.get(PN_PARENTANCESTORLEVEL, 1);
 
       // inherit from supertype
       this.inheritFromSuperType = pathDefProps.get(PN_INHERIT, true);
 
     }
 
     @Override
     public @NotNull String getPageComponentPath() {
       return this.pageComponentPath;
     }
 
     @Override
     public Pattern getPathPattern() {
       return this.pathPattern;
     }
 
     @Override
     public @NotNull Set<String> getAllowedChildren() {
       return this.allowedChildren;
     }
 
     @Override
     public @NotNull Set<String> getDeniedChildren() {
       return this.deniedChildren;
     }
 
     @Override
     public @NotNull Set<String> getAllowedParents() {
       return this.allowedParents;
     }
 
     @Override
     public int getParentAncestorLevel() {
       return this.parentAncestorLevel;
     }
 
     @Override
     public boolean isInherit() {
       return this.inheritFromSuperType;
     }
 
     @Override
     public String toString() {
       return this.pathPattern.toString() + ", "
           + "allowedChildren=[" + StringUtils.join(this.allowedChildren, ",") + "], "
           + "deniedChildren=[" + StringUtils.join(this.deniedChildren, ",") + "], "
           + "allowedParents=[" + StringUtils.join(this.allowedParents, ",") + "], "
           + "parentAncestorLevel=" + this.parentAncestorLevel + ","
           + "inheritFromSuperType=" + this.inheritFromSuperType;
     }
 
   }
 
 }