/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.chemistry.opencmis.client.util;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.Set;
  
  import org.apache.chemistry.opencmis.client.api.OperationContext;
  import org.apache.chemistry.opencmis.client.runtime.OperationContextImpl;
  import org.apache.chemistry.opencmis.commons.PropertyIds;
  import org.apache.chemistry.opencmis.commons.enums.IncludeRelationships;
  
  /**
   * Constants and methods to create and manipulate {@link OperationContext}
   * objects.
   */
  public final class OperationContextUtils {
  
      private static final char[] INVALID_QUERY_NAME_CHARS = " \t\n\r\f\"',\\.()".toCharArray();
  
      public static final String PROPERTIES_STAR = "*";
      public static final String RENDITION_NONE = "cmis:none";
  
      private OperationContextUtils() {
      }
  
      /**
       * Creates a new OperationContext object.
       */
      public static OperationContext createOperationContext() {
          return new OperationContextImpl();
      }
  
      /**
       * Copies an OperationContext object.
       */
      public static OperationContext copyOperationContext(OperationContext context) {
          return new OperationContextImpl(context);
      }
  
      /**
       * Creates a new OperationContext object with the given parameters.
       */
      public static OperationContext createOperationContext(Set<String> filter, boolean includeAcls,
              boolean includeAllowableActions, boolean includePolicies, IncludeRelationships includeRelationships,
              Set<String> renditionFilter, boolean includePathSegments, String orderBy, boolean cacheEnabled,
              int maxItemsPerPage) {
          if (!checkQueryNames(filter)) {
              throw new IllegalArgumentException("Invalid filter: " + filter);
          }
  
          return new OperationContextImpl(filter, includeAcls, includeAllowableActions, includePolicies,
                  includeRelationships, renditionFilter, includePathSegments, orderBy, cacheEnabled, maxItemsPerPage);
      }
  
      /**
       * Creates a new OperationContext object that only selects the bare minimum.
       * Caching is enabled.
       */
      public static OperationContext createMinimumOperationContext() {
          return createMinimumOperationContext((String[]) null);
      }
  
      /**
       * Creates a new OperationContext object that only selects the bare minimum
       * plus the provided properties. Caching is enabled.
       */
      public static OperationContext createMinimumOperationContext(String... propertyQueryNames) {
          Set<String> filter = new HashSet<String>();
          filter.add(PropertyIds.OBJECT_ID);
          filter.add(PropertyIds.OBJECT_TYPE_ID);
          filter.add(PropertyIds.BASE_TYPE_ID);
  
          if (propertyQueryNames != null) {
              for (String prop : propertyQueryNames) {
                  if (!checkQueryName(prop)) {
                      throw new IllegalArgumentException("Not a valid property query name: " + prop);
                  }
                  filter.add(prop);
              }
          }
 
         return new OperationContextImpl(filter, false, false, false, IncludeRelationships.NONE,
                 Collections.singleton(RENDITION_NONE), false, null, true, 100);
     }
 
     /**
      * Creates a new OperationContext object that selects everything.
      */
     public static OperationContext createMaximumOperationContext() {
         return new OperationContextImpl(Collections.singleton(PROPERTIES_STAR), true, true, true,
                 IncludeRelationships.BOTH, Collections.singleton("*"), false, null, true, 100);
     }
 
     /**
      * Returns an unmodifiable view of the specified OperationContext.
      * 
      * Attempts to modify the returned OperationContext object result in an
      * {@code UnsupportedOperationException}.
      */
     public static OperationContext unmodifiableOperationContext(final OperationContext context) {
         return new OperationContext() {
 
             private static final long serialVersionUID = 1L;
 
             @Override
             public Set<String> getFilter() {
                 return Collections.unmodifiableSet(context.getFilter());
             }
 
             @Override
             public void setFilter(Set<String> propertyFilter) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public void setFilterString(String propertyFilter) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public String getFilterString() {
                 return context.getFilterString();
             }
 
             @Override
             public void setLoadSecondaryTypeProperties(boolean load) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public boolean loadSecondaryTypeProperties() {
                 return context.loadSecondaryTypeProperties();
             }
 
             @Override
             public boolean isIncludeAllowableActions() {
                 return context.isIncludeAllowableActions();
             }
 
             @Override
             public void setIncludeAllowableActions(boolean include) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public boolean isIncludeAcls() {
                 return context.isIncludeAcls();
             }
 
             @Override
             public void setIncludeAcls(boolean include) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public IncludeRelationships getIncludeRelationships() {
                 return context.getIncludeRelationships();
             }
 
             @Override
             public void setIncludeRelationships(IncludeRelationships include) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public boolean isIncludePolicies() {
                 return context.isIncludePolicies();
             }
 
             @Override
             public void setIncludePolicies(boolean include) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public Set<String> getRenditionFilter() {
                 return Collections.unmodifiableSet(context.getRenditionFilter());
             }
 
             @Override
             public void setRenditionFilter(Set<String> renditionFilter) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public void setRenditionFilterString(String renditionFilter) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public String getRenditionFilterString() {
                 return context.getRenditionFilterString();
             }
 
             @Override
             public boolean isIncludePathSegments() {
                 return context.isIncludePathSegments();
             }
 
             @Override
             public void setIncludePathSegments(boolean include) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public String getOrderBy() {
                 return context.getOrderBy();
             }
 
             @Override
             public void setOrderBy(String orderBy) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public boolean isCacheEnabled() {
                 return context.isCacheEnabled();
             }
 
             @Override
             public void setCacheEnabled(boolean cacheEnabled) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public String getCacheKey() {
                 return context.getCacheKey();
             }
 
             @Override
             public void setMaxItemsPerPage(int maxItemsPerPage) {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             public int getMaxItemsPerPage() {
                 return context.getMaxItemsPerPage();
             }
 
             @Override
             public String toString() {
                 return context.toString();
             }
         };
     }
 
     // --- helpers ---
 
     /**
      * Checks if a property query name is valid.
      * 
      * @param queryName
      *            the query name
      * @return {@code true} if the query name is valid, {@code false} otherwise
      */
     private static boolean checkQueryName(String queryName) {
         if (queryName == null || queryName.length() == 0) {
             return false;
         }
 
         int n = queryName.length();
         for (int i = 0; i < n; i++) {
             char c = queryName.charAt(i);
             for (char ic : INVALID_QUERY_NAME_CHARS) {
                 if (c == ic) {
                     return false;
                 }
             }
         }
 
         return true;
     }
 
     /**
      * Checks if a set of property query name is valid.
      * 
      * @param queryNames
      *            the query names
      * @return {@code true} if all query names are valid, {@code false}
      *         otherwise
      */
     private static boolean checkQueryNames(Collection<String> queryNames) {
         if (queryNames == null || queryNames.isEmpty()) {
             return true;
         }
 
         for (String qn : queryNames) {
             if (!checkQueryName(qn)) {
                 return false;
             }
         }
 
         return true;
     }
 }