/**
 * 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.solr.update.processor;

import org.apache.solr.core.SolrCore;
import org.apache.solr.schema.IndexSchema;
import org.apache.solr.schema.FieldType;
import org.apache.solr.schema.SchemaField;
import org.apache.solr.schema.TextField;
import org.apache.solr.schema.StrField;

import org.apache.solr.common.SolrInputField;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.response.SolrQueryResponse;

import org.apache.commons.lang.StringUtils;

/**
 * Concatenates multiple values for fields matching the specified 
 * conditions using a configurable <code>delimiter</code> which defaults 
 * to "<code> ,</code>".
 * <p>
 * By default, this processor concatenates the values for any field name 
 * which according to the schema is <code>multiValued="false"</code> 
 * and uses <code>TextField</code> or <code>StrField</code>
 * </p>
 * 
 * <p>
 * For example, in the configuration below, any "single valued" string and 
 * text field which is found to contain multiple values <i>except</i> for 
 * the <code>primary_author</code> field will be concatenated using the 
 * string "<code> ;</code>" as a delimeter.  For the 
 * <code>primary_author</code> field, the multiple values will be left 
 * alone for <code>FirstFieldValueUpdateProcessorFactory</code> to deal with.
 * </p>
 *
 * <pre class="prettyprint">
 *  &lt;updateRequestProcessorChain&gt;
 *    &lt;processor class="solr.ConcatFieldUpdateProcessorFactory"&gt;
 *      &lt;str name="delimiter"&gt;; &lt;/str&gt;
 *      &lt;lst name="exclude"&gt;
 *        &lt;str name="fieldName"&gt;primary_author&lt;/str&gt;
 *      &lt;/lst&gt;
 *    &lt;/processor&gt;
 *    &lt;processor class="solr.FirstFieldValueUpdateProcessorFactory"&gt;
 *      &lt;str name="fieldName"&gt;primary_author&lt;/str&gt;
 *    &lt;/processor&gt;
 *  &lt;/updateRequestProcessorChain&gt;
 * </pre>
 */
public final class ConcatFieldUpdateProcessorFactory extends FieldMutatingUpdateProcessorFactory {

  String delimiter = ", ";

  @SuppressWarnings("unchecked")
  @Override
  public void init(NamedList args) {
    Object d = args.remove("delimiter");
    if (null != d) delimiter = d.toString();

    super.init(args);
  }
  
  @Override
  public UpdateRequestProcessor getInstance(SolrQueryRequest req,
                                            SolrQueryResponse rsp,
                                            UpdateRequestProcessor next) {
    return new FieldMutatingUpdateProcessor(getSelector(), next) {
      protected SolrInputField mutate(final SolrInputField src) {
        if (src.getValueCount() <= 1) return src;

        SolrInputField result = new SolrInputField(src.getName());
        result.setValue(StringUtils.join(src.getValues(), delimiter), 
                        src.getBoost());
        return result;
      }
    };
  }

  @Override
  public FieldMutatingUpdateProcessor.FieldNameSelector 
    getDefaultSelector(final SolrCore core) {

    final IndexSchema schema = core.getSchema();
    return new FieldMutatingUpdateProcessor.FieldNameSelector() {
      public boolean shouldMutate(final String fieldName) {

        // first check type since it should be fastest
        FieldType type = schema.getFieldTypeNoEx(fieldName);
        if (null == type) return false;
        
        if (! (TextField.class.isInstance(type) 
               || StrField.class.isInstance(type))) {
          return false;
        }

        // only ask for SchemaField if we passed the type check.
        SchemaField sf = schema.getFieldOrNull(fieldName);
        // shouldn't be null since since type wasn't, but just in case
        if (null == sf) return false;
        
        return ! sf.multiValued();
      }
    };
  }
  
}


@@ -1487,10 +1487,10 @@
 ode%3E
- 
 ,
+ 
 %3C/co
@@ -1970,10 +1970,10 @@
 ode%3E
- 
 ;
+ 
 %3C/co

fix delimiter string