/*
 * 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.schema;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import org.apache.lucene.document.SortedDocValuesField;
import org.apache.lucene.document.SortedSetDocValuesField;
import org.apache.lucene.index.IndexableField;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.queries.function.valuesource.SortedSetFieldSource;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.SortedSetSelector;
import org.apache.lucene.util.BytesRef;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.util.ByteArrayUtf8CharSequence;
import org.apache.solr.response.TextResponseWriter;
import org.apache.solr.search.QParser;
import org.apache.solr.uninverting.UninvertingReader.Type;

public class StrField extends PrimitiveFieldType {

  @Override
  protected void init(IndexSchema schema, Map<String,String> args) {
    super.init(schema, args);
  }

  @Override
  public List<IndexableField> createFields(SchemaField field, Object value) {
    IndexableField fval = createField(field, value);

    if (field.hasDocValues()) {
      IndexableField docval;
      final BytesRef bytes = getBytesRef(value);
      if (field.multiValued()) {
        docval = new SortedSetDocValuesField(field.getName(), bytes);
      } else {
        docval = new SortedDocValuesField(field.getName(), bytes);
      }

      // Only create a list of we have 2 values...
      if (fval != null) {
        List<IndexableField> fields = new ArrayList<>(2);
        fields.add(fval);
        fields.add(docval);
        return fields;
      }

      fval = docval;
    }
    return Collections.singletonList(fval);
  }

  public static BytesRef getBytesRef(Object value) {
    if (value instanceof ByteArrayUtf8CharSequence) {
      ByteArrayUtf8CharSequence utf8 = (ByteArrayUtf8CharSequence) value;
      return new BytesRef(utf8.getBuf(), utf8.offset(), utf8.size());
    } else return new BytesRef(value.toString());
  }


  @Override
  public boolean isUtf8Field() {
    return true;
  }

  @Override
  public SortField getSortField(SchemaField field,boolean reverse) {
    return getStringSort(field,reverse);
  }

  @Override
  public Type getUninversionType(SchemaField sf) {
    if (sf.multiValued()) {
      return Type.SORTED_SET_BINARY;
    } else {
      return Type.SORTED;
    }
  }

  @Override
  public void write(TextResponseWriter writer, String name, IndexableField f) throws IOException {
    writer.writeStr(name, toExternal(f), true);
  }

  @Override
  public ValueSource getValueSource(SchemaField field, QParser parser) {
    field.checkFieldCacheSource();
    return new StrFieldSource(field.getName());
  }

  @Override
  public Object toObject(SchemaField sf, BytesRef term) {
    return term.utf8ToString();
  }

  @Override
  public Object marshalSortValue(Object value) {
    return marshalStringSortValue(value);
  }

  @Override
  public Object unmarshalSortValue(Object value) {
    return unmarshalStringSortValue(value);
  }

  @Override
  public ValueSource getSingleValueSource(MultiValueSelector choice, SchemaField field, QParser parser) {
    // trivial base case
    if (!field.multiValued()) {
      // single value matches any selector
      return getValueSource(field, parser);
    }
    
    // See LUCENE-6709
    if (! field.hasDocValues()) {
      throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
                              "docValues='true' is required to select '" + choice.toString() +
                              "' value from multivalued field ("+ field.getName() +") at query time");
    }
    SortedSetSelector.Type selectorType = choice.getSortedSetSelectorType();
    if (null == selectorType) {
      throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
                              choice.toString() + " is not a supported option for picking a single value"
                              + " from the multivalued field: " + field.getName() +
                              " (type: " + this.getTypeName() + ")");
    }
    
    return new SortedSetFieldSource(field.getName(), selectorType);
  }
}