/**
 *
 */
package org.eclipse.smila.solr.update;

import java.util.Map.Entry;

import org.apache.solr.common.SolrInputDocument;
import org.eclipse.smila.datamodel.Any;
import org.eclipse.smila.datamodel.AnyMap;
import org.eclipse.smila.datamodel.AnySeq;
import org.eclipse.smila.datamodel.Record;
import org.eclipse.smila.datamodel.Value;
import org.eclipse.smila.datamodel.util.AnyUtil;

import com.google.common.base.Strings;

/**
 * @author pwissel
 *
 */
public class AdvancedSolrDocumentConverter {

  private final AnyMap _mapping;

  private final String _idField;

  public AdvancedSolrDocumentConverter() {
    this(null);
  }

  public AdvancedSolrDocumentConverter(final AnyMap mapping) {
    this(mapping, Record.RECORD_ID);
  }

  public AdvancedSolrDocumentConverter(final AnyMap mapping, final String idField) {
    _mapping = mapping;
    _idField = idField;
  }

  public SolrInputDocument convert(final Record record) {
    if (_mapping != null) {
      return createDocumentWithMapping(record);
    }
    return null;
  }

  private SolrInputDocument createDocumentWithMapping(final Record record) {
    final String id = record.getMetadata().getStringValue(_idField);
    final SolrInputDocument document = newDocument(id);
    for (final Entry<String, Any> mapping : _mapping.entrySet()) {
      final String attributeOrAttachmentName = mapping.getKey();
      final Any any = mapping.getValue();
      final Object fieldName = getFieldName(attributeOrAttachmentName, any);
      addFieldFromAttribute(document, attributeOrAttachmentName, (String) fieldName, record);
    }
    return document;
  }

  private SolrInputDocument newDocument(final String id) {
    final SolrInputDocument document = new SolrInputDocument();
    document.addField(_idField, id);
    return document;
  }

  private Object getFieldName(final String attributeOrAttachmentName, final Any any) {
    if (any.isValue()) {
      // AnyValue
      final Value value = any.asValue();
      if (value != null) {
        String fieldName = Strings.emptyToNull(value.asString());
        return fieldName != null ? fieldName : attributeOrAttachmentName;
      }
    } else if (any.isSeq()) {
      // AnySeq
      final AnySeq seq = any.asSeq();
      if (seq != null && !seq.isEmpty()) {
        return seq.asStrings().toArray(new String[seq.size()]);
      }
    } else if (any.isMap()) {
      final AnyMap map = any.asMap();
      if (map != null && !map.isEmpty()) {
        String fieldName = Strings.emptyToNull(map.getStringValue("fieldName"));
        return fieldName != null ? fieldName : attributeOrAttachmentName;
      }
    }
    return null;
  }

  private void addFieldFromAttribute(final SolrInputDocument document, final String attributeName,
    final String fieldName, final Record record) {
    final Any any = record.getMetadata().get(attributeName);
    if (any != null) {
      final Object value = AnyUtil.anyToNative(any);
      Float boost = null;
      if (any.isMap()) {
        final Any boostValue = any.asMap().remove("fieldBoost");
        if (boostValue != null) {
          boost = boostValue.asValue().asDouble().floatValue();
        }
      }
      if (boost != null) {
        document.addField(fieldName, value, boost);
      } else {
        document.addField(fieldName, value);
      }
    }
  }

}