import org.opensearch.action.bulk.BulkItemResponse;
import org.opensearch.action.bulk.BulkRequestBuilder;
import org.opensearch.action.bulk.BulkResponse;
import org.opensearch.action.delete.DeleteResponse;
import org.opensearch.action.get.GetResponse;
import org.opensearch.action.index.IndexResponse;
import org.opensearch.action.search.SearchRequestBuilder;
import org.opensearch.action.search.SearchResponse;

import org.codelibs.fess.suggest.util.SuggestUtil;
import org.opensearch.action.search.SearchRequestBuilder;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.index.query.QueryBuilder;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.search.SearchHit;
import org.opensearch.search.sort.SortBuilder;
import org.opensearch.transport.client.Client;

/**
 * <p>

import org.opensearch.action.fieldcaps.FieldCapabilitiesRequestBuilder;
import org.opensearch.action.fieldcaps.FieldCapabilitiesResponse;
import org.opensearch.action.get.GetRequest;
import org.opensearch.action.get.GetRequestBuilder;
import org.opensearch.action.get.GetResponse;
import org.opensearch.action.get.MultiGetRequest;
import org.opensearch.action.get.MultiGetRequestBuilder;
import org.opensearch.action.get.MultiGetResponse;

- **Data Persistence**: Multiple backend options including OpenSearch integration

## Technology Stack

- **Java**: 21+ (requires Java 21 or higher)
- **Build System**: Maven 3.x
- **DI Container**: LastaFlute DI
- **HTTP Client**: Apache HttpComponents
- **Content Extraction**: Apache Tika, Apache POI, PDFBox
- **Testing**: JUnit 4, UTFlute, Testcontainers
- **Storage Backends**: OpenSearch, Memory-based

## Quick Start

import org.codelibs.fess.suggest.settings.SuggestSettings;
import org.opensearch.action.bulk.BulkRequestBuilder;
import org.opensearch.action.bulk.BulkResponse;
import org.opensearch.action.delete.DeleteRequest;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.common.xcontent.json.JsonXContent;
import org.opensearch.core.action.ActionListener;
import org.opensearch.core.xcontent.XContentBuilder;

import org.codelibs.fess.crawler.util.OpenSearchResultList;
import org.opensearch.action.DocWriteRequest.OpType;
import org.opensearch.action.search.SearchRequestBuilder;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.common.unit.TimeValue;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.search.SearchHit;
import org.opensearch.search.SearchHits;

import jakarta.annotation.PostConstruct;

/**

import org.opensearch.action.DocWriteRequest.OpType;
import org.opensearch.action.bulk.BulkRequestBuilder;
import org.opensearch.action.bulk.BulkResponse;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.action.support.WriteRequest.RefreshPolicy;
import org.opensearch.action.update.UpdateRequestBuilder;
import org.opensearch.common.unit.TimeValue;

import org.codelibs.fess.suggest.util.SuggestUtil;
import org.opensearch.action.admin.indices.create.CreateIndexResponse;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.common.xcontent.XContentFactory;
import org.opensearch.common.xcontent.XContentType;
import org.opensearch.common.xcontent.json.JsonXContent;
import org.opensearch.core.xcontent.XContentBuilder;
import org.opensearch.index.IndexNotFoundException;

import org.opensearch.action.search.SearchResponse;
import org.opensearch.cluster.metadata.AliasMetadata;
import org.opensearch.common.xcontent.XContentType;
import org.opensearch.index.query.QueryBuilder;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.transport.client.Client;

/**
 * The Suggester class provides functionality for managing and querying suggestion indices.

- **Popular Words Analytics**: Track and analyze frequently searched terms
- **Flexible Text Processing**: Configurable converters and normalizers for text transformation
- **OpenSearch Integration**: Seamless integration with OpenSearch/Elasticsearch clusters
- **Asynchronous Operations**: Non-blocking suggestion requests with callback support
- **Index Management**: Automatic index creation, switching, and maintenance