content: /*
   *  Copyright (c) 2023-2025, Agents-Flex (fuhai999@gmail.com).
   *  <p>
   *  Licensed 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
   *  <p>
   *  http://www.apache.org/licenses/LICENSE-2.0
   *  <p>
   *  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 com.agentsflex.core.document.splitter;
  
  import com.agentsflex.core.document.Document;
  import com.agentsflex.core.document.DocumentSplitter;
  import com.agentsflex.core.document.id.DocumentIdGenerator;
  import com.agentsflex.core.util.StringUtil;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  public class SimpleDocumentSplitter implements DocumentSplitter {
      private int chunkSize;
      private int overlapSize;
  
      public SimpleDocumentSplitter(int chunkSize) {
          this.chunkSize = chunkSize;
          if (this.chunkSize <= 0) {
              throw new IllegalArgumentException("chunkSize must be greater than 0, chunkSize: " + this.chunkSize);
          }
      }
  
      public SimpleDocumentSplitter(int chunkSize, int overlapSize) {
          this.chunkSize = chunkSize;
          this.overlapSize = overlapSize;
  
          if (this.chunkSize <= 0) {
              throw new IllegalArgumentException("chunkSize must be greater than 0, chunkSize: " + this.chunkSize);
          }
          if (this.overlapSize >= this.chunkSize) {
              throw new IllegalArgumentException("overlapSize must be less than chunkSize, overlapSize: " + this.overlapSize + ", chunkSize: " + this.chunkSize);
          }
      }
  
      public int getChunkSize() {
          return chunkSize;
      }
  
      public void setChunkSize(int chunkSize) {
          this.chunkSize = chunkSize;
      }
  
      public int getOverlapSize() {
          return overlapSize;
      }
  
      public void setOverlapSize(int overlapSize) {
          this.overlapSize = overlapSize;
      }
  
      @Override
      public List<Document> split(Document document, DocumentIdGenerator idGenerator) {
          if (document == null || StringUtil.noText(document.getContent())) {
              return Collections.emptyList();
          }
  
          String content = document.getContent();
          int index = 0, currentIndex = index;
          int maxIndex = content.length();
  
          List<Document> chunks = new ArrayList<>();
          while (currentIndex < maxIndex) {
              int endIndex = Math.min(currentIndex + chunkSize, maxIndex);
              String chunk = content.substring(currentIndex, endIndex).trim();
              currentIndex = currentIndex + chunkSize - overlapSize;
  
              if (chunk.isEmpty()) {
                  continue;
              }
  
              Document newDocument = new Document();
              newDocument.addMetadata(document.getMetadataMap());
              newDocument.setContent(chunk);
  
              //we should invoke setId after setContent
              newDocument.setId(idGenerator == null ? null : idGenerator.generateId(newDocument));
              chunks.add(newDocument);
          }
  
          return chunks;
      }
  }
  