package edu.jiangxin.apktoolbox.word;
   
   import org.apache.logging.log4j.LogManager;
   import org.apache.logging.log4j.Logger;
   import org.apache.poi.hpsf.SummaryInformation;
   import org.apache.poi.hwpf.HWPFDocument;
   import org.apache.poi.xwpf.usermodel.XWPFDocument;
   
   import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  
  public class WordUtils {
  
      private static final Logger LOGGER = LogManager.getLogger(WordUtils.class.getSimpleName());
  
      private WordUtils() {
          // utility class
      }
  
      /**
       * 读取 Word 文档的页数。
       * - .doc  使用 HWPFDocument（poi-scratchpad）
       * - .docx 使用 XWPFDocument（poi-ooxml）
       * 若读取失败或页数 <= 0，返回 0。
       *
       * @param file Word 文档文件
       * @return 文档页数，若无法读取则返回 0
       */
      public static int getPageCount(File file) {
          if (file == null || !file.exists() || !file.isFile()) {
              LOGGER.warn("Invalid file: {}", file);
              return 0;
          }
  
          String name = file.getName().toLowerCase();
          if (name.endsWith(".doc")) {
              return getDocPageCount(file);
          } else if (name.endsWith(".docx")) {
              return getDocxPageCount(file);
          } else {
              LOGGER.warn("Unsupported file type: {}", file.getPath());
              return 0;
          }
      }
  
      private static int getDocPageCount(File file) {
          try (FileInputStream fis = new FileInputStream(file);
               HWPFDocument document = new HWPFDocument(fis)) {
              SummaryInformation si = document.getSummaryInformation();
              int pageCount = (si != null) ? si.getPageCount() : 0;
              if (pageCount <= 0) {
                  LOGGER.info("Page count <= 0 for .doc file: {}, returning 0", file.getPath());
                  return 0;
              }
              LOGGER.info("Processing .doc file: {}, page count: {}", file.getPath(), pageCount);
              return pageCount;
          } catch (IOException e) {
              LOGGER.error("Error reading .doc file: {}, message: {}", file.getPath(), e.getMessage());
              return 0;
          }
      }
  
      private static int getDocxPageCount(File file) {
          try (FileInputStream fis = new FileInputStream(file);
               XWPFDocument document = new XWPFDocument(fis)) {
              // 优先从 ExtendedProperties 读取页数
              int pageCount = 0;
              if (document.getProperties() != null
                      && document.getProperties().getExtendedProperties() != null
                      && document.getProperties().getExtendedProperties().getUnderlyingProperties() != null) {
                  pageCount = document.getProperties().getExtendedProperties().getUnderlyingProperties().getPages();
              }
              // 若 ExtendedProperties 无效，尝试从 CoreProperties 读取 revision 作为备选
              if (pageCount <= 0) {
                  String revision = null;
                  if (document.getProperties() != null
                          && document.getProperties().getCoreProperties() != null) {
                      revision = document.getProperties().getCoreProperties().getRevision();
                  }
                  if (revision != null && !revision.isEmpty()) {
                      try {
                          pageCount = Integer.parseInt(revision);
                      } catch (NumberFormatException e) {
                          LOGGER.warn("Cannot parse revision as page count for .docx file: {}", file.getPath());
                          pageCount = 0;
                      }
                  }
              }
              if (pageCount <= 0) {
                  LOGGER.info("Page count <= 0 for .docx file: {}, returning 0", file.getPath());
                  return 0;
              }
              LOGGER.info("Processing .docx file: {}, page count: {}", file.getPath(), pageCount);
              return pageCount;
          } catch (IOException e) {
              LOGGER.error("Error reading .docx file: {}, message: {}", file.getPath(), e.getMessage());
              return 0;
          }
     }
 }