package edu.jiangxin.apktoolbox.file.core;
   
   import java.io.BufferedReader;
   import java.io.BufferedWriter;
   import java.io.File;
   import java.io.FileInputStream;
   import java.io.FileOutputStream;
   import java.io.InputStreamReader;
   import java.io.OutputStreamWriter;
  import java.util.Collection;
  import java.util.Iterator;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  /**
   * 文件编码转换的工具类.
   * 
   * @author jiangxin
   * @author 2018-09-09
   *
   */
  public class EncoderConvert {
  
      private static final String TMP_SUFFIX = ".temp";
      private static final Logger logger = LogManager.getLogger(EncoderDetector.class.getSimpleName());
  
      /**
       * 实现对文件的编码转换.
       * 
       * @param srcFileString 源文件文件名
       * @param srcEncoder    源文件编码
       * @param desFileString 目的文件文件名
       * @param desEncoder    需要转换的编码
       */
      public static void encodeFile(String srcFileString, String srcEncoder, String desFileString, String desEncoder) {
          if (srcFileString.equals(desFileString)) {
              srcFileString = srcFileString + EncoderConvert.TMP_SUFFIX;
              FileProcess.copyFile(desFileString, srcFileString);
          }
          File srcFileFile = new File(srcFileString);
          File desFileFile = new File(desFileString);
  
          File parentDir = desFileFile.getParentFile();
          if (!parentDir.exists()) {
              boolean success = parentDir.mkdirs();
              if (!success) {
                  logger.error("delete srcFileFile failed");
                  return;
              }
          }
  
          try (BufferedReader reader = new BufferedReader(
                  new InputStreamReader(new FileInputStream(srcFileFile), srcEncoder));
                  BufferedWriter writer = new BufferedWriter(
                          new OutputStreamWriter(new FileOutputStream(desFileFile), desEncoder))) {
              int ch = 0;
              while ((ch = reader.read()) != -1) {
                  writer.write(ch);
              }
          } catch (Exception e) {
              logger.error("Exception", e);
              return;
          }
  
          if (srcFileString.equals(desFileString + EncoderConvert.TMP_SUFFIX)) {
              boolean success = srcFileFile.delete();
              if (!success) {
                  logger.error("delete srcFileFile failed");
              }
          }
      }
  
      /**
       * 实现文件的编码转换. see {@link #encodeFile(String, String, String, String)}
       * 
       * @param fileString 文件名
       * @param srcEncoder 原始编码
       * @param desEncoder 需要转换的编码
       */
      public static void encodeFile(String fileString, String srcEncoder, String desEncoder) {
          encodeFile(fileString, srcEncoder, fileString, desEncoder);
      }
  
      /**
       * 实现文件夹中特定文件的批量编码转换. see {@link #encodeFile(String, String, String, String)}
       * 
       * @param srcDirString 原始文件夹
       * @param srcEncoder   原始编码
       * @param desDirString 目的文件夹
       * @param desEncoder   需要转换的编码
       * @param suffix       指定需要转换的后缀
       */
      public static void encodeDir(String srcDirString, String srcEncoder, String desDirString, String desEncoder,
              String suffix) {
          // File srcDirFile = new File(srcDirString);
          File desDirFile = new File(desDirString);
         // 获取所有符合条件的文件
         String[] extensions = null;
         if (StringUtils.isNotEmpty(suffix)) {
             extensions = suffix.split(",");
         }
         Collection<File> files = FileUtils.listFiles(new File(srcDirString), extensions, true);
         Iterator<File> it = files.iterator();
         while (it.hasNext()) {
             File tempFile = it.next();
             String desFileString = desDirFile.getAbsolutePath() + File.separator + tempFile.getName();
             String srcFileString = tempFile.getAbsolutePath();
             encodeFile(srcFileString, srcEncoder, desFileString, desEncoder);
         }
     }
 
     /**
      * 实现文件夹中特定文件的批量编码转换. see {@link #encodeFile(String, String, String, String)}
      * 
      * @param srcDirString 原始文件夹
      * @param srcEncoder   原始编码
      * @param desDirString 目的文件夹
      * @param desEncoder   需要转换的编码
      */
     public static void encodeDir(String srcDirString, String srcEncoder, String desDirString, String desEncoder) {
         encodeDir(srcDirString, srcEncoder, desDirString, desEncoder, null);
     }
 }