package edu.jiangxin.apktoolbox.file.password.recovery.category.dictionary.singlethread;
   
   import edu.jiangxin.apktoolbox.file.core.EncoderDetector;
   import edu.jiangxin.apktoolbox.file.password.recovery.RecoveryPanel;
   import edu.jiangxin.apktoolbox.file.password.recovery.category.ICategory;
   import edu.jiangxin.apktoolbox.utils.Utils;
   import org.apache.logging.log4j.LogManager;
   import org.apache.logging.log4j.Logger;
   
  import javax.swing.*;
  import java.io.*;
  import java.util.Optional;
  import java.util.function.Function;
  import java.util.function.Predicate;
  import java.util.stream.Stream;
  
  public class DictionarySingleThreadProxy implements ICategory {
      private static final Logger logger = LogManager.getLogger(DictionarySingleThreadProxy.class.getSimpleName());
  
      private boolean isCancelled;
  
      private static class DictionarySingleThreadProxyHolder {
          private static final DictionarySingleThreadProxy instance = new DictionarySingleThreadProxy();
      }
  
      private DictionarySingleThreadProxy() {
      }
  
      public static DictionarySingleThreadProxy getInstance() {
          return DictionarySingleThreadProxy.DictionarySingleThreadProxyHolder.instance;
      }
  
      private String startAndGet(String charsetName, RecoveryPanel panel) {
          isCancelled = false;
          Predicate<String> isRecoveringPredicate = password -> (!isCancelled);
          Function<String, Stream<String>> generator = password -> {
              panel.setCurrentPassword(password);
              panel.increaseProgressBarValue();
              return Stream.of(password.toLowerCase(), password.toUpperCase());
          };
          Predicate<String> verifier = panel.getCurrentFileChecker()::checkPassword;
          try (BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(panel.getDictionaryFile()), charsetName))) {
              // java.util.stream.BaseStream.parallel can not increase the speed in test
              Optional<String> password = br.lines().takeWhile(isRecoveringPredicate).flatMap(generator).filter(verifier).findFirst();
              return password.orElse(null);
          } catch (FileNotFoundException e) {
              logger.info("FileNotFoundException");
          } catch (IOException e) {
              logger.info("IOException");
          }
          return null;
      }
  
      @Override
      public void start(RecoveryPanel panel) {
          File dictionaryFile = panel.getDictionaryFile();
          if (!dictionaryFile.isFile()) {
              JOptionPane.showMessageDialog(panel, "Invalid dictionary file");
              return;
          }
          String charsetName = EncoderDetector.judgeFile(dictionaryFile.getAbsolutePath());
          logger.info("dictionary file: {}, charset: {}", dictionaryFile.getAbsolutePath(), charsetName);
          if (charsetName == null) {
              JOptionPane.showMessageDialog(panel, "Invalid charsetName");
              return;
          }
          panel.resetProgressMaxValue(Utils.getFileLineCount(dictionaryFile));
          String password = startAndGet(charsetName, panel);
          panel.showResultWithDialog(password);
      }
  
      @Override
      public void cancel() {
          isCancelled = true;
      }
  }