/*
    * Copyright 2012-2025 CodeLibs Project and the Others.
    *
    * 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
    *
    *     http://www.apache.org/licenses/LICENSE-2.0
    *
   * 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 org.codelibs.fess.dict.kuromoji;
  
  import java.io.BufferedReader;
  import java.io.BufferedWriter;
  import java.io.Closeable;
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.OutputStreamWriter;
  import java.io.Writer;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Date;
  import java.util.List;
  
  import org.codelibs.core.io.CloseableUtil;
  import org.codelibs.core.lang.StringUtil;
  import org.codelibs.curl.CurlResponse;
  import org.codelibs.fess.Constants;
  import org.codelibs.fess.dict.DictionaryException;
  import org.codelibs.fess.dict.DictionaryFile;
  import org.codelibs.fess.util.ComponentUtil;
  import org.codelibs.fess.util.KuromojiCSVUtil;
  import org.dbflute.optional.OptionalEntity;
  
  /**
   * A dictionary file for Kuromoji.
   */
  public class KuromojiFile extends DictionaryFile<KuromojiItem> {
      private static final String KUROMOJI = "kuromoji";
  
      List<KuromojiItem> kuromojiItemList;
  
      /**
       * Constructs a new Kuromoji file.
       *
       * @param id The ID of the dictionary file.
       * @param path The path of the dictionary file.
       * @param timestamp The timestamp of the dictionary file.
       */
      public KuromojiFile(final String id, final String path, final Date timestamp) {
          super(id, path, timestamp);
      }
  
      @Override
      public String getType() {
          return KUROMOJI;
      }
  
      @Override
      public String getPath() {
          return path;
      }
  
      @Override
      public synchronized OptionalEntity<KuromojiItem> get(final long id) {
          if (kuromojiItemList == null) {
              reload(null);
          }
  
          for (final KuromojiItem kuromojiItem : kuromojiItemList) {
              if (id == kuromojiItem.getId()) {
                  return OptionalEntity.of(kuromojiItem);
              }
          }
          return OptionalEntity.empty();
      }
  
      @Override
      public synchronized PagingList<KuromojiItem> selectList(final int offset, final int size) {
          if (kuromojiItemList == null) {
              reload(null);
          }
  
          if (offset >= kuromojiItemList.size() || offset < 0) {
              return new PagingList<>(Collections.<KuromojiItem> emptyList(), offset, size, kuromojiItemList.size());
          }
  
          int toIndex = offset + size;
          if (toIndex > kuromojiItemList.size()) {
              toIndex = kuromojiItemList.size();
          }
 
         return new PagingList<>(kuromojiItemList.subList(offset, toIndex), offset, size, kuromojiItemList.size());
     }
 
     @Override
     public synchronized void insert(final KuromojiItem item) {
         try (KuromojiUpdater updater = new KuromojiUpdater(item)) {
             reload(updater);
         }
     }
 
     @Override
     public synchronized void update(final KuromojiItem item) {
         try (KuromojiUpdater updater = new KuromojiUpdater(item)) {
             reload(updater);
         }
     }
 
     @Override
     public synchronized void delete(final KuromojiItem item) {
         final KuromojiItem kuromojiItem = item;
         kuromojiItem.setNewToken(StringUtil.EMPTY);
         try (KuromojiUpdater updater = new KuromojiUpdater(item)) {
             reload(updater);
         }
     }
 
     /**
      * Reloads the dictionary file.
      *
      * @param updater The updater.
      */
     protected void reload(final KuromojiUpdater updater) {
         try (CurlResponse curlResponse = dictionaryManager.getContentResponse(this)) {
             reload(updater, curlResponse.getContentAsStream());
         } catch (final IOException e) {
             throw new DictionaryException("Failed to parse " + path, e);
         }
     }
 
     /**
      * Reloads the dictionary file.
      *
      * @param updater The updater.
      * @param in The input stream.
      */
     protected void reload(final KuromojiUpdater updater, final InputStream in) {
         final List<KuromojiItem> itemList = new ArrayList<>();
         try (BufferedReader reader = new BufferedReader(new InputStreamReader(in, Constants.UTF_8))) {
             long id = 0;
             String line = null;
             while ((line = reader.readLine()) != null) {
                 // Remove comments
                 final String replacedLine = line.replaceAll("#.*$", StringUtil.EMPTY).trim();
 
                 // Skip empty lines or comment lines
                 if (replacedLine.length() == 0) {
                     if (updater != null) {
                         updater.write(line);
                     }
                     continue;
                 }
 
                 final String[] values = KuromojiCSVUtil.parse(replacedLine);
                 String token = null;
                 String segmentation = null;
                 String reading = null;
                 String pos = null;
                 switch (values.length) {
                 case 4:
                     pos = values[3];
                 case 3:
                     reading = values[2];
                 case 2:
                     segmentation = values[1];
                 case 1:
                     token = values[0];
                 default:
                     break;
                 }
 
                 id++;
                 final KuromojiItem item = new KuromojiItem(id, token, segmentation, reading, pos);
                 if (updater != null) {
                     final KuromojiItem newItem = updater.write(item);
                     if (newItem != null) {
                         itemList.add(newItem);
                     } else {
                         id--;
                     }
                 } else {
                     itemList.add(item);
                 }
             }
             if (updater != null) {
                 final KuromojiItem item = updater.commit();
                 if (item != null) {
                     itemList.add(item);
                 }
             }
             kuromojiItemList = itemList;
         } catch (final IOException e) {
             throw new DictionaryException("Failed to parse " + path, e);
         }
     }
 
     /**
      * Returns the simple name of the file.
      *
      * @return The simple name of the file.
      */
     public String getSimpleName() {
         return new File(path).getName();
     }
 
     /**
      * Updates the dictionary file with the given input stream.
      *
      * @param in The input stream.
      * @throws IOException If an I/O error occurs.
      */
     public synchronized void update(final InputStream in) throws IOException {
         try (KuromojiUpdater updater = new KuromojiUpdater(null)) {
             reload(updater, in);
         }
     }
 
     @Override
     public String toString() {
         return "KuromojiFile [path=" + path + ", kuromojiItemList=" + kuromojiItemList + ", id=" + id + "]";
     }
 
     /**
      * An updater for Kuromoji files.
      */
     protected class KuromojiUpdater implements Closeable {
 
         /** True if the changes have been committed. */
         protected boolean isCommit = false;
 
         /** The new file. */
         protected File newFile;
 
         /** The writer for the new file. */
         protected Writer writer;
 
         /** The item to be added or updated. */
         protected KuromojiItem item;
 
         /**
          * Constructs a new Kuromoji updater.
          *
          * @param newItem The new item to be added or updated.
          */
         protected KuromojiUpdater(final KuromojiItem newItem) {
             FileOutputStream fos = null;
             try {
                 newFile = ComponentUtil.getSystemHelper().createTempFile(KUROMOJI, ".txt");
                 fos = new FileOutputStream(newFile);
                 writer = new BufferedWriter(new OutputStreamWriter(fos, Constants.UTF_8));
                 fos = null; // Successfully wrapped, no need to close explicitly
             } catch (final Exception e) {
                 if (fos != null) {
                     try {
                         fos.close();
                     } catch (final IOException ioe) {
                         // Ignore close exception
                     }
                 }
                 if (newFile != null) {
                     newFile.delete();
                 }
                 throw new DictionaryException("Failed to write a userDict file.", e);
             }
             item = newItem;
         }
 
         /**
          * Writes the old item to the new file.
          *
          * @param oldItem The old item.
          * @return The new item if it was updated, otherwise the old item.
          */
         public KuromojiItem write(final KuromojiItem oldItem) {
             try {
                 if (item == null || item.getId() != oldItem.getId() || !item.isUpdated()) {
                     writer.write(oldItem.toLineString());
                     writer.write(Constants.LINE_SEPARATOR);
                     return oldItem;
                 }
                 if (!item.equals(oldItem)) {
                     throw new DictionaryException("Kuromoji file was updated: old=" + oldItem + " : new=" + item);
                 }
                 try {
                     if (!item.isDeleted()) {
                         // update
                         writer.write(item.toLineString());
                         writer.write(Constants.LINE_SEPARATOR);
                         return new KuromojiItem(item.getId(), item.getNewToken(), item.getNewSegmentation(), item.getNewReading(),
                                 item.getNewPos());
                     }
                     return null;
                 } finally {
                     item.setNewToken(null);
                 }
             } catch (final IOException e) {
                 throw new DictionaryException("Failed to write: " + oldItem + " -> " + item, e);
             }
         }
 
         /**
          * Writes a line to the new file.
          *
          * @param line The line to write.
          */
         public void write(final String line) {
             try {
                 writer.write(line);
                 writer.write(Constants.LINE_SEPARATOR);
             } catch (final IOException e) {
                 throw new DictionaryException("Failed to write: " + line, e);
             }
         }
 
         /**
          * Commits the changes.
          *
          * @return The new item if it was committed, otherwise null.
          */
         public KuromojiItem commit() {
             isCommit = true;
             if (item != null && item.isUpdated()) {
                 try {
                     writer.write(item.toLineString());
                     writer.write(Constants.LINE_SEPARATOR);
                     return item;
                 } catch (final IOException e) {
                     throw new DictionaryException("Failed to write: " + item, e);
                 }
             }
             return null;
         }
 
         @Override
         public void close() {
             try {
                 writer.flush();
             } catch (final IOException e) {
                 // ignore
             }
             CloseableUtil.closeQuietly(writer);
 
             if (isCommit) {
                 try {
                     dictionaryManager.store(KuromojiFile.this, newFile);
                 } finally {
                     newFile.delete();
                 }
             } else {
                 newFile.delete();
             }
         }
     }
 
 }