/*
    * 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.protwords;
  
  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.dbflute.optional.OptionalEntity;
  
  /**
   * Dictionary file for protected words.
   * This class manages the reading, writing, and updating of protected words dictionary files.
   */
  public class ProtwordsFile extends DictionaryFile<ProtwordsItem> {
      private static final String PROTWORDS = "protwords";
  
      List<ProtwordsItem> protwordsItemList;
  
      /**
       * Constructor for ProtwordsFile.
       * @param id the file identifier
       * @param path the file path
       * @param timestamp the file timestamp
       */
      public ProtwordsFile(final String id, final String path, final Date timestamp) {
          super(id, path, timestamp);
      }
  
      @Override
      public String getType() {
          return PROTWORDS;
      }
  
      @Override
      public String getPath() {
          return path;
      }
  
      @Override
      public synchronized OptionalEntity<ProtwordsItem> get(final long id) {
          if (protwordsItemList == null) {
              reload(null);
          }
  
          for (final ProtwordsItem ProtwordsItem : protwordsItemList) {
              if (id == ProtwordsItem.getId()) {
                  return OptionalEntity.of(ProtwordsItem);
              }
          }
          return OptionalEntity.empty();
      }
  
      @Override
      public synchronized PagingList<ProtwordsItem> selectList(final int offset, final int size) {
          if (protwordsItemList == null) {
              reload(null);
          }
  
          if (offset >= protwordsItemList.size() || offset < 0) {
              return new PagingList<>(Collections.<ProtwordsItem> emptyList(), offset, size, protwordsItemList.size());
          }
  
          int toIndex = offset + size;
          if (toIndex > protwordsItemList.size()) {
              toIndex = protwordsItemList.size();
          }
  
         return new PagingList<>(protwordsItemList.subList(offset, toIndex), offset, size, protwordsItemList.size());
     }
 
     @Override
     public synchronized void insert(final ProtwordsItem item) {
         try (ProtwordsUpdater updater = new ProtwordsUpdater(item)) {
             reload(updater);
         }
     }
 
     @Override
     public synchronized void update(final ProtwordsItem item) {
         try (ProtwordsUpdater updater = new ProtwordsUpdater(item)) {
             reload(updater);
         }
     }
 
     @Override
     public synchronized void delete(final ProtwordsItem item) {
         final ProtwordsItem ProtwordsItem = item;
         ProtwordsItem.setNewInput(StringUtil.EMPTY);
         try (ProtwordsUpdater updater = new ProtwordsUpdater(item)) {
             reload(updater);
         }
     }
 
     /**
      * Reloads the dictionary file with the specified updater.
      * @param updater the updater to use for processing items
      */
     protected void reload(final ProtwordsUpdater 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 with the specified updater and input stream.
      * @param updater the updater to use for processing items
      * @param in the input stream containing the file content
      */
     protected void reload(final ProtwordsUpdater updater, final InputStream in) {
         final List<ProtwordsItem> 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) {
                 if (line.length() == 0 || line.charAt(0) == '#') {
                     if (updater != null) {
                         updater.write(line);
                     }
                     continue; // ignore empty lines and comments
                 }
 
                 final String inputStrings = line;
                 final String input = unescape(inputStrings);
 
                 if (input.length() > 0) {
                     id++;
                     final ProtwordsItem item = new ProtwordsItem(id, input);
                     if (updater != null) {
                         final ProtwordsItem newItem = updater.write(item);
                         if (newItem != null) {
                             itemList.add(newItem);
                         } else {
                             id--;
                         }
                     } else {
                         itemList.add(item);
                     }
                 }
             }
             if (updater != null) {
                 final ProtwordsItem item = updater.commit();
                 if (item != null) {
                     itemList.add(item);
                 }
             }
             protwordsItemList = itemList;
         } catch (final IOException e) {
             throw new DictionaryException("Failed to parse " + path, e);
         }
     }
 
     private String unescape(final String s) {
         if (s.indexOf('\\') >= 0) {
             final StringBuilder sb = new StringBuilder();
             for (int i = 0; i < s.length(); i++) {
                 final char ch = s.charAt(i);
                 if (ch == '\\' && i < s.length() - 1) {
                     i++;
                     sb.append(s.charAt(i));
                 } else {
                     sb.append(ch);
                 }
             }
             return sb.toString();
         }
         return s;
     }
 
     /**
      * Gets the simple name of this dictionary file.
      * @return the simple name of the file
      */
     public String getSimpleName() {
         return new File(path).getName();
     }
 
     /**
      * Updates the dictionary file with content from the input stream.
      * @param in the input stream containing the new content
      * @throws IOException if an I/O error occurs
      */
     public synchronized void update(final InputStream in) throws IOException {
         try (ProtwordsUpdater updater = new ProtwordsUpdater(null)) {
             reload(updater, in);
         }
     }
 
     @Override
     public String toString() {
         return "ProtwordsFile [path=" + path + ", protwordsItemList=" + protwordsItemList + ", id=" + id + "]";
     }
 
     /**
      * Updater class for processing protwords items during dictionary updates.
      * This class handles the writing and committing of changes to the dictionary file.
      */
     protected class ProtwordsUpdater implements Closeable {
 
         /** Flag indicating if the update should be committed */
         protected boolean isCommit = false;
 
         /** Temporary file for storing updates */
         protected File newFile;
 
         /** Writer for writing to the temporary file */
         protected Writer writer;
 
         /** The item being updated */
         protected ProtwordsItem item;
 
         /**
          * Constructor for ProtwordsUpdater.
          * @param newItem the item to be updated
          */
         protected ProtwordsUpdater(final ProtwordsItem newItem) {
             FileOutputStream fos = null;
             try {
                 newFile = ComponentUtil.getSystemHelper().createTempFile(PROTWORDS, ".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 a protwords item to the temporary file.
          * @param oldItem the item to write
          * @return the written item or null if deleted
          */
         public ProtwordsItem write(final ProtwordsItem 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("Protwords file was updated: old=" + oldItem + " : new=" + item);
                 }
                 try {
                     if (!item.isDeleted()) {
                         // update
                         writer.write(item.toLineString());
                         writer.write(Constants.LINE_SEPARATOR);
                         return new ProtwordsItem(item.getId(), item.getNewInput());
                     }
                     return null;
                 } finally {
                     item.setNewInput(null);
                 }
             } catch (final IOException e) {
                 throw new DictionaryException("Failed to write: " + oldItem + " -> " + item, e);
             }
         }
 
         /**
          * Writes a string line to the temporary 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 current item to the temporary file.
          * @return the committed item or null if no item to commit
          */
         public ProtwordsItem 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(ProtwordsFile.this, newFile);
                 } finally {
                     newFile.delete();
                 }
             } else {
                 newFile.delete();
             }
         }
     }
 }