/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The ASF licenses this file to You 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.apache.geode.internal.i18n;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.Locale;

import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;

import org.apache.geode.InternalGemFireException;
import org.apache.geode.i18n.StringId;
import org.apache.geode.internal.classloader.ClassPathLoader;


/**
 * Baseclass for all {@link StringId} based ResourceBundles
 *
 * @see java.util.ResourceBundle
 *
 * @since GemFire 5.7
 */
public class AbstractStringIdResourceBundle {
  private Int2ObjectOpenHashMap data;

  /**
   * Init method to populate the TIntObjectHashMap for Non-english locales
   * <code>data = new TIntObjectHashMap();</code>
   *
   * The default bundle, English, will be <code>data = null</code>
   */
  private void initData(String baseName, Locale l) {
    String resource = baseName + "_" + l.getLanguage() + ".txt";

    InputStream is = null;
    try {
      is = ClassPathLoader.getLatest().getResourceAsStream(getClass(), resource);
    } catch (SecurityException se) {
      // We do not have a logger yet
      System.err.println(
          "A SecurityException occurred while attempting to load the resource bundle, defaulting to English."
              + se);
      se.printStackTrace();
      System.err.flush();
    }
    if (is == null) {
      // No matching data file for the requested langauge,
      // defaulting to English
      data = null;
    } else {
      data = readDataFile(is);
    }
  }

  private Int2ObjectOpenHashMap readDataFile(InputStream is) {
    Int2ObjectOpenHashMap map = new Int2ObjectOpenHashMap();
    boolean complete = false;
    BufferedReader input = null;
    try {
      input = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8));
      String line = null;
      while ((line = input.readLine()) != null) {
        int equalSign = line.indexOf('=');
        String idAsString = line.substring(0, equalSign - 1).trim();
        // The +2 is because we need to skip the "= ", we dont use trim because some messages want
        // leading whitespace
        String message = line.substring(equalSign + 2).replaceAll("\\\\n", "\n");
        try {
          int id = Integer.parseInt(idAsString);
          map.put(id, message);
        } catch (NumberFormatException nfe) {
          // unit tests should prevent this from happening in a customer situation
          throw new InternalGemFireException(nfe);
        }
        complete = true;
      }
    } catch (IOException ioe) {
      // @TODO log this exception
    } finally {
      if (!complete) {
        // something went wrong, clean up and revert back to English
        try {
          if (input != null) {
            input.close();
          } else {
            is.close();
          }
        } catch (IOException ignore) {
        }
        // set map back to null so we default to English
        map = null;
      }
    }
    return map;
  }

  private AbstractStringIdResourceBundle() {
    // Intentionally blank
  }

  /**
   * @param key StringId passed for translation.
   * @return a String translated to the current {@link java.util.Locale}
   */
  public String getString(StringId key) {
    if (usingRawMode()) {
      return key.getRawText();
    }
    String txt = (String) data.get(key.id);
    if (txt != null) {
      return txt;
    } else {
      // found an untranslated message, use the English as a fall back
      return key.getRawText();
    }

  }

  /**
   * Returns true if this resource bundle will always return english strings.
   */
  public boolean usingRawMode() {
    return data == null;
  }

  public static AbstractStringIdResourceBundle getBundle(String baseName, Locale l) {
    AbstractStringIdResourceBundle newMessageBundle = new AbstractStringIdResourceBundle();
    newMessageBundle.initData(baseName, l);
    return newMessageBundle;
  }

}