/*
    * 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.myfaces.tobago.internal.util;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.faces.context.FacesContext;
  import java.lang.invoke.MethodHandles;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * This class is for debugging the access keys.
   */
  public final class AccessKeyLogger extends HashMap<Character, List<String>> {
  
    private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  
    private static final char[] KEYS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
        'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
  
    private AccessKeyLogger() {
    }
  
    private static AccessKeyLogger getInstance(final FacesContext facesContext) {
      final Map<String, Object> requestMap = facesContext.getExternalContext().getRequestMap();
      AccessKeyLogger keyMap = (AccessKeyLogger) requestMap.get(AccessKeyLogger.class.getName());
      if (keyMap == null) {
        keyMap = new AccessKeyLogger();
        requestMap.put(AccessKeyLogger.class.getName(), keyMap);
      }
      return keyMap;
    }
  
    public static void addAccessKey(final FacesContext facesContext, final Character key, final String clientId) {
      if (LOG.isDebugEnabled()) {
        final AccessKeyLogger instance = getInstance(facesContext);
        final List<String> clientIds;
        if (instance.containsKey(key)) {
          clientIds = instance.get(key);
        } else {
          clientIds = new ArrayList<>();
          instance.put(key, clientIds);
        }
        clientIds.add(clientId);
        // should only be called, when debug is enabled
        LOG.debug("Using accessKey='{}' for clientId='{}'", key, clientId);
      }
    }
  
    public static void logStatus(final FacesContext facesContext) {
      if (LOG.isDebugEnabled()) {
        final StringBuilder builder = new StringBuilder();
        final AccessKeyLogger instance = AccessKeyLogger.getInstance(facesContext);
        builder.append("Used access keys:");
        for (final Map.Entry<Character, List<String>> entry : instance.entrySet()) {
          builder.append("\n'");
          builder.append(entry.getKey());
          builder.append("' -> ");
          builder.append(entry.getValue());
        }
        builder.append("\nFree access keys: ");
        for (final char key : KEYS) {
          builder.append(instance.containsKey(Character.valueOf(key)) ? '.' : key);
        }
        LOG.debug(builder.toString());
      }
    }
  }