/*
    * 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.renderkit;
  
  import org.apache.myfaces.tobago.component.ClientBehaviors;
  
  import javax.faces.context.FacesContext;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Map of commands to be send to the user agent.
   * It contains the command which shall be executed by click or other events.
   *
   * @since 2.0.0
   */
  public class CommandMap {
  
    private static final String KEY = CommandMap.class.getName() + ".KEY";
  
    private Command click;
    private Map<ClientBehaviors, Command> other;
  
    /**
     * Creates an empty command map, which may hold different command triggered by different keys.
     */
    public CommandMap() {
    }
  
    /**
     * Creates a command map, which hold the given command triggered by "click".
     */
    public CommandMap(final Command click) {
      this.click = click;
    }
  
    public void setClick(final Command click) {
      this.click = click;
    }
  
    public Command getClick() {
      return click;
    }
  
    public void addCommand(final ClientBehaviors name, final Command command) {
      if (name == ClientBehaviors.click) {
        setClick(command);
      } else {
        if (other == null) {
          other = new HashMap<>();
        }
  
        other.put(name, command);
      }
    }
  
    public Map<ClientBehaviors, Command> getOther() {
      if (other != null) {
        return Collections.unmodifiableMap(other);
      } else {
        return null;
      }
    }
  
    /**
     * Merges these two maps.
     * If one is null, the other one will be return. It may also return null.
     * If both are not null, m1 will be filled with the data of m2.
     * @param m1 map 1
     * @param m2 map 2
     * @return m1 or m2
     */
    public static CommandMap merge(final CommandMap m1, final CommandMap m2) {
      if (m1 == null) {
        return m2;
      } else {
        if (m2 == null) {
          return m1;
        } else {
          final Command c2 = m2.getClick();
          if (c2 != null) {
           final Command c1 = m1.getClick();
           if (c1 == null) {
             m1.setClick(c2);
           } else {
             c1.merge(c2);
           }
         } else {
           if (m1.other != null && m2.getOther() != null) {
             for (final Map.Entry<ClientBehaviors, Command> entry : m2.getOther().entrySet()) {
               final ClientBehaviors key = entry.getKey();
               final Command value = entry.getValue();
               if (m1.other.containsKey(key)) {
                 final Command command = m1.other.get(key);
                 command.merge(value);
               } else {
                 m1.addCommand(key, value);
               }
             }
           }
         }
         return m1;
       }
     }
   }
 
   public static CommandMap restoreCommandMap(final FacesContext facesContext) {
     return (CommandMap) facesContext.getAttributes().get(KEY);
   }
 
   public static void storeCommandMap(final FacesContext facesContext, final CommandMap map) {
     facesContext.getAttributes().put(KEY, map);
   }
 
   public boolean isEmpty() {
     return click == null && other == null;
   }
 }