/*
    * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.properties.api.config.domain.key;
  
  import java.io.Serializable;
  
  import static org.apache.commons.lang.StringUtils.defaultIfBlank;
  import org.apache.commons.lang.ObjectUtils;
  
  import de.smartics.util.lang.Arg;
  
  /**
   * Defines an environment an application is deployed to.
   */
  public final class EnvironmentId implements Serializable,
      Comparable<EnvironmentId>
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * The class version identifier.
     */
    private static final long serialVersionUID = 1L;
  
    /**
     * Defines the application for any environment.
     */
    public static final EnvironmentId ANY_ENV = new EnvironmentId(null, null);
  
    // --- members --------------------------------------------------------------
  
    /**
     * The name of the environment.
     *
     * @serial
     */
    private final String name;
  
    /**
     * The optional identifier of the node within the given environment.
     *
     * @serial
     */
    private final String node;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Convenience constructor without a node.
     *
     * @param name the name of the environment.
     * @throws IllegalArgumentException if {@code name} is the empty string or
     *           contains only white spaces.
     */
    public EnvironmentId(final String name) throws IllegalArgumentException
    {
      this(name, null);
    }
  
    /**
     * Default constructor.
     *
     * @param name the name of the environment.
     * @param node the optional identifier of the node within the given
     *          environment.
     * @throws IllegalArgumentException if {@code name} or {@code node} is the
     *           empty string or contains only white spaces.
     */
    public EnvironmentId(final String name, final String node)
      throws IllegalArgumentException
    {
      this.name = Arg.checkNotBlankExceptNull("name", name);
      this.node = Arg.checkNotBlankExceptNull("node", node);
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
 
   /**
    * Returns the name of the environment.
    *
    * @return the name of the environment.
    */
   public String getName()
   {
     return name;
   }
 
   /**
    * Returns the optional identifier of the node within the given environment.
    *
    * @return the optional identifier of the node within the given environment.
    */
   public String getNode()
   {
     return node;
   }
 
   // --- business -------------------------------------------------------------
 
   // --- object basics --------------------------------------------------------
 
   /**
    * Returns the hash code of the object.
    *
    * @return the hash code.
    */
   @Override
   public int hashCode()
   {
     int result = 17;
     result = 37 * result + ObjectUtils.hashCode(name);
     result = 37 * result + ObjectUtils.hashCode(node);
     return result;
   }
 
   /**
    * Returns <code>true</code> if the given object is semantically equal to the
    * given object, <code>false</code> otherwise.
    *
    * @param object the instance to compare to.
    * @return <code>true</code> if the given object is semantically equal to the
    *         given object, <code>false</code> otherwise.
    */
   @Override
   public boolean equals(final Object object)
   {
     if (this == object)
     {
       return true;
     }
     else if (object == null || getClass() != object.getClass())
     {
       return false;
     }
 
     final EnvironmentId other = (EnvironmentId) object;
 
     return (ObjectUtils.equals(name, other.name) && ObjectUtils.equals(node,
         other.node));
   }
 
   /**
    * {@inheritDoc}
    *
    * @see java.lang.Comparable#compareTo(java.lang.Object)
    */
   @Override
   public int compareTo(final EnvironmentId o)
   {
     int result = ObjectUtils.compare(name, o.name);
     if (result == 0)
     {
       result = ObjectUtils.compare(node, o.node);
     }
 
     return result;
   }
 
   /**
    * Returns the string representation of the object as a path. All elements are
    * separated by a slash.
    *
    * @return the string representation of the object.
    */
   public String toPath()
   {
     return ObjectUtils.toString(name, "") + '/'
            + ObjectUtils.toString(node, "");
   }
 
   /**
    * Returns the string representation of the object.
    *
    * @return the string representation of the object.
    */
   @Override
   public String toString()
   {
     return ObjectUtils.toString(name, "") + ':'
            + ObjectUtils.toString(node, "");
   }
 
   /**
    * Returns an {@link EnvironmentId} for the given String or throws an
    * {@link IllegalArgumentException} if the String is not valid.
    *
    * @param environmentString a string describing an environment.
    * @return an envrironmentId for the given String.
    * @throws IllegalArgumentException if an invalid environmentString has been
    *           passed.
    */
   public static EnvironmentId valueOf(final String environmentString)
     throws IllegalArgumentException
   {
     if (environmentString == null)
     {
       return new EnvironmentId(null);
     }
     final String[] environmentParts = environmentString.split(":", -1);
     final int length = environmentParts.length;
     if (length == 1)
     {
       return new EnvironmentId(environmentParts[0]);
     }
     else if (length == 2)
     {
       return new EnvironmentId(defaultIfBlank(environmentParts[0], null),
           defaultIfBlank(environmentParts[1], null));
     }
     else
     {
       throw new IllegalArgumentException(
           String
               .format(
                   "Could not create an instance out of the key %s. It has too many delimiters!",
                   environmentString));
     }
   }
 }