/*

  * 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));

     }

   }

 }