/*
    * 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.spi.config.domain.key;
  
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.lang.StringUtils;
  
  import de.smartics.properties.api.config.domain.key.ConfigurationKey;
  import de.smartics.util.lang.Arg;
  
  /**
   * Matches a path that may contain wildcards at the end of the path.
   */
  public final class PathMatcher implements PropertiesResourceMatcher
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * The class version identifier.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    private static final long serialVersionUID = 1L;
  
    // --- members --------------------------------------------------------------
  
    /**
     * The configuration key the matcher is responsible for.
     *
     * @serial
     */
    private final ConfigurationKey<?> configurationKey;
  
    /**
     * The list of matchers to consult in the given order.
     *
     * @serial
     */
    private final List<Matcher> matchers;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param configurationKey the configuration key the matcher is responsible
     *          for.
     * @param matchers the matchers to use for matching.
     */
    private PathMatcher(final ConfigurationKey<?> configurationKey,
        final List<Matcher> matchers)
    {
      this.configurationKey = configurationKey;
      this.matchers = matchers;
    }
  
    // ****************************** Inner Classes *****************************
  
    /**
     * Matcher of a single path.
     */
    public static final class Matcher implements Serializable
    {
      // ******************************** Fields ********************************
  
      // --- constants ----------------------------------------------------------
  
      /**
       * The class version identifier.
       * <p>
       * The value of this constant is {@value}.
       * </p>
       */
      private static final long serialVersionUID = 1L;
  
      // --- members ------------------------------------------------------------
  
      /**
      * The path to match.
      *
      * @serial
      */
     private final String path;
 
     /**
      * The flag to indicate whether {@code path} is a prefix to be match (
      * <code>true</code>) or if it is an exact match (<code>false</code>).
      *
      * @serial
      */
     private final boolean wildcardMatch;
 
     // ***************************** Initializer ******************************
 
     // ***************************** Constructors *****************************
 
     /**
      * Default constructor.
      *
      * @param path the path to match.
      */
     public Matcher(final String path)
     {
       this.wildcardMatch = Arg.checkNotNull("path", path).endsWith("*");
       this.path = wildcardMatch ? StringUtils.chop(path) : path;
     }
 
     // ***************************** Inner Classes ****************************
 
     // ******************************** Methods *******************************
 
     // --- init ---------------------------------------------------------------
 
     // --- get&set ------------------------------------------------------------
 
     // --- business -----------------------------------------------------------
 
     private boolean match(final String id)
     {
       final boolean match =
           wildcardMatch ? id.startsWith(path) : id.equals(path);
       return match;
     }
 
     // --- object basics ------------------------------------------------------
 
     /**
      * Returns the string representation of the object.
      *
      * @return the string representation of the object.
      */
     @Override
     public String toString()
     {
       final StringBuilder buffer = new StringBuilder();
 
       buffer.append(path);
 
       if (wildcardMatch)
       {
         buffer.append("*");
       }
 
       return buffer.toString();
     }
   }
 
   // ********************************* Methods ********************************
 
   // --- factories ------------------------------------------------------------
 
   /**
    * Constructs an instance based on the given paths.
    *
    * @param configurationKey the configuration key the matcher is responsible
    *          for.
    * @param paths the list of paths to match. A path may end with <code>*</code>
    *          signaling a wildcard match.
    * @return the constructed instance.
    */
   public static PathMatcher forPaths(
       final ConfigurationKey<?> configurationKey, final List<String> paths)
   {
     return forMatchers(configurationKey, convertToMatchers(paths));
   }
 
   /**
    * Constructs an instance based on the given matchers.
    *
    * @param configurationKey the configuration key the matcher is responsible
    *          for.
    * @param matchers the matchers to use for matching.
    * @return the constructed instance.
    */
   public static PathMatcher forMatchers(
       final ConfigurationKey<?> configurationKey, final List<Matcher> matchers)
   {
     return new PathMatcher(configurationKey, matchers);
   }
 
   // --- init -----------------------------------------------------------------
 
   private static List<Matcher> convertToMatchers(final List<String> paths)
   {
     final List<Matcher> matchers = new ArrayList<Matcher>(paths.size());
 
     for (final String path : paths)
     {
       final Matcher matcher = new Matcher(path);
       matchers.add(matcher);
     }
 
     return matchers;
   }
 
   // --- get&set --------------------------------------------------------------
 
   /**
    * Returns the configuration key the matcher is responsible for.
    *
    * @return the configuration key the matcher is responsible for.
    */
   @Override
   public ConfigurationKey<?> getConfigurationKey()
   {
     return configurationKey;
   }
 
   // --- business -------------------------------------------------------------
 
   @Override
   public boolean match(final String id)
   {
     for (final Matcher matcher : matchers)
     {
       final boolean match = matcher.match(id);
       if (match)
       {
         return true;
       }
     }
     return false;
   }
 
   // --- object basics --------------------------------------------------------
 
   /**
    * Returns the string representation of the object.
    *
    * @return the string representation of the object.
    */
   @Override
   public String toString()
   {
     final StringBuilder buffer = new StringBuilder();
 
     buffer.append(configurationKey).append(':');
 
     for (final Matcher matcher : matchers)
     {
       buffer.append(' ').append(matcher);
     }
 
     return buffer.toString();
   }
 }