/*
    * Copyright 2008-2013 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.maven.issues.util;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import org.apache.maven.artifact.versioning.ArtifactVersion;
  import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
  import org.apache.maven.artifact.versioning.Restriction;
  import org.apache.maven.artifact.versioning.VersionRange;
  import org.codehaus.plexus.util.StringUtils;
  
  /**
   * Utilities for this package.
   *
   * @author <a href="mailto:robert.reiner@smartics.de">Robert Reiner</a>
   * @version $Revision:591 $
   */
  public final class Utils
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    // --- members --------------------------------------------------------------
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Utility class pattern.
     */
    private Utils()
    {
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    // --- business -------------------------------------------------------------
  
    /**
     * Normalizes the key to an issue information to be a valid key element to
     * select a value in a resource bundle.
     *
     * @param key the key to normalize.
     * @return the normalized key.
     */
    public static String normalizeKey(final String key)
    {
      if (key == null || "".equals(key))
      {
        return key;
      }
  
      final char[] trimmed = key.trim().toCharArray();
      boolean uppercase = false;
      int currentPos = 0;
      for (int i = 0; i < trimmed.length; i++, currentPos++)
      {
        final char c = trimmed[i];
        if (Character.isWhitespace(c))
        {
          uppercase = true;
          --currentPos;
        }
        else if (uppercase)
        {
          trimmed[currentPos] = Character.toUpperCase(c);
          uppercase = false;
        }
        else
        {
          trimmed[currentPos] = c;
        }
      }
  
      return new String(trimmed).substring(0, currentPos);
   }
 
   /**
    * Splits a comma separated list of values from a {@link String} into a list
    * of {@link String}s.
    *
    * @param commaSeparatedValues the {@link String} value containing comma
    *          separated values. Blanks in front or after the items are trimmed.
    * @return the list of {@link String}s or the empty list if the given value
    *         was blank.
    */
   public static List<String> splitToList(final String commaSeparatedValues)
   {
     if (StringUtils.isNotBlank(commaSeparatedValues))
     {
       final String[] items = commaSeparatedValues.split(",");
       final List<String> list = new ArrayList<String>(items.length);
       for (String item : items)
       {
         list.add(item.trim());
       }
       return list;
     }
     else
     {
       return Collections.emptyList();
     }
   }
 
   /**
    * Returns a representative from within the version range.
    * <p>
    * It is expected that the restrictions are ordered by the version numbers
    * they define ascending.
    * </p>
    *
    * @param range the range of version where the lowest version is requested.
    * @return the version representative within the given range or a version
    *         instance representing <code>0.0.0</code> if the range has no lower
    *         bound.
    * @throws NullPointerException if the given <code>range</code> is
    *           <code>null</code>.
    * @throws IllegalArgumentException if no bound is inclusive and the upper
    *           bound is <code>null</code> and the lower bound is not
    *           <code>null</code>.
    */
   @SuppressWarnings("unchecked")
   public static ArtifactVersion findVersionRepresentative(
       final VersionRange range) throws NullPointerException,
     IllegalArgumentException
   {
     final List<Restriction> restrictions = range.getRestrictions();
     final ArtifactVersion currentLowerBound;
     final ArtifactVersion recommendedVersion = range.getRecommendedVersion();
     if (recommendedVersion != null)
     {
       currentLowerBound = recommendedVersion;
     }
     else if (!restrictions.isEmpty())
     {
       currentLowerBound = handleRestriction(restrictions);
     }
     else
     {
       currentLowerBound = new DefaultArtifactVersion("0.0.0");
     }
 
     return currentLowerBound;
   }
 
   /**
    * Handles restrictions for {@link #findVersionRepresentative(VersionRange)}.
    *
    * @param restrictions the restrictions to find a representative for.
    * @return the representative of the restrictions.
    * @throws IllegalArgumentException if no bound of the first restriction is
    *           inclusive and the upper bound is <code>null</code> and the lower
    *           bound is not <code>null</code>.
    */
   private static ArtifactVersion handleRestriction(
       final List<Restriction> restrictions) throws IllegalArgumentException
   {
     final ArtifactVersion currentLowerBound;
     final Restriction restriction = restrictions.get(0);
     final ArtifactVersion lowerBound = restriction.getLowerBound();
     if (lowerBound == null)
     {
       currentLowerBound = new DefaultArtifactVersion("0.0.0");
     }
     else if (restriction.isLowerBoundInclusive())
     {
       currentLowerBound = lowerBound;
     }
     else
     {
       currentLowerBound = handleUpperBound(restriction);
     }
     return currentLowerBound;
   }
 
   /**
    * Tries to find a version representative derived from the upper bound.
    *
    * @param restriction the restriction with the upper bound information.
    * @return the derived version representative.
    * @throws IllegalArgumentException if no bound of the first restriction is
    *           inclusive and the upper bound is <code>null</code> and the lower
    *           bound is not <code>null</code>.
    */
   private static ArtifactVersion handleUpperBound(final Restriction restriction)
     throws IllegalArgumentException
   {
     assert !restriction.isLowerBoundInclusive();
     final ArtifactVersion upperBound = restriction.getUpperBound();
     if (restriction.isUpperBoundInclusive() && upperBound != null)
     {
       return upperBound;
     }
     else
     {
       throw new IllegalArgumentException(
           "At least one bound is required to be inclusive and not 'null'.");
     }
   }
 
   // --- object basics --------------------------------------------------------
 
 }