package org.eclipse.aether.util.version;
   
   /*
    * 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.
   */
  
  import org.eclipse.aether.version.InvalidVersionSpecificationException;
  import org.eclipse.aether.version.Version;
  import org.eclipse.aether.version.VersionRange;
  
  /**
   * A version range inspired by mathematical range syntax. For example, "[1.0,2.0)", "[1.0,)" or "[1.0]".
   */
  final class GenericVersionRange
      implements VersionRange
  {
  
      private final Bound lowerBound;
  
      private final Bound upperBound;
  
      /**
       * Creates a version range from the specified range specification.
       * 
       * @param range The range specification to parse, must not be {@code null}.
       * @throws InvalidVersionSpecificationException If the range could not be parsed.
       */
      GenericVersionRange( String range )
          throws InvalidVersionSpecificationException
      {
          String process = range;
  
          boolean lowerBoundInclusive, upperBoundInclusive;
          Version lowerBound, upperBound;
  
          if ( range.startsWith( "[" ) )
          {
              lowerBoundInclusive = true;
          }
          else if ( range.startsWith( "(" ) )
          {
              lowerBoundInclusive = false;
          }
          else
          {
              throw new InvalidVersionSpecificationException( range, "Invalid version range " + range
                  + ", a range must start with either [ or (" );
          }
  
          if ( range.endsWith( "]" ) )
          {
              upperBoundInclusive = true;
          }
          else if ( range.endsWith( ")" ) )
          {
              upperBoundInclusive = false;
          }
          else
          {
              throw new InvalidVersionSpecificationException( range, "Invalid version range " + range
                  + ", a range must end with either [ or (" );
          }
  
          process = process.substring( 1, process.length() - 1 );
  
          int index = process.indexOf( "," );
  
          if ( index < 0 )
          {
              if ( !lowerBoundInclusive || !upperBoundInclusive )
              {
                  throw new InvalidVersionSpecificationException( range, "Invalid version range " + range
                      + ", single version must be surrounded by []" );
              }
  
              String version = process.trim();
              if ( version.endsWith( ".*" ) )
              {
                  String prefix = version.substring( 0, version.length() - 1 );
                  lowerBound = parse( prefix + "min" );
                  upperBound = parse( prefix + "max" );
              }
              else
              {
                 lowerBound = upperBound = parse( version );
             }
         }
         else
         {
             String parsedLowerBound = process.substring( 0, index ).trim();
             String parsedUpperBound = process.substring( index + 1 ).trim();
 
             // more than two bounds, e.g. (1,2,3)
             if ( parsedUpperBound.contains( "," ) )
             {
                 throw new InvalidVersionSpecificationException( range, "Invalid version range " + range
                     + ", bounds may not contain additional ','" );
             }
 
             lowerBound = parsedLowerBound.length() > 0 ? parse( parsedLowerBound ) : null;
             upperBound = parsedUpperBound.length() > 0 ? parse( parsedUpperBound ) : null;
 
             if ( upperBound != null && lowerBound != null )
             {
                 if ( upperBound.compareTo( lowerBound ) < 0 )
                 {
                     throw new InvalidVersionSpecificationException( range, "Invalid version range " + range
                         + ", lower bound must not be greater than upper bound" );
                 }
             }
         }
 
         this.lowerBound = ( lowerBound != null ) ? new Bound( lowerBound, lowerBoundInclusive ) : null;
         this.upperBound = ( upperBound != null ) ? new Bound( upperBound, upperBoundInclusive ) : null;
     }
 
     private Version parse( String version )
     {
         return new GenericVersion( version );
     }
 
     public Bound getLowerBound()
     {
         return lowerBound;
     }
 
     public Bound getUpperBound()
     {
         return upperBound;
     }
 
     public boolean containsVersion( Version version )
     {
         if ( lowerBound != null )
         {
             int comparison = lowerBound.getVersion().compareTo( version );
 
             if ( comparison == 0 && !lowerBound.isInclusive() )
             {
                 return false;
             }
             if ( comparison > 0 )
             {
                 return false;
             }
         }
 
         if ( upperBound != null )
         {
             int comparison = upperBound.getVersion().compareTo( version );
 
             if ( comparison == 0 && !upperBound.isInclusive() )
             {
                 return false;
             }
             if ( comparison < 0 )
             {
                 return false;
             }
         }
 
         return true;
     }
 
     @Override
     public boolean equals( Object obj )
     {
         if ( obj == this )
         {
             return true;
         }
         else if ( obj == null || !getClass().equals( obj.getClass() ) )
         {
             return false;
         }
 
         GenericVersionRange that = (GenericVersionRange) obj;
 
         return eq( upperBound, that.upperBound ) && eq( lowerBound, that.lowerBound );
     }
 
     private static <T> boolean eq( T s1, T s2 )
     {
         return s1 != null ? s1.equals( s2 ) : s2 == null;
     }
 
     @Override
     public int hashCode()
     {
         int hash = 17;
         hash = hash * 31 + hash( upperBound );
         hash = hash * 31 + hash( lowerBound );
         return hash;
     }
 
     private static int hash( Object obj )
     {
         return obj != null ? obj.hashCode() : 0;
     }
 
     @Override
     public String toString()
     {
         StringBuilder buffer = new StringBuilder( 64 );
         if ( lowerBound != null )
         {
             buffer.append( lowerBound.isInclusive() ? '[' : '(' );
             buffer.append( lowerBound.getVersion() );
         }
         else
         {
             buffer.append( '(' );
         }
         buffer.append( ',' );
         if ( upperBound != null )
         {
             buffer.append( upperBound.getVersion() );
             buffer.append( upperBound.isInclusive() ? ']' : ')' );
         }
         else
         {
             buffer.append( ')' );
         }
         return buffer.toString();
     }
 
 }