/*
 * Copyright (C) 2010 ZXing authors
 *
 * 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.
 */

/*
 * These authors would like to acknowledge the Spanish Ministry of Industry,
 * Tourism and Trade, for the support in the project TSI020301-2008-2
 * "PIRAmIDE: Personalizable Interactions with Resources on AmI-enabled
 * Mobile Dynamic Environments", led by Treelogic
 * ( http://www.treelogic.com/ ):
 *
 *   http://www.piramidepse.com/
 */

using System;

namespace ZXing.OneD.RSS.Expanded
{
   /// <summary>
   /// <author>Pablo Orduña, University of Deusto (pablo.orduna@deusto.es)</author>
   /// </summary>
   internal sealed class ExpandedPair
   {
      internal bool MayBeLast { get; private set; }
      internal DataCharacter LeftChar { get; private set; }
      internal DataCharacter RightChar { get; private set; }
      internal FinderPattern FinderPattern { get; private set; }

      internal ExpandedPair(DataCharacter leftChar,
                   DataCharacter rightChar,
                   FinderPattern finderPattern,
                   bool mayBeLast)
      {
         LeftChar = leftChar;
         RightChar = rightChar;
         FinderPattern = finderPattern;
         MayBeLast = mayBeLast;
      }

      public bool MustBeLast
      {
         get { return RightChar == null; }
      }

      override public String ToString()
      {
         return
             "[ " + LeftChar + " , " + RightChar + " : " +
             (FinderPattern == null ? "null" : FinderPattern.Value.ToString()) + " ]";
      }

      override public bool Equals(Object o)
      {
         if (!(o is ExpandedPair))
         {
            return false;
         }
         ExpandedPair that = (ExpandedPair)o;
         return
             EqualsOrNull(LeftChar, that.LeftChar) &&
             EqualsOrNull(RightChar, that.RightChar) &&
             EqualsOrNull(FinderPattern, that.FinderPattern);
      }

      private static bool EqualsOrNull(Object o1, Object o2)
      {
         return o1 == null ? o2 == null : o1.Equals(o2);
      }

      override public int GetHashCode()
      {
         return hashNotNull(LeftChar) ^ hashNotNull(RightChar) ^ hashNotNull(FinderPattern);
      }

      private static int hashNotNull(Object o)
      {
         return o == null ? 0 : o.GetHashCode();
      }
   }
}