package com.atlassian.marketplace.client.api;
   
   import com.atlassian.fugue.Either;
   import com.atlassian.fugue.Option;
   
   import static com.atlassian.fugue.Option.some;
   
   /**
    * Encapsulates parameters that can be passed to {@link Applications#getVersion}.
   */
  public final class ApplicationVersionSpecifier
  {
      private final Option<Either<String, Integer>> nameOrBuild;
      
      private ApplicationVersionSpecifier(Option<Either<String, Integer>> nameOrBuild)
      {
          this.nameOrBuild = nameOrBuild;
      }
      
      /**
       * Searches for an application version by build number.
       */
      public static ApplicationVersionSpecifier buildNumber(int buildNumber)
      {
          return new ApplicationVersionSpecifier(some(Either.<String, Integer>right(buildNumber)));
      }
      
      /**
       * Searches for an application version by name (version string, e.g. "1.0.0").
       */
      public static ApplicationVersionSpecifier versionName(String name)
      {
          return new ApplicationVersionSpecifier(some(Either.<String, Integer>left(name))); 
      }
      
      /**
       * Searches for the latest version.
       */
      public static ApplicationVersionSpecifier latest()
      {
          return new ApplicationVersionSpecifier(Option.<Either<String, Integer>>none());
      }
      
      /**
       * Used internally to access the previously set details of the specifier.  
       */
      public Option<Either<String, Integer>> getSpecifiedVersion()
      {
          return nameOrBuild;
      }
      
      @Override
      public String toString()
      {
          for (Either<String, Integer> vob: nameOrBuild)
          {
              for (Integer b: vob.right())
              {
                  return "buildNumber(" + b + ")";
              }
              for (String n: vob.left())
              {
                  return "name(" + n + ")";
              }
          }
          return "latest";
      }
      
      @Override
      public boolean equals(Object other)
      {
          return (other instanceof ApplicationVersionSpecifier) && ((ApplicationVersionSpecifier) other).nameOrBuild.equals(this.nameOrBuild);
      }
      
      @Override
      public int hashCode()
      {
          return nameOrBuild.hashCode();
      }
  }