/*************************************************************************
 * Copyright 2009-2012 Eucalyptus Systems, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/.
 *
 * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
 * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need
 * additional information or have any questions.
 ************************************************************************/
package com.eucalyptus.util;

import static org.hamcrest.CoreMatchers.notNullValue;
import static org.hamcrest.Matchers.not;
import static org.hamcrest.text.IsEmptyString.isEmptyOrNullString;
import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.StringDescription;

/**
 *
 */
public class Parameters {

  public static <T> T checkParam( final T value,
                                  final Matcher<? super T> matcher ) {
    return checkParam( "", value, matcher );
  }

  public static <T> T checkParam( final String reason,
                                  final T value,
                                  final Matcher<? super T> matcher ) {
    if ( !matcher.matches( value ) ) {
      final Description description = new StringDescription();
      description.appendText( reason )
          .appendText( "\nExpected: " )
          .appendDescriptionOf( matcher )
          .appendText( "\n     but: " );
      matcher.describeMismatch( value, description );

      throw new IllegalArgumentException( description.toString() );
    }

    return value;
  }

  public static <T> T checkParamNotNull( final String reason,
                                         final T value ) {
    return checkParam( reason, value, notNullValue( ) );
  }

  public static String checkParamNotNullOrEmpty( final String reason,
                                                 final String value ) {
    return checkParam( reason, value, not( isEmptyOrNullString( ) ) );
  }
}