/*
    * Grapht, an open source dependency injector.
    * Copyright 2014-2015 various contributors (see CONTRIBUTORS.txt)
    * Copyright 2010-2014 Regents of the University of Minnesota
    *
    * This program is free software; you can redistribute it and/or modify
    * it under the terms of the GNU Lesser General Public License as
    * published by the Free Software Foundation; either version 2.1 of the
    * License, or (at your option) any later version.
   *
   * 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, write to the Free Software Foundation, Inc., 51
   * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   */
  package org.grouplens.grapht.util;
  
  import org.grouplens.grapht.InjectionException;
  import org.grouplens.grapht.InvalidBindingException;
  import org.grouplens.grapht.reflect.Qualifiers;
  
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Modifier;
  
  /**
   * Utility to organize checks for common assertions, and to throw
   * appropriately worded exceptions on failure.
   * 
   * @author <a href="http://grouplens.org">GroupLens Research</a>
   */
  public final class Preconditions {
      private Preconditions() { }
  
      @SuppressWarnings("unchecked")
      public static void isQualifier(Class<?> type) {
          if (!Annotation.class.isAssignableFrom(type)) {
              throw new InvalidBindingException(type, "Type is not an Annotation");
          }
          if (!Qualifiers.isQualifier((Class<? extends Annotation>) type)) {
              throw new InvalidBindingException(type, "Annotation is not annotated with @Qualifier");
          }
      }
      
      public static void isAssignable(Class<?> source, Class<?> impl) {
          if (!source.isAssignableFrom(impl)) {
              throw new InvalidBindingException(impl, "Type is not assignable to " + source);
          }
      }
  
      public static void notNull(String name, Object value) {
          if (value == null) {
              throw new NullPointerException(name + " cannot be null");
          }
      }
      
      public static void inRange(int value, int min, int max) {
          if (value < min || value >= max) {
              throw new IndexOutOfBoundsException(value + " must be in [" + min + ", " + max + ")");
          }
      }
  }