/*
    * 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.
   */
  package org.apache.commons.collections;
  
  import java.util.Collection;
  
  import org.apache.commons.collections.functors.AllPredicate;
  import org.apache.commons.collections.functors.AndPredicate;
  import org.apache.commons.collections.functors.AnyPredicate;
  import org.apache.commons.collections.functors.EqualPredicate;
  import org.apache.commons.collections.functors.ExceptionPredicate;
  import org.apache.commons.collections.functors.FalsePredicate;
  import org.apache.commons.collections.functors.IdentityPredicate;
  import org.apache.commons.collections.functors.InstanceofPredicate;
  import org.apache.commons.collections.functors.InvokerTransformer;
  import org.apache.commons.collections.functors.NonePredicate;
  import org.apache.commons.collections.functors.NotNullPredicate;
  import org.apache.commons.collections.functors.NotPredicate;
  import org.apache.commons.collections.functors.NullIsExceptionPredicate;
  import org.apache.commons.collections.functors.NullIsFalsePredicate;
  import org.apache.commons.collections.functors.NullIsTruePredicate;
  import org.apache.commons.collections.functors.NullPredicate;
  import org.apache.commons.collections.functors.OnePredicate;
  import org.apache.commons.collections.functors.OrPredicate;
  import org.apache.commons.collections.functors.TransformedPredicate;
  import org.apache.commons.collections.functors.TransformerPredicate;
  import org.apache.commons.collections.functors.TruePredicate;
  import org.apache.commons.collections.functors.UniquePredicate;
  
  /**
   * <code>PredicateUtils</code> provides reference implementations and utilities
   * for the Predicate functor interface. The supplied predicates are:
   * <ul>
   * <li>Invoker - returns the result of a method call on the input object
   * <li>InstanceOf - true if the object is an instanceof a class
   * <li>Equal - true if the object equals() a specified object
   * <li>Identity - true if the object == a specified object
   * <li>Null - true if the object is null
   * <li>NotNull - true if the object is not null
   * <li>Unique - true if the object has not already been evaluated
   * <li>And/All - true if all of the predicates are true
   * <li>Or/Any - true if any of the predicates is true
   * <li>Either/One - true if only one of the predicate is true
   * <li>Neither/None - true if none of the predicates are true
   * <li>Not - true if the predicate is false, and vice versa
   * <li>Transformer - wraps a Transformer as a Predicate
   * <li>True - always return true
   * <li>False - always return false
   * <li>Exception - always throws an exception
   * <li>NullIsException/NullIsFalse/NullIsTrue - check for null input
   * <li>Transformed - transforms the input before calling the predicate
   * </ul>
   * All the supplied predicates are Serializable.
   *
   * @since 3.0
   * @version $Id: PredicateUtils.java 1436345 2013-01-21 13:49:53Z tn $
   */
  public class PredicateUtils {
  
      /**
       * This class is not normally instantiated.
       */
      public PredicateUtils() {
          super();
      }
  
      // Simple predicates
      //-----------------------------------------------------------------------------
  
      /**
       * Gets a Predicate that always throws an exception.
       * This could be useful during testing as a placeholder.
       *
       * @param <T>  the type that the predicate queries
       * @return the predicate
       * @see org.apache.commons.collections.functors.ExceptionPredicate
       */
      public static <T> Predicate<T> exceptionPredicate() {
          return ExceptionPredicate.<T>exceptionPredicate();
      }
  
      /**
       * Gets a Predicate that always returns true.
       *
       * @param <T>  the type that the predicate queries
      * @return the predicate
      * @see org.apache.commons.collections.functors.TruePredicate
      */
     public static <T> Predicate<T> truePredicate() {
         return TruePredicate.truePredicate();
     }
 
     /**
      * Gets a Predicate that always returns false.
      *
      * @param <T>  the type that the predicate queries
      * @return the predicate
      * @see org.apache.commons.collections.functors.FalsePredicate
      */
     public static <T> Predicate<T> falsePredicate() {
         return FalsePredicate.<T> falsePredicate();
     }
 
     /**
      * Gets a Predicate that checks if the input object passed in is null.
      *
      * @param <T>  the type that the predicate queries
      * @return the predicate
      * @see org.apache.commons.collections.functors.NullPredicate
      */
     public static <T> Predicate<T> nullPredicate() {
         return NullPredicate.nullPredicate();
     }
 
     /**
      * Gets a Predicate that checks if the input object passed in is not null.
      *
      * @param <T>  the type that the predicate queries
      * @return the predicate
      * @see org.apache.commons.collections.functors.NotNullPredicate
      */
     public static <T> Predicate<T> notNullPredicate() {
         return NotNullPredicate.<T>notNullPredicate();
     }
 
     /**
      * Creates a Predicate that checks if the input object is equal to the
      * specified object using equals().
      *
      * @param <T>  the type that the predicate queries
      * @param value  the value to compare against
      * @return the predicate
      * @see org.apache.commons.collections.functors.EqualPredicate
      */
     public static <T> Predicate<T> equalPredicate(final T value) {
         return EqualPredicate.equalPredicate(value);
     }
 
     /**
      * Creates a Predicate that checks if the input object is equal to the
      * specified object by identity.
      *
      * @param <T>  the type that the predicate queries
      * @param value  the value to compare against
      * @return the predicate
      * @see org.apache.commons.collections.functors.IdentityPredicate
      */
     public static <T> Predicate<T> identityPredicate(final T value) {
         return IdentityPredicate.<T>identityPredicate(value);
     }
 
     /**
      * Creates a Predicate that checks if the object passed in is of
      * a particular type, using instanceof. A <code>null</code> input
      * object will return <code>false</code>.
      *
      * @param type  the type to check for, may not be null
      * @return the predicate
      * @throws IllegalArgumentException if the class is null
      * @see org.apache.commons.collections.functors.InstanceofPredicate
      */
     public static Predicate<Object> instanceofPredicate(final Class<?> type) {
         return InstanceofPredicate.instanceOfPredicate(type);
     }
 
     /**
      * Creates a Predicate that returns true the first time an object is
      * encountered, and false if the same object is received
      * again. The comparison is by equals(). A <code>null</code> input object
      * is accepted and will return true the first time, and false subsequently
      * as well.
      *
      * @param <T>  the type that the predicate queries
      * @return the predicate
      * @see org.apache.commons.collections.functors.UniquePredicate
      */
     public static <T> Predicate<T> uniquePredicate() {
         // must return new instance each time
         return UniquePredicate.<T>uniquePredicate();
     }
 
     /**
      * Creates a Predicate that invokes a method on the input object.
      * The method must return either a boolean or a non-null Boolean,
      * and have no parameters. If the input object is null, a
      * PredicateException is thrown.
      * <p>
      * For example, <code>PredicateUtils.invokerPredicate("isEmpty");</code>
      * will call the <code>isEmpty</code> method on the input object to
      * determine the predicate result.
      *
      * @param <T>  the type that the predicate queries
      * @param methodName  the method name to call on the input object, may not be null
      * @return the predicate
      * @throws IllegalArgumentException if the methodName is null.
      * @see org.apache.commons.collections.functors.InvokerTransformer
      * @see org.apache.commons.collections.functors.TransformerPredicate
      */
     public static <T> Predicate<T> invokerPredicate(final String methodName) {
         // reuse transformer as it has caching - this is lazy really, should have inner class here
         return asPredicate(InvokerTransformer.<Object, Boolean>invokerTransformer(methodName));
     }
 
     /**
      * Creates a Predicate that invokes a method on the input object.
      * The method must return either a boolean or a non-null Boolean,
      * and have no parameters. If the input object is null, a
      * PredicateException is thrown.
      * <p>
      * For example, <code>PredicateUtils.invokerPredicate("isEmpty");</code>
      * will call the <code>isEmpty</code> method on the input object to
      * determine the predicate result.
      *
      * @param <T>  the type that the predicate queries
      * @param methodName  the method name to call on the input object, may not be null
      * @param paramTypes  the parameter types
      * @param args  the arguments
      * @return the predicate
      * @throws IllegalArgumentException if the method name is null
      * @throws IllegalArgumentException if the paramTypes and args don't match
      * @see org.apache.commons.collections.functors.InvokerTransformer
      * @see org.apache.commons.collections.functors.TransformerPredicate
      */
     public static <T> Predicate<T> invokerPredicate(final String methodName, final Class<?>[] paramTypes,
                                                     final Object[] args) {
         // reuse transformer as it has caching - this is lazy really, should have inner class here
         return asPredicate(InvokerTransformer.<Object, Boolean>invokerTransformer(methodName, paramTypes, args));
     }
 
     // Boolean combinations
     //-----------------------------------------------------------------------------
 
     /**
      * Create a new Predicate that returns true only if both of the specified
      * predicates are true.
      *
      * @param <T>  the type that the predicate queries
      * @param predicate1  the first predicate, may not be null
      * @param predicate2  the second predicate, may not be null
      * @return the <code>and</code> predicate
      * @throws IllegalArgumentException if either predicate is null
      * @see org.apache.commons.collections.functors.AndPredicate
      */
     public static <T> Predicate<T> andPredicate(final Predicate<? super T> predicate1,
                                                 final Predicate<? super T> predicate2) {
         return AndPredicate.<T>andPredicate(predicate1, predicate2);
     }
 
     /**
      * Create a new Predicate that returns true only if all of the specified
      * predicates are true.
      * If the array of predicates is empty, then this predicate returns true.
      *
      * @param <T>  the type that the predicate queries
      * @param predicates  an array of predicates to check, may not be null
      * @return the <code>all</code> predicate
      * @throws IllegalArgumentException if the predicates array is null
      * @throws IllegalArgumentException if any predicate in the array is null
      * @see org.apache.commons.collections.functors.AllPredicate
      */
     public static <T> Predicate<T> allPredicate(final Predicate<? super T>... predicates) {
         return AllPredicate.allPredicate(predicates);
     }
 
     /**
      * Create a new Predicate that returns true only if all of the specified
      * predicates are true. The predicates are checked in iterator order.
      * If the collection of predicates is empty, then this predicate returns true.
      *
      * @param <T>  the type that the predicate queries
      * @param predicates  a collection of predicates to check, may not be null
      * @return the <code>all</code> predicate
      * @throws IllegalArgumentException if the predicates collection is null
      * @throws IllegalArgumentException if any predicate in the collection is null
      * @see org.apache.commons.collections.functors.AllPredicate
      */
     public static <T> Predicate<T> allPredicate(final Collection<? extends Predicate<T>> predicates) {
         return AllPredicate.allPredicate(predicates);
     }
 
     /**
      * Create a new Predicate that returns true if either of the specified
      * predicates are true.
      *
      * @param <T>  the type that the predicate queries
      * @param predicate1  the first predicate, may not be null
      * @param predicate2  the second predicate, may not be null
      * @return the <code>or</code> predicate
      * @throws IllegalArgumentException if either predicate is null
      * @see org.apache.commons.collections.functors.OrPredicate
      */
     public static <T> Predicate<T> orPredicate(final Predicate<? super T> predicate1,
                                                final Predicate<? super T> predicate2) {
         return OrPredicate.<T>orPredicate(predicate1, predicate2);
     }
 
     /**
      * Create a new Predicate that returns true if any of the specified
      * predicates are true.
      * If the array of predicates is empty, then this predicate returns false.
      *
      * @param <T>  the type that the predicate queries
      * @param predicates  an array of predicates to check, may not be null
      * @return the <code>any</code> predicate
      * @throws IllegalArgumentException if the predicates array is null
      * @throws IllegalArgumentException if any predicate in the array is null
      * @see org.apache.commons.collections.functors.AnyPredicate
      */
     public static <T> Predicate<T> anyPredicate(final Predicate<? super T>... predicates) {
         return AnyPredicate.anyPredicate(predicates);
     }
 
     /**
      * Create a new Predicate that returns true if any of the specified
      * predicates are true. The predicates are checked in iterator order.
      * If the collection of predicates is empty, then this predicate returns false.
      *
      * @param <T>  the type that the predicate queries
      * @param predicates  a collection of predicates to check, may not be null
      * @return the <code>any</code> predicate
      * @throws IllegalArgumentException if the predicates collection is null
      * @throws IllegalArgumentException if any predicate in the collection is null
      * @see org.apache.commons.collections.functors.AnyPredicate
      */
     public static <T> Predicate<T> anyPredicate(final Collection<? extends Predicate<T>> predicates) {
         return AnyPredicate.anyPredicate(predicates);
     }
 
     /**
      * Create a new Predicate that returns true if one, but not both, of the
      * specified predicates are true. XOR
      *
      * @param <T>  the type that the predicate queries
      * @param predicate1  the first predicate, may not be null
      * @param predicate2  the second predicate, may not be null
      * @return the <code>either</code> predicate
      * @throws IllegalArgumentException if either predicate is null
      * @see org.apache.commons.collections.functors.OnePredicate
      */
     public static <T> Predicate<T> eitherPredicate(final Predicate<? super T> predicate1,
                                                    final Predicate<? super T> predicate2) {
         @SuppressWarnings("unchecked")
         final Predicate<T> onePredicate = PredicateUtils.<T>onePredicate(predicate1, predicate2);
         return onePredicate;
     }
 
     /**
      * Create a new Predicate that returns true if only one of the specified
      * predicates are true.
      * If the array of predicates is empty, then this predicate returns false.
      *
      * @param <T>  the type that the predicate queries
      * @param predicates  an array of predicates to check, may not be null
      * @return the <code>one</code> predicate
      * @throws IllegalArgumentException if the predicates array is null
      * @throws IllegalArgumentException if any predicate in the array is null
      * @see org.apache.commons.collections.functors.OnePredicate
      */
     public static <T> Predicate<T> onePredicate(final Predicate<? super T>... predicates) {
         return OnePredicate.onePredicate(predicates);
     }
 
     /**
      * Create a new Predicate that returns true if only one of the specified
      * predicates are true. The predicates are checked in iterator order.
      * If the collection of predicates is empty, then this predicate returns false.
      *
      * @param <T>  the type that the predicate queries
      * @param predicates  a collection of predicates to check, may not be null
      * @return the <code>one</code> predicate
      * @throws IllegalArgumentException if the predicates collection is null
      * @throws IllegalArgumentException if any predicate in the collection is null
      * @see org.apache.commons.collections.functors.OnePredicate
      */
     public static <T> Predicate<T> onePredicate(final Collection<Predicate<T>> predicates) {
         return OnePredicate.onePredicate(predicates);
     }
 
     /**
      * Create a new Predicate that returns true if neither of the specified
      * predicates are true.
      *
      * @param <T>  the type that the predicate queries
      * @param predicate1  the first predicate, may not be null
      * @param predicate2  the second predicate, may not be null
      * @return the <code>neither</code> predicate
      * @throws IllegalArgumentException if either predicate is null
      * @see org.apache.commons.collections.functors.NonePredicate
      */
     public static <T> Predicate<T> neitherPredicate(final Predicate<? super T> predicate1,
                                                     final Predicate<? super T> predicate2) {
         @SuppressWarnings("unchecked")
         final Predicate<T> nonePredicate = PredicateUtils.<T>nonePredicate(predicate1, predicate2);
         return nonePredicate;
     }
 
     /**
      * Create a new Predicate that returns true if none of the specified
      * predicates are true.
      * If the array of predicates is empty, then this predicate returns true.
      *
      * @param <T>  the type that the predicate queries
      * @param predicates  an array of predicates to check, may not be null
      * @return the <code>none</code> predicate
      * @throws IllegalArgumentException if the predicates array is null
      * @throws IllegalArgumentException if any predicate in the array is null
      * @see org.apache.commons.collections.functors.NonePredicate
      */
     public static <T> Predicate<T> nonePredicate(final Predicate<? super T>... predicates) {
         return NonePredicate.nonePredicate(predicates);
     }
 
     /**
      * Create a new Predicate that returns true if none of the specified
      * predicates are true. The predicates are checked in iterator order.
      * If the collection of predicates is empty, then this predicate returns true.
      *
      * @param <T>  the type that the predicate queries
      * @param predicates  a collection of predicates to check, may not be null
      * @return the <code>none</code> predicate
      * @throws IllegalArgumentException if the predicates collection is null
      * @throws IllegalArgumentException if any predicate in the collection is null
      * @see org.apache.commons.collections.functors.NonePredicate
      */
     public static <T> Predicate<T> nonePredicate(final Collection<? extends Predicate<T>> predicates) {
         return NonePredicate.nonePredicate(predicates);
     }
 
     /**
      * Create a new Predicate that returns true if the specified predicate
      * returns false and vice versa.
      *
      * @param <T>  the type that the predicate queries
      * @param predicate  the predicate to not
      * @return the <code>not</code> predicate
      * @throws IllegalArgumentException if the predicate is null
      * @see org.apache.commons.collections.functors.NotPredicate
      */
     public static <T> Predicate<T> notPredicate(final Predicate<? super T> predicate) {
         return NotPredicate.notPredicate(predicate);
     }
 
     // Adaptors
     //-----------------------------------------------------------------------------
 
     /**
      * Create a new Predicate that wraps a Transformer. The Transformer must
      * return either Boolean.TRUE or Boolean.FALSE otherwise a PredicateException
      * will be thrown.
      *
      * @param <T>  the type that the predicate queries
      * @param transformer  the transformer to wrap, may not be null
      * @return the transformer wrapping predicate
      * @throws IllegalArgumentException if the transformer is null
      * @see org.apache.commons.collections.functors.TransformerPredicate
      */
     public static <T> Predicate<T> asPredicate(final Transformer<? super T, Boolean> transformer) {
         return TransformerPredicate.transformerPredicate(transformer);
     }
 
     // Null handlers
     //-----------------------------------------------------------------------------
 
     /**
      * Gets a Predicate that throws an exception if the input object is null,
      * otherwise it calls the specified Predicate. This allows null handling
      * behaviour to be added to Predicates that don't support nulls.
      *
      * @param <T>  the type that the predicate queries
      * @param predicate  the predicate to wrap, may not be null
      * @return the predicate
      * @throws IllegalArgumentException if the predicate is null.
      * @see org.apache.commons.collections.functors.NullIsExceptionPredicate
      */
     public static <T> Predicate<T> nullIsExceptionPredicate(final Predicate<? super T> predicate){
         return NullIsExceptionPredicate.nullIsExceptionPredicate(predicate);
     }
 
     /**
      * Gets a Predicate that returns false if the input object is null, otherwise
      * it calls the specified Predicate. This allows null handling behaviour to
      * be added to Predicates that don't support nulls.
      *
      * @param <T>  the type that the predicate queries
      * @param predicate  the predicate to wrap, may not be null
      * @return the predicate
      * @throws IllegalArgumentException if the predicate is null.
      * @see org.apache.commons.collections.functors.NullIsFalsePredicate
      */
     public static <T> Predicate<T> nullIsFalsePredicate(final Predicate<? super T> predicate){
         return NullIsFalsePredicate.nullIsFalsePredicate(predicate);
     }
 
     /**
      * Gets a Predicate that returns true if the input object is null, otherwise
      * it calls the specified Predicate. This allows null handling behaviour to
      * be added to Predicates that don't support nulls.
      *
      * @param <T>  the type that the predicate queries
      * @param predicate  the predicate to wrap, may not be null
      * @return the predicate
      * @throws IllegalArgumentException if the predicate is null.
      * @see org.apache.commons.collections.functors.NullIsTruePredicate
      */
     public static <T> Predicate<T> nullIsTruePredicate(final Predicate<? super T> predicate){
         return NullIsTruePredicate.nullIsTruePredicate(predicate);
     }
 
     // Transformed
     //-----------------------------------------------------------------------
     /**
      * Creates a predicate that transforms the input object before passing it
      * to the predicate.
      *
      * @param <T>  the type that the predicate queries
      * @param transformer  the transformer to call first
      * @param predicate  the predicate to call with the result of the transform
      * @return the predicate
      * @throws IllegalArgumentException if the transformer or the predicate is null
      * @see org.apache.commons.collections.functors.TransformedPredicate
      * @since 3.1
      */
     public static <T> Predicate<T> transformedPredicate(
             final Transformer<? super T, ? extends T> transformer, final Predicate<? super T> predicate) {
         return TransformedPredicate.<T>transformedPredicate(transformer, predicate);
     }
 
 }