/*
    * Copyright 2002-2013 the original author or 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.
   */
  
  package org.springframework.aop.support;
  
  import java.io.Serializable;
  
  import org.springframework.aop.ClassFilter;
  import org.springframework.aop.MethodMatcher;
  import org.springframework.aop.Pointcut;
  import org.springframework.util.Assert;
  import org.springframework.util.ObjectUtils;
  
  /**
   * Convenient class for building up pointcuts. All methods return
   * ComposablePointcut, so we can use a concise idiom like:
   *
   * {@code
   * Pointcut pc = new ComposablePointcut().union(classFilter).intersection(methodMatcher).intersection(pointcut);
   * }
   *
   * @author Rod Johnson
   * @author Juergen Hoeller
   * @author Rob Harrop
   * @since 11.11.2003
   * @see Pointcuts
   */
  public class ComposablePointcut implements Pointcut, Serializable {
  
  	/** use serialVersionUID from Spring 1.2 for interoperability */
  	private static final long serialVersionUID = -2743223737633663832L;
  
  	private ClassFilter classFilter;
  
  	private MethodMatcher methodMatcher;
  
  
  	/**
  	 * Create a default ComposablePointcut, with {@code ClassFilter.TRUE}
  	 * and {@code MethodMatcher.TRUE}.
  	 */
  	public ComposablePointcut() {
  		this.classFilter = ClassFilter.TRUE;
  		this.methodMatcher = MethodMatcher.TRUE;
  	}
  
  	/**
  	 * Create a ComposablePointcut based on the given Pointcut.
  	 * @param pointcut the original Pointcut
  	 */
  	public ComposablePointcut(Pointcut pointcut) {
  		Assert.notNull(pointcut, "Pointcut must not be null");
  		this.classFilter = pointcut.getClassFilter();
  		this.methodMatcher = pointcut.getMethodMatcher();
  	}
  
  	/**
  	 * Create a ComposablePointcut for the given ClassFilter,
  	 * with {@code MethodMatcher.TRUE}.
  	 * @param classFilter the ClassFilter to use
  	 */
  	public ComposablePointcut(ClassFilter classFilter) {
  		Assert.notNull(classFilter, "ClassFilter must not be null");
  		this.classFilter = classFilter;
  		this.methodMatcher = MethodMatcher.TRUE;
  	}
  
  	/**
  	 * Create a ComposablePointcut for the given MethodMatcher,
  	 * with {@code ClassFilter.TRUE}.
  	 * @param methodMatcher the MethodMatcher to use
  	 */
  	public ComposablePointcut(MethodMatcher methodMatcher) {
  		Assert.notNull(methodMatcher, "MethodMatcher must not be null");
  		this.classFilter = ClassFilter.TRUE;
  		this.methodMatcher = methodMatcher;
  	}
  
  	/**
  	 * Create a ComposablePointcut for the given ClassFilter and MethodMatcher.
  	 * @param classFilter the ClassFilter to use
  	 * @param methodMatcher the MethodMatcher to use
  	 */
  	public ComposablePointcut(ClassFilter classFilter, MethodMatcher methodMatcher) {
  		Assert.notNull(classFilter, "ClassFilter must not be null");
  		Assert.notNull(methodMatcher, "MethodMatcher must not be null");
 		this.classFilter = classFilter;
 		this.methodMatcher = methodMatcher;
 	}
 
 
 	/**
 	 * Apply a union with the given ClassFilter.
 	 * @param other the ClassFilter to apply a union with
 	 * @return this composable pointcut (for call chaining)
 	 */
 	public ComposablePointcut union(ClassFilter other) {
 		this.classFilter = ClassFilters.union(this.classFilter, other);
 		return this;
 	}
 
 	/**
 	 * Apply an intersection with the given ClassFilter.
 	 * @param other the ClassFilter to apply an intersection with
 	 * @return this composable pointcut (for call chaining)
 	 */
 	public ComposablePointcut intersection(ClassFilter other) {
 		this.classFilter = ClassFilters.intersection(this.classFilter, other);
 		return this;
 	}
 
 	/**
 	 * Apply a union with the given MethodMatcher.
 	 * @param other the MethodMatcher to apply a union with
 	 * @return this composable pointcut (for call chaining)
 	 */
 	public ComposablePointcut union(MethodMatcher other) {
 		this.methodMatcher = MethodMatchers.union(this.methodMatcher, other);
 		return this;
 	}
 
 	/**
 	 * Apply an intersection with the given MethodMatcher.
 	 * @param other the MethodMatcher to apply an intersection with
 	 * @return this composable pointcut (for call chaining)
 	 */
 	public ComposablePointcut intersection(MethodMatcher other) {
 		this.methodMatcher = MethodMatchers.intersection(this.methodMatcher, other);
 		return this;
 	}
 
 	/**
 	 * Apply a union with the given Pointcut.
 	 * <p>Note that for a Pointcut union, methods will only match if their
 	 * original ClassFilter (from the originating Pointcut) matches as well.
 	 * MethodMatchers and ClassFilters from different Pointcuts will never
 	 * get interleaved with each other.
 	 * @param other the Pointcut to apply a union with
 	 * @return this composable pointcut (for call chaining)
 	 */
 	public ComposablePointcut union(Pointcut other) {
 		this.methodMatcher = MethodMatchers.union(
 				this.methodMatcher, this.classFilter, other.getMethodMatcher(), other.getClassFilter());
 		this.classFilter = ClassFilters.union(this.classFilter, other.getClassFilter());
 		return this;
 	}
 
 	/**
 	 * Apply an intersection with the given Pointcut.
 	 * @param other the Pointcut to apply an intersection with
 	 * @return this composable pointcut (for call chaining)
 	 */
 	public ComposablePointcut intersection(Pointcut other) {
 		this.classFilter = ClassFilters.intersection(this.classFilter, other.getClassFilter());
 		this.methodMatcher = MethodMatchers.intersection(this.methodMatcher, other.getMethodMatcher());
 		return this;
 	}
 
 
 	@Override
 	public ClassFilter getClassFilter() {
 		return this.classFilter;
 	}
 
 	@Override
 	public MethodMatcher getMethodMatcher() {
 		return this.methodMatcher;
 	}
 
 	@Override
 	public boolean equals(Object other) {
 		if (this == other) {
 			return true;
 		}
 		if (!(other instanceof ComposablePointcut)) {
 			return false;
 		}
 		ComposablePointcut that = (ComposablePointcut) other;
 		return ObjectUtils.nullSafeEquals(that.classFilter, this.classFilter) &&
 				ObjectUtils.nullSafeEquals(that.methodMatcher, this.methodMatcher);
 	}
 
 	@Override
 	public int hashCode() {
 		int code = 17;
 		if (this.classFilter != null) {
 			code = 37 * code + this.classFilter.hashCode();
 		}
 		if (this.methodMatcher != null) {
 			code = 37 * code + this.methodMatcher.hashCode();
 		}
 		return code;
 	}
 
 	@Override
 	public String toString() {
 		return "ComposablePointcut: " + this.classFilter + ", " +this.methodMatcher;
 	}
 
 }