/*
 * Copyright 2002-2018 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.beans.factory.config;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * Context object for evaluating an expression within a bean definition.
 *
 * @author Juergen Hoeller
 * @since 3.0
 */
public class BeanExpressionContext {

	private final ConfigurableBeanFactory beanFactory;

	@Nullable
	private final Scope scope;


	public BeanExpressionContext(ConfigurableBeanFactory beanFactory, @Nullable Scope scope) {
		Assert.notNull(beanFactory, "BeanFactory must not be null");
		this.beanFactory = beanFactory;
		this.scope = scope;
	}

	public final ConfigurableBeanFactory getBeanFactory() {
		return this.beanFactory;
	}

	@Nullable
	public final Scope getScope() {
		return this.scope;
	}


	public boolean containsObject(String key) {
		return (this.beanFactory.containsBean(key) ||
				(this.scope != null && this.scope.resolveContextualObject(key) != null));
	}

	@Nullable
	public Object getObject(String key) {
		if (this.beanFactory.containsBean(key)) {
			return this.beanFactory.getBean(key);
		}
		else if (this.scope != null) {
			return this.scope.resolveContextualObject(key);
		}
		else {
			return null;
		}
	}


	@Override
	public boolean equals(Object other) {
		if (this == other) {
			return true;
		}
		if (!(other instanceof BeanExpressionContext)) {
			return false;
		}
		BeanExpressionContext otherContext = (BeanExpressionContext) other;
		return (this.beanFactory == otherContext.beanFactory && this.scope == otherContext.scope);
	}

	@Override
	public int hashCode() {
		return this.beanFactory.hashCode();
	}

}
