/*
 * Copyright 2002-2017 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
 *
 *      https://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.beans.BeanMetadataElement;
import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
import org.springframework.util.StringUtils;

/**
 * Holder for a BeanDefinition with name and aliases.
 * Can be registered as a placeholder for an inner bean.
 *
 * <p>Can also be used for programmatic registration of inner bean
 * definitions. If you don't care about BeanNameAware and the like,
 * registering RootBeanDefinition or ChildBeanDefinition is good enough.
 *
 * @author Juergen Hoeller
 * @since 1.0.2
 * @see org.springframework.beans.factory.BeanNameAware
 * @see org.springframework.beans.factory.support.RootBeanDefinition
 * @see org.springframework.beans.factory.support.ChildBeanDefinition
 */
public class BeanDefinitionHolder implements BeanMetadataElement {

        private final BeanDefinition beanDefinition;

        private final String beanName;

        @Nullable
        private final String[] aliases;


        /**
         * Create a new BeanDefinitionHolder.
         * @param beanDefinition the BeanDefinition to wrap
         * @param beanName the name of the bean, as specified for the bean definition
         */
        public BeanDefinitionHolder(BeanDefinition beanDefinition, String beanName) {
                this(beanDefinition, beanName, null);
        }

        /**
         * Create a new BeanDefinitionHolder.
         * @param beanDefinition the BeanDefinition to wrap
         * @param beanName the name of the bean, as specified for the bean definition
         * @param aliases alias names for the bean, or {@code null} if none
         */
        public BeanDefinitionHolder(BeanDefinition beanDefinition, String beanName, @Nullable String[] aliases) {
                Assert.notNull(beanDefinition, "BeanDefinition must not be null");
                Assert.notNull(beanName, "Bean name must not be null");
                this.beanDefinition = beanDefinition;
                this.beanName = beanName;
                this.aliases = aliases;
        }

        /**
         * Copy constructor: Create a new BeanDefinitionHolder with the
         * same contents as the given BeanDefinitionHolder instance.
         * <p>Note: The wrapped BeanDefinition reference is taken as-is;
         * it is {@code not} deeply copied.
         * @param beanDefinitionHolder the BeanDefinitionHolder to copy
         */
        public BeanDefinitionHolder(BeanDefinitionHolder beanDefinitionHolder) {
                Assert.notNull(beanDefinitionHolder, "BeanDefinitionHolder must not be null");
                this.beanDefinition = beanDefinitionHolder.getBeanDefinition();
                this.beanName = beanDefinitionHolder.getBeanName();
                this.aliases = beanDefinitionHolder.getAliases();
        }


        /**
         * Return the wrapped BeanDefinition.
         */
        public BeanDefinition getBeanDefinition() {
                return this.beanDefinition;
        }

        /**
         * Return the primary name of the bean, as specified for the bean definition.
         */
        public String getBeanName() {
                return this.beanName;
        }

        /**
         * Return the alias names for the bean, as specified directly for the bean definition.
         * @return the array of alias names, or {@code null} if none
         */
        @Nullable
        public String[] getAliases() {
                return this.aliases;
        }

        /**
         * Expose the bean definition's source object.
         * @see BeanDefinition#getSource()
         */
        @Override
        @Nullable
        public Object getSource() {
                return this.beanDefinition.getSource();
        }

        /**
         * Determine whether the given candidate name matches the bean name
         * or the aliases stored in this bean definition.
         */
        public boolean matchesName(@Nullable String candidateName) {
                return (candidateName != null && (candidateName.equals(this.beanName) ||
                                candidateName.equals(BeanFactoryUtils.transformedBeanName(this.beanName)) ||
                                ObjectUtils.containsElement(this.aliases, candidateName)));
        }


        /**
         * Return a friendly, short description for the bean, stating name and aliases.
         * @see #getBeanName()
         * @see #getAliases()
         */
        public String getShortDescription() {
                if (this.aliases == null) {
                        return "Bean definition with name '" + this.beanName + "'";
                }
                return "Bean definition with name '" + this.beanName + "' and aliases [" + StringUtils.arrayToCommaDelimitedString(this.aliases) + ']';
        }

        /**
         * Return a long description for the bean, including name and aliases
         * as well as a description of the contained {@link BeanDefinition}.
         * @see #getShortDescription()
         * @see #getBeanDefinition()
         */
        public String getLongDescription() {
                return getShortDescription() + ": " + this.beanDefinition;
        }

        /**
         * This implementation returns the long description. Can be overridden
         * to return the short description or any kind of custom description instead.
         * @see #getLongDescription()
         * @see #getShortDescription()
         */
        @Override
        public String toString() {
                return getLongDescription();
        }


        @Override
        public boolean equals(@Nullable Object other) {
                if (this == other) {
                        return true;
                }
                if (!(other instanceof BeanDefinitionHolder)) {
                        return false;
                }
                BeanDefinitionHolder otherHolder = (BeanDefinitionHolder) other;
                return this.beanDefinition.equals(otherHolder.beanDefinition) &&
                                this.beanName.equals(otherHolder.beanName) &&
                                ObjectUtils.nullSafeEquals(this.aliases, otherHolder.aliases);
        }

        @Override
        public int hashCode() {
                int hashCode = this.beanDefinition.hashCode();
                hashCode = 29 * hashCode + this.beanName.hashCode();
                hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.aliases);
                return hashCode;
        }

}