/*
 * Copyright 2002-2014 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.scheduling.quartz;

import java.lang.reflect.InvocationTargetException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.DisallowConcurrentExecution;
import org.quartz.JobDetail;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.quartz.PersistJobDataAfterExecution;
import org.quartz.Scheduler;
import org.quartz.impl.JobDetailImpl;

import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.support.ArgumentConvertingMethodInvoker;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.MethodInvoker;

/**
 * {@link org.springframework.beans.factory.FactoryBean} that exposes a
 * {@link org.quartz.JobDetail} object which delegates job execution to a
 * specified (static or non-static) method. Avoids the need for implementing
 * a one-line Quartz Job that just invokes an existing service method on a
 * Spring-managed target bean.
 *
 * <p>Inherits common configuration properties from the {@link MethodInvoker}
 * base class, such as {@link #setTargetObject "targetObject"} and
 * {@link #setTargetMethod "targetMethod"}, adding support for lookup of the target
 * bean by name through the {@link #setTargetBeanName "targetBeanName"} property
 * (as alternative to specifying a "targetObject" directly, allowing for
 * non-singleton target objects).
 *
 * <p>Supports both concurrently running jobs and non-currently running
 * jobs through the "concurrent" property. Jobs created by this
 * MethodInvokingJobDetailFactoryBean are by default volatile and durable
 * (according to Quartz terminology).
 *
 * <p><b>NOTE: JobDetails created via this FactoryBean are <i>not</i>
 * serializable and thus not suitable for persistent job stores.</b>
 * You need to implement your own Quartz Job as a thin wrapper for each case
 * where you want a persistent job to delegate to a specific service method.
 *
 * <p>Compatible with Quartz 2.1.4 and higher, as of Spring 4.1.
 *
 * @author Juergen Hoeller
 * @author Alef Arendsen
 * @since 18.02.2004
 * @see #setTargetBeanName
 * @see #setTargetObject
 * @see #setTargetMethod
 * @see #setConcurrent
 */
public class MethodInvokingJobDetailFactoryBean extends ArgumentConvertingMethodInvoker
                implements FactoryBean<JobDetail>, BeanNameAware, BeanClassLoaderAware, BeanFactoryAware, InitializingBean {

        private String name;

        private String group = Scheduler.DEFAULT_GROUP;

        private boolean concurrent = true;

        private String targetBeanName;

        private String beanName;

        private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();

        private BeanFactory beanFactory;

        private JobDetail jobDetail;


        /**
         * Set the name of the job.
         * <p>Default is the bean name of this FactoryBean.
         */
        public void setName(String name) {
                this.name = name;
        }

        /**
         * Set the group of the job.
         * <p>Default is the default group of the Scheduler.
         * @see org.quartz.Scheduler#DEFAULT_GROUP
         */
        public void setGroup(String group) {
                this.group = group;
        }

        /**
         * Specify whether or not multiple jobs should be run in a concurrent fashion.
         * The behavior when one does not want concurrent jobs to be executed is
         * realized through adding the {@code @PersistJobDataAfterExecution} and
         * {@code @DisallowConcurrentExecution} markers.
         * More information on stateful versus stateless jobs can be found
         * <a href="https://www.quartz-scheduler.org/documentation/quartz-2.1.x/tutorials/tutorial-lesson-03">here</a>.
         * <p>The default setting is to run jobs concurrently.
         */
        public void setConcurrent(boolean concurrent) {
                this.concurrent = concurrent;
        }

        /**
         * Set the name of the target bean in the Spring BeanFactory.
         * <p>This is an alternative to specifying {@link #setTargetObject "targetObject"},
         * allowing for non-singleton beans to be invoked. Note that specified
         * "targetObject" and {@link #setTargetClass "targetClass"} values will
         * override the corresponding effect of this "targetBeanName" setting
         * (i.e. statically pre-define the bean type or even the bean object).
         */
        public void setTargetBeanName(String targetBeanName) {
                this.targetBeanName = targetBeanName;
        }

        @Override
        public void setBeanName(String beanName) {
                this.beanName = beanName;
        }

        @Override
        public void setBeanClassLoader(ClassLoader classLoader) {
                this.beanClassLoader = classLoader;
        }

        @Override
        public void setBeanFactory(BeanFactory beanFactory) {
                this.beanFactory = beanFactory;
        }

        @Override
        protected Class<?> resolveClassName(String className) throws ClassNotFoundException {
                return ClassUtils.forName(className, this.beanClassLoader);
        }


        @Override
        @SuppressWarnings("unchecked")
        public void afterPropertiesSet() throws ClassNotFoundException, NoSuchMethodException {
                prepare();

                // Use specific name if given, else fall back to bean name.
                String name = (this.name != null ? this.name : this.beanName);

                // Consider the concurrent flag to choose between stateful and stateless job.
                Class<?> jobClass = (this.concurrent ? MethodInvokingJob.class : StatefulMethodInvokingJob.class);

                // Build JobDetail instance.
                JobDetailImpl jdi = new JobDetailImpl();
                jdi.setName(name);
                jdi.setGroup(this.group);
                jdi.setJobClass((Class) jobClass);
                jdi.setDurability(true);
                jdi.getJobDataMap().put("methodInvoker", this);
                this.jobDetail = jdi;

                postProcessJobDetail(this.jobDetail);
        }

        /**
         * Callback for post-processing the JobDetail to be exposed by this FactoryBean.
         * <p>The default implementation is empty. Can be overridden in subclasses.
         * @param jobDetail the JobDetail prepared by this FactoryBean
         */
        protected void postProcessJobDetail(JobDetail jobDetail) {
        }


        /**
         * Overridden to support the {@link #setTargetBeanName "targetBeanName"} feature.
         */
        @Override
        public Class<?> getTargetClass() {
                Class<?> targetClass = super.getTargetClass();
                if (targetClass == null && this.targetBeanName != null) {
                        Assert.state(this.beanFactory != null, "BeanFactory must be set when using 'targetBeanName'");
                        targetClass = this.beanFactory.getType(this.targetBeanName);
                }
                return targetClass;
        }

        /**
         * Overridden to support the {@link #setTargetBeanName "targetBeanName"} feature.
         */
        @Override
        public Object getTargetObject() {
                Object targetObject = super.getTargetObject();
                if (targetObject == null && this.targetBeanName != null) {
                        Assert.state(this.beanFactory != null, "BeanFactory must be set when using 'targetBeanName'");
                        targetObject = this.beanFactory.getBean(this.targetBeanName);
                }
                return targetObject;
        }


        @Override
        public JobDetail getObject() {
                return this.jobDetail;
        }

        @Override
        public Class<? extends JobDetail> getObjectType() {
                return (this.jobDetail != null ? this.jobDetail.getClass() : JobDetail.class);
        }

        @Override
        public boolean isSingleton() {
                return true;
        }


        /**
         * Quartz Job implementation that invokes a specified method.
         * Automatically applied by MethodInvokingJobDetailFactoryBean.
         */
        public static class MethodInvokingJob extends QuartzJobBean {

                protected static final Log logger = LogFactory.getLog(MethodInvokingJob.class);

                private MethodInvoker methodInvoker;

                /**
                 * Set the MethodInvoker to use.
                 */
                public void setMethodInvoker(MethodInvoker methodInvoker) {
                        this.methodInvoker = methodInvoker;
                }

                /**
                 * Invoke the method via the MethodInvoker.
                 */
                @Override
                protected void executeInternal(JobExecutionContext context) throws JobExecutionException {
                        try {
                                context.setResult(this.methodInvoker.invoke());
                        }
                        catch (InvocationTargetException ex) {
                                if (ex.getTargetException() instanceof JobExecutionException) {
                                        // -> JobExecutionException, to be logged at info level by Quartz
                                        throw (JobExecutionException) ex.getTargetException();
                                }
                                else {
                                        // -> "unhandled exception", to be logged at error level by Quartz
                                        throw new JobMethodInvocationFailedException(this.methodInvoker, ex.getTargetException());
                                }
                        }
                        catch (Exception ex) {
                                // -> "unhandled exception", to be logged at error level by Quartz
                                throw new JobMethodInvocationFailedException(this.methodInvoker, ex);
                        }
                }
        }


        /**
         * Extension of the MethodInvokingJob, implementing the StatefulJob interface.
         * Quartz checks whether or not jobs are stateful and if so,
         * won't let jobs interfere with each other.
         */
        @PersistJobDataAfterExecution
        @DisallowConcurrentExecution
        public static class StatefulMethodInvokingJob extends MethodInvokingJob {

                // No implementation, just an addition of the tag interface StatefulJob
                // in order to allow stateful method invoking jobs.
        }

}