/*
 * 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.ode.bpel.engine.replayer;

import java.util.Date;
import java.util.Map;
import java.util.PriorityQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.Future;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.ode.bpel.iapi.ContextException;
import org.apache.ode.bpel.iapi.Scheduler;
import org.apache.ode.dao.bpel.BpelDAOConnection;

/**
 * Manages events invocation in sorted order during replaying. 
 *  
 * @author Rafal Rusin
 *
 */
public class ReplayerScheduler implements Scheduler {
    private static final Log __log = LogFactory.getLog(ReplayerScheduler.class);

    public Replayer replayer;
    
    public static ThreadLocal<TaskElement> currentTaskElement = new ThreadLocal<TaskElement>();
    
    private PriorityQueue<TaskElement> taskQueue = new PriorityQueue<TaskElement>();

    private static class TaskElement implements Comparable<TaskElement> {
        public final Date when;
        public final Callable<Object> action;
        public final ReplayerBpelRuntimeContextImpl runtimeContext;

        public TaskElement(Date when, Callable<Object> action, ReplayerBpelRuntimeContextImpl runtimeContext) {
            super();
            this.when = when;
            this.action = action;
            this.runtimeContext = runtimeContext;
        }

        public int compareTo(TaskElement o) {
            return when.compareTo(o.when);
        }
    }

    public void scheduleReplayerJob(Callable action, Date when, ReplayerBpelRuntimeContextImpl runtimeContext) {
        taskQueue.add(new TaskElement(when, action, runtimeContext));
    }

    public void cancelJob(String jobId) throws ContextException {
        throw new IllegalStateException();
    }

    public <T> T execTransaction(Callable<T> transaction) throws Exception, ContextException {
        throw new IllegalStateException();
    }

    public <T> T execTransaction(Callable<T> transaction, int timeout) throws Exception, ContextException {
        throw new IllegalStateException();
    }
    
    public boolean isTransacted() {
        return true;
    }

    public void registerSynchronizer(Synchronizer synch) throws ContextException {
        throw new IllegalStateException();
    }

    public void setJobProcessor(JobProcessor processor) throws ContextException {
        throw new IllegalStateException();
    }

    public void setRollbackOnly() throws Exception {
        throw new IllegalStateException();
    }

    public void shutdown() {
    }

    public void startReplaying(Replayer replayer) throws Exception {
        this.replayer = replayer;
        while (!taskQueue.isEmpty()) {
            TaskElement taskElement = taskQueue.remove();
            
            try {
                currentTaskElement.set(taskElement);
                __log.debug("executing action at time " + taskElement.when);
                if (taskElement.runtimeContext != null) {
                    taskElement.runtimeContext.setCurrentEventDateTime(taskElement.when);
                }
                taskElement.action.call();
            } finally {
                currentTaskElement.set(null);
            }
        }
    }

    public void stop() {
    }

    public void start() {
    }

    public <T> Future<T> execIsolatedTransaction(Callable<T> transaction) throws Exception, ContextException {
        return null;
    }

    public String scheduleMapSerializableRunnable(MapSerializableRunnable runnable, Date when) throws ContextException {
        return null;
    }

    public String schedulePersistedJob(final JobDetails jobDetail, final Date when1) throws ContextException {
        final Date when = when1 == null ? currentTaskElement.get().when : when1;
        __log.debug("schedulePersistedJob " + jobDetail + " " + when, new Exception());
        scheduleReplayerJob(new Callable<Void>() {
            public Void call() throws Exception {
                replayer.handleJobDetails(jobDetail, when);
                return null;
            }
        }, when, null);
        
        return null;
    }

    public void setPolledRunnableProcesser(JobProcessor polledRunnableProcessor) {
    }

    public String scheduleVolatileJob(boolean transacted, JobDetails jobDetail, Date when) throws ContextException {
        // TODO Auto-generated method stub
        __log.debug("scheduleVolatileJob");
        return null;
    }

    public String scheduleVolatileJob(boolean transacted, JobDetails jobDetail) throws ContextException {
        // TODO Auto-generated method stub
        __log.debug("scheduleVolatileJob");
        return null;
    }
}
