/*

 *  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.tools.ant.taskdefs; */

/* * Portion Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.*/

package com.nokia.helium.core.ant.taskdefs;

import org.apache.tools.ant.BuildException;

import org.apache.tools.ant.Project;

import org.apache.tools.ant.Task;

import org.apache.tools.ant.TaskContainer;

/**

 * Retries the nested task a set number of times

 * 

 * @since Ant 1.7.1

 * @ant.task name="retry" category="Core"

 */

public class RetryTask extends Task implements TaskContainer {

    /**

     * task to execute n times

     */

    private Task nestedTask;

    /**

     * set retryCount to 1 by default

     */

    private int retryCount = 1;

    /**

     * set sleepTime to 0 by default

     */

    private int sleepTime;

    /**

     * set the task

     * 

     * @param t

     *            the task to retry.

     */

    public synchronized void addTask(Task t) {

        if (nestedTask != null) {

            throw new BuildException(

                    "The retry task container accepts a single nested task"

                            + " (which may be a sequential task container)");

        }

        nestedTask = t;

    }

    /**

     * set the number of times to retry the task

     * 

     * @param n

     *            the number to use.

     * @ant.not-required Default is 1.

     */

    public void setRetryCount(int n) {

        retryCount = n;

    }

    /**

     * set the sleep time inbetween each retry

     * 

     * @param n

     *            the time in ms to sleep between each retry.

     * @ant.not-required Default is 0.

     */

    public void setSleepTime(int n) {

        sleepTime = n;

    }

    /**

     * perform the work

     * 

     * @throws BuildException

     *             if there is an error.

     */

    public void execute() {

        if (nestedTask == null) {

            throw new BuildException("The nested retry task not defined");

        }

        StringBuffer errorMessages = new StringBuffer();

        String br = getProject().getProperty("line.separator");

        for (int i = 0; i <= retryCount; i++) {

            try {

                nestedTask.perform();

                break;

            } catch (BuildException e) {

                errorMessages.append(e.getMessage());

                if (i >= retryCount) {

                    StringBuffer exceptionMessage = new StringBuffer();

                    exceptionMessage.append("Task [").append(

                            nestedTask.getTaskName());

                    exceptionMessage.append("] failed after [").append(

                            retryCount);

                    exceptionMessage.append("] attempts; giving up.")

                            .append(br);

                    exceptionMessage.append("Error messages:").append(br);

                    exceptionMessage.append(errorMessages);

                    throw new BuildException(exceptionMessage.toString(),

                            getLocation());

                }

                log("Attempt [" + i + "]:  error occurred; retrying...", e,

                        Project.MSG_INFO);

                errorMessages.append(br);

                if (sleepTime > 0) {

                    Sleep sleepTimer = new Sleep();

                    sleepTimer.setMilliseconds(sleepTime);

                    sleepTimer.execute();

                }

            }

        }

    }

}