/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.tools.ant.taskdefs;

import org.apache.tools.ant.Project;

import java.net.*;
import junit.framework.*;
import java.io.*;

/**
 * Simple testcase for the ExecuteWatchdog class.
 *
 * @author <a href="mailto:sbailliez@imediation.com">Stephane Bailliez</a>
 */
public class ExecuteWatchdogTest extends TestCase {

    private final static int TIME_OUT = 5000;

    private final static String TEST_CLASSPATH = getTestClassPath();

    private final static int CLOCK_ERROR=200;
    private final static int TIME_OUT_TEST=TIME_OUT-CLOCK_ERROR;
    
    private ExecuteWatchdog watchdog;

    public ExecuteWatchdogTest(String name) {
        super(name);
    }

    protected void setUp(){
        watchdog = new ExecuteWatchdog(TIME_OUT);
    }

    /**
     * Dangerous method to obtain the classpath for the test. This is
     * severely tighted to the build.xml properties.
     */
    private static String getTestClassPath(){
        String classpath = System.getProperty("build.tests");
        if (classpath == null) {
            System.err.println("WARNING: 'build.tests' property is not available !");
            classpath = System.getProperty("java.class.path");
        }

                // JDK 1.1 needs classes.zip in -classpath argument
                if (Project.getJavaVersion() == Project.JAVA_1_1) {
                    classpath +=   File.pathSeparator
                                 + System.getProperty("java.home")
                                 + File.separator + "lib"
                                 + File.separator + "classes.zip";
                }

        return classpath;
    }

    private Process getProcess(int timetorun) throws Exception {
        String[] cmdArray = {
            "java", "-classpath", TEST_CLASSPATH,
            TimeProcess.class.getName(), String.valueOf(timetorun)
        };
        //System.out.println("Testing with classpath: " + System.getProperty("java.class.path"));
        return Runtime.getRuntime().exec(cmdArray);
    }

    private String getErrorOutput(Process p) throws Exception {
        BufferedReader err = new BufferedReader( new InputStreamReader(p.getErrorStream()) );
        StringBuffer buf = new StringBuffer();
        String line;
        while ( (line = err.readLine()) != null){
            buf.append(line);
        }
        return buf.toString();
    }
    
    private int waitForEnd(Process p) throws Exception {
        int retcode = p.waitFor();
        if (retcode != 0){
            String err = getErrorOutput(p);
            if (err.length() > 0){
                System.err.println("ERROR:");
                System.err.println(err);
            }
        }
        return retcode;
    }

    public void testNoTimeOut() throws Exception {
        Process process = getProcess(TIME_OUT/2);
        watchdog.start(process);
        int retCode = waitForEnd(process);
        assertTrue("process should not have been killed", !watchdog.killedProcess());
        assertEquals(0, retCode);
    }

    // test that the watchdog ends the process
    public void testTimeOut() throws Exception {
        Process process = getProcess(TIME_OUT*2);
        long now = System.currentTimeMillis();
        watchdog.start(process);
        int retCode = process.waitFor();
        long elapsed = System.currentTimeMillis() - now;
        assertTrue("process should have been killed", watchdog.killedProcess());
                //      assertTrue("return code is invalid: " + retCode, retCode!=0);
        assertTrue("elapse time of "+elapsed+" ms is less than timeout value of "+TIME_OUT_TEST+" ms", elapsed >= TIME_OUT_TEST);
        assertTrue("elapse time of "+elapsed+" ms is greater than run value of "+(TIME_OUT*2)+" ms", elapsed < TIME_OUT*2);
    }

    // test a process that runs and failed
    public void testFailed() throws Exception {
        Process process = getProcess(-1); // process should abort
        watchdog.start(process);
        int retCode = process.waitFor();
        assertTrue("process should not have been killed", !watchdog.killedProcess());
        assertTrue("return code is invalid: " + retCode, retCode!=0);
    }

    public void testManualStop() throws Exception {
        final Process process = getProcess(TIME_OUT*2);
        watchdog.start(process);

        // I assume that starting this takes less than TIME_OUT/2 ms...
        Thread thread = new Thread(){
                public void run(){
                    try {
                        process.waitFor();
                    } catch(InterruptedException e){
                        // not very nice but will do the job
                        fail("process interrupted in thread");
                    }
                }
        };
        thread.start();

        // wait for TIME_OUT/2, there should be about TIME_OUT/2 ms remaining before timeout
        thread.join(TIME_OUT/2);

         // now stop the watchdog.
        watchdog.stop();

        // wait for the thread to die, should be the end of the process
        thread.join();

        // process should be dead and well finished
        assertEquals(0, process.exitValue());
        assertTrue("process should not have been killed", !watchdog.killedProcess());
    }

    public static class TimeProcess {
        public static void main(String[] args) throws Exception {
            int time = Integer.parseInt(args[0]);
            if (time < 1) {
                throw new IllegalArgumentException("Invalid time: " + time);
            }
            Thread.sleep(time);
        }
    }
}
