/*
 * Copyright 2004-2009 H2 Group. Multiple-Licensed under the H2 License,
 * Version 1.0, and under the Eclipse Public License, Version 1.0
 * (http://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */
package org.h2.test.db;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import org.h2.test.unit.SelfDestructor;

/**
 * A task that can be run as a separate process.
 */
public abstract class Task {

    /**
     * Run the class. This method is called by the task framework, and should
     * not be called directly from the application.
     *
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        SelfDestructor.startCountdown(60);
        Task task;
        try {
            String className = args[0];
            task = (Task) Class.forName(className).newInstance();
            System.out.println("running");
        } catch (Throwable t) {
            System.out.println("init error: " + t);
            t.printStackTrace();
            return;
        }
        try {
            String[] taskArgs = new String[args.length - 1];
            System.arraycopy(args, 0, taskArgs, 0, args.length - 1);
            task.run(taskArgs);
        } catch (Throwable t) {
            System.out.println("error: " + t);
            t.printStackTrace();
        }
    }

    /**
     * Run the task.
     *
     * @param args the command line arguments
     */
    abstract void run(String[] args) throws Exception;

    /**
     * Receive a message from the process over the standard output.
     *
     * @return the message
     */
    protected String receive() {
        try {
            return new BufferedReader(new InputStreamReader(System.in)).readLine();
        } catch (IOException e) {
            throw new RuntimeException("Error reading from input", e);
        }
    }

    /**
     * Send a message to the process over the standard input.
     *
     * @param message the message
     */
    protected void send(String message) {
        System.out.println(message);
        System.out.flush();
    }

}
