/* ProcessMonitor.cs
 * License: NCSA Open Source License
 * 
 * Copyright: Merijn Hendriks
 * AUTHORS:
 * Merijn Hendriks
 */


using System;
using System.Diagnostics;
using System.Timers;

namespace SPT.Launcher.MiniCommon
{
    public class ProcessMonitor
    {
        private Timer monitor;
        private readonly string processName;
        private readonly Action<ProcessMonitor> aliveCallback;
        private readonly Action<ProcessMonitor> exitCallback;

        public ProcessMonitor(string processName, double interval, Action<ProcessMonitor> aliveCallback, Action<ProcessMonitor> exitCallback)
        {
            monitor = new Timer(interval);
            monitor.Elapsed += OnPollEvent;
            monitor.AutoReset = true;

            this.processName = processName;
            this.aliveCallback = aliveCallback;
            this.exitCallback = exitCallback;
        }

        public void Start()
        {
            monitor.Enabled = true;
        }

        public void Stop()
        {
            monitor.Enabled = false;
        }

        private void OnPollEvent(object source, ElapsedEventArgs e)
        {
            Process[] clientProcess = Process.GetProcessesByName(processName);

            // client instances still running
            if (clientProcess.Length > 0)
            {
                aliveCallback(this);
                return;
            }

            // all client instances stopped running
            exitCallback(this);
        }
    }
}