ServerSniffer.cs

using System;
using System.IO;
using System.Threading;

namespace obsidianUpdater.Utility
{
	public class ServerSniffer
	{
		private StreamReader _reader;
		private int _progress = 0;

		public ServerStatus Status { get; private set; }

		public ServerSniffer(StreamReader reader)
		{
			_reader = reader;
		}

		public void WaitUntilRunning()
		{
			Status = ServerStatus.Starting;
			Console.WriteLine();
			while (Status < ServerStatus.Running)
				ParseLine(_reader.ReadLine());
			if (Status > ServerStatus.Running)
				throw new Exception("There was an error while starting up the server.");
		}

		public void WaitUntilStopped()
		{
			Status = ServerStatus.Running;
			Console.WriteLine();
			while (Status < ServerStatus.Stopped)
				ParseLine(_reader.ReadLine());
		}


		public void ParseLine(string line)
		{
			if (line == null) {
				Thread.Sleep(0);
				return;
			}
			// TODO: Detect crashing.
			switch (Status) {
				case ServerStatus.Starting:
					if (_startup[_progress](line, _progress, _startup.Length - 1) && (++_progress >= _startup.Length))
						Status = ServerStatus.Running;
					break;
				case ServerStatus.Running:
					if (UpdateStatus(LookForText(line, 44, "Sending event FMLServerStoppingEvent"), 0.5F, "Server stopping"))
						Status = ServerStatus.Stopping;
					break;
				case ServerStatus.Stopping:
					if (UpdateStatus(LookForText(line, 44, "Sending event FMLServerStoppedEvent"), 1.0F, "Server stopped!"))
						Status = ServerStatus.Stopped;
					break;
			}
		}


		private static readonly Func<string, int, int, bool>[] _startup = new Func<string, int, int, bool>[]{
			LookForText(31, "Forge Mod Loader version", "FML initializing"),

			LookForText(51, "Attempting early MinecraftForge initialization", "Forge initializing"),

			LookForEvent("FMLConstructionEvent", "Construction"),

			LookForEvent("FMLConstructionEvent", "Construction", false) +
			LookForEvent("FMLPreInitializationEvent", "Pre-initialization"),

			LookForEvent("FMLPreInitializationEvent", "Pre-initialization", false) +
			LookForEvent("FMLInitializationEvent", "Initialization"),

			LookForEvent("FMLInitializationEvent", "Initialization", false) +
			LookForEvent("FMLPostInitializationEvent", "Post-initialization"),

			LookForEvent("FMLPostInitializationEvent", "Post-initialization", false) +
			LookForText(40, "Injecting existing block and item data into this server instance", "Server about to start"),

			LookForText(40, "Applying holder lookups", "Server starting"),

			LookForText(44, "Sending event FMLServerStartedEvent", "Server started!")
		};


		private static bool UpdateStatus(bool update, float progress, string status)
		{
			if (!update)
				return false;
			string format;
			if (!Console.IsOutputRedirected) {
				Console.SetCursorPosition(Console.CursorLeft, Console.CursorTop - 1);
				format = "[{0,3}%] {1,-" + (Console.WindowWidth - 7) + "}";
			} else
				format = "[{0,3}%] {1}";
			Console.WriteLine(String.Format(format, (int)(progress * 100), status));
			return true;
		}

		private static bool LookForText(string line, int start, string message)
		{
			return ((line.Length >= start + message.Length) && (line[0] == '[') &&
			        (line.IndexOf(message, start, message.Length) >= 0));
		}
		private static Func<string, int, int, bool> LookForText(int start, string message, string status)
		{
			return (line, progress, maxProgress) => UpdateStatus(
				LookForText(line, start, message), (float)progress / maxProgress, status);
		}

		private static bool LookForEvent(string line, string eventName, out string modName)
		{
			int slashIndex;
			modName = null;
			return ((line.Length >= 63 + eventName.Length) && (line[33] == '[') &&
			        ((slashIndex = line.IndexOf('/', 35, line.Length - 63)) >= 0) &&
			        (line.Length >= 60 + eventName.Length + (modName = line.Substring(34, slashIndex - 34)).Length * 3) &&
			        (line.IndexOf("Sending event", 38 + modName.Length * 2, 13) >= 0) &&
			        (line.IndexOf(eventName, 52 + modName.Length * 2, eventName.Length) >= 0));
		}
		private static Func<string, int, int, bool> LookForEvent(string eventName, string status, bool last = true)
		{
			string modName;
			return (line, progress, maxProgress) => UpdateStatus(
				LookForEvent(line, eventName, out modName),
				(float)(progress - (last ? 0 : 1)) / maxProgress, status + ": " + modName);
		}
	}

	public enum ServerStatus
	{
		Unknown,
		Starting,
		Running,
		Stopping,
		Stopped,
		Crashed
	}
}