bepin/BepInEx/Logging/PreloaderLogWriter.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Text;
using BepInEx.Bootstrap;
using BepInEx.ConsoleUtil;

namespace BepInEx.Logging
{
	/// <summary>
	/// A log writer specific to the <see cref="Preloader"/>.
	/// </summary>
	/// <inheritdoc cref="BaseLogger"/>
	public class PreloaderLogWriter : BaseLogger
	{
		/// <summary>
		/// The <see cref="System.Text.StringBuilder"/> which contains all logged entries, so it may be passed onto another log writer.
		/// </summary>
		public StringBuilder StringBuilder { get; protected set; } = new StringBuilder();

		/// <summary>
		/// Whether or not the log writer is redirecting console output, so it can be logged.
		/// </summary>
		public bool IsRedirectingConsole { get; protected set; }

		protected TextWriter stdout;
		protected LoggerTraceListener traceListener;

		private bool _enabled = false;

		/// <summary>
		/// Whether or not the log writer is writing and/or redirecting.
		/// </summary>
		public bool Enabled
		{
			get => _enabled;
			set
			{
				if (value)
					Enable();
				else
					Disable();
			}
		}

		/// <param name="redirectConsole">Whether or not to redirect the console standard output.</param>
		public PreloaderLogWriter(bool redirectConsole)
		{
			IsRedirectingConsole = redirectConsole;

			stdout = Console.Out;
			traceListener = new LoggerTraceListener(this);
		}

		/// <summary>
		/// Enables the log writer.
		/// </summary>
		public void Enable()
		{
			if (_enabled)
				return;

			if (IsRedirectingConsole)
				Console.SetOut(this);
			else
				Console.SetOut(Null);

			Trace.Listeners.Add(traceListener);

			_enabled = true;
		}

		/// <summary>
		/// Disables the log writer.
		/// </summary>
		public void Disable()
		{
			if (!_enabled)
				return;

			Console.SetOut(stdout);

			Trace.Listeners.Remove(traceListener);

			_enabled = false;
		}

		/// <summary>
		/// Logs an entry to the Logger instance.
		/// </summary>
		/// <param name="level">The level of the entry.</param>
		/// <param name="entry">The textual value of the entry.</param>
		public override void Log(LogLevel level, object entry)
		{
			Kon.ForegroundColor = level.GetConsoleColor();
			base.Log(level, entry);
			Kon.ForegroundColor = ConsoleColor.Gray;
		}

		public override void Write(char value)
		{
			StringBuilder.Append(value);

			stdout.Write(value);
		}

		public override void Write(string value)
		{
			StringBuilder.Append(value);

			stdout.Write(value);
		}

		protected override void Dispose(bool disposing)
		{
			Disable();
			StringBuilder.Length = 0;

			traceListener?.Dispose();
			traceListener = null;
		}

		public override string ToString()
		{
			return StringBuilder.ToString().Trim();
		}
	}
}