Console.cs

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using System;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
 
using Tgstation.Server.Host.System;
 
namespace Tgstation.Server.Host.IO
{
    sealed class Console : IConsole, IDisposable
    {
        public string? Title => platformIdentifier.IsWindows
            ? global::System.Console.Title
            : null;
 
        public bool Available => Environment.UserInteractive;
 
        public CancellationToken CancelKeyPress => cancelKeyCts.Token;
 
        readonly IPlatformIdentifier platformIdentifier;
 
        readonly CancellationTokenSource cancelKeyCts;
 
        bool disposed;
 
        public Console(IPlatformIdentifier platformIdentifier)
        {
            this.platformIdentifier = platformIdentifier ?? throw new ArgumentNullException(nameof(platformIdentifier));
 
            cancelKeyCts = new CancellationTokenSource();
            global::System.Console.CancelKeyPress += (sender, e) =>
            {
                lock (cancelKeyCts)
                {
                    if (!disposed)
                        cancelKeyCts.Cancel();
                }
            };
        }
 
        public void Dispose()
        {
            lock (cancelKeyCts)
            {
                cancelKeyCts.Dispose();
                disposed = true;
            }
        }
 
        public Task PressAnyKeyAsync(CancellationToken cancellationToken) => Task.Factory.StartNew(
            () =>
            {
                CheckAvailable();
                global::System.Console.Read();
            },
            cancellationToken,
            DefaultIOManager.BlockingTaskCreationOptions,
            TaskScheduler.Current);
 
        public Task<string> ReadLineAsync(bool usePasswordChar, CancellationToken cancellationToken) => Task.Factory.StartNew(
            () =>
            {
                // TODO: Make this better: https://stackoverflow.com/questions/9479573/how-to-interrupt-console-readline
                CheckAvailable();
                if (!usePasswordChar)
                    return global::System.Console.ReadLine()
                    ?? throw new InvalidOperationException("Console input has been closed!");
 
                var passwordBuilder = new StringBuilder();
                do
                {
                    var keyDescription = global::System.Console.ReadKey(true);
                    if (keyDescription.Key == ConsoleKey.Enter)
                        break;
                    else if (keyDescription.Key == ConsoleKey.Backspace)
                    {
                        if (passwordBuilder.Length > 0)
                        {
                            --passwordBuilder.Length;
                            global::System.Console.Write("\b \b");
                        }
                    }
                    else if (keyDescription.KeyChar != '\u0000')
                    {
                        // KeyChar == '\u0000' if the key pressed does not correspond to a printable character, e.g. F1, Pause-Break, etc
                        passwordBuilder.Append(keyDescription.KeyChar);
                        global::System.Console.Write('*');
                    }
                }
                while (!cancellationToken.IsCancellationRequested);
 
                cancellationToken.ThrowIfCancellationRequested();
                global::System.Console.WriteLine();
                return passwordBuilder.ToString();
            },
            cancellationToken,
            DefaultIOManager.BlockingTaskCreationOptions,
            TaskScheduler.Current)
            .WaitAsync(cancellationToken);
 
        public Task WriteAsync(string? text, bool newLine, CancellationToken cancellationToken) => Task.Factory.StartNew(
            () =>
            {
                CheckAvailable();
                if (text == null)
                {
                    if (!newLine)
                        throw new InvalidOperationException("Cannot write null text without a new line!");
                    global::System.Console.WriteLine();
                }
                else if (newLine)
                    global::System.Console.WriteLine(text);
                else
                    global::System.Console.Write(text);
            },
            cancellationToken,
            DefaultIOManager.BlockingTaskCreationOptions,
            TaskScheduler.Current);
 
        public void SetTitle(string newTitle)
        {
            ArgumentNullException.ThrowIfNull(newTitle);
            global::System.Console.Title = newTitle;
        }
 
        void CheckAvailable()
        {
            if (!Available)
                throw new InvalidOperationException("Console unavailable");
        }
    }
}