#if !NETSTANDARD1_3

using System;
using System.Threading;
using Unosquare.Swan.Abstractions;
namespace Unosquare.Swan.Components {
  /// <summary>
  /// Use this singleton to wait for a specific <c>TimeSpan</c> or time.
  ///
  /// Internally this class will use a <c>Timer</c> and a <c>ManualResetEvent</c> to block until
  /// the time condition is satisfied.
  /// </summary>
  /// <seealso cref="SingletonBase{TimerControl}" />
  public class TimerControl : SingletonBase<TimerControl> {
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Codequalität", "IDE0052:Ungelesene private Member entfernen", Justification = "<Ausstehend>")]
    private readonly Timer _innerTimer;
    private readonly IWaitEvent _delayLock = WaitEventFactory.Create(true);

    /// <summary>
    /// Initializes a new instance of the <see cref="TimerControl"/> class.
    /// </summary>
    protected TimerControl() => this._innerTimer = new Timer(
                x => {
                  try {
                    this._delayLock.Complete();
                    this._delayLock.Begin();
                  } catch {
                    // ignore
                  }
                },
                null,
                0,
                15);

    /// <summary>
    /// Waits until the time is elapsed.
    /// </summary>
    /// <param name="untilDate">The until date.</param>
    /// <param name="ct">The cancellation token.</param>
    public void WaitUntil(DateTime untilDate, CancellationToken ct = default) {
      while(!ct.IsCancellationRequested && DateTime.UtcNow < untilDate) {
        this._delayLock.Wait();
      }
    }

    /// <summary>
    /// Waits the specified wait time.
    /// </summary>
    /// <param name="waitTime">The wait time.</param>
    /// <param name="ct">The cancellation token.</param>
    public void Wait(TimeSpan waitTime, CancellationToken ct = default) =>
        this.WaitUntil(DateTime.UtcNow.Add(waitTime), ct);
  }
}
#endif