using System;
using System.ComponentModel;
using TINK.Settings;

namespace TINK.ViewModel.Settings
{
	/// <summary> Polling relagted parameters</summary>
	public class PollingViewModel : INotifyPropertyChanged
	{
		/// <summary>Holds the views polling parameters.</summary>
		private PollingParameters m_oPolling = PollingParameters.Default;

		/// <summary> Current polling period. Used to check whether values were modified or not.</summary>
		private readonly PollingParameters m_oPollingActive;

		/// <summary> Constructs polling object. </summary>
		/// <param name="p_oSource">Object to construct from</param>
		public PollingViewModel(PollingParameters p_oSource)
		{
			m_oPollingActive = p_oSource
				?? throw new ArgumentException("Can not instantiate polling parameters view model- object. Polling parameter object is null.");

			m_oPolling = p_oSource;
		}

		/// <summary> Gets the immutable version of polling parameters.</summary>
		/// <returns>Polling parameters object.</returns>
		public PollingParameters ToImmutable() { return m_oPolling; }

		/// <summary> Holds value whether polling is activated or not.</summary>
		public bool IsActivated
		{
			get
			{
				return m_oPolling.IsActivated;
			}

			set
			{
				if (value == m_oPolling.IsActivated)
				{
					// Nothing to do.
					return;
				}

				m_oPolling = new PollingParameters(m_oPolling.Periode, value);

				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(IsActivated)));
				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(PeriodeTotalSeconds)));
				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(PeriodeTotalSecondsText)));
				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(PollingText)));
			}
		}

		/// <summary> Gests or sets the polling period [sec]. </summary>
		public int PeriodeTotalSeconds
		{
			get
			{
				return (int)m_oPolling.Periode.TotalSeconds;
			}

			set
			{
				if (value == (int)m_oPolling.Periode.TotalSeconds)
				{
					// Nothing to do.
					return;
				}

				m_oPolling = new PollingParameters(new TimeSpan(0, 0, value), IsActivated);

				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(PeriodeTotalSeconds)));
				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(PeriodeTotalSecondsText)));
				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(PollingText)));
			}
		}

		/// <summary> Gets info about polling period.</summary>
		public string PeriodeTotalSecondsText
		{
			get
			{
				if (IsActivated)
				{
					return $"Polling Periode: {PeriodeTotalSeconds} [Sek.]";
				}

				return $"Polling abgeschalten.";
			}
		}

		/// <summary> Gets the text of the polling related controls.</summary>
		public string PollingText
		{
			get
			{
				if (m_oPolling == m_oPollingActive)
				{
					return "Polling";
				}

				return "Polling\r\nAnsicht verlassen um Änderungen anzuwenden.";
			}
		}

		/// <summary> Notifies GUI about modified values.</summary>
		public event PropertyChangedEventHandler PropertyChanged;
	}
}