using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;
using BuzzGUI.Interfaces;
using BuzzGUI.Common;
using PropertyChanged;

namespace BuzzGUI.MachineView.ParametersTab
{

	[DoNotNotify]
	public class ParametersTabVM : INotifyPropertyChanged
	{
		MachineView view;

		public enum MachineFilterGroups { All, Selected };
		MachineFilterGroups visibleMachines = MachineFilterGroups.All;

		public MachineFilterGroups VisibleMachines
		{
			get { return visibleMachines; }
			set
			{
				visibleMachines = value;
				PropertyChanged.Raise(this, "VisibleMachines");
				UpdateMachines();
			}
		}

		List<MachineVM> machines;
		public IEnumerable<MachineVM> Machines
		{
			get
			{
				if (machines == null)
				{
					machines = (VisibleMachines == MachineFilterGroups.All ? view.Machines : view.SelectedMachines)
					   .Select(mc => new MachineVM(this, mc.Machine)).OrderBy(m => m.Name).ToList();
				}

				return machines;
			}
		}

		string machineFilter = "";
		public string MachineFilter
		{
			get	{ return machineFilter; }
			set
			{
				machineFilter = value;
				if (machines != null)
				{
					foreach (var m in machines)
						PropertyChanged.Raise(m, "Visibility");
				}
			}
		}

		string parameterFilter = "";
		public string ParameterFilter
		{
			get { return parameterFilter; }
			set
			{
				parameterFilter = value;
				if (machines != null)
				{
					foreach (var m in machines)
					{
						PropertyChanged.Raise(m, "Visibility");

						foreach (var p in m.Parameters)
							PropertyChanged.Raise(p, "Visibility");
					}
				}
			}
		}

		public ParametersTabVM(MachineView view)
		{
			this.view = view;
			view.PropertyChanged += view_PropertyChanged;
		}

		public void Release()
		{
			view.PropertyChanged -= view_PropertyChanged;
		}

		void view_PropertyChanged(object sender, PropertyChangedEventArgs e)
		{
			switch (e.PropertyName)
			{
				case "Machines":
					if (VisibleMachines == MachineFilterGroups.All)
						UpdateMachines();
					break;

				case "SelectedMachines":
					if (VisibleMachines == MachineFilterGroups.Selected)
						UpdateMachines();
					break;
			}

		}


		void UpdateMachines()
		{
			if (machines != null)
			{
				if ((VisibleMachines == MachineFilterGroups.All ? view.Machines : view.SelectedMachines)
					.Select(mc => mc.Machine).OrderBy(m => m.Name).SequenceEqual(machines.Select(vm => vm.Machine)))
					return;

				foreach (var m in machines) m.Release();
				machines = null;
			}

			PropertyChanged.Raise(this, "Machines");
		}

		#region INotifyPropertyChanged Members

		public event PropertyChangedEventHandler PropertyChanged;

		#endregion
	}
}