//
//  Copyright 2012, Xamarin Inc.
//
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
//
//        http://www.apache.org/licenses/LICENSE-2.0
//
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.
//
using System;
using EmployeeDirectory.Data;
using System.Collections.ObjectModel;

namespace EmployeeDirectory.ViewModels
{
	public class FavoritesViewModel : ViewModelBase
	{
		IFavoritesRepository favoritesRepository;
		bool groupByLastName;

		public ObservableCollection<PeopleGroup> Groups { get; private set; }

		public ObservableCollection<Person> People { get; private set; }

		public bool IsEmpty {
			get {
				return Groups.Count == 0;
			}
		}

		public FavoritesViewModel (IFavoritesRepository favoritesRepository, bool groupByLastName)
		{
			if (favoritesRepository == null)
				throw new ArgumentNullException ("favoritesRepository");

			this.favoritesRepository = favoritesRepository;
			this.groupByLastName = groupByLastName;

			CreateGroups ();

			favoritesRepository.Changed += delegate {
				CreateGroups ();
			};
		}

		private void CreateGroups ()
		{
			People = new ObservableCollection<Person> (favoritesRepository.GetAll ());
			Groups = PeopleGroup.CreateGroups (
				favoritesRepository.GetAll (),
				groupByLastName);
			OnPropertyChanged ("Groups");
		}
	}
}

