using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using YouTubeViewers.WPF.Commands;
using YouTubeViewers.Domain.Models;
using YouTubeViewers.WPF.Stores;

namespace YouTubeViewers.WPF.ViewModels
{
    public class YouTubeViewersListingViewModel : ViewModelBase
    {
        private readonly ObservableCollection<YouTubeViewersListingItemViewModel> _youtubeViewersListingItemViewModels;
        private readonly YouTubeViewersStore _youTubeViewersStore;
        private readonly SelectedYouTubeViewerStore _selectedYouTubeViewerStore;
        private readonly ModalNavigationStore _modalNavigationStore;

        public IEnumerable<YouTubeViewersListingItemViewModel> YouTubeViewersListingItemViewModels => _youtubeViewersListingItemViewModels;

        private YouTubeViewersListingItemViewModel _selectedYouTubeViewerListingItemViewModel;

        public YouTubeViewersListingItemViewModel SelectedYouTubeViewerListingItemViewModel
        {
            get { return _selectedYouTubeViewerListingItemViewModel; }
            set
            {
                _selectedYouTubeViewerListingItemViewModel = value;
                OnPropertyChanged(nameof(SelectedYouTubeViewerListingItemViewModel));
                _selectedYouTubeViewerStore.SelectedYouTubeViewer = _selectedYouTubeViewerListingItemViewModel?.YouTubeViewer;

            }
        }

       

        public YouTubeViewersListingViewModel(
            YouTubeViewersStore youTubeViewersStore,
            SelectedYouTubeViewerStore selectedYouTubeViewerStore,
            ModalNavigationStore modalNavigationStore)
        {
            _youTubeViewersStore = youTubeViewersStore;
            _selectedYouTubeViewerStore = selectedYouTubeViewerStore;
            _modalNavigationStore = modalNavigationStore;
            _youtubeViewersListingItemViewModels = new ObservableCollection<YouTubeViewersListingItemViewModel>();


            _youTubeViewersStore.YouTubeViewersLoaded += _youTubeViewersStore_YouTubeViewersLoaded;
            _youTubeViewersStore.YouTubeViewerAdded += YouTubeViewersStore_YouTubeViewerAdded;
            _youTubeViewersStore.YouTubeViewerUpdated += YouTubeViewersStore_YouTubeViewerUpdated;
            _youTubeViewersStore.YouTubeViewerDeleted += YouTubeViewersStore_YouTubeViewerDeleted;
        }


        private void _youTubeViewersStore_YouTubeViewersLoaded()
        {
            _youtubeViewersListingItemViewModels.Clear();
            foreach (YouTubeViewer youTubeViewer in _youTubeViewersStore.YouTubeViewers)
            {
                AddYouTubeViewer(youTubeViewer);
            }
        }

        private void YouTubeViewersStore_YouTubeViewerUpdated(YouTubeViewer youTubeViewer)
        {
            YouTubeViewersListingItemViewModel youTubeViewerViewModel =
                _youtubeViewersListingItemViewModels.FirstOrDefault(x => x.YouTubeViewer.Id == youTubeViewer.Id);

            if (youTubeViewerViewModel != null)
            {
                youTubeViewerViewModel.Update(youTubeViewer);
            }
        }



        protected override void Dispose()
        {
            _youTubeViewersStore.YouTubeViewersLoaded -= _youTubeViewersStore_YouTubeViewersLoaded;
            _youTubeViewersStore.YouTubeViewerAdded -= YouTubeViewersStore_YouTubeViewerAdded;
            _youTubeViewersStore.YouTubeViewerUpdated -= YouTubeViewersStore_YouTubeViewerUpdated;
            _youTubeViewersStore.YouTubeViewerDeleted -= YouTubeViewersStore_YouTubeViewerDeleted;
            
            base.Dispose();
        }
        private void YouTubeViewersStore_YouTubeViewerAdded(YouTubeViewer youTubeViewer)
        {
            AddYouTubeViewer(youTubeViewer);
        }

        private void AddYouTubeViewer(YouTubeViewer youTubeViewer)
        {
            YouTubeViewersListingItemViewModel itemViewModel =
                new YouTubeViewersListingItemViewModel(youTubeViewer, _youTubeViewersStore, _modalNavigationStore);
            _youtubeViewersListingItemViewModels.Add(itemViewModel);
        }        
        
        private void YouTubeViewersStore_YouTubeViewerDeleted(Guid id)
        {
            YouTubeViewersListingItemViewModel itemViewModel =  _youtubeViewersListingItemViewModels.FirstOrDefault(y => y.YouTubeViewer?.Id == id);

            if (itemViewModel != null)
            {
                _youtubeViewersListingItemViewModels.Remove(itemViewModel);
            }
        }

    }
}