using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Data;
using Tango.Core.Commands;
using Tango.Core.DI;
using Tango.FSE.Common;
using Tango.FSE.Common.Storage;
using Tango.FSE.Insights.SciChart;
using Tango.SharedUI.Components;

namespace Tango.FSE.Insights.Dialogs
{
    public class ExportToCsvDialogViewVM : FSEDialogViewVM
    {
        private ICollectionView _view;
        private bool _preventSelectAllChange;

        [TangoInject]
        private IStorageProvider StorageProvider { get; set; }

        public SelectedObjectCollection<InsightsChart> SelectedCharts { get; set; }

        private String _filter;
        public String Filter
        {
            get { return _filter; }
            set { _filter = value; RaisePropertyChangedAuto(); OnFilterChanged(); }
        }

        private bool? _selectAll;
        public bool? SelectAll
        {
            get { return _selectAll; }
            set
            {
                if (_selectAll != value)
                {
                    _selectAll = value;
                    RaisePropertyChangedAuto();
                    OnSelectAllChanged();
                }
            }
        }

        private String _selectedFile;
        public String SelectedFile
        {
            get { return _selectedFile; }
            set { _selectedFile = value; RaisePropertyChangedAuto(); InvalidateRelayCommands(); }
        }

        public RelayCommand SelectFileCommand { get; set; }

        public ExportToCsvDialogViewVM(List<InsightsChart> availableCharts, List<InsightsChart> visibleCharts)
        {
            TangoIOC.Default.Inject(this);

            OKText = "EXPORT";
            SelectedCharts = new SelectedObjectCollection<InsightsChart>(availableCharts.OrderByDescending(x => visibleCharts.Contains(x)).ToObservableCollection(), visibleCharts.ToObservableCollection());
            SelectedCharts.SelectionChanged += SelectedCharts_SelectionChanged;

            _view = CollectionViewSource.GetDefaultView(SelectedCharts);
            _view.Filter = FilterCharts;

            SelectFileCommand = new RelayCommand(SelectFile);
        }

        private async void SelectFile()
        {
            var result = await StorageProvider.SaveFile("Export Monitors CSV", "CSV Files|*.csv", null, ".csv");

            if (result.Confirmed)
            {
                SelectedFile = result.SelectedItem;
            }
        }

        private bool FilterCharts(object obj)
        {
            if (String.IsNullOrWhiteSpace(Filter)) return true;
            return (obj as SelectedObject<InsightsChart>).Data.Description.ToLower().Contains(Filter.ToLower());
        }

        private void SelectedCharts_SelectionChanged(object sender, EventArgs e)
        {
            if (!_preventSelectAllChange)
            {
                if (SelectedCharts.All(x => x.IsSelected))
                {
                    _selectAll = true;
                }
                else if (SelectedCharts.Any(x => x.IsSelected))
                {
                    _selectAll = null;
                }
                else
                {
                    _selectAll = false;
                }
            }

            RaisePropertyChanged(nameof(SelectAll));

            InvalidateRelayCommands();
        }

        protected override bool CanOK()
        {
            return base.CanOK() && SelectedCharts.SynchedSource.Count > 0 && SelectedFile != null;
        }

        private void OnFilterChanged()
        {
            _view?.Refresh();
        }

        private void OnSelectAllChanged()
        {
            if (SelectAll != null)
            {
                _preventSelectAllChange = true;
                SelectedCharts.ToList().ForEach(x => x.IsSelected = SelectAll.Value);
                _preventSelectAllChange = false;
            }
        }
    }
}