using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace HashCalculator.GUI
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        private readonly FileSystemSuggestions _suggestions = new FileSystemSuggestions();
        private readonly ViewModel _model = new ViewModel();

        public MainWindow()
        {
            InitializeComponent();
            DataContext = _model;
        }

        private void OnTextChanged(object sender, TextChangedEventArgs e)
        {
            if (sender is InputBar)
            {
                var inputValue = _model.Text;
                if(inputValue != null)
                {
                    _model.Items = _suggestions.ProvideFileSystemSuggestions(inputValue)
                        .Prepend(new InputEntry(InputEntryType.Text, inputValue, inputValue));
                }
            }
        }
    }

    internal class ViewModel : INotifyPropertyChanged
    {
        #region INotifyPropertyChanged
        public event PropertyChangedEventHandler? PropertyChanged;

        private void Notify(string name)
        {
            System.Diagnostics.Debug.WriteLine($"Updating {name}");
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
        }

        private void SetField<X>(ref X field, X value, [CallerMemberName] string? propertyName = null)
        {
            if (propertyName == null)
            {
                throw new InvalidOperationException();
            }

            if (EqualityComparer<X>.Default.Equals(field, value))
            {
                return;
            }

            field = value;

            Notify(propertyName);
        }
        #endregion

        private IEnumerable<InputEntry>? _items;
        public IEnumerable<InputEntry>? Items
        {
            get => _items;
            set => SetField(ref _items, value);
        }

        private InputEntry? selectedItem;
        public InputEntry? SelectedItem
        {
            get { return selectedItem; }
            set { SetField(ref selectedItem, value); }
        }

        private string? selectedValue;
        public string? SelectedValue
        {
            get { return selectedValue; }
            set { SetField(ref selectedValue, value); }
        }

        private string? _text;
        public string? Text
        {
            get { return _text; }
            set { SetField(ref _text, value); }
        }
    }

}