using Microsoft.UI.Xaml.Controls;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;

// To learn more about WinUI, the WinUI project structure,
// and more about our project templates, see: http://aka.ms/winui-project-info.

namespace wakka
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class FeelsFeedPage : Page
    {
        private readonly Feels Feels = new Feels();
        private readonly ObservableCollection<FeelsPost> LiveFeelsPosts = [];
        private readonly List<List<FeelsPost>> AllFeels;
        private int CurrentChunk = 0;

        public FeelsFeedPage()
        {
            this.InitializeComponent();
            var feels = Feels.AllFeels();
            AllFeels = (List<List<FeelsPost>>)feels.Chunk(4).Select(chunk => chunk.ToList()).ToList();
            LoadFeelsChunk();
            feelsListView.ItemsSource = LiveFeelsPosts;
        }

        private void LoadFeelsChunk()
        {
            var chunk = AllFeels[CurrentChunk];
            foreach (var feel in chunk)
            {
                var date = DateTimeOffset.FromUnixTimeSeconds(feel.M_Time).DateTime.ToLocalTime();
                feel.TimeString = date.ToString("HH:mm (dddd, MMMM dd, yyyy)");
                var body = Feels.GetFeelsBody(feel);
                char[] delimiters = new char[] { ' ', '\n' };
                feel.WordCount = body.Split(delimiters, StringSplitOptions.RemoveEmptyEntries).Length;
                feel.Body = body;
                LiveFeelsPosts.Add(feel);
            }
            CurrentChunk++;
        }

        private void ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
        {
            var scrollViewer = sender as ScrollViewer;
            if (scrollViewer != null)
            {
                if (scrollViewer.VerticalOffset >= scrollViewer.ScrollableHeight)
                {
                    LoadFeelsChunk();
                }
            }
        }
    }
}