using System.Collections.Generic;
using System.Threading.Tasks;
using Gallery.Resources.UI;
using Gallery.Util;
using Gallery.Util.Interface;
using Gallery.Util.Model;
using Xamarin.Forms;

namespace Gallery.Views
{
    public partial class GalleryPage : GalleryCollectionPage
    {
        private int currentPage;

        public GalleryPage(IGallerySource source) : base(source)
        {
            Resources.Add("cardView", GetCardViewTemplate());
            InitializeComponent();

            currentPage = 1;
        }

        protected override ActivityIndicator LoadingIndicator => activityLoading;

        protected override void OnAppearing()
        {
            if (currentPage != 1 && Gallery == null)
            {
                currentPage = 1;
            }
            base.OnAppearing();
        }

        protected override async Task<GalleryItem[]> DoloadGalleryData(bool force)
        {
            var result = await Source.GetRecentItemsAsync(currentPage);
            return result;
        }

        protected override IEnumerable<GalleryItem> DoGetGalleryList(GalleryItem[] data, out int tag)
        {
            tag = currentPage;
            return data;
        }

        private void FlowLayout_MaxHeightChanged(object sender, HeightEventArgs e)
        {
            SetOffset(e.ContentHeight - scrollView.Bounds.Height - SCROLL_OFFSET);
        }

        protected override bool CheckRefresh()
        {
            currentPage++;
#if DEBUG
            Log.Print($"loading page: {currentPage}");
#endif
            return true;
        }

        private void ScrollView_Scrolled(object sender, ScrolledEventArgs e)
        {
            var y = e.ScrollY;
            OnScrolled(y);
        }
    }
}