using Android.Content;
using Android.Views;
using Android.Widget;
using Google.Android.Material.BottomNavigation;
using Google.Android.Material.Tabs;
using System;
using Xamarin.Forms;
using Project.Android.Renderers;
using Project.Views;
using Xamarin.Forms.Platform.Android;
using Xamarin.Forms.Platform.Android.AppCompat;

[assembly: ExportRenderer(typeof(TabbedPage), typeof(DashboardTabbedPageRenderer))]
namespace project.Android.Renderers
{
    /// <summary>
    /// Dahs board tabbed page renderer.
    /// </summary>
    public class DashboardTabbedPageRenderer : TabbedPageRenderer
    {
        private TabLayout _tabLayout;
        private TabbedPage _page;
        private BottomNavigationView _bottomNavigationView;
        private int _lastItemId = -1;
        private Context _context;
        private TextView _badgeView;

        public DashboardTabbedPageRenderer(Context context) : base(context)
        {
            _context = context;
        }

        /// <summary>
        /// Ons the element changed.
        /// </summary>
        /// <param name="e">E.</param>
        protected override void OnElementChanged(ElementChangedEventArgs<TabbedPage> e)
        {
            base.OnElementChanged(e);

            if (Element != null)
            {
                _tabLayout = (TabLayout)ViewGroup.GetChildAt(1);

                for (var i = 0; i < Element.Children.Count; i++)
                {
                    var child = Element.Children[i];
                }

                for (var i = 0; i < ViewGroup.ChildCount; i++)
                {
                    var layousst = ViewGroup.GetChildAt(i);
                }
            }

            if (e.NewElement != null)
            {
                _page = e.NewElement;
                _page.CurrentPageChanged += Page_CurrentPageChanged;
                ((DashboardTabPage)e.NewElement).DashboardBadgeEvent += DashboardTabbedPageRenderer_BadgeEvent;
            }
            else
            {
                _page = e.OldElement;
                _page.CurrentPageChanged -= Page_CurrentPageChanged;
                ((DashboardTabPage)e.NewElement).DashboardBadgeEvent -= DashboardTabbedPageRenderer_BadgeEvent;
            }
        }

        void Page_CurrentPageChanged(object sender, EventArgs e)
        {
            Device.BeginInvokeOnMainThread(() =>
            {
                try
                {
                    //NOTE: BottomNavigationView was getting disposed and crashing the Android app
                    _bottomNavigationView.SelectedItemId = _lastItemId;
                }
                catch (ObjectDisposedException disposedExc)
                {
                    if (_page != null)
                    {
                        //NOTE: If disposed need to unsubscribe the Page because it was infinitely being subscribed to
                        _page.CurrentPageChanged -= Page_CurrentPageChanged;
                    }
                    Console.WriteLine($"DashboardTabbedPageRenderer Disposed Exception: {disposedExc}");
                }
            });
        }

        private void DashboardTabbedPageRenderer_BadgeEvent(object sender, int count)
        {
            Device.BeginInvokeOnMainThread(() =>
            {
                UpdateBadge(count);
            });
        }

        /// <summary>
        /// Ons the element property changed.
        /// </summary>
        /// <param name="sender">Sender.</param>
        /// <param name="e">E.</param>
        protected override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
        {
            base.OnElementPropertyChanged(sender, e);

            if (_tabLayout == null && e.PropertyName == "Renderer")
            {
                _tabLayout = (TabLayout)ViewGroup.GetChildAt(1);
            }

            if (_tabLayout != null && e.PropertyName == "CurrentPage")
            {
                _tabLayout.GetTabAt(1).Select();
            }

            for (var i = 0; i < ViewGroup.ChildCount; i++)
            {
                var view = ViewGroup.GetChildAt(i) as global::Android.Widget.RelativeLayout;

                for (var j = 0; j < view.ChildCount; j++)
                {
                    var child = view.GetChildAt(j);

                    if (child is BottomNavigationView)
                    {
                        _bottomNavigationView = child as BottomNavigationView;

                        _bottomNavigationView.NavigationItemSelected -= BottomNavigationView_NavigationItemSelected;
                        _bottomNavigationView.NavigationItemSelected += BottomNavigationView_NavigationItemSelected;

                        _bottomNavigationView.NavigationItemReselected -= BottomNavigationView_NavigationItemReselected;
                        _bottomNavigationView.NavigationItemReselected += BottomNavigationView_NavigationItemReselected;
                    }
                }
            }
        }

        void BottomNavigationView_NavigationItemReselected(object sender, BottomNavigationView.NavigationItemReselectedEventArgs e)
        {
            _lastItemId = e.Item.ItemId;
            _page.CurrentPage = _page.Children[_lastItemId];
        }

        void BottomNavigationView_NavigationItemSelected(object sender, BottomNavigationView.NavigationItemSelectedEventArgs e)
        {
            _lastItemId = e.Item.ItemId;
            _page.CurrentPage = _page.Children[_lastItemId];
        }

        private void UpdateBadge(int count)
        {
            try
            {
                if (_bottomNavigationView == null)
                    return;

                if (count == 0)
                {
                    RemoveBadge();
                    return;
                }

                if (_badgeView == null)
                {
                    BottomNavigationMenuView view = (BottomNavigationMenuView)_bottomNavigationView.GetChildAt(0);
                    var itemView = (BottomNavigationItemView)view.GetChildAt(0);
                    var badgeLayout = LayoutInflater.From(_context).Inflate(Resource.Layout.CustomTabLayout, itemView, true);
                    _badgeView = badgeLayout.FindViewById<TextView>(Resource.Id.text_badge);
                }

                _badgeView.Visibility = ViewStates.Visible;
                _badgeView.SetText(count.ToString(), TextView.BufferType.Normal);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex);
            }
        }

        private void RemoveBadge()
        {
            if (_bottomNavigationView == null)
                return;

            if (_badgeView == null)
            {
                BottomNavigationMenuView view = (BottomNavigationMenuView)_bottomNavigationView.GetChildAt(0);
                var itemView = (BottomNavigationItemView)view.GetChildAt(0);
                var badgeLayout = LayoutInflater.From(_context).Inflate(Resource.Layout.CustomTabLayout, itemView, true);
                _badgeView = badgeLayout.FindViewById<TextView>(Resource.Id.text_badge);
            }

            _badgeView.Visibility = ViewStates.Gone;
            _badgeView.SetText("0", TextView.BufferType.Normal);
        }
    }
}