using System;

using System.Collections.Generic;

using System.Reactive.Disposables;

using System.Threading;

using Android.Views;

using Android.Widget;

using Splat;

namespace ReactiveUI

{

public class ReactiveListAdapter<TViewModel> : BaseAdapter<TViewModel>, IEnableLogger

where TViewModel : class

{

readonly IReadOnlyReactiveList<TViewModel> list;

readonly Func<TViewModel, ViewGroup, View> viewCreator;

readonly Action<TViewModel, View> viewInitializer;

IDisposable _inner;

public ReactiveListAdapter(

IReadOnlyReactiveList<TViewModel> backingList,

Func<TViewModel, ViewGroup, View> viewCreator,

Action<TViewModel, View> viewInitializer = null)

{

this.list = backingList;

this.viewCreator = viewCreator;

this.viewInitializer = viewInitializer;

_inner = this.list.Changed.Subscribe(_ => NotifyDataSetChanged());

}

public override TViewModel this[int index] {

get { return list[index]; }

}

public override long GetItemId(int position) {

return list[position].GetHashCode();

}

public override bool HasStableIds {

get { return true; }

}

public override int Count {

get { return list.Count; }

}

public override View GetView(int position, View convertView, ViewGroup parent)

{

View theView = convertView;

var data = list[position];

if (theView == null) {

theView = viewCreator(data, parent);

}

var ivf = theView.GetViewHost() as IViewFor<TViewModel>;

if (ivf != null) {

ivf.ViewModel = data;

}

if (viewInitializer != null) {

viewInitializer(data, theView);

}

return theView;

}

protected override void Dispose(bool disposing)

{

base.Dispose(disposing);

Interlocked.Exchange(ref _inner, Disposable.Empty).Dispose();

}

}

}