using System;
using System.Runtime.CompilerServices;
using UnityEngine;
using UnityEngine.Networking;

namespace QuestAppLauncher
{
    /// <summary>
    /// Awaiter implementation for UnityWebRequest - allows us to use async / await pattern on UnityWebRequest.
    /// </summary>
    public class UnityWebRequestAwaiter : INotifyCompletion
    {
        private UnityWebRequestAsyncOperation asyncOp;
        private Action continuation;

        public UnityWebRequestAwaiter(UnityWebRequestAsyncOperation asyncOp)
        {
            this.asyncOp = asyncOp;
            asyncOp.completed += OnRequestCompleted;
        }

        public bool IsCompleted { get { return asyncOp.isDone; } }

        public void GetResult() { }

        public void OnCompleted(Action continuation)
        {
            this.continuation = continuation;
        }

        private void OnRequestCompleted(AsyncOperation obj)
        {
            continuation();
        }
    }

    public static class ExtensionMethods
    {
        public static UnityWebRequestAwaiter GetAwaiter(this UnityWebRequestAsyncOperation asyncOp)
        {
            return new UnityWebRequestAwaiter(asyncOp);
        }
    }
}