// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace WebSocketSample
{
    public class Program
    {
        public static async Task<int> Main(string[] args)
        {
            if (args.Length < 1)
            {
                Console.Error.WriteLine("Usage: WebSocketSample <URL>");
                Console.Error.WriteLine("");
                Console.Error.WriteLine("To connect to an ASP.NET Connection Handler, use 'ws://example.com/path/to/hub' or 'wss://example.com/path/to/hub' (for HTTPS)");
                return 1;
            }

            await RunWebSockets(args[0]);
            return 0;
        }

        private static async Task RunWebSockets(string url)
        {
            var ws = new ClientWebSocket();
            await ws.ConnectAsync(new Uri(url), CancellationToken.None);

            Console.WriteLine("Connected");

            var sending = Task.Run(async () =>
            {
                string line;
                while ((line = Console.ReadLine()) != null)
                {
                    var bytes = Encoding.UTF8.GetBytes(line);
                    await ws.SendAsync(new ArraySegment<byte>(bytes), WebSocketMessageType.Text, endOfMessage: true, cancellationToken: CancellationToken.None);
                }

                await ws.CloseOutputAsync(WebSocketCloseStatus.NormalClosure, "", CancellationToken.None);
            });

            var receiving = Receiving(ws);

            await Task.WhenAll(sending, receiving);
        }

        private static async Task Receiving(ClientWebSocket ws)
        {
            var buffer = new byte[2048];

            while (true)
            {
                var result = await ws.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);

                if (result.MessageType == WebSocketMessageType.Text)
                {
                    Console.WriteLine(Encoding.UTF8.GetString(buffer, 0, result.Count));
                }
                else if (result.MessageType == WebSocketMessageType.Binary)
                {
                }
                else if (result.MessageType == WebSocketMessageType.Close)
                {
                    await ws.CloseOutputAsync(WebSocketCloseStatus.NormalClosure, "", CancellationToken.None);
                    break;
                }

            }
        }
    }
}
