// 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.Collections.Concurrent;
using System.Net.Http;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http.Connections;
using Microsoft.AspNetCore.SignalR.Client;

namespace JwtClientSample
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var app = new Program();
            await Task.WhenAll(
                app.RunConnection(HttpTransportType.WebSockets),
                app.RunConnection(HttpTransportType.ServerSentEvents),
                app.RunConnection(HttpTransportType.LongPolling));
        }

        private const string ServerUrl = "http://localhost:54543";

        private readonly ConcurrentDictionary<string, Task<string>> _tokens = new ConcurrentDictionary<string, Task<string>>(StringComparer.Ordinal);
        private readonly Random _random = new Random();

        private async Task RunConnection(HttpTransportType transportType)
        {
            var userId = "C#" + transportType;
            _tokens[userId] = GetJwtToken(userId);

            var hubConnection = new HubConnectionBuilder()
                .WithUrl(ServerUrl + "/broadcast", options =>
                {
                    options.Transports = transportType;
                    options.AccessTokenProvider = () => _tokens[userId];
                })
                .Build();

            var closedTcs = new TaskCompletionSource<object>();
            hubConnection.Closed += e =>
            {
                closedTcs.SetResult(null);
                return Task.CompletedTask;
            };

            hubConnection.On<string, string>("Message", (sender, message) => Console.WriteLine($"[{userId}] {sender}: {message}"));
            await hubConnection.StartAsync();
            Console.WriteLine($"[{userId}] Connection Started");

            var ticks = 0;
            var nextMsgAt = 3;

            try
            {
                while (!closedTcs.Task.IsCompleted)
                {
                    await Task.Delay(1000);
                    ticks++;
                    if (ticks % 15 == 0)
                    {
                        // no need to refresh the token for websockets
                        if (transportType != HttpTransportType.WebSockets)
                        {
                            _tokens[userId] = GetJwtToken(userId);
                            Console.WriteLine($"[{userId}] Token refreshed");
                        }
                    }

                    if (ticks % nextMsgAt == 0)
                    {
                        await hubConnection.SendAsync("Broadcast", userId, $"Hello at {DateTime.Now.ToString()}");
                        nextMsgAt = _random.Next(2, 5);
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"[{userId}] Connection terminated with error: {ex}");
            }
        }

        private async Task<string> GetJwtToken(string userId)
        {
            var httpResponse = await new HttpClient().GetAsync(ServerUrl + $"/generatetoken?user={userId}");
            httpResponse.EnsureSuccessStatusCode();
            return await httpResponse.Content.ReadAsStringAsync();
        }
    }
}