// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Buffers;
using System.IO;
using System.IO.Pipelines;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Connections;
using Microsoft.AspNetCore.Http.Connections.Client;
using Microsoft.Extensions.CommandLineUtils;
 
namespace ClientSample;
 
internal class RawSample
{
    internal static void Register(CommandLineApplication app)
    {
        app.Command("raw", cmd =>
        {
            cmd.Description = "Tests a connection to an endpoint";
 
            var baseUrlArgument = cmd.Argument("<BASEURL>", "The URL to the Chat EndPoint to test");
 
            cmd.OnExecute(() => ExecuteAsync(baseUrlArgument.Value));
        });
    }
 
    public static async Task<int> ExecuteAsync(string baseUrl)
    {
        baseUrl = string.IsNullOrEmpty(baseUrl) ? "http://localhost:5000/chat" : baseUrl;
 
        Console.WriteLine($"Connecting to {baseUrl}...");
 
        var connectionOptions = new HttpConnectionOptions
        {
            Url = new Uri(baseUrl),
            DefaultTransferFormat = TransferFormat.Text,
        };
 
        var connection = new HttpConnection(connectionOptions, loggerFactory: null);
 
        try
        {
            await connection.StartAsync();
 
            Console.WriteLine($"Connected to {baseUrl}");
            var shutdown = new TaskCompletionSource<object>();
            Console.CancelKeyPress += (sender, a) =>
            {
                a.Cancel = true;
                shutdown.TrySetResult(null);
            };
 
            _ = ReceiveLoop(Console.Out, connection.Transport.Input);
            _ = SendLoop(Console.In, connection.Transport.Output);
 
            await shutdown.Task;
        }
        catch (AggregateException aex) when (aex.InnerExceptions.All(e => e is OperationCanceledException))
        {
        }
        catch (OperationCanceledException)
        {
        }
        finally
        {
            await connection.DisposeAsync();
        }
        return 0;
    }
 
    private static async Task ReceiveLoop(TextWriter output, PipeReader input)
    {
        while (true)
        {
            var result = await input.ReadAsync();
            var buffer = result.Buffer;
 
            try
            {
                if (!buffer.IsEmpty)
                {
                    await output.WriteLineAsync(Encoding.UTF8.GetString(buffer.ToArray()));
                }
                else if (result.IsCompleted)
                {
                    // No more data, and the pipe is complete
                    break;
                }
            }
            finally
            {
                input.AdvanceTo(buffer.End);
            }
        }
    }
 
    private static async Task SendLoop(TextReader input, PipeWriter output)
    {
        while (true)
        {
            var result = await input.ReadLineAsync();
            await output.WriteAsync(Encoding.UTF8.GetBytes(result));
        }
    }
}