// This file is part of the EonaCat project(s) which is released under the Apache License.
// See the LICENSE file or go to https://EonaCat.com/License for full license details.

using System.Net.Security;
using System.Reflection;
using System.Security.Authentication;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using EonaCat.WebSockets;

internal class Program
{
    private static AsyncWebSocketClient _client;
    private static AsyncWebSocketServer _server;

    private static async Task Main(string[] args)
    {
        // Menu loop
        while (true)
        {
            Console.WriteLine("0. Create a HTTPS certificate");
            Console.WriteLine("1. Start the server and client");
            Console.WriteLine("2. Send Message");
            Console.WriteLine("3. Quit");

            var choice = Console.ReadLine();

            switch (choice)
            {
                case "0":
                    CreateCertificate();
                    break;

                case "1":
                    await CreateServerAndClientAsync().ConfigureAwait(false);
                    break;

                case "2":
                    if (_client != null)
                    {
                        Console.Write("Enter message: ");
                        var message = Console.ReadLine();
                        await _client.SendTextAsync(message).ConfigureAwait(false);
                    }

                    break;

                case "3":
                    _client?.CloseAsync().ConfigureAwait(false);
                    return;

                default:
                    Console.WriteLine("Invalid choice. Try again.");
                    break;
            }
        }
    }

    private static async Task CreateServerAndClientAsync()
    {
        var serverUri = "wss://localhost:8443";
        var clientUri = "wss://localhost:8443/Welcome";
        var certificatePath = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "localhost.pfx");
        var certificatePassword = "";
        var requiredPassword = "";

        // Start the server
        StartServer(serverUri, certificatePath, certificatePassword, requiredPassword);

        // Start the client in the main thread
        await StartClientAsync(clientUri, certificatePath, certificatePassword).ConfigureAwait(false);
        Console.WriteLine("Connected to the server.");
    }

    private static async Task StartClientAsync(string clientUri, string certificatePath, string certificatePassword)
    {
        var configuration = new AsyncWebSocketClientConfiguration();
        configuration.SslTargetHost = "localhost";
        configuration.SslEncryptionPolicy = EncryptionPolicy.RequireEncryption;
        configuration.SslCheckCertificateRevocation = false;
        configuration.SslPolicyErrorsBypassed = true;
        configuration.SslEnabledProtocols = SslProtocols.Tls12 | SslProtocols.Tls13;
        configuration.SslClientCertificates = new X509CertificateCollection { new X509Certificate2(certificatePath, certificatePassword) };

        _client = new AsyncWebSocketClient(new Uri(clientUri), OnServerTextReceived, OnServerBinaryReceived, OnServerConnected, OnServerDisconnected, OnServerFragmentationStreamOpened, OnServerFragmentationStreamOpened, OnServerFragmentationStreamClosed, configuration);
        await _client.ConnectAsync().ConfigureAwait(false);
    }

    private static Task OnServerFragmentationStreamClosed(AsyncWebSocketClient arg1, byte[] arg2, int arg3, int arg4)
    {
        // Do nothing
        return Task.CompletedTask;
    }

    private static Task OnServerFragmentationStreamOpened(AsyncWebSocketClient arg1, byte[] arg2, int arg3, int arg4)
    {
        // Do nothing
        return Task.CompletedTask;
    }

    private static Task OnServerDisconnected(AsyncWebSocketClient arg)
    {
        Console.WriteLine("Disconnected from server.");
        return Task.CompletedTask;
    }

    private static Task OnServerConnected(AsyncWebSocketClient arg)
    {
        Console.WriteLine("Connected to server.");
        return Task.CompletedTask;
    }

    private static Task OnServerBinaryReceived(AsyncWebSocketClient arg1, byte[] bytes, int arg3, int arg4)
    {
        Console.WriteLine($"Received binary {bytes} {arg3} {arg4}");
        return Task.CompletedTask;
    }

    private static Task OnServerTextReceived(AsyncWebSocketClient arg1, string data)
    {
        Console.WriteLine($"Received message from server: {data}");
        return Task.CompletedTask;
    }

    private static void CreateCertificate()
    {
        Console.Write("Enter hostname: (default: localhost) ");
        var hostname = Console.ReadLine();

        if (string.IsNullOrWhiteSpace(hostname))
        {
            hostname = "localhost";
        }

        var days = 30;
        Console.Write("Enter days until expiration: (default: 30 days) ");
        if (int.TryParse(Console.ReadLine(), out var givenDays))
        {
            days = givenDays;
        }

        Console.Write("Enter password, enter to skip: ");
        var password = Console.ReadLine();

        var rsa = RSA.Create();

        // Create a certificate request with the specified subject and key pair
        var request = new CertificateRequest(
            $"CN={hostname}",
            rsa,
            HashAlgorithmName.SHA256,
            RSASignaturePadding.Pkcs1);

        // Create a self-signed certificate from the certificate request
        var certificate = request.CreateSelfSigned(DateTimeOffset.UtcNow, DateTimeOffset.UtcNow.AddDays(days));

        // Export the certificate to a file with password
        var certBytes = string.IsNullOrEmpty(password)
            ? certificate.Export(X509ContentType.Pfx)
            : certificate.Export(X509ContentType.Pfx, password);
        File.WriteAllBytes($"{hostname}.pfx", certBytes);

        Console.WriteLine(
            $"Certificate for {hostname} created successfully and will expire on {certificate.NotAfter}.");
        Console.WriteLine($"Path: {Path.Combine(AppContext.BaseDirectory, hostname)}.pfx");
    }

    private static void StartServer(string serverUri, string certificatePath, string certificatePassword,
        string requiredPassword)
    {
        // split the server uri to get the port
        var uri = new Uri(serverUri);
        var port = uri.Port;

        var test = new AsyncWebSocketServerModuleCatalog();
        test.RegisterModule(new TestModule());
        var configuration = new AsyncWebSocketServerConfiguration();
        configuration.SslEnabled = true;
        configuration.SslEncryptionPolicy = EncryptionPolicy.RequireEncryption;
        configuration.SslCheckCertificateRevocation = false;
        configuration.SslPolicyErrorsBypassed = true;
        configuration.SslClientCertificateRequired = true;
        configuration.SslEnabledProtocols = SslProtocols.Tls12 | SslProtocols.Tls13;
        configuration.SslServerCertificate = new X509Certificate2(certificatePath, certificatePassword);
        _server = new AsyncWebSocketServer(port, test, configuration);
        _server.Listen();
    }
}