using System;
using System.Runtime.InteropServices;
using System.Text;
using System.IO;
using System.Net;
using System.Net.Sockets;
using wolfSSL.CSharp;

public class wolfSSL_TLS_CSHarp
{
    /// <summary>
    /// Example of a logging function
    /// </summary>
    /// <param name="lvl">level of log</param>
    /// <param name="msg">message to log</param>
    public static void standard_log(int lvl, StringBuilder msg)
    {
        Console.WriteLine(msg);
    }

    public static void Main(string[] args)
    {
        IntPtr ctx;
        IntPtr ssl;
        Socket fd;

        /* These paths should be changed for use */
        string fileCert = @"server-cert.pem";
        string fileKey = @"server-key.pem";
        StringBuilder dhparam = new StringBuilder("dh2048.pem");

        StringBuilder buff = new StringBuilder(1024);
        StringBuilder reply = new StringBuilder("Hello, this is the wolfSSL C# wrapper");

        //example of function used for setting logging
        wolfssl.SetLogging(standard_log);

        wolfssl.Init();

        Console.WriteLine("Calling ctx Init from wolfSSL");
        ctx = wolfssl.CTX_new(wolfssl.usev23_server());
        Console.WriteLine("Finished init of ctx .... now load in cert and key");

        if (!File.Exists(fileCert) || !File.Exists(fileKey))
        {
            Console.WriteLine("Could not find cert or key file");
            return;
        }

        if (wolfssl.CTX_use_certificate_file(ctx, fileCert, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting cert file");
            return;
        }

        if (wolfssl.CTX_use_PrivateKey_file(ctx, fileKey, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting key file");
            return;
        }


        StringBuilder ciphers = new StringBuilder(new String(' ', 4096));
        wolfssl.get_ciphers(ciphers, 4096);
        Console.WriteLine("Ciphers : " + ciphers.ToString());

        short minDhKey = 128;
        wolfssl.CTX_SetMinDhKey_Sz(ctx, minDhKey);

        /* set up TCP socket */
        IPAddress ip = IPAddress.Parse("0.0.0.0"); //bind to any
        TcpListener tcp = new TcpListener(ip, 11111);
        tcp.Start();

        Console.WriteLine("Started TCP and waiting for a connection");
        fd = tcp.AcceptSocket();
        ssl = wolfssl.new_ssl(ctx);

        Console.WriteLine("Connection made wolfSSL_accept ");
        if (wolfssl.set_fd(ssl, fd) != wolfssl.SUCCESS)
        {
            /* get and print out the error */
            Console.Write(wolfssl.get_error(ssl));
            return;
        }

        wolfssl.SetTmpDH_file(ssl, dhparam, wolfssl.SSL_FILETYPE_PEM);

        if (wolfssl.accept(ssl) != 1)
        {
            /* get and print out the error */
            Console.Write(wolfssl.get_error(ssl));
            return;
        }

        /* print out results of TLS/SSL accept */
        Console.WriteLine("SSL version is " + wolfssl.get_version(ssl));
        Console.WriteLine("SSL cipher suite is " + wolfssl.get_current_cipher(ssl));

        /* read and print out the message then reply */
        if (wolfssl.read(ssl, buff, 1023) < 0)
        {
            Console.WriteLine("Error in read");
            return;
        }
        Console.WriteLine(buff);

        if (wolfssl.write(ssl, reply, reply.Length) != reply.Length)
        {
            Console.WriteLine("Error in write");
            return;
        }

        wolfssl.shutdown(ssl);
        wolfssl.free(ssl);
        fd.Close();

        wolfssl.CTX_free(ctx);
        wolfssl.Cleanup();
    }
}