using System;
using System.IO;
using System.Runtime.InteropServices;

using Shadowsocks.Controller;
using Shadowsocks.Properties;
using Shadowsocks.Util;

namespace Shadowsocks.Encryption
{
    public class Sodium
    {
        const string DLLNAME = "libsscrypto";

        static Sodium()
        {
            string dllPath = Utils.GetTempPath("libsscrypto.dll");
            try
            {
                FileManager.UncompressFile(dllPath, Resources.libsscrypto_dll);
            }
            catch (IOException)
            {
            }
            catch (Exception e)
            {
                Logging.LogUsefulException(e);
            }
            LoadLibrary(dllPath);
        }

        [DllImport("Kernel32.dll")]
        private static extern IntPtr LoadLibrary(string path);

        [DllImport(DLLNAME, CallingConvention = CallingConvention.Cdecl)]
        public extern static int crypto_stream_salsa20_xor_ic(byte[] c, byte[] m, ulong mlen, byte[] n, ulong ic, byte[] k);

        [DllImport(DLLNAME, CallingConvention = CallingConvention.Cdecl)]
        public extern static int crypto_stream_chacha20_xor_ic(byte[] c, byte[] m, ulong mlen, byte[] n, ulong ic, byte[] k);

        [DllImport(DLLNAME, CallingConvention = CallingConvention.Cdecl)]
        public extern static int crypto_stream_chacha20_ietf_xor_ic(byte[] c, byte[] m, ulong mlen, byte[] n, uint ic, byte[] k);

        [DllImport(DLLNAME, CallingConvention = CallingConvention.Cdecl)]
        public extern static void ss_sha1_hmac_ex(byte[] key, uint keylen,
            byte[] input, int ioff, uint ilen,
            byte[] output);
    }
}