using System.IO;

namespace Essgee.Emulation
{
    public static class SaveStateHandler
    {
        //public static string ExpectedVersion = $"ESGST{new Version(EmuStandInfo.ProductVersion).Major:D3}";

        //public static Dictionary<string, object> Load(Stream stream, string machineName)
        //{
        //    stream.Position = 0;

        //    using (var reader = new BinaryReader(stream))
        //    {
        //        /* Read and check version string */
        //        var version = Encoding.ASCII.GetString(reader.ReadBytes(ExpectedVersion.Length));
        //        if (version != ExpectedVersion) throw new EmulationException("Unsupported savestate version");

        //        /* Read and check filesize */
        //        var filesize = reader.ReadUInt32();
        //        if (filesize != reader.BaseStream.Length) throw new EmulationException("Savestate filesize mismatch");

        //        /* Read CRC32 */
        //        var crc32 = reader.ReadUInt32();

        //        /* Read and check machine ID */
        //        var machineId = Encoding.ASCII.GetString(reader.ReadBytes(16));
        //        if (machineId != GenerateMachineIdString(machineName)) throw new EmulationException("Savestate machine mismatch");

        //        /* Check CRC32 */
        //        using (var stateStream = new MemoryStream())
        //        {
        //            reader.BaseStream.CopyTo(stateStream);
        //            stateStream.Position = 0;
        //            var expectedCrc32 = Crc32.Calculate(stateStream);
        //            if (crc32 != expectedCrc32) throw new EmulationException("Savestate checksum error");

        //            /* Read state data */
        //            var binaryFormatter = new BinaryFormatter();
        //            return (binaryFormatter.Deserialize(stateStream) as Dictionary<string, object>);
        //        }
        //    }
        //}

        public static AxiEssgssStatusData LoadAxiStatus(Stream stream, string machineName)
        {
            using (var reader = new BinaryReader(stream))
            {
                /* Check CRC32 */
                using (var stateStream = new MemoryStream())
                {
                    reader.BaseStream.CopyTo(stateStream);
                    return stateStream.ToArray().ToAxiEssgssStatusData();
                }
            }
        }

        //public static void Save(Stream stream, string machineName, Dictionary<string, object> state)
        //{
        //    using (var writer = new BinaryWriter(new MemoryStream()))
        //    {
        //        /* Write version string */
        //        writer.Write(Encoding.ASCII.GetBytes(ExpectedVersion));

        //        /* Write filesize placeholder */
        //        var filesizePosition = writer.BaseStream.Position;
        //        writer.Write(uint.MaxValue);

        //        /* Write CRC32 placeholder */
        //        var crc32Position = writer.BaseStream.Position;
        //        writer.Write(uint.MaxValue);

        //        /* Write machine ID */
        //        writer.Write(Encoding.ASCII.GetBytes(GenerateMachineIdString(machineName)));

        //        /* Current position is end of header, store for later */
        //        var headerSize = writer.BaseStream.Position;

        //        /* Write state data */
        //        var binaryFormatter = new BinaryFormatter();
        //        binaryFormatter.Serialize(writer.BaseStream, state);

        //        /* Write filesize */
        //        var lastOffset = writer.BaseStream.Position;
        //        writer.BaseStream.Position = filesizePosition;
        //        writer.Write((uint)writer.BaseStream.Length);
        //        writer.BaseStream.Position = lastOffset;

        //        /* Calculate CRC32 for state data, then write CRC32 */
        //        lastOffset = writer.BaseStream.Position;

        //        writer.BaseStream.Position = 0;
        //        var crc32 = Crc32.Calculate(writer.BaseStream, (int)headerSize, (int)(writer.BaseStream.Length - headerSize));

        //        writer.BaseStream.Position = crc32Position;
        //        writer.Write(crc32);
        //        writer.BaseStream.Position = lastOffset;

        //        /* Copy to file */
        //        writer.BaseStream.Position = 0;
        //        writer.BaseStream.CopyTo(stream);
        //    }
        //}

        public static void Save(Stream stream, string machineName, AxiEssgssStatusData state)
        {
            byte[] data = state.ToByteArray();
            stream.Write(data, 0, data.Length);
        }
        //private static string GenerateMachineIdString(string machineId)
        //{
        //    return machineId.Substring(0, Math.Min(machineId.Length, 16)).PadRight(16);
        //}

        ////public static void PerformSetState(object obj, Dictionary<string, dynamic> state)

        //public static void PerformSetState(object obj, Dictionary<string, object> state)
        //{
        //    if (obj != null)
        //    {
        //        /* Restore property values from state */
        //        foreach (var prop in obj.GetType().GetProperties(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance).Where(x => x.GetCustomAttributes(typeof(StateRequiredAttribute), false).Length != 0))
        //        {
        //            prop.SetValue(obj, state[prop.Name]);
        //        }

        //        /* Restore field values from state */
        //        foreach (var field in obj.GetType().GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance).Where(x => x.GetCustomAttributes(typeof(StateRequiredAttribute), false).Length != 0))
        //        {
        //            field.SetValue(obj, state[field.Name]);
        //        }
        //    }
        //}

        ////public static Dictionary<string, dynamic> PerformGetState(object obj)
        //public static Dictionary<string, object> PerformGetState(object obj)
        //{
        //    //var state = new Dictionary<string, dynamic>();
        //    var state = new Dictionary<string, object>();

        //    if (obj != null)
        //    {
        //        /* Copy property values to state */
        //        foreach (var prop in obj.GetType().GetProperties(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance).Where(x => x.GetCustomAttributes(typeof(StateRequiredAttribute), false).Length != 0))
        //        {
        //            state.Add(prop.Name, prop.GetValue(obj));
        //        }

        //        /* Copy field values to state */
        //        foreach (var field in obj.GetType().GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance).Where(x => x.GetCustomAttributes(typeof(StateRequiredAttribute), false).Length != 0))
        //        {
        //            state.Add(field.Name, field.GetValue(obj));
        //        }
        //    }

        //    return state;
        //}
    }
}