/*

  This Source Code Form is subject to the terms of the Mozilla Public

  License, v. 2.0. If a copy of the MPL was not distributed with this

  file, You can obtain one at http://mozilla.org/MPL/2.0/.

  Copyright (C) 2009-2010 Michael Möller <mmoeller@openhardwaremonitor.org>

*/

using System;

using System.Runtime.InteropServices;

namespace OpenHardwareMonitor.Hardware.TBalancer {

  internal enum FT_DEVICE : uint {

    FT_DEVICE_232BM,

    FT_DEVICE_232AM,

    FT_DEVICE_100AX,

    FT_DEVICE_UNKNOWN,

    FT_DEVICE_2232C,

    FT_DEVICE_232R,

    FT_DEVICE_2232H,

    FT_DEVICE_4232H

  }

  internal enum FT_STATUS {

    FT_OK,

    FT_INVALID_HANDLE,

    FT_DEVICE_NOT_FOUND,

    FT_DEVICE_NOT_OPENED,

    FT_IO_ERROR,

    FT_INSUFFICIENT_RESOURCES,

    FT_INVALID_PARAMETER,

    FT_INVALID_BAUD_RATE,

    FT_DEVICE_NOT_OPENED_FOR_ERASE,

    FT_DEVICE_NOT_OPENED_FOR_WRITE,

    FT_FAILED_TO_WRITE_DEVICE,

    FT_EEPROM_READ_FAILED,

    FT_EEPROM_WRITE_FAILED,

    FT_EEPROM_ERASE_FAILED,

    FT_EEPROM_NOT_PRESENT,

    FT_EEPROM_NOT_PROGRAMMED,

    FT_INVALID_ARGS,

    FT_OTHER_ERROR

  }

  internal enum FT_FLOW_CONTROL : ushort {

    FT_FLOW_DTR_DSR = 512,

    FT_FLOW_NONE = 0,

    FT_FLOW_RTS_CTS = 256,

    FT_FLOW_XON_XOFF = 1024,

  }

  internal enum FT_PURGE : uint {

    FT_PURGE_RX = 1,

    FT_PURGE_TX = 2,

    FT_PURGE_ALL = 3,

  }

  [StructLayout(LayoutKind.Sequential)]

  internal struct FT_HANDLE {

    private readonly uint handle;

  }

  [StructLayout(LayoutKind.Sequential)]

  internal struct FT_DEVICE_INFO_NODE {    

    public uint Flags;

    public FT_DEVICE Type; 

    public uint ID; 

    public uint LocId; 

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 16)]

    public string SerialNumber; 

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 64)]

    public string Description;

    public FT_HANDLE Handle;

  }

  internal class FTD2XX {

    public delegate FT_STATUS FT_CreateDeviceInfoListDelegate(

      out uint numDevices);

    public delegate FT_STATUS FT_GetDeviceInfoListDelegate(

      [Out] FT_DEVICE_INFO_NODE[] deviceInfoNodes, ref uint length);

    public delegate FT_STATUS FT_OpenDelegate(int device, out FT_HANDLE handle);

    public delegate FT_STATUS FT_CloseDelegate(FT_HANDLE handle);

    public delegate FT_STATUS FT_SetBaudRateDelegate(FT_HANDLE handle,

      uint baudRate);

    public delegate FT_STATUS FT_SetDataCharacteristicsDelegate(

      FT_HANDLE handle, byte wordLength, byte stopBits, byte parity);

    public delegate FT_STATUS FT_SetFlowControlDelegate(FT_HANDLE handle,

      FT_FLOW_CONTROL flowControl, byte xon, byte xoff);

    public delegate FT_STATUS FT_SetTimeoutsDelegate(FT_HANDLE handle,

      uint readTimeout, uint writeTimeout);

    public delegate FT_STATUS FT_WriteDelegate(FT_HANDLE handle, byte[] buffer,

      uint bytesToWrite, out uint bytesWritten);

    public delegate FT_STATUS FT_PurgeDelegate(FT_HANDLE handle, FT_PURGE mask);

    public delegate FT_STATUS FT_GetStatusDelegate(FT_HANDLE handle,

      out uint amountInRxQueue, out uint amountInTxQueue, out uint eventStatus);

    public delegate FT_STATUS FT_ReadDelegate(FT_HANDLE handle, 

      [Out] byte[] buffer, uint bytesToRead, out uint bytesReturned);

    public static readonly FT_CreateDeviceInfoListDelegate 

      FT_CreateDeviceInfoList = CreateDelegate<

      FT_CreateDeviceInfoListDelegate>("FT_CreateDeviceInfoList");

    public static readonly FT_GetDeviceInfoListDelegate 

      FT_GetDeviceInfoList = CreateDelegate<

      FT_GetDeviceInfoListDelegate>("FT_GetDeviceInfoList");

    public static readonly FT_OpenDelegate 

      FT_Open = CreateDelegate<

      FT_OpenDelegate>("FT_Open");

    public static readonly FT_CloseDelegate 

      FT_Close = CreateDelegate<

      FT_CloseDelegate>("FT_Close");

    public static readonly FT_SetBaudRateDelegate 

      FT_SetBaudRate = CreateDelegate<

      FT_SetBaudRateDelegate>("FT_SetBaudRate");

    public static readonly FT_SetDataCharacteristicsDelegate 

      FT_SetDataCharacteristics = CreateDelegate<

      FT_SetDataCharacteristicsDelegate>("FT_SetDataCharacteristics");

    public static readonly FT_SetFlowControlDelegate 

      FT_SetFlowControl = CreateDelegate<

      FT_SetFlowControlDelegate>("FT_SetFlowControl");

    public static readonly FT_SetTimeoutsDelegate 

      FT_SetTimeouts = CreateDelegate<

      FT_SetTimeoutsDelegate>("FT_SetTimeouts");

    public static readonly FT_WriteDelegate 

      FT_Write = CreateDelegate<

      FT_WriteDelegate>("FT_Write");

    public static readonly FT_PurgeDelegate 

      FT_Purge = CreateDelegate<

      FT_PurgeDelegate>("FT_Purge");

    public static readonly FT_GetStatusDelegate 

      FT_GetStatus = CreateDelegate<

      FT_GetStatusDelegate>("FT_GetStatus");

    public static readonly FT_ReadDelegate 

      FT_Read = CreateDelegate<

      FT_ReadDelegate>("FT_Read");

    private FTD2XX() { }

    public static FT_STATUS Write(FT_HANDLE handle, byte[] buffer) {

      uint bytesWritten;

      FT_STATUS status = FT_Write(handle, buffer, (uint)buffer.Length, 

        out bytesWritten);

      if (bytesWritten != buffer.Length)

        return FT_STATUS.FT_FAILED_TO_WRITE_DEVICE;

      else

        return status;

    }

    public static int BytesToRead(FT_HANDLE handle) {

      uint amountInRxQueue;

      uint amountInTxQueue;

      uint eventStatus;

      if (FT_GetStatus(handle, out amountInRxQueue, out amountInTxQueue,

        out eventStatus) == FT_STATUS.FT_OK) {

        return (int)amountInRxQueue;

      } else {

        return 0;

      }

    }

    public static byte ReadByte(FT_HANDLE handle) {

      byte[] buffer = new byte[1];

      uint bytesReturned;

      FT_STATUS status = FT_Read(handle, buffer, 1, out bytesReturned);

      if (status != FT_STATUS.FT_OK || bytesReturned != 1)

        throw new InvalidOperationException();

      return buffer[0];

    }

    private static string GetDllName() {

      int p = (int)Environment.OSVersion.Platform;

      if ((p == 4) || (p == 128))

        return "libftd2xx.so";

      else

        return "ftd2xx.dll";

    }

    private static T CreateDelegate<T>(string entryPoint)

      where T : class {

      DllImportAttribute attribute = new DllImportAttribute(GetDllName());

      attribute.CallingConvention = CallingConvention.StdCall;

      attribute.PreserveSig = true;

      attribute.EntryPoint = entryPoint;

      T newDelegate;

      PInvokeDelegateFactory.CreateDelegate(attribute, out newDelegate);

      return newDelegate;

    }

  }

}