/* Ruby/SerialPort
 * Guillaume Pierronnet <moumar@netcourrier.com>
 * Alan Stern <stern@rowland.harvard.edu>
 * Daniel E. Shipton <dshipton@redshiptechnologies.com>
 * Hector G. Parra <hector@hectorparra.com>
 *
 * This code is hereby licensed for public consumption under either the
 * GNU GPL v2 or greater.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * For documentation on serial programming, see the excellent:
 * "Serial Programming Guide for POSIX Operating Systems"
 * written Michael R. Sweet.
 * http://www.easysw.com/~mike/serial/
 */

#include "serialport.h"

#if defined(OS_MSWIN) || defined(OS_BCCWIN) || defined(OS_MINGW)

#include <stdio.h>   /* Standard input/output definitions */
#include <io.h>      /* Low-level I/O definitions */
#include <fcntl.h>   /* File control definitions */
#include <windows.h> /* Windows standard function definitions */


static char sGetCommState[] = "GetCommState";
static char sSetCommState[] = "SetCommState";
static char sGetCommTimeouts[] = "GetCommTimeouts";
static char sSetCommTimeouts[] = "SetCommTimeouts";


static HANDLE get_handle_helper(obj)
   VALUE obj;
{
  HANDLE fh;
  Data_Get_Struct(rb_iv_get(obj,"@fh"), HANDLE, fh);
  return fh;
}

/* hack to work around the fact that Ruby doesn't use GetLastError? */
static void _rb_win32_fail(const char *function_call) {
  rb_raise(
    rb_eRuntimeError, 
    "%s failed: GetLastError returns %d", 
    function_call, GetLastError( )
  );
}

VALUE RB_SERIAL_EXPORT sp_create_impl(class, _port)
   VALUE class, _port;
{
   int fd;
   HANDLE fh;
   VALUE vfh;
   int num_port;
   char *str_port;
   char port[260]; /* Windows XP MAX_PATH. See http://msdn.microsoft.com/en-us/library/aa365247(VS.85).aspx */

   DCB dcb;

   NEWOBJ(sp, struct RObject);
   rb_secure(4);
   OBJSETUP(sp, class, T_OBJECT);

   switch(TYPE(_port))
   {
      case T_FIXNUM:
         num_port = FIX2INT(_port);
         if (num_port < 0)
         {
            rb_raise(rb_eArgError, "illegal port number");
         }
        snprintf(port, sizeof(port) - 1, "\\\\.\\COM%d", num_port + 1); /* '0' is actually COM1, etc. */
        port[sizeof(port) - 1] = 0;
      break;

      case T_STRING:
         SafeStringValue(_port);
         str_port = RSTRING_PTR(_port);
		 if (str_port[0] != '\\') /* Check for Win32 Device Namespace prefix "\\.\" */
		 {
			snprintf(port, sizeof(port) - 1, "\\\\.\\%s", str_port);
                        port[sizeof(port) - 1] = 0;
		 }
		 else
		 {
			snprintf(port, sizeof(port) - 1, "%s", str_port);
                        port[sizeof(port) - 1] = 0;
	 	 }
         break;

      default:
         rb_raise(rb_eTypeError, "wrong argument type");
         break;
   }

   fh = CreateFile(port, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
   vfh = Data_Wrap_Struct(class, 0, CloseHandle, fh);
   rb_iv_set((VALUE) sp,"@fh",vfh);

   if (fh == INVALID_HANDLE_VALUE){
      CloseHandle(fh);
      rb_sys_fail(port);
   }

   if (SetupComm(fh, 1024, 1024) == 0)
   {
      CloseHandle(fh);
      rb_raise(rb_eArgError, "not a serial port");
   }

   dcb.DCBlength = sizeof(dcb);
   if (GetCommState(fh, &dcb) == 0)
   {
      CloseHandle(fh);
      _rb_win32_fail(sGetCommState);
   }
   dcb.fBinary = TRUE;
   dcb.fParity = FALSE;
   dcb.fOutxDsrFlow = FALSE;
   dcb.fDtrControl = DTR_CONTROL_ENABLE;
   dcb.fDsrSensitivity = FALSE;
   dcb.fTXContinueOnXoff = FALSE;
   dcb.fErrorChar = FALSE;
   dcb.fNull = FALSE;
   dcb.fAbortOnError = FALSE;
   dcb.XonChar = 17;
   dcb.XoffChar = 19;
   if (SetCommState(fh, &dcb) == 0)
   {
      CloseHandle(fh);
      _rb_win32_fail(sSetCommState);
   }
   
   errno = 0;
   return (VALUE) sp;
}

VALUE RB_SERIAL_EXPORT sp_set_modem_params_impl(argc, argv, self)
   int argc;
   VALUE *argv, self;
{
   HANDLE fh;
   DCB dcb;
   VALUE _data_rate, _data_bits, _parity, _stop_bits;
   int use_hash = 0;
   int data_rate, data_bits, parity;

   if (argc == 0)
   {
      return self;
   }
   if (argc == 1 && T_HASH == TYPE(argv[0]))
   {
      use_hash = 1;
      _data_rate = rb_hash_aref(argv[0], sBaud);
      _data_bits = rb_hash_aref(argv[0], sDataBits);
      _stop_bits = rb_hash_aref(argv[0], sStopBits);
      _parity = rb_hash_aref(argv[0], sParity);
   }

   fh = get_handle_helper(self);
   dcb.DCBlength = sizeof(dcb);
   if (GetCommState(fh, &dcb) == 0)
   {
      _rb_win32_fail(sGetCommState);
   }

   if (!use_hash)
   {
      _data_rate = argv[0];
   }

   if (NIL_P(_data_rate))
   {
      goto SkipDataRate;
   }

   Check_Type(_data_rate, T_FIXNUM);

   data_rate = FIX2INT(_data_rate);
   dcb.BaudRate = data_rate;

   SkipDataRate:

   if (!use_hash)
   {
      _data_bits = (argc >= 2 ? argv[1] : INT2FIX(8));
   }

   if (NIL_P(_data_bits))
   {
      goto SkipDataBits;
   }

   Check_Type(_data_bits, T_FIXNUM);

   data_bits = FIX2INT(_data_bits);
   if (4 <= data_bits && data_bits <= 8)
   {
      dcb.ByteSize = data_bits;
   }
   else
   {
      rb_raise(rb_eArgError, "unknown character size");
   }

   SkipDataBits:

   if (!use_hash)
   {
      _stop_bits = (argc >= 3 ? argv[2] : INT2FIX(1));
   }

   if (NIL_P(_stop_bits))
   {
      goto SkipStopBits;
   }

   Check_Type(_stop_bits, T_FIXNUM);

   switch (FIX2INT(_stop_bits))
   {
      case 1:
         dcb.StopBits = ONESTOPBIT;
         break;
      case 2:
         dcb.StopBits = TWOSTOPBITS;
         break;
      default:
         rb_raise(rb_eArgError, "unknown number of stop bits");
         break;
   }

   SkipStopBits:

   if (!use_hash)
   {
      _parity = (argc >= 4 ? argv[3] : (dcb.ByteSize == 8 ?
               INT2FIX(NOPARITY) : INT2FIX(EVENPARITY)));
   }

   if (NIL_P(_parity))
   {
      goto SkipParity;
   }

   Check_Type(_parity, T_FIXNUM);

   parity = FIX2INT(_parity);
   switch (parity)
   {
      case EVENPARITY:
      case ODDPARITY:
      case MARKPARITY:
      case SPACEPARITY:
      case NOPARITY:
         dcb.Parity = parity;
         break;

      default:
         rb_raise(rb_eArgError, "unknown parity");
         break;
   }

   SkipParity:

   if (SetCommState(fh, &dcb) == 0)
   {
      _rb_win32_fail(sSetCommState);
   }

   return argv[0];
}

void RB_SERIAL_EXPORT get_modem_params_impl(self, mp)
   VALUE self;
   struct modem_params *mp;
{
   HANDLE fh;
   DCB dcb;

   fh = get_handle_helper(self);
   dcb.DCBlength = sizeof(dcb);
   if (GetCommState(fh, &dcb) == 0)
   {
      _rb_win32_fail(sGetCommState);
   }

   mp->data_rate = dcb.BaudRate;
   mp->data_bits = dcb.ByteSize;
   mp->stop_bits = (dcb.StopBits == ONESTOPBIT ? 1 : 2);
   mp->parity = dcb.Parity;
}

VALUE RB_SERIAL_EXPORT sp_set_flow_control_impl(self, val)
   VALUE self, val;
{
   HANDLE fh;
   int flowc;
   DCB dcb;

   Check_Type(val, T_FIXNUM);

   fh = get_handle_helper(self);
   dcb.DCBlength = sizeof(dcb);
   if (GetCommState(fh, &dcb) == 0)
   {
      _rb_win32_fail(sGetCommState);
   }

   flowc = FIX2INT(val);
   if (flowc & HARD)
   {
      dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
      dcb.fOutxCtsFlow = TRUE;
   }
   else
   {
      dcb.fRtsControl = RTS_CONTROL_ENABLE;
      dcb.fOutxCtsFlow = FALSE;
   }

   if (flowc & SOFT)
   {
      dcb.fOutX = dcb.fInX = TRUE;
   }
   else
   {
      dcb.fOutX = dcb.fInX = FALSE;
   }

   if (SetCommState(fh, &dcb) == 0)
   {
      _rb_win32_fail(sSetCommState);
   }

   return val;
}

VALUE RB_SERIAL_EXPORT sp_get_flow_control_impl(self)
   VALUE self;
{
   HANDLE fh;
   int ret;
   DCB dcb;

   fh = get_handle_helper(self);
   dcb.DCBlength = sizeof(dcb);
   if (GetCommState(fh, &dcb) == 0)
   {
      _rb_win32_fail(sGetCommState);
   }

   ret = 0;
   if (dcb.fOutxCtsFlow)
   {
      ret += HARD;
   }

   if (dcb.fOutX)
   {
      ret += SOFT;
   }

   return INT2FIX(ret);
}

VALUE RB_SERIAL_EXPORT sp_set_read_timeout_impl(self, val)
   VALUE self, val;
{
   int timeout;
   HANDLE fh;
   COMMTIMEOUTS ctout;

   Check_Type(val, T_FIXNUM);
   timeout = FIX2INT(val);

   fh = get_handle_helper(self);
   if (GetCommTimeouts(fh, &ctout) == 0)
   {
      _rb_win32_fail(sGetCommTimeouts);
   }

   if (timeout < 0)
   {
      ctout.ReadIntervalTimeout = MAXDWORD;
      ctout.ReadTotalTimeoutMultiplier = 0;
      ctout.ReadTotalTimeoutConstant = 0;
   }
   else if (timeout == 0)
   {
      ctout.ReadIntervalTimeout = MAXDWORD;
      ctout.ReadTotalTimeoutMultiplier = MAXDWORD;
      ctout.ReadTotalTimeoutConstant = MAXDWORD - 1;
   }
   else
   {
      ctout.ReadIntervalTimeout = timeout;
      ctout.ReadTotalTimeoutMultiplier = 0;
      ctout.ReadTotalTimeoutConstant = timeout;
   }

   if (SetCommTimeouts(fh, &ctout) == 0)
   {
      _rb_win32_fail(sSetCommTimeouts);
   }

   return val;
}

VALUE RB_SERIAL_EXPORT sp_get_read_timeout_impl(self)
   VALUE self;
{
   HANDLE fh;
   COMMTIMEOUTS ctout;

   fh = get_handle_helper(self);
   if (GetCommTimeouts(fh, &ctout) == 0)
   {
      _rb_win32_fail(sGetCommTimeouts);
   }

   switch (ctout.ReadTotalTimeoutConstant)
   {
      case 0:
         return INT2FIX(-1);
      case MAXDWORD:
         return INT2FIX(0);
   }

   return INT2FIX(ctout.ReadTotalTimeoutConstant);
}

VALUE RB_SERIAL_EXPORT sp_set_write_timeout_impl(self, val)
   VALUE self, val;
{
   int timeout;
   HANDLE fh;
   COMMTIMEOUTS ctout;

   Check_Type(val, T_FIXNUM);
   timeout = FIX2INT(val);

   fh = get_handle_helper(self);
   if (GetCommTimeouts(fh, &ctout) == 0)
   {
      _rb_win32_fail(sGetCommTimeouts);
   }

   if (timeout <= 0)
   {
      ctout.WriteTotalTimeoutMultiplier = 0;
      ctout.WriteTotalTimeoutConstant = 0;
   }
   else
   {
      ctout.WriteTotalTimeoutMultiplier = timeout;
      ctout.WriteTotalTimeoutConstant = 0;
   }

   if (SetCommTimeouts(fh, &ctout) == 0)
   {
      _rb_win32_fail(sSetCommTimeouts);
   }

   return val;
}

VALUE RB_SERIAL_EXPORT sp_get_write_timeout_impl(self)
   VALUE self;
{
   HANDLE fh;
   COMMTIMEOUTS ctout;

   fh = get_handle_helper(self);
   if (GetCommTimeouts(fh, &ctout) == 0)
   {
      _rb_win32_fail(sGetCommTimeouts);
   }

   return INT2FIX(ctout.WriteTotalTimeoutMultiplier);
}

static void delay_ms(time)
   int time;
{
   HANDLE ev;

   ev = CreateEvent(NULL, FALSE, FALSE, NULL);
   if (!ev)
   {
      _rb_win32_fail("CreateEvent");
   }

   if (WaitForSingleObject(ev, time) == WAIT_FAILED)
   {
      _rb_win32_fail("WaitForSingleObject");
   }

   CloseHandle(ev);
}

VALUE RB_SERIAL_EXPORT sp_break_impl(self, time)
   VALUE self, time;
{
   HANDLE fh;

   Check_Type(time, T_FIXNUM);

   fh = get_handle_helper(self);
   if (SetCommBreak(fh) == 0)
   {
      _rb_win32_fail("SetCommBreak");
   }

   delay_ms(FIX2INT(time) * 100);
   ClearCommBreak(fh);

   return Qnil;
}

void RB_SERIAL_EXPORT get_line_signals_helper_impl(obj, ls)
   VALUE obj;
   struct line_signals *ls;
{
   HANDLE fh;
   unsigned long status; /* DWORD */

   fh = get_handle_helper(obj);
   if (GetCommModemStatus(fh, &status) == 0)
   {
      _rb_win32_fail("GetCommModemStatus");
   }

   ls->cts = (status & MS_CTS_ON ? 1 : 0);
   ls->dsr = (status & MS_DSR_ON ? 1 : 0);
   ls->dcd = (status & MS_RLSD_ON ? 1 : 0);
   ls->ri  = (status & MS_RING_ON ? 1 : 0);
}

static VALUE set_signal(obj, val, sigoff, sigon)
   VALUE obj,val;
   int sigoff, sigon;
{
   HANDLE fh;
   int set, sig;

   Check_Type(val, T_FIXNUM);
   fh = get_handle_helper(obj);

   set = FIX2INT(val);
   if (set == 0)
   {
      sig = sigoff;
   }
   else if (set == 1)
   {
      sig = sigon;
   }
   else
   {
      rb_raise(rb_eArgError, "invalid value");
   }

   if (EscapeCommFunction(fh, sig) == 0)
   {
      _rb_win32_fail("EscapeCommFunction");
   }

   return val;
}

VALUE RB_SERIAL_EXPORT sp_set_rts_impl(self, val)
   VALUE self, val;
{
   return set_signal(self, val, CLRRTS, SETRTS);
}

VALUE RB_SERIAL_EXPORT sp_set_dtr_impl(self, val)
   VALUE self, val;
{
   return set_signal(self, val, CLRDTR, SETDTR);
}

VALUE RB_SERIAL_EXPORT sp_get_rts_impl(self)
   VALUE self;
{
   rb_notimplement();
   return self;
}

VALUE RB_SERIAL_EXPORT sp_get_dtr_impl(self)
   VALUE self;
{
   rb_notimplement();
   return self;
}

VALUE RB_SERIAL_EXPORT sp_write_impl(self, str)
  VALUE self, str;
{
  char *c_str = RSTRING_PTR(str);
  int len = RSTRING_LEN(str);
  
  HANDLE fh;
  DWORD n = 0;
  Data_Get_Struct(rb_iv_get(self,"@fh"), HANDLE, fh);
  if(FALSE == WriteFile(fh, c_str, len, &n, NULL)){
    _rb_win32_fail("WriteFile");
  }
  
  //rb_iv_set(self,"@byte_offset", rb_iv_get(self,"@initial_byte_offset"));
  return INT2FIX(n);
}

VALUE RB_SERIAL_EXPORT sp_read_impl(argc, argv, self)
  int argc;
  VALUE *argv, self;
{
  long bytes = 1024;

  if (argc > 1){
    rb_raise(rb_eArgError, "Wrong number of arguments in read()");
  }
  else if (argc == 1){
    bytes = FIX2LONG(argv[0]); 
  }
  
  char ReadBuffer[bytes];
  DWORD n = 0;
  DWORD w;
  HANDLE fh;
  Data_Get_Struct(rb_iv_get(self,"@fh"), HANDLE, fh);
  /*
  w = SetFilePointer(fh, FIX2LONG(rb_iv_get(self,"@byte_offset")), NULL, FILE_BEGIN);
  if (w == INVALID_SET_FILE_POINTER){
    _rb_win32_fail("SetFilePointer");
  }*/
  if (FALSE == ReadFile(fh, ReadBuffer, bytes, &n, NULL)){
    _rb_win32_fail("ReadFile");
  }
  //rb_iv_set(self,"@byte_offset", FIX2LONG(rb_iv_get(self, "@byte_offset")) + bytes);
  return rb_str_new(ReadBuffer, n);
}

void RB_SERIAL_EXPORT sp_close_impl(self)
  VALUE self;
{
  HANDLE fh;
  Data_Get_Struct(rb_iv_get(self,"@fh"), HANDLE, fh);
  CloseHandle(fh);
}

void RB_SERIAL_EXPORT sp_set_initial_offset_impl(self, offset)
  VALUE self, offset;
{
  //rb_iv_set(self,"@initial_byte_offset", offset);
}

#endif /* defined(OS_MSWIN) || defined(OS_BCCWIN) || defined(OS_MINGW) */