/*  Part of SWI-Prolog

    Author:        Jan Wielemaker
    E-mail:        J.Wielemaker@vu.nl
    WWW:           http://www.swi-prolog.org
    Copyright (c)  1985-2022, University of Amsterdam
                              VU University Amsterdam
			      SWI-Prolog Solutions b.v.
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.
*/

#ifdef __WINDOWS__
#include <winsock2.h>
#include <windows.h>
#endif

#ifdef __WINDOWS__

#define INCLUDE_DDEML_H
#include "pl-incl.h"
#include "pl-nt.h"
#include "pl-modul.h"
#include "pl-funct.h"
#include "pl-fli.h"

#if O_DDE
#include <string.h>

#define FASTBUFSIZE 512			/* use local buffer upto here */
#define MAX_CONVERSATIONS 32		/* Max. # of conversations */
#define TIMEOUT_VERY_LONG 0x7fffffff;	/* largest positive int */

static HCONV conv_handle[MAX_CONVERSATIONS];
static HCONV server_handle[MAX_CONVERSATIONS];

static Module	 MODULE_dde;		/* win_dde */
static functor_t FUNCTOR_dde_connect3;
static functor_t FUNCTOR_dde_connect_confirm3;
static functor_t FUNCTOR_dde_disconnect1;
static functor_t FUNCTOR_dde_request4;
static functor_t FUNCTOR_dde_execute3;

static const char *
dde_error_message(int errn)
{ GET_LD
  const char *err;

  if ( errn <= 0 )
    errn = DdeGetLastError(LD->os.dde_instance);

  switch(errn)
  { case DMLERR_ADVACKTIMEOUT:
    case DMLERR_DATAACKTIMEOUT:
    case DMLERR_EXECACKTIMEOUT:
    case DMLERR_POKEACKTIMEOUT:
    case DMLERR_UNADVACKTIMEOUT:	err = "Timeout";		break;
    case DMLERR_BUSY:			err = "Service busy";		break;
    case DMLERR_DLL_NOT_INITIALIZED:	err = "DDL not initialised";	break;
    case DMLERR_INVALIDPARAMETER:	err = "Invalid parameter";	break;
    case DMLERR_MEMORY_ERROR:		err = "Memory error";		break;
    case DMLERR_NO_CONV_ESTABLISHED:	err = "No conversation";	break;
    case DMLERR_NO_ERROR:		err = "No error???";		break;
    case DMLERR_NOTPROCESSED:		err = "Not processed";		break;
    case DMLERR_POSTMSG_FAILED:		err = "PostMessage() failed";	break;
    case DMLERR_REENTRANCY:		err = "Reentrance";		break;
    case DMLERR_SERVER_DIED:		err = "Server died";		break;
    default:				err = "Unknown error";		break;
  }

  return err;
}


static int
dde_warning(const char *cmd)
{ const char *err = dde_error_message(-1);

  return PL_error(NULL, 0, NULL, ERR_DDE_OP, cmd, err);
}


static int
unify_hsz(DWORD ddeInst, term_t term, HSZ hsz)
{ wchar_t buf[FASTBUFSIZE];
  int len;

  if ( !(len=DdeQueryStringW(ddeInst, hsz, buf,
			     sizeof(buf)/sizeof(wchar_t)-1, CP_WINUNICODE)) )
  { dde_warning("string handle");
    return NULL_ATOM;
  }

  if ( len == sizeof(buf)/sizeof(wchar_t)-1 )
  { if ( (len=DdeQueryStringW(ddeInst, hsz, NULL, 0, CP_WINUNICODE)) > 0 )
    { wchar_t *b2;
      int rc;

      if ( !(b2 = malloc((len+1)*sizeof(wchar_t))) )
	return PL_no_memory();

      DdeQueryStringW(ddeInst, hsz, b2, len+1, CP_WINUNICODE);
      rc = PL_unify_wchars(term, PL_ATOM, len, b2);
      free(b2);

      return rc;
    }

    dde_warning("string handle");
  }

  return PL_unify_wchars(term, PL_ATOM, len, buf);
}


static word
unify_hdata(term_t t, HDDEDATA data)
{ BYTE buf[FASTBUFSIZE];
  DWORD len;

  if ( !(len=DdeGetData(data, buf, sizeof(buf), 0)) )
    return dde_warning("data handle");

  DEBUG(1, Sdprintf("DdeGetData() returned %ld bytes\n", (long)len));

  if ( len == sizeof(buf) )
  { if ( (len=DdeGetData(data, NULL, 0, 0)) > 0 )
    { LPBYTE b2;
      int rval;

      if ( !(b2 = malloc(len)) )
	return PL_no_memory();

      DdeGetData(data, b2, len, 0);
      rval = PL_unify_wchars(t, PL_ATOM, len/sizeof(wchar_t)-1, (wchar_t*)b2);
      free(b2);

      return rval;
    }

    return dde_warning("data handle");
  }

  return PL_unify_wchars(t, PL_ATOM, len/sizeof(wchar_t)-1, (wchar_t*)buf);
}


static int
get_hsz(DWORD ddeInst, term_t data, HSZ *rval)
{ wchar_t *s;
  size_t len;

  if ( PL_get_wchars(data, &len, &s, CVT_ALL|CVT_EXCEPTION) )
  { HSZ h;

    assert(s[len] == 0);			/* Must be 0-terminated */

    DEBUG(2, SdprintfX("Get HSZ for %Ws ...\n", s));
    if ( (h=DdeCreateStringHandleW(ddeInst, s, CP_WINUNICODE)) )
    { DEBUG(2, Sdprintf("\tHSZ = %p\n", h));
      *rval = h;
      succeed;
    }

    return PL_error(NULL, 0, WinError(), ERR_SYSCALL, "DdeCreateStringHandleW");
  }

  fail;
}


static int
allocServerHandle(HCONV handle)
{ int i;

  PL_LOCK(L_DDE);
  for(i=0; i<MAX_CONVERSATIONS; i++)
  { if ( !server_handle[i] )
    { server_handle[i] = handle;
      break;
    }
  }
  PL_UNLOCK(L_DDE);

  if ( i<MAX_CONVERSATIONS )
    return i;

  PL_error(NULL, 0, NULL, ERR_RESOURCE, ATOM_max_dde_handles);
  return -1;
}


static int
findServerHandle(HCONV handle)
{ int i;

  for(i=0; i<MAX_CONVERSATIONS; i++)		/* can be unlocked */
  { if ( server_handle[i] == handle )
      return i;
  }

  return -1;
}


static HDDEDATA CALLBACK
DdeCallback(UINT type, UINT fmt, HCONV hconv, HSZ hsz1, HSZ hsz2,
            HDDEDATA hData, DWORD dwData1, DWORD dwData2)
{ GET_LD
  DWORD ddeInst = LD->os.dde_instance;

  switch(type)
  {  case XTYP_CONNECT:
     { fid_t cid = PL_open_foreign_frame();
       term_t argv = PL_new_term_refs(3);
       predicate_t pred = PL_pred(FUNCTOR_dde_connect3, MODULE_dde);
       int rval;

       if ( unify_hsz(ddeInst, argv+0, hsz2) &&		/* topic */
	    unify_hsz(ddeInst, argv+1, hsz1) &&		/* service */
	    PL_unify_integer(argv+2, dwData2 ? 1 : 0) )	/* same instance */
       { rval = PL_call_predicate(MODULE_dde, TRUE, pred, argv);
       } else
       { rval = FALSE;
       }
       PL_discard_foreign_frame(cid);

       return (void *)(intptr_t)rval;
     }
     case XTYP_CONNECT_CONFIRM:
     { int plhandle;

       if ( (plhandle = allocServerHandle(hconv)) >= 0 )
       { fid_t cid = PL_open_foreign_frame();
	 term_t argv = PL_new_term_refs(3);
	 predicate_t pred = PL_pred(FUNCTOR_dde_connect_confirm3, MODULE_dde);

	 if ( unify_hsz(ddeInst, argv+0, hsz2) &&		/* topic */
	      unify_hsz(ddeInst, argv+1, hsz1) &&		/* service */
	      PL_unify_integer(argv+2, plhandle) )
	   PL_call_predicate(MODULE_dde, TRUE, pred, argv);

	 PL_discard_foreign_frame(cid);
       }

       return NULL;
     }
     case XTYP_DISCONNECT:
     { fid_t cid = PL_open_foreign_frame();
       term_t argv = PL_new_term_refs(1);
       predicate_t pred = PL_pred(FUNCTOR_dde_disconnect1, MODULE_dde);
       int plhandle = findServerHandle(hconv);

       if ( plhandle >= 0 && plhandle < MAX_CONVERSATIONS )
	 server_handle[plhandle] = (HCONV)NULL;

       PL_put_integer(argv+0, plhandle);
       PL_call_predicate(MODULE_dde, TRUE, pred, argv);
       PL_discard_foreign_frame(cid);

       return NULL;
     }
     case XTYP_EXECUTE:
     { int plhandle = findServerHandle(hconv);
       HDDEDATA rval = DDE_FNOTPROCESSED;
       fid_t cid = PL_open_foreign_frame();
       term_t argv = PL_new_term_refs(3);
       predicate_t pred = PL_pred(FUNCTOR_dde_execute3, MODULE_dde);

       DEBUG(1, Sdprintf("Got XTYP_EXECUTE request\n"));

       PL_put_integer(argv+0, plhandle);
       unify_hsz(ddeInst, argv+1, hsz1);
       unify_hdata(   argv+2, hData);
       if ( PL_call_predicate(MODULE_dde, TRUE, pred, argv) )
	 rval = (void *) DDE_FACK;
       PL_discard_foreign_frame(cid);
       DdeFreeDataHandle(hData);
       return rval;
     }
     case XTYP_REQUEST:
     { HDDEDATA data = (HDDEDATA) NULL;

       if ( fmt == CF_UNICODETEXT )
       { fid_t cid = PL_open_foreign_frame();
	 term_t argv = PL_new_term_refs(4);
	 predicate_t pred = PL_pred(FUNCTOR_dde_request4, MODULE_dde);
	 int plhandle = findServerHandle(hconv);

	 PL_put_integer( argv+0, plhandle);
	 unify_hsz(ddeInst, argv+1, hsz1);	/* topic */
	 unify_hsz(ddeInst, argv+2, hsz2);	/* item */

	 if ( PL_call_predicate(MODULE_dde, TRUE, pred, argv) )
	 { wchar_t *s;
	   size_t len;

					/* TBD: error handling */
	   if ( PL_get_wchars(argv+3, &len, &s, CVT_ALL) )
	     data = DdeCreateDataHandle(ddeInst,
					(unsigned char*) s,
					(DWORD)(len+1)*sizeof(wchar_t),
					0, hsz2, CF_UNICODETEXT, 0);
	 }
	 PL_discard_foreign_frame(cid);
       }

       return data;
     }
     default:
       ;
  }

  return (HDDEDATA)NULL;
}


static void
dde_init_constants(void)
{ static int done = FALSE;

  if ( !done )				/* no worries if this happens twice */
  { GET_LD
    MODULE_dde = lookupModule(PL_new_atom("win_dde"));

    FUNCTOR_dde_connect3  =
	lookupFunctorDef(PL_new_atom("$dde_connect"), 3);
    FUNCTOR_dde_connect_confirm3 =
	lookupFunctorDef(PL_new_atom("$dde_connect_confirm"), 3);
    FUNCTOR_dde_disconnect1 =
        lookupFunctorDef(PL_new_atom("$dde_disconnect"), 1);
    FUNCTOR_dde_request4  =
	lookupFunctorDef(PL_new_atom("$dde_request"), 4);
    FUNCTOR_dde_execute3  =
	lookupFunctorDef(PL_new_atom("$dde_execute"), 3);

    done = TRUE;
  }
}

static void
dde_uninitialise(void *closure)
{ GET_LD
  DWORD ddeInst;

  if ( (ddeInst=LD->os.dde_instance) )
  { LD->os.dde_instance = 0;

    DdeUninitialize(ddeInst);
  }

  FUNCTOR_dde_connect3 = 0;
  FUNCTOR_dde_connect_confirm3 = 0;
  FUNCTOR_dde_disconnect1 = 0;
  FUNCTOR_dde_request4 = 0;
  FUNCTOR_dde_execute3 = 0;
}


static DWORD
dde_initialise(void)
{ GET_LD
  DWORD ddeInst;

  dde_init_constants();

  if ( !(ddeInst=LD->os.dde_instance) )
  { if ( DdeInitializeW(&ddeInst, (PFNCALLBACK)DdeCallback,
			APPCLASS_STANDARD|CBF_FAIL_ADVISES|CBF_FAIL_POKES|
			CBF_SKIP_REGISTRATIONS|CBF_SKIP_UNREGISTRATIONS,
			0L) == DMLERR_NO_ERROR)
    { LD->os.dde_instance = ddeInst;
#ifdef O_PLMT
      PL_thread_at_exit(dde_uninitialise, NULL, FALSE);
#endif
    } else
    { dde_warning("initialise");
    }

    DEBUG(MSG_WIN_DDE, Sdprintf("Thread %d: created ddeInst %ld\n",
				PL_thread_self(), (long)ddeInst));

  }

  return ddeInst;
}


static
PRED_IMPL("$dde_register_service", 2, dde_register_service, 0)
{ HSZ t;
  int a;
  DWORD ddeInst;

  term_t topic = A1;
  term_t onoff = A2;

  if ( !(ddeInst=dde_initialise()) )
    return FALSE;
  if ( !get_hsz(ddeInst, topic, &t) )
    fail;
  if ( !PL_get_bool(onoff, &a) )
    return PL_error(NULL, 0, NULL, ERR_TYPE, ATOM_bool, onoff);

  if ( !a )
  { int rval = (intptr_t)DdeNameService(ddeInst, t, 0L, DNS_UNREGISTER);
    DdeFreeStringHandle(ddeInst, t);
    return rval ? TRUE : FALSE;
  } else
  { if ( DdeNameService(ddeInst, t, 0L, DNS_REGISTER|DNS_FILTERON) )
      succeed;				/* should we free too? */

    DdeFreeStringHandle(ddeInst, t);
    return dde_warning("register_request");
  }
}

static
PRED_IMPL("open_dde_conversation", 3, open_dde_conversation, 0)
{ PRED_LD
  UINT i;
  HSZ Hservice = 0, Htopic = 0;
  int rc = TRUE;
  DWORD ddeInst;

  term_t service = A1;
  term_t topic   = A2;
  term_t handle  = A3;

  if ( !(ddeInst=dde_initialise()) )
    fail;

  if ( !get_hsz(ddeInst, service, &Hservice) ||
       !get_hsz(ddeInst, topic, &Htopic) )
  { rc = FALSE;
    goto out;
  }

  /* Establish a connection and get a handle for it */
  PL_LOCK(L_DDE);
  for (i=0; i < MAX_CONVERSATIONS; i++)		/* Find an open slot */
  { if (conv_handle[i] == (HCONV)NULL)
    { conv_handle[i] = (HCONV)~0;		/* reserve it */
      break;
    }
  }
  PL_UNLOCK(L_DDE);
  if (i == MAX_CONVERSATIONS)
  { rc = PL_error(NULL, 0, NULL, ERR_RESOURCE, ATOM_max_dde_handles);
    goto out;
  }

  if ( !(conv_handle[i] = DdeConnect(ddeInst, Hservice, Htopic, 0)) )
  { DEBUG(MSG_WIN_DDE,
	  Sdprintf("DDE Connect failed: %s\n", dde_error_message(-1)));
    rc = dde_warning("connect");
    goto out;
  }
  DEBUG(MSG_WIN_DDE, Sdprintf("Connected (%d)\n", (int)i));

  rc = PL_unify_integer(handle, i);

out:
  if ( Hservice )
    DdeFreeStringHandle(ddeInst, Hservice);
  if ( Htopic )
    DdeFreeStringHandle(ddeInst, Htopic);

  return rc;
}


static int
get_conv_handle(term_t handle, int *theh)
{ GET_LD
  int h;

  if ( !PL_get_integer(handle, &h) || h < 0 || h >= MAX_CONVERSATIONS )
    return PL_error(NULL, 0, NULL, ERR_TYPE, ATOM_dde_handle, handle);

  if ( !conv_handle[h] )
    return PL_error(NULL, 0, 0, ERR_EXISTENCE, ATOM_dde_handle, handle);

  *theh = h;
  succeed;
}


static
PRED_IMPL("close_dde_conversation", 1, close_dde_conversation, 0)
{ int hdl;

  term_t handle = A1;

  if ( !get_conv_handle(handle, &hdl) )
    fail;

  DdeDisconnect(conv_handle[hdl]);
  conv_handle[hdl] = (HCONV)NULL;

  succeed;
}


/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
NOTE: Windows-XP gives the wrong value for valuelen below. Hence we will
use nul-terminated strings.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

static
PRED_IMPL("dde_request", 4, dde_request, 0)
{ int hdl;
  int rval;
  HSZ Hitem;
  DWORD result, valuelen;
  HDDEDATA Hvalue;
  long tmo;
  static UINT fmt[] = {CF_UNICODETEXT, CF_TEXT};
  int fmti;
  DWORD ddeInst;

  term_t handle  = A1;
  term_t item    = A2;
  term_t value   = A3;
  term_t timeout = A4;

  if ( !(ddeInst=dde_initialise()) )
    return FALSE;

  if ( !get_conv_handle(handle, &hdl) ||
       !get_hsz(ddeInst, item, &Hitem) ||
       !PL_get_long_ex(timeout, &tmo) )
    fail;

  if ( tmo <= 0 )
    tmo = TIMEOUT_VERY_LONG;

  for(fmti = 0; fmti<2; fmti++)
  { Hvalue = DdeClientTransaction(NULL, 0, conv_handle[hdl], Hitem, fmt[fmti],
				  XTYP_REQUEST, (DWORD)tmo, &result);
    if ( Hvalue )
      break;
  }
  DdeFreeStringHandle(ddeInst, Hitem);

  if ( Hvalue)
  { LPBYTE valuedata;

    if ( (valuedata = DdeAccessData(Hvalue, &valuelen)) )
    { DEBUG(1, Sdprintf("valuelen = %ld; format = %d\n", valuelen, fmti));
      if ( fmt[fmti] == CF_TEXT )
      { DEBUG(1, Sdprintf("ANSI text\n"));
	rval = PL_unify_string_chars(value, (char*)valuedata);
      } else
	rval = PL_unify_wchars(value, PL_STRING, -1, (wchar_t*)valuedata);
      DdeUnaccessData(Hvalue);
      return rval;
    } else
    { return dde_warning("access_data");
    }
  } else
  { return dde_warning("request");
  }
}


static
PRED_IMPL("dde_execute", 3, dde_execute, 0)
{ int hdl;
  wchar_t *cmdstr;
  size_t cmdlen;
  HDDEDATA Hvalue, data;
  DWORD result;
  DWORD ddeInst;
  long tmo;

  term_t handle  = A1;
  term_t command = A2;
  term_t timeout = A3;

  if ( !(ddeInst=dde_initialise()) ||
       !get_conv_handle(handle, &hdl) ||
       !PL_get_wchars(command, &cmdlen, &cmdstr, CVT_ALL|CVT_EXCEPTION) ||
       !PL_get_long_ex(timeout, &tmo) )
    fail;

  if ( tmo <= 0 )
    tmo = TIMEOUT_VERY_LONG;

  if ( !(data = DdeCreateDataHandle(ddeInst,
				    (unsigned char*)cmdstr,
				    (DWORD)(cmdlen+1)*sizeof(wchar_t),
				    0, 0, CF_UNICODETEXT, 0)) )
    return dde_warning("dde_execute/3");

  Hvalue = DdeClientTransaction((LPBYTE) data, (DWORD) -1,
				conv_handle[hdl], 0L, 0,
				XTYP_EXECUTE, (DWORD) tmo, &result);
  if ( Hvalue )
    succeed;

  return dde_warning("execute");
}


static
PRED_IMPL("dde_poke", 4, dde_poke, 0)
{ int hdl;
  wchar_t *datastr;
  size_t datalen;
  HDDEDATA Hvalue;
  HSZ Hitem;
  long tmo;
  DWORD ddeInst;

  term_t handle  = A1;
  term_t item    = A2;
  term_t data    = A3;
  term_t timeout = A4;

  if ( !(ddeInst=dde_initialise()) ||
       !get_conv_handle(handle, &hdl) ||
       !get_hsz(ddeInst, item, &Hitem) )
    fail;
  if ( !PL_get_wchars(data, &datalen, &datastr, CVT_ALL|CVT_EXCEPTION) )
    fail;
  if ( !PL_get_long_ex(timeout, &tmo) )
    fail;

  if ( tmo <= 0 )
    tmo = TIMEOUT_VERY_LONG;

  Hvalue = DdeClientTransaction((unsigned char*)datastr,
				(DWORD)(datalen+1)*sizeof(wchar_t),
				conv_handle[hdl], Hitem, CF_UNICODETEXT,
				XTYP_POKE, (DWORD)tmo, NULL);

  if ( !Hvalue )
    return dde_warning("poke");

  succeed;
}

		 /*******************************
		 *      PUBLISH PREDICATES	*
		 *******************************/

BeginPredDefs(dde)
  PRED_DEF("$dde_register_service",  2, dde_register_service,   0)
  PRED_DEF("open_dde_conversation",  3, open_dde_conversation,  0)
  PRED_DEF("close_dde_conversation", 1, close_dde_conversation, 0)
  PRED_DEF("dde_request",	     4, dde_request,		0)
  PRED_DEF("dde_execute",	     3, dde_execute,		0)
  PRED_DEF("dde_poke",		     4, dde_poke,		0)
EndPredDefs

#endif /*O_DDE*/
#endif /*__WINDOWS__*/