/*************************************************************************
 *									 *
 *	 YAP Prolog 							 *
 *									 *
 *	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
 *									 *
 * Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
 *									 *
 **************************************************************************
 *									 *
 * File:		load_foreign.c					 *
 * comments:	dynamic loader of external routines			 *
 *									 *
 *************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%.2";
#endif

#include "Yap.h"
#include "YapHeap.h"
#include "YapText.h"
#include "Yatom.h"
#include "yapio.h"
#include <stdlib.h>
#if HAVE_STRING_H
#include <string.h>
#endif

#include "Foreign.h"

#if _WIN32 || defined(__CYGWIN__)
#ifndef SO_EXT
#define SO_EXT "dll"
#endif
#endif

Int p_load_foreign(USES_REGS1);

Int p_load_foreign(USES_REGS1) {
  StringList ofiles = NULL;
  StringList libs = NULL;
  char *InitProcName;
  YapInitProc InitProc = NULL;
  Term t, t1;
  StringList new;
  bool returncode = FALSE;
  yhandle_t CurSlot = Yap_StartSlots();
#if __ANDROID__
return true;
#endif

  //  Yap_DebugPlWrite(ARG1);  printf("%s\n", " \n");
  // Yap_DebugPlWrite(ARG2);  printf("%s\n", " \n");
  // ap_DebugPlWrite(ARG3);  printf("%s\n", " \n");

  /* collect the list of object files */
  t = Deref(ARG1);
  while (1) {
    if (t == TermNil)
      break;
    t1 = HeadOfTerm(t);
    t = TailOfTerm(t);
    new = (StringList)Yap_AllocCodeSpace(sizeof(StringListItem));
    new->next = ofiles;
    new->name = AtomOfTerm(t1);
    ofiles = new;
  }

  /* collect the list of library files */
  t = Deref(ARG2);
  while (1) {
    if (t == TermNil)
      break;
    t1 = HeadOfTerm(t);
    t = TailOfTerm(t);
    new = (StringList)Yap_AllocCodeSpace(sizeof(StringListItem));
    new->next = libs;
    new->name = AtomOfTerm(t1);
    libs = new;
  }

  /* get the initialization function name */
  t1 = Deref(ARG3);
  InitProcName = (char *)RepAtom(AtomOfTerm(t1))->StrOfAE;

  // verify if it was waiting for initialization
  if (Yap_LateInit(InitProcName)) {
    returncode = true;
  } else
      /* call the OS specific function for dynamic loading */
      if (Yap_LoadForeign(ofiles, libs, InitProcName, &InitProc) ==
          LOAD_SUCCEEDED) {
    if (InitProc == NULL) {
      char *f;
      if (ofiles) {
        f = RepAtom(ofiles->name)->StrOfAE;
      } else {
        f = RepAtom(libs->name)->StrOfAE;
      }
     Yap_Error(SYSTEM_ERROR_OPERATING_SYSTEM, ARG3,
                "Foreign module %s does not have initialization function %s", f,
                InitProcName);
      return false;
    }
    Yap_StartSlots();
    (*InitProc)();
    Yap_CloseSlots(CurSlot);
    returncode = true;
  }

  /* I should recover space if load foreign fails */
  if (returncode == TRUE) {
    ForeignObj *f_code = (ForeignObj *)Yap_AllocCodeSpace(sizeof(ForeignObj));
    f_code->objs = ofiles;
    f_code->libs = libs;
    f_code->f = AtomOfTerm(t1);
    f_code->next = ForeignCodeLoaded;
    f_code->module = CurrentModule;
    ForeignCodeLoaded = f_code;
  } else {
    while (ofiles) {
      new = ofiles->next;
      Yap_FreeCodeSpace((ADDR)ofiles);
      ofiles = new;
    }
    while (libs) {
      new = libs->next;
      Yap_FreeCodeSpace((ADDR)libs);
      libs = new;
    }
  }
  return returncode;
}

static Int p_open_shared_object(USES_REGS1) {
  Term t = Deref(ARG1);
  Term tflags = Deref(ARG2);
  char *s;
  void *handle;

  if (IsVarTerm(t)) {
    Yap_Error(INSTANTIATION_ERROR, t, "open_shared_object/3");
    return FALSE;
  }
  if (!IsAtomTerm(t)) {
    Yap_Error(TYPE_ERROR_ATOM, t, "open_shared_object/3");
    return FALSE;
  }

  if (IsVarTerm(tflags)) {
    Yap_Error(INSTANTIATION_ERROR, tflags, "open_shared_object/3");
    return FALSE;
  }
  if (!IsIntegerTerm(tflags)) {
    Yap_Error(TYPE_ERROR_INTEGER, tflags, "open_shared_object/3");
    return FALSE;
  }

  s = (char *)RepAtom(AtomOfTerm(t))->StrOfAE;
  if ((handle = Yap_LoadForeignFile(s, IntegerOfTerm(tflags))) == NULL) {
    Yap_Error(EXISTENCE_ERROR_SOURCE_SINK, t,
              "open_shared_object_failed for %s"
              " with %s\n",
              s, LOCAL_ErrorMessage);
    return FALSE;
  } else {
    return Yap_unify(MkIntegerTerm((Int)handle), ARG3);
  }
}

static Int p_close_shared_object(USES_REGS1) {
  Term t = Deref(ARG1);
  void *handle;

  if (IsVarTerm(t)) {
    Yap_Error(INSTANTIATION_ERROR, t, "close_shared_object/1");
    return FALSE;
  }
  if (!IsIntegerTerm(t)) {
    Yap_Error(TYPE_ERROR_INTEGER, t, "close_shared_object/1");
    return FALSE;
  }
  handle = (char *)IntegerOfTerm(t);

  return Yap_CloseForeignFile(handle);
}

static Int p_call_shared_object_function(USES_REGS1) {
  Term t = Deref(ARG1);
  Term tfunc = Deref(ARG2);
  Term tmod;
  void *handle;
  Term OldCurrentModule = CurrentModule;
  Int res;

  tmod = CurrentModule;
restart:
  if (IsVarTerm(t)) {
    Yap_Error(INSTANTIATION_ERROR, t, "call_shared_object_function/2");
    return FALSE;
  } else if (IsApplTerm(t)) {
    Functor fun = FunctorOfTerm(t);
    if (fun == FunctorModule) {
      tmod = ArgOfTerm(1, t);
      if (IsVarTerm(tmod)) {
        Yap_Error(INSTANTIATION_ERROR, t, "call_shared_object_function/2");
        return FALSE;
      }
      if (!IsAtomTerm(tmod)) {
        Yap_Error(TYPE_ERROR_ATOM, ARG1, "call_shared_object_function/2");
        return FALSE;
      }
      t = ArgOfTerm(2, t);
      goto restart;
    }
  } else if (!IsIntegerTerm(t)) {
    Yap_Error(TYPE_ERROR_INTEGER, t, "call_shared_object_function/2");
    return FALSE;
  }
  handle = (void *)IntegerOfTerm(t);
  if (IsVarTerm(tfunc)) {
    Yap_Error(INSTANTIATION_ERROR, t, "call_shared_object_function/2");
    return FALSE;
  }
  if (!IsAtomTerm(tfunc)) {
    Yap_Error(TYPE_ERROR_ATOM, t, "call_shared_object_function/2/3");
    return FALSE;
  }
  CurrentModule = tmod;
  res =
      Yap_CallForeignFile(handle, (char *)RepAtom(AtomOfTerm(tfunc))->StrOfAE);
  CurrentModule = OldCurrentModule;
  return res;
}

static Int p_obj_suffix(USES_REGS1) {
  return Yap_unify(Yap_CharsToListOfCodes(SO_EXT, ENC_ISO_LATIN1 PASS_REGS),
                   ARG1);
}

static Int p_open_shared_objects(USES_REGS1) {
#ifdef SO_EXT
  return TRUE;
#else
  return FALSE;
#endif
}

void Yap_InitLoadForeign(void) {
  Yap_InitCPred("$load_foreign_files", 3, p_load_foreign,
                SafePredFlag | SyncPredFlag);
  Yap_InitCPred("$open_shared_objects", 0, p_open_shared_objects, SafePredFlag);
  Yap_InitCPred("$open_shared_object", 3, p_open_shared_object, SyncPredFlag);
  Yap_InitCPred("close_shared_object", 1, p_close_shared_object,
                SyncPredFlag | SafePredFlag);
  /** @pred close_shared_object(+ _Handle_)

  Detach the shared object identified by  _Handle_.


  */
  Yap_InitCPred("$call_shared_object_function", 2,
                p_call_shared_object_function, SyncPredFlag);
  Yap_InitCPred("$obj_suffix", 1, p_obj_suffix, SafePredFlag);
}

void Yap_ReOpenLoadForeign(void) {
  CACHE_REGS
  ForeignObj *f_code = ForeignCodeLoaded;
  Term OldModule = CurrentModule;

  while (f_code != NULL) {
    YapInitProc InitProc = NULL;

    CurrentModule = f_code->module;
    if (Yap_ReLoadForeign(f_code->objs, f_code->libs,
                          (char *)RepAtom(f_code->f)->StrOfAE,
                          &InitProc) == LOAD_SUCCEEDED) {
      if (InitProc)
        (*InitProc)();
    }
    f_code = f_code->next;
  }
  CurrentModule = OldModule;
}

X_API bool load_none(void)
{
  return true;
}