#include "Yap.h"
#include "Yatom.h"



/** 
 * Scan a list of arguments and output results to a pre-processed vector. 
 * 
 * @param listl: input list
 * @param def parameter definition
 * 
 * @return all arguments, some of them set, some of them not.
 */

static xarg *
matchKey(Atom key, xarg *e0, int n, const param_t *def)
{
  int i;
  for (i=0; i< n; i++) {
    if (!strcmp((char *)def->name, (char *)RepAtom(key)->StrOfAE)) {
      return e0;
    }
    def++;
    e0++;
  }
  return NULL;
}

/**
 * Returns the index of an argument key, or -1 if not found.
 *
 */
int
Yap_ArgKey(Atom key, const param_t *def, int n)
{
  int i;
  for (i=0; i< n; i++) {
    if (!strcmp((char *)def->name, (char *)RepAtom(key)->StrOfAE)) {
      return i;
    }
    def++;
  }
  return -1;
}

static xarg *
failed( yap_error_number e, Term t, xarg *a)
{
  free( a );      
  LOCAL_Error_TYPE = e;
  LOCAL_Error_Term = t;
  return NULL;
}


xarg *
Yap_ArgListToVector (Term listl, const param_t *def, int n)
{
  CACHE_REGS
    xarg *a = calloc(  n , sizeof(xarg) );
  LOCAL_Error_TYPE = YAP_NO_ERROR;
  if (IsApplTerm(listl) && FunctorOfTerm(listl) == FunctorModule)
    listl = ArgOfTerm(2,listl);
  if (!IsPairTerm(listl) && listl != TermNil) {
    if (IsVarTerm(listl) ) {
      return failed( INSTANTIATION_ERROR, listl, a);      
    }
    if (IsAtomTerm(listl) ) {
      xarg *na = matchKey( AtomOfTerm(listl), a, n, def);
      if (!na) {
        return failed( TYPE_ERROR_LIST, listl, a);      
      }
    } else if (IsApplTerm(listl)) {
      Functor f = FunctorOfTerm( listl );
      if (IsExtensionFunctor(f)) {
        return failed( TYPE_ERROR_LIST, listl, a);      
      }
      arity_t arity = ArityOfFunctor( f );
      if (arity != 1) {
        return failed( TYPE_ERROR_LIST, listl, a);      
      }
      xarg *na = matchKey( NameOfFunctor( f ), a, n, def);
      if (!na) {
        return failed( TYPE_ERROR_LIST, listl, a);      
      }
    } else {
      return failed( TYPE_ERROR_LIST, listl, a);      
    }
    listl = MkPairTerm( listl, TermNil );
  }
  while (IsPairTerm(listl)) {
    Term hd = HeadOfTerm( listl );
    listl = TailOfTerm( listl );
    if (IsVarTerm(hd) || IsVarTerm(listl))  {
      if (IsVarTerm(hd)) {
        return failed( INSTANTIATION_ERROR, hd, a);      
      } else {
        return failed( INSTANTIATION_ERROR, listl, a);      
      }
    }
    if (IsAtomTerm(hd)) {
      xarg *na = matchKey( AtomOfTerm( hd ), a, n, def);
      if (!na)
        return failed( DOMAIN_ERROR, hd, a);      
      na->used = true;
      na->tvalue = TermNil;
      continue;
    } else if (IsApplTerm( hd )) {
      Functor f = FunctorOfTerm( hd );
      if (IsExtensionFunctor(f)) {
        return failed( TYPE_ERROR_PARAMETER, hd, a);      
      }
      arity_t arity = ArityOfFunctor( f );
      if (arity != 1) {
        return failed( DOMAIN_ERROR_OUT_OF_RANGE, hd, a);      
      }
      xarg *na = matchKey( NameOfFunctor( f ), a, n, def);
      if (!na) {
        return failed( DOMAIN_ERROR, hd, a);      
      }
      na->used = 1;
      na->tvalue = ArgOfTerm(1, hd);      
    } else {
      return failed( TYPE_ERROR_PARAMETER, hd, a);      
    }
  }
  if (IsVarTerm(listl)) {
    return failed( INSTANTIATION_ERROR, listl, a);      
  } else if (listl != TermNil) {
    return failed( TYPE_ERROR_LIST, listl, a);      
  }
  return a;
}              

static xarg *
matchKey2(Atom key, xarg *e0, int n, const param2_t *def)
{
  int i;
  for (i=0; i< n; i++) {
    if (!strcmp((char*)def->name, (char*)RepAtom(key)->StrOfAE)) {
      return e0;
    }
    def++;
    e0++;
  }
  return NULL;
}


/// Yap_ArgList2ToVector is much the same as before,
/// but assumes parameters also have something called a
/// scope
xarg *
Yap_ArgList2ToVector (Term listl, const param2_t *def, int n)
{
  CACHE_REGS
    xarg *a = calloc(  n , sizeof(xarg) );
  if (!IsPairTerm(listl) && listl != TermNil) {
    if (IsVarTerm(listl) ) {
      return failed( INSTANTIATION_ERROR, listl, a);      
    }
    if (IsAtomTerm(listl) ) {
      xarg *na = matchKey2( AtomOfTerm(listl), a, n, def);
      if (!na) {
        return failed( DOMAIN_ERROR, listl, a);      
      }
    }
    if (IsApplTerm(listl)) {
      Functor f = FunctorOfTerm( listl );
      if (IsExtensionFunctor(f)) {
        return failed( TYPE_ERROR_PARAMETER, listl, a);      
      }
      arity_t arity = ArityOfFunctor( f );
      if (arity != 1) {
        return failed( TYPE_ERROR_LIST, listl, a);      
      }
      xarg *na = matchKey2( NameOfFunctor( f ), a, n, def);
      if (!na) {
        return failed( DOMAIN_ERROR, listl, a);      
      }
    } else {
      return failed( TYPE_ERROR_LIST, listl, a);      
    }
    listl = MkPairTerm( listl, TermNil );
  }
  while (IsPairTerm(listl)) {
    Term hd = HeadOfTerm( listl );
    if (IsVarTerm(hd))  {
      return failed( INSTANTIATION_ERROR, hd, a);      
    }
    if (IsAtomTerm(hd)) {
      xarg *na = matchKey2( AtomOfTerm( hd ), a, n, def);
      if (!na) {
	return failed( DOMAIN_ERROR, hd, a);      
      }
      na->used = true;
      na->tvalue = TermNil;
      continue;
    } else if (IsApplTerm( hd )) {
      Functor f = FunctorOfTerm( hd );
      if (IsExtensionFunctor(f)) {
        return failed( TYPE_ERROR_PARAMETER, hd, a);      
      }
      arity_t arity = ArityOfFunctor( f );
      if (arity != 1) {
        return failed( DOMAIN_ERROR, hd, a);      
      }
      xarg *na = matchKey2( NameOfFunctor( f ), a, n, def);
      if (na) {
	na->used = 1;
	na->tvalue = ArgOfTerm(1, hd);
      } else {
	return failed( DOMAIN_ERROR, hd, a);      
      }
    } else {
      return failed( INSTANTIATION_ERROR, hd, a);      
    }
    listl = TailOfTerm(listl);
  }
  if (IsVarTerm(listl))  {
    return failed( INSTANTIATION_ERROR, listl, a);      
  }
  if (TermNil != listl) {
    return failed( TYPE_ERROR_LIST, listl, a);      
  }
  return a;
}