/*
 *  Main authors:
 *     Christian Schulte <schulte@gecode.org>
 *     Gabor Szokoli <szokoli@gecode.org>
 *
 *  Copyright:
 *     Christian Schulte, 2003
 *     Gabor Szokoli, 2003
 *
 *  Last modified:
 *     $Date: 2006-08-04 16:03:26 +0200 (Fri, 04 Aug 2006) $ by $Author: schulte $
 *     $Revision: 3512 $
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
 *
 *  See the file "LICENSE" for information on usage and
 *  redistribution of this file, and for a
 *     DISCLAIMER OF ALL WARRANTIES.
 *
 */

namespace Gecode { namespace Int { namespace Rel {

  /*
   * Less or equal propagator
   *
   */

  template <class View>
  forceinline
  Lq<View>::Lq(Space* home, View x0, View x1)
    : BinaryPropagator<View,PC_INT_BND>(home,x0,x1) {}

  template <class View>
  ExecStatus
  Lq<View>::post(Space* home, View x0, View x1) {
    GECODE_ME_CHECK(x0.lq(home,x1.max()));
    GECODE_ME_CHECK(x1.gq(home,x0.min()));
    if (!same(x0,x1) && (x0.max() > x1.min()))
      (void) new (home) Lq<View>(home,x0,x1);
    return ES_OK;
  }

  template <class View>
  forceinline
  Lq<View>::Lq(Space* home, bool share, Lq<View>& p)
    : BinaryPropagator<View,PC_INT_BND>(home,share,p) {}

  template <class View>
  Actor*
  Lq<View>::copy(Space* home, bool share) {
    return new (home) Lq<View>(home,share,*this);
  }

  template <class View>
  ExecStatus
  Lq<View>::propagate(Space* home) {
    GECODE_ME_CHECK(x0.lq(home,x1.max()));
    GECODE_ME_CHECK(x1.gq(home,x0.min()));
    return (x0.max() <= x1.min()) ? ES_SUBSUMED : ES_FIX;
  }




  /*
   * Less propagator
   *
   */

  template <class View>
  forceinline
  Le<View>::Le(Space* home, View x0, View x1)
    : BinaryPropagator<View,PC_INT_BND>(home,x0,x1) {}

  template <class View>
  ExecStatus
  Le<View>::post(Space* home, View x0, View x1) {
    if (same(x0,x1))
      return ES_FAILED;
    GECODE_ME_CHECK(x0.le(home,x1.max()));
    GECODE_ME_CHECK(x1.gr(home,x0.min()));
    if (x0.max() >= x1.min())
      (void) new (home) Le<View>(home,x0,x1);
    return ES_OK;
  }

  template <class View>
  forceinline
  Le<View>::Le(Space* home, bool share, Le<View>& p)
    : BinaryPropagator<View,PC_INT_BND>(home,share,p) {}

  template <class View>
  Actor*
  Le<View>::copy(Space* home, bool share) {
    return new (home) Le<View>(home,share,*this);
  }

  template <class View>
  ExecStatus
  Le<View>::propagate(Space* home) {
    GECODE_ME_CHECK(x0.le(home,x1.max()));
    GECODE_ME_CHECK(x1.gr(home,x0.min()));
    return (x0.max() < x1.min()) ? ES_SUBSUMED : ES_FIX;
  }


  /*
   * Reified less or equal propagator
   *
   */

  template <class View, class CtrlView>
  forceinline
  ReLq<View,CtrlView>::ReLq(Space* home, View x0, View x1, CtrlView b)
    : ReBinaryPropagator<View,PC_INT_BND,CtrlView>(home,x0,x1,b) {}

  template <class View, class CtrlView>
  ExecStatus
  ReLq<View,CtrlView>::post(Space* home, View x0, View x1, CtrlView b) {
    if (b.one())
      return Lq<View>::post(home,x0,x1);
    if (b.zero())
      return Le<View>::post(home,x1,x0);
    if (!same(x0,x1)) {
      switch (rtest_lq(x0,x1)) {
      case RT_TRUE:
	b.t_one_none(home); break;
      case RT_FALSE:
	b.t_zero_none(home); break;
      case RT_MAYBE:
	(void) new (home) ReLq<View,CtrlView>(home,x0,x1,b); break;
      default: GECODE_NEVER;
      }
    } else {
      b.t_one_none(home);
    }
    return ES_OK;
  }

  template <class View, class CtrlView>
  forceinline
  ReLq<View,CtrlView>::ReLq(Space* home, bool share, ReLq& p)
    : ReBinaryPropagator<View,PC_INT_BND,CtrlView>(home,share,p) {}

  template <class View, class CtrlView>
  Actor*
  ReLq<View,CtrlView>::copy(Space* home, bool share) {
    return new (home) ReLq<View,CtrlView>(home,share,*this);
  }

  template <class View, class CtrlView>
  ExecStatus
  ReLq<View,CtrlView>::propagate(Space* home) {
    if (b.one()) {
      if (Lq<View>::post(home,x0,x1) == ES_FAILED)
	return ES_FAILED;
      return ES_SUBSUMED;
    }
    if (b.zero()) {
      if (Le<View>::post(home,x1,x0) == ES_FAILED)
	return ES_FAILED;
      return ES_SUBSUMED;
    }
    switch (rtest_lq(x0,x1)) {
    case RT_TRUE:
      b.t_one_none(home);  return ES_SUBSUMED;
    case RT_FALSE:
      b.t_zero_none(home); return ES_SUBSUMED;
    case RT_MAYBE:
      break;
    default: GECODE_NEVER;
    }
    return ES_FIX;
  }

  /*
   * Reified less or equal propagator involving one variable
   *
   */

  template <class View, class CtrlView>
  forceinline
  ReLqInt<View,CtrlView>::ReLqInt(Space* home, View x, int c0, CtrlView b)
    : ReUnaryPropagator<View,PC_INT_BND,CtrlView>(home,x,b), c(c0) {}

  template <class View, class CtrlView>
  ExecStatus
  ReLqInt<View,CtrlView>::post(Space* home, View x, int c, CtrlView b) {
    if (b.one()) {
      GECODE_ME_CHECK(x.lq(home,c));
    } else if (b.zero()) {
      GECODE_ME_CHECK(x.gr(home,c));
    } else {
      switch (rtest_lq(x,c)) {
      case RT_TRUE:
	b.t_one_none(home); break;
      case RT_FALSE:
	b.t_zero_none(home); break;
      case RT_MAYBE:
	(void) new (home) ReLqInt<View,CtrlView>(home,x,c,b); break;
      default: GECODE_NEVER;
      }
    }
    return ES_OK;
  }


  template <class View, class CtrlView>
  forceinline
  ReLqInt<View,CtrlView>::ReLqInt(Space* home, bool share, ReLqInt& p)
    : ReUnaryPropagator<View,PC_INT_BND,CtrlView>(home,share,p), c(p.c) {}

  template <class View, class CtrlView>
  Actor*
  ReLqInt<View,CtrlView>::copy(Space* home, bool share) {
    return new (home) ReLqInt<View,CtrlView>(home,share,*this);
  }

  template <class View, class CtrlView>
  ExecStatus
  ReLqInt<View,CtrlView>::propagate(Space* home) {
    if (b.one()) {
      GECODE_ME_CHECK(x0.lq(home,c)); return ES_SUBSUMED;
    }
    if (b.zero()) {
      GECODE_ME_CHECK(x0.gr(home,c));  return ES_SUBSUMED;
    }
    switch (rtest_lq(x0,c)) {
    case RT_TRUE:
      b.t_one_none(home);  return ES_SUBSUMED;
    case RT_FALSE:
      b.t_zero_none(home); return ES_SUBSUMED;
    case RT_MAYBE:
      break;
    default: GECODE_NEVER;
    }
    return ES_FIX;
  }

}}}

// STATISTICS: int-prop