/*********************                                                        */
/*! \file rep_set.cpp
 ** \verbatim
 ** Top contributors (to current version):
 **   Andrew Reynolds, Morgan Deters, Tim King
 ** This file is part of the CVC4 project.
 ** Copyright (c) 2009-2016 by the authors listed in the file AUTHORS
 ** in the top-level source directory) and their institutional affiliations.
 ** All rights reserved.  See the file COPYING in the top-level source
 ** directory for licensing information.\endverbatim
 **
 ** \brief Implementation of representative set
 **/

#include "theory/rep_set.h"
#include "theory/type_enumerator.h"
#include "theory/quantifiers/bounded_integers.h"
#include "theory/quantifiers/term_database.h"
#include "theory/quantifiers/first_order_model.h"

using namespace std;
using namespace CVC4;
using namespace CVC4::kind;
using namespace CVC4::context;
using namespace CVC4::theory;

void RepSet::clear(){
  d_type_reps.clear();
  d_type_complete.clear();
  d_tmap.clear();
  d_values_to_terms.clear();
}

bool RepSet::hasRep( TypeNode tn, Node n ) {
  std::map< TypeNode, std::vector< Node > >::iterator it = d_type_reps.find( tn );
  if( it==d_type_reps.end() ){
    return false;
  }else{
    return std::find( it->second.begin(), it->second.end(), n )!=it->second.end();
  }
}

int RepSet::getNumRepresentatives( TypeNode tn ) const{
  std::map< TypeNode, std::vector< Node > >::const_iterator it = d_type_reps.find( tn );
  if( it!=d_type_reps.end() ){
    return (int)it->second.size();
  }else{
    return 0;
  }
}

bool containsStoreAll( Node n, std::vector< Node >& cache ){
  if( std::find( cache.begin(), cache.end(), n )==cache.end() ){
    cache.push_back( n );
    if( n.getKind()==STORE_ALL ){
      return true;
    }else{
      for( unsigned i=0; i<n.getNumChildren(); i++ ){
        if( containsStoreAll( n[i], cache ) ){
          return true;
        }
      }
    }
  }
  return false;
}

void RepSet::add( TypeNode tn, Node n ){
  //for now, do not add array constants FIXME
  if( tn.isArray() ){
    std::vector< Node > cache;
    if( containsStoreAll( n, cache ) ){
      return;
    }
  }
  Trace("rsi-debug") << "Add rep #" << d_type_reps[tn].size() << " for " << tn << " : " << n << std::endl;
  Assert( n.getType().isSubtypeOf( tn ) );
  d_tmap[ n ] = (int)d_type_reps[tn].size();
  d_type_reps[tn].push_back( n );
}

int RepSet::getIndexFor( Node n ) const {
  std::map< Node, int >::const_iterator it = d_tmap.find( n );
  if( it!=d_tmap.end() ){
    return it->second;
  }else{
    return -1;
  }
}

bool RepSet::complete( TypeNode t ){
  std::map< TypeNode, bool >::iterator it = d_type_complete.find( t );
  if( it==d_type_complete.end() ){
    //remove all previous
    for( unsigned i=0; i<d_type_reps[t].size(); i++ ){
      d_tmap.erase( d_type_reps[t][i] );
    }
    d_type_reps[t].clear();
    //now complete the type
    d_type_complete[t] = true;
    TypeEnumerator te(t);
    while( !te.isFinished() ){
      Node n = *te;
      if( std::find( d_type_reps[t].begin(), d_type_reps[t].end(), n )==d_type_reps[t].end() ){
        add( t, n );
      }
      ++te;
    }
    for( size_t i=0; i<d_type_reps[t].size(); i++ ){
      Trace("reps-complete") << d_type_reps[t][i] << " ";
    }
    Trace("reps-complete") << std::endl;
    return true;
  }else{
    return it->second;
  }
}

void RepSet::toStream(std::ostream& out){
  for( std::map< TypeNode, std::vector< Node > >::iterator it = d_type_reps.begin(); it != d_type_reps.end(); ++it ){
    if( !it->first.isFunction() && !it->first.isPredicate() ){
      out << "(" << it->first << " " << it->second.size();
      out << " (";
      for( unsigned i=0; i<it->second.size(); i++ ){
        if( i>0 ){ out << " "; }
        out << it->second[i];
      }
      out << ")";
      out << ")" << std::endl;
    }
  }
}


RepSetIterator::RepSetIterator( QuantifiersEngine * qe, RepSet* rs ) : d_qe(qe), d_rep_set( rs ){
  d_incomplete = false;
}

int RepSetIterator::domainSize( int i ) {
  Assert(i>=0);
  int v = d_var_order[i];
  return d_domain_elements[v].size();
}

bool RepSetIterator::setQuantifier( Node f, RepBoundExt* rext ){
  Trace("rsi") << "Make rsi for " << f << std::endl;
  Assert( d_types.empty() );
  //store indicies
  for( size_t i=0; i<f[0].getNumChildren(); i++ ){
    d_types.push_back( f[0][i].getType() );
  }
  d_owner = f;
  return initialize( rext );
}

bool RepSetIterator::setFunctionDomain( Node op, RepBoundExt* rext ){
  Trace("rsi") << "Make rsi for " << op << std::endl;
  Assert( d_types.empty() );
  TypeNode tn = op.getType();
  for( size_t i=0; i<tn.getNumChildren()-1; i++ ){
    d_types.push_back( tn[i] );
  }
  d_owner = op;
  return initialize( rext );
}

bool RepSetIterator::initialize( RepBoundExt* rext ){
  Trace("rsi") << "Initialize rep set iterator..." << std::endl;
  for( unsigned v=0; v<d_types.size(); v++ ){
    d_index.push_back( 0 );
    //store default index order
    d_index_order.push_back( v );
    d_var_order[v] = v;
    //store default domain
    //d_domain.push_back( RepDomain() );
    d_domain_elements.push_back( std::vector< Node >() );
    TypeNode tn = d_types[v];
    Trace("rsi") << "Var #" << v << " is type " << tn << "..." << std::endl;
    if( tn.isSort() ){
      //must ensure uninterpreted type is non-empty.
      if( !d_rep_set->hasType( tn ) ){
        //FIXME:
        // terms in rep_set are now constants which mapped to terms through TheoryModel
        // thus, should introduce a constant and a term.  for now, just a term.

        //Node c = d_qe->getTermDatabase()->getEnumerateTerm( tn, 0 );
        Node var = d_qe->getModel()->getSomeDomainElement( tn );
        Trace("mkVar") << "RepSetIterator:: Make variable " << var << " : " << tn << std::endl;
        d_rep_set->add( tn, var );
      }
    }
    bool inc = true;
    //check if it is externally bound
    if( rext && rext->setBound( d_owner, v, tn, d_domain_elements[v] ) ){
      d_enum_type.push_back( ENUM_DEFAULT );
      inc = false;
    //builtin: check if it is bound by bounded integer module
    }else if( d_owner.getKind()==FORALL && d_qe && d_qe->getBoundedIntegers() ){
      if( d_qe->getBoundedIntegers()->isBoundVar( d_owner, d_owner[0][v] ) ){
        unsigned bvt = d_qe->getBoundedIntegers()->getBoundVarType( d_owner, d_owner[0][v] );
        if( bvt!=quantifiers::BoundedIntegers::BOUND_FINITE ){
          d_enum_type.push_back( ENUM_BOUND_INT );
          inc = false;
        }else{
          //will treat in default way
        }
      }
    }
    if( !tn.isSort() ){
      if( inc ){
        if( d_qe->getTermDatabase()->mayComplete( tn ) ){
          Trace("rsi") << "  do complete, since cardinality is small (" << tn.getCardinality() << ")..." << std::endl;
          d_rep_set->complete( tn );
          //must have succeeded
          Assert( d_rep_set->hasType( tn ) );
        }else{
          Trace("rsi") << "  variable cannot be bounded." << std::endl;
          Trace("fmf-incomplete") << "Incomplete because of quantification of type " << tn << std::endl;
          d_incomplete = true;
        }
      }
    }

    //if we have yet to determine the type of enumeration
    if( d_enum_type.size()<=v ){
      if( d_rep_set->hasType( tn ) ){
        d_enum_type.push_back( ENUM_DEFAULT );
        for( unsigned j=0; j<d_rep_set->d_type_reps[tn].size(); j++ ){
          //d_domain[v].push_back( j );
          d_domain_elements[v].push_back( d_rep_set->d_type_reps[tn][j] );
        }
      }else{
        Assert( d_incomplete );
        return false;
      }
    }
  }
  //must set a variable index order based on bounded integers
  if( d_owner.getKind()==FORALL && d_qe && d_qe->getBoundedIntegers() ){
    Trace("bound-int-rsi") << "Calculating variable order..." << std::endl;
    std::vector< int > varOrder;
    for( unsigned i=0; i<d_qe->getBoundedIntegers()->getNumBoundVars( d_owner ); i++ ){
      Node v = d_qe->getBoundedIntegers()->getBoundVar( d_owner, i );
      Trace("bound-int-rsi") << "  bound var #" << i << " is " << v << std::endl;
      varOrder.push_back( d_qe->getTermDatabase()->getVariableNum( d_owner, v ) );
    }
    for( unsigned i=0; i<d_owner[0].getNumChildren(); i++) {
      if( !d_qe->getBoundedIntegers()->isBoundVar(d_owner, d_owner[0][i])) {
        varOrder.push_back(i);
      }
    }
    Trace("bound-int-rsi") << "Variable order : ";
    for( unsigned i=0; i<varOrder.size(); i++) {
      Trace("bound-int-rsi") << varOrder[i] << " ";
    }
    Trace("bound-int-rsi") << std::endl;
    std::vector< int > indexOrder;
    indexOrder.resize(varOrder.size());
    for( unsigned i=0; i<varOrder.size(); i++){
      indexOrder[varOrder[i]] = i;
    }
    Trace("bound-int-rsi") << "Will use index order : ";
    for( unsigned i=0; i<indexOrder.size(); i++) {
      Trace("bound-int-rsi") << indexOrder[i] << " ";
    }
    Trace("bound-int-rsi") << std::endl;
    setIndexOrder( indexOrder );
  }
  //now reset the indices
  do_reset_increment( -1, true );
  return true;
}

void RepSetIterator::setIndexOrder( std::vector< int >& indexOrder ){
  d_index_order.clear();
  d_index_order.insert( d_index_order.begin(), indexOrder.begin(), indexOrder.end() );
  //make the d_var_order mapping
  for( unsigned i=0; i<d_index_order.size(); i++ ){
    d_var_order[d_index_order[i]] = i;
  }
}

int RepSetIterator::resetIndex( int i, bool initial ) {
  d_index[i] = 0;
  int v = d_var_order[i];
  Trace("bound-int-rsi") << "Reset " << i << ", var order = " << v << ", initial = " << initial << std::endl;
  if( d_enum_type[v]==ENUM_BOUND_INT ){
    Assert( d_owner.getKind()==FORALL );
    if( !d_qe->getBoundedIntegers()->getBoundElements( this, initial, d_owner, d_owner[0][v], d_domain_elements[v] ) ){
      return -1;
    }
  }
  return d_domain_elements[v].empty() ? 0 : 1;
}

int RepSetIterator::increment2( int i ){
  Assert( !isFinished() );
#ifdef DISABLE_EVAL_SKIP_MULTIPLE
  i = (int)d_index.size()-1;
#endif
  //increment d_index
  if( i>=0){
    Trace("rsi-debug") << "domain size of " << i << " is " << domainSize(i) << std::endl;
  }
  while( i>=0 && d_index[i]>=(int)(domainSize(i)-1) ){
    i--;
    if( i>=0){
      Trace("rsi-debug") << "domain size of " << i << " is " << domainSize(i) << std::endl;
    }
  }
  if( i==-1 ){
    d_index.clear();
    return -1;
  }else{
    Trace("rsi-debug") << "increment " << i << std::endl;
    d_index[i]++;
    return do_reset_increment( i );
  }
}

int RepSetIterator::do_reset_increment( int i, bool initial ) {
  bool emptyDomain = false;
  for( unsigned ii=(i+1); ii<d_index.size(); ii++ ){
    int ri_res = resetIndex( ii, initial );
    if( ri_res==-1 ){
      //failed
      d_index.clear();
      d_incomplete = true;
      break;
    }else if( ri_res==0 ){
      emptyDomain = true;
    }
    //force next iteration if currently an empty domain
    if( emptyDomain ){
      d_index[ii] = domainSize(ii)-1;
    }
  }
  if( emptyDomain ){
    Trace("rsi-debug") << "This is an empty domain, increment." << std::endl;
    return increment();
  }else{
    return i;
  }
}

int RepSetIterator::increment(){
  if( !isFinished() ){
    return increment2( (int)d_index.size()-1 );
  }else{
    return -1;
  }
}

bool RepSetIterator::isFinished(){
  return d_index.empty();
}

Node RepSetIterator::getCurrentTerm( int v ){
  int ii = d_index_order[v];
  int curr = d_index[ii];
  Trace("rsi-debug") << "rsi : get term " << v << ", index order = " << d_index_order[v] << std::endl;
  Trace("rsi-debug") << "rsi : curr = " << curr << " / " << d_domain_elements[v].size() << std::endl;
  Assert( 0<=curr && curr<(int)d_domain_elements[v].size() );
  return d_domain_elements[v][curr];
}

void RepSetIterator::debugPrint( const char* c ){
  for( unsigned v=0; v<d_index.size(); v++ ){
    Debug( c ) << v << " : " << getCurrentTerm( v ) << std::endl;
  }
}

void RepSetIterator::debugPrintSmall( const char* c ){
  Debug( c ) << "RI: ";
  for( unsigned v=0; v<d_index.size(); v++ ){
    Debug( c ) << v << ": " << getCurrentTerm( v ) << " ";
  }
  Debug( c ) << std::endl;
}