/*********************                                                        */
/*! \file theory.cpp
 ** \verbatim
 ** Original author: mdeters
 ** Major contributors: ajreynol, dejan
 ** Minor contributors (to current version): taking
 ** This file is part of the CVC4 prototype.
 ** Copyright (c) 2009-2012  New York University and The University of Iowa
 ** See the file COPYING in the top-level source directory for licensing
 ** information.\endverbatim
 **
 ** \brief Base for theory interface.
 **
 ** Base for theory interface.
 **/

#include "theory/theory.h"
#include "util/cvc4_assert.h"
#include "theory/quantifiers_engine.h"

#include <vector>

using namespace std;

namespace CVC4 {
namespace theory {

/** Default value for the uninterpreted sorts is the UF theory */
TheoryId Theory::s_uninterpretedSortOwner = THEORY_UF;

/** By default, we use the type based theoryOf */
TheoryOfMode Theory::s_theoryOfMode = THEORY_OF_TYPE_BASED;

std::ostream& operator<<(std::ostream& os, Theory::Effort level){
  switch(level){
  case Theory::EFFORT_STANDARD:
    os << "EFFORT_STANDARD"; break;
  case Theory::EFFORT_FULL:
    os << "EFFORT_FULL"; break;
  case Theory::EFFORT_COMBINATION:
    os << "EFFORT_COMBINATION"; break;
  case Theory::EFFORT_LAST_CALL:
    os << "EFFORT_LAST_CALL"; break;
  default:
      Unreachable();
  }
  return os;
}/* ostream& operator<<(ostream&, Theory::Effort) */

Theory::~Theory() {
  StatisticsRegistry::unregisterStat(&d_computeCareGraphTime);
}

TheoryId Theory::theoryOf(TheoryOfMode mode, TNode node) {

  Trace("theory::internal") << "theoryOf(" << node << ")" << std::endl;

  switch(mode) {
  case THEORY_OF_TYPE_BASED:
    // Constants, variables, 0-ary constructors
    if (node.isVar() || node.isConst()) {
      return theoryOf(node.getType());
    }
    // Equality is owned by the theory that owns the domain
    if (node.getKind() == kind::EQUAL) {
      return theoryOf(node[0].getType());
    }
    // Regular nodes are owned by the kind
    return kindToTheoryId(node.getKind());
    break;
  case THEORY_OF_TERM_BASED:
    // Variables
    if (node.isVar()) {
      if (theoryOf(node.getType()) != theory::THEORY_BOOL) {
        // We treat the varibables as uninterpreted
        return s_uninterpretedSortOwner;
      } else {
        // Except for the Boolean ones, which we just ignore anyhow
        return theory::THEORY_BOOL;
      }
    }
    // Constants
    if (node.isConst()) {
      // Constants go to the theory of the type
      return theoryOf(node.getType());
    }
    // Equality
    if (node.getKind() == kind::EQUAL) {
      // If one of them is an ITE, it's irelevant, since they will get replaced out anyhow
      if (node[0].getKind() == kind::ITE) {
        return theoryOf(node[0].getType());
      }
      if (node[1].getKind() == kind::ITE) {
        return theoryOf(node[1].getType());
      }
      // If both sides belong to the same theory the choice is easy
      TheoryId T1 = theoryOf(node[0]);
      TheoryId T2 = theoryOf(node[1]);
      if (T1 == T2) {
        return T1;
      }
      TheoryId T3 = theoryOf(node[0].getType());
      // This is a case of
      // * x*y = f(z) -> UF
      // * x = c      -> UF
      // * f(x) = read(a, y) -> either UF or ARRAY
      // at least one of the theories has to be parametric, i.e. theory of the type is different
      // from the theory of the term
      if (T1 == T3) {
        return T2;
      }
      if (T2 == T3) {
        return T1;
      }
      // If both are parametric, we take the smaller one (arbitraty)
      return T1 < T2 ? T1 : T2;
    }
    // Regular nodes are owned by the kind
    return kindToTheoryId(node.getKind());
    break;
  default:
    Unreachable();
  }
}

void Theory::addSharedTermInternal(TNode n) {
  Debug("sharing") << "Theory::addSharedTerm<" << getId() << ">(" << n << ")" << endl;
  Debug("theory::assertions") << "Theory::addSharedTerm<" << getId() << ">(" << n << ")" << endl;
  d_sharedTerms.push_back(n);
  addSharedTerm(n);
}

void Theory::computeCareGraph() {
  Debug("sharing") << "Theory::computeCareGraph<" << getId() << ">()" << endl;
  for (unsigned i = 0; i < d_sharedTerms.size(); ++ i) {
    TNode a = d_sharedTerms[i];
    TypeNode aType = a.getType();
    for (unsigned j = i + 1; j < d_sharedTerms.size(); ++ j) {
      TNode b = d_sharedTerms[j];
      if (b.getType() != aType) {
        // We don't care about the terms of different types
        continue;
      }
      switch (d_valuation.getEqualityStatus(a, b)) {
      case EQUALITY_TRUE_AND_PROPAGATED:
      case EQUALITY_FALSE_AND_PROPAGATED:
  	// If we know about it, we should have propagated it, so we can skip
  	break;
      default:
  	// Let's split on it
  	addCarePair(a, b);
  	break;
      }
    }
  }
}

void Theory::printFacts(std::ostream& os) const {
  unsigned i, n = d_facts.size();
  for(i = 0; i < n; i++){
    const Assertion& a_i = d_facts[i];
    Node assertion  = a_i;
    os << d_id << '[' << i << ']' << " " << assertion << endl;
  }
}

void Theory::debugPrintFacts() const{
  DebugChannel.getStream() << "Theory::debugPrintFacts()" << endl;
  printFacts(DebugChannel.getStream());
}

std::hash_set<TNode, TNodeHashFunction> Theory::currentlySharedTerms() const{
  std::hash_set<TNode, TNodeHashFunction> currentlyShared;
  for(shared_terms_iterator i = shared_terms_begin(), i_end = shared_terms_end(); i != i_end; ++i){
    currentlyShared.insert (*i);
  }
  return currentlyShared;
}


void Theory::collectTerms(TNode n, set<Node>& termSet)
{
  if (termSet.find(n) != termSet.end()) {
    return;
  }
  Trace("theory::collectTerms") << "Theory::collectTerms: adding " << n << endl;
  termSet.insert(n);
  if (n.getKind() == kind::NOT || n.getKind() == kind::EQUAL || !isLeaf(n)) {
    for(TNode::iterator child_it = n.begin(); child_it != n.end(); ++child_it) {
      collectTerms(*child_it, termSet);
    }
  }
}


void Theory::computeRelevantTerms(set<Node>& termSet)
{
  // Collect all terms appearing in assertions
  context::CDList<Assertion>::const_iterator assert_it = facts_begin(), assert_it_end = facts_end();
  for (; assert_it != assert_it_end; ++assert_it) {
    collectTerms(*assert_it, termSet);
  }

  // Add terms that are shared terms
  context::CDList<TNode>::const_iterator shared_it = shared_terms_begin(), shared_it_end = shared_terms_end();
  for (; shared_it != shared_it_end; ++shared_it) {
    collectTerms(*shared_it, termSet);
  }
}


}/* CVC4::theory namespace */
}/* CVC4 namespace */