/******************************************************************************

 * Top contributors (to current version):

 *   Andrew Reynolds, Tim King, Morgan Deters

 *

 * This file is part of the cvc5 project.

 *

 * Copyright (c) 2009-2021 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.

 * ****************************************************************************

 *

 * Theory of datatypes.

 */

#include "cvc5_private.h"

#ifndef CVC5__THEORY__DATATYPES__THEORY_DATATYPES_H

#define CVC5__THEORY__DATATYPES__THEORY_DATATYPES_H

#include <iostream>

#include <map>

#include "context/cdlist.h"

#include "expr/attribute.h"

#include "expr/node_trie.h"

#include "theory/datatypes/datatypes_rewriter.h"

#include "theory/datatypes/inference_manager.h"

#include "theory/datatypes/proof_checker.h"

#include "theory/datatypes/sygus_extension.h"

#include "theory/theory.h"

#include "theory/theory_eq_notify.h"

#include "theory/theory_state.h"

#include "theory/uf/equality_engine.h"

#include "util/hash.h"

namespace cvc5 {

namespace theory {

namespace datatypes {

class TheoryDatatypes : public Theory {

 private:

  typedef context::CDList<Node> NodeList;

  /** maps nodes to an index in a vector */

  typedef context::CDHashMap<Node, size_t> NodeUIntMap;

  typedef context::CDHashMap<Node, bool> BoolMap;

  typedef context::CDHashMap<Node, Node> NodeMap;

 private:

  //notification class for equality engine

  {

    TheoryDatatypes& d_dt;

  public:

   {

   {

    {

  };/* class TheoryDatatypes::NotifyClass */

private:

  /** equivalence class info

   * d_inst is whether the instantiate rule has been applied,

   * d_constructor is a node of kind APPLY_CONSTRUCTOR (if any) in this equivalence class,

   * d_selectors is whether a selector has been applied to this equivalence class.

   */

  class EqcInfo

  {

  public:

    EqcInfo( context::Context* c );

    //whether we have instantiatied this eqc

    context::CDO< bool > d_inst;

    //constructor equal to this eqc

    context::CDO< Node > d_constructor;

    //all selectors whose argument is this eqc

    context::CDO< bool > d_selectors;

  };

  /** does eqc of n have a label (do we know its constructor)? */

  bool hasLabel( EqcInfo* eqc, Node n );

  /** get the label associated to n */

  Node getLabel( Node n );

  /** get the index of the label associated to n */

  int getLabelIndex( EqcInfo* eqc, Node n );

  /** does eqc of n have any testers? */

  bool hasTester( Node n );

  /** get the possible constructors for n */

  void getPossibleCons( EqcInfo* eqc, Node n, std::vector< bool >& cons );

  /** skolems for terms */

  NodeMap d_term_sk;

  Node getTermSkolemFor( Node n );

private:

  /** information necessary for equivalence classes */

  std::map< Node, EqcInfo* > d_eqc_info;

  //---------------------------------labels

  /** labels for each equivalence class

   *

   * For each eqc r, d_labels[r] is testers that hold for this equivalence

   * class, either:

   * a list of equations of the form

   *   NOT is_[constructor_1]( t1 )...NOT is_[constructor_n]( tn ), each of

   *   which are unique testers, n is less than the number of possible

   *   constructors for t minus one,

   * or a list of equations of the form

   *   NOT is_[constructor_1]( t1 )...NOT is_[constructor_n]( tn ) followed by

   *   is_[constructor_(n+1)]( t{n+1} ), each of which is a unique tester.

   * In both cases, t1, ..., tn, t{n+1} are terms in the equivalence class of r.

   *

   * We store this list in a context-dependent way, using the four data

   * structures below. The three vectors d_labels_data, d_labels_args, and

   * d_labels_tindex store the tester applications, their arguments and the

   * tester index of the application. The map d_labels stores the number of

   * values in these vectors that is valid in the current context (this is an

   * optimization that ensures we don't need to pop data when changing SAT

   * contexts).

   */

  NodeUIntMap d_labels;

  /** the tester applications */

  std::map< Node, std::vector< Node > > d_labels_data;

  /** the argument of each node in d_labels_data */

  std::map<Node, std::vector<Node> > d_labels_args;

  /** the tester index of each node in d_labels_data */

  std::map<Node, std::vector<unsigned> > d_labels_tindex;

  //---------------------------------end labels

  /** selector apps for eqch equivalence class */

  NodeUIntMap d_selector_apps;

  std::map< Node, std::vector< Node > > d_selector_apps_data;

  /** The conflict node */

  Node d_conflictNode;

  /**

   * SAT-context dependent cache for which terms we have called

   * collectTerms(...) on.

   */

  BoolMap d_collectTermsCache;

  /**

   * User-context dependent cache for which terms we have called

   * collectTerms(...) on.

   */

  BoolMap d_collectTermsCacheU;

  /** All the function terms that the theory has seen */

  context::CDList<TNode> d_functionTerms;

  /** counter for forcing assignments (ensures fairness) */

  unsigned d_dtfCounter;

  /** uninterpreted constant to variable map */

  std::map< Node, Node > d_uc_to_fresh_var;

private:

  /** singleton lemmas (for degenerate co-datatype case) */

  std::map< TypeNode, Node > d_singleton_lemma[2];

  /** Cache for singleton equalities processed */

  BoolMap d_singleton_eq;

private:

  /** assert fact */

  void assertFact( Node fact, Node exp );

  /** get or make eqc info */

  EqcInfo* getOrMakeEqcInfo( TNode n, bool doMake = false );

  /** has eqc info */

  /** get eqc constructor */

  TNode getEqcConstructor( TNode r );

 protected:

  void addCarePairs(TNodeTrie* t1,

                    TNodeTrie* t2,

                    unsigned arity,

                    unsigned depth,

                    unsigned& n_pairs);

  /** compute care graph */

  void computeCareGraph() override;

 public:

  TheoryDatatypes(Env& env, OutputChannel& out, Valuation valuation);

  ~TheoryDatatypes();

  //--------------------------------- initialization

  /** get the official theory rewriter of this theory */

  TheoryRewriter* getTheoryRewriter() override;

  /** get the proof checker of this theory */

  ProofRuleChecker* getProofChecker() override;

  /**

   * Returns true if we need an equality engine. If so, we initialize the

   * information regarding how it should be setup. For details, see the

   * documentation in Theory::needsEqualityEngine.

   */

  bool needsEqualityEngine(EeSetupInfo& esi) override;

  /** finish initialization */

  void finishInit() override;

  //--------------------------------- end initialization

  /** propagate */

  bool propagateLit(TNode literal);

  /** Conflict when merging two constants */

  void conflict(TNode a, TNode b);

  /** explain */

  TrustNode explain(TNode literal) override;

  /** called when a new equivalance class is created */

  void eqNotifyNewClass(TNode t);

  /** called when two equivalance classes have merged */

  void eqNotifyMerge(TNode t1, TNode t2);

  //--------------------------------- standard check

  /** Do we need a check call at last call effort? */

  bool needsCheckLastEffort() override;

  /** Pre-check, called before the fact queue of the theory is processed. */

  bool preCheck(Effort level) override;

  /** Post-check, called after the fact queue of the theory is processed. */

  void postCheck(Effort level) override;

  /** Notify fact */

  void notifyFact(TNode atom, bool pol, TNode fact, bool isInternal) override;

  //--------------------------------- end standard check

  void preRegisterTerm(TNode n) override;

  TrustNode ppRewrite(TNode n, std::vector<SkolemLemma>& lems) override;

  EqualityStatus getEqualityStatus(TNode a, TNode b) override;

  {

  }

  /** debug print */

  void printModelDebug( const char* c );

  /** entailment check */

  std::pair<bool, Node> entailmentCheck(TNode lit) override;

 private:

  /** add tester to equivalence class info */

  void addTester(unsigned ttindex, Node t, EqcInfo* eqc, Node n, Node t_arg);

  /** add selector to equivalence class info */

  void addSelector( Node s, EqcInfo* eqc, Node n, bool assertFacts = true );

  /** add constructor */

  void addConstructor( Node c, EqcInfo* eqc, Node n );

  /** merge the equivalence class info of t1 and t2 */

  void merge( Node t1, Node t2 );

  /** collapse selector, s is of the form sel( n ) where n = c */

  void collapseSelector( Node s, Node c );

  /** for checking if cycles exist */

  void checkCycles();

  Node searchForCycle(TNode n,

                      TNode on,

                      std::map<TNode, bool>& visited,

                      std::map<TNode, bool>& proc,

                      std::vector<Node>& explanation,

                      bool firstTime = true);

  /** for checking whether two codatatype terms must be equal */

  void separateBisimilar(std::vector<Node>& part,

                         std::vector<std::vector<Node> >& part_out,

                         std::vector<Node>& exp,

                         std::map<Node, Node>& cn,

                         std::map<Node, std::map<Node, int> >& dni,

                         int dniLvl,

                         bool mkExp);

  /** build model */

  Node getCodatatypesValue( Node n, std::map< Node, Node >& eqc_cons, std::map< Node, int >& vmap, int depth );

  /** get singleton lemma */

  Node getSingletonLemma( TypeNode tn, bool pol );

  /** collect terms */

  void collectTerms( Node n );

  /** get instantiate cons */

  Node getInstantiateCons(Node n, const DType& dt, int index);

  /** check instantiate, return true if an inference was generated. */

  bool instantiate(EqcInfo* eqc, Node n);

 private:

  //equality queries

  bool hasTerm( TNode a );

  bool areEqual( TNode a, TNode b );

  bool areDisequal( TNode a, TNode b );

  bool areCareDisequal( TNode x, TNode y );

  TNode getRepresentative( TNode a );

  /** Collect model values in m based on the relevant terms given by termSet */

  bool collectModelValues(TheoryModel* m,

                          const std::set<Node>& termSet) override;

  /**

   * Compute relevant terms. This includes datatypes in non-singleton

   * equivalence classes.

   */

  void computeRelevantTerms(std::set<Node>& termSet) override;

  /** Commonly used terms */

  Node d_true;

  Node d_zero;

  /** sygus symmetry breaking utility */

  std::unique_ptr<SygusExtension> d_sygusExtension;

  /** The theory rewriter for this theory. */

  DatatypesRewriter d_rewriter;

  /** A (default) theory state object */

  TheoryState d_state;

  /** The inference manager */

  InferenceManager d_im;

  /** The notify class */

  NotifyClass d_notify;

  /** Proof checker for datatypes */

  DatatypesProofRuleChecker d_checker;

};/* class TheoryDatatypes */

}  // namespace datatypes

}  // namespace theory

}  // namespace cvc5

#endif /* CVC5__THEORY__DATATYPES__THEORY_DATATYPES_H */