/*********************                                                        */
/*! \file smt2.h
 ** \verbatim
 ** Top contributors (to current version):
 **   Andrew Reynolds, Morgan Deters, Christopher L. Conway
 ** This file is part of the CVC4 project.
 ** Copyright (c) 2009-2019 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 Definitions of SMT2 constants.
 **
 ** Definitions of SMT2 constants.
 **/

#include "cvc4parser_private.h"

#ifndef CVC4__PARSER__SMT2_H
#define CVC4__PARSER__SMT2_H

#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <utility>

#include "api/cvc4cpp.h"
#include "parser/parser.h"
#include "parser/smt2/parse_op.h"
#include "smt/command.h"
#include "theory/logic_info.h"
#include "util/abstract_value.h"

namespace CVC4 {

class SExpr;

namespace api {
class Solver;
}

namespace parser {

class Smt2 : public Parser
{
  friend class ParserBuilder;

 public:
  enum Theory
  {
    THEORY_ARRAYS,
    THEORY_BITVECTORS,
    THEORY_CORE,
    THEORY_DATATYPES,
    THEORY_INTS,
    THEORY_REALS,
    THEORY_TRANSCENDENTALS,
    THEORY_REALS_INTS,
    THEORY_QUANTIFIERS,
    THEORY_SETS,
    THEORY_STRINGS,
    THEORY_UF,
    THEORY_FP,
    THEORY_SEP
  };

 private:
  /** Has the logic been set (either by forcing it or a set-logic command)? */
  bool d_logicSet;
  /** Have we seen a set-logic command yet? */
  bool d_seenSetLogic;

  LogicInfo d_logic;
  std::unordered_map<std::string, Kind> operatorKindMap;
  /**
   * Maps indexed symbols to the kind of the operator (e.g. "extract" to
   * BITVECTOR_EXTRACT_OP).
   */
  std::unordered_map<std::string, api::Kind> d_indexedOpKindMap;
  std::pair<Expr, std::string> d_lastNamedTerm;
  // for sygus
  std::vector<Expr> d_sygusVars, d_sygusVarPrimed, d_sygusConstraints,
      d_sygusFunSymbols;

 protected:
  Smt2(api::Solver* solver,
       Input* input,
       bool strictMode = false,
       bool parseOnly = false);

 public:
  /**
   * Add theory symbols to the parser state.
   *
   * @param theory the theory to open (e.g., Core, Ints)
   */
  void addTheory(Theory theory);

  void addOperator(Kind k, const std::string& name);

  /**
   * Registers an indexed function symbol.
   *
   * @param tKind The kind of the term that uses the operator kind (e.g.
   *              BITVECTOR_EXTRACT). NOTE: this is an internal kind for now
   *              because that is what we use to create expressions. Eventually
   *              it will be an api::Kind.
   * @param opKind The kind of the operator term (e.g. BITVECTOR_EXTRACT_OP)
   * @param name The name of the symbol (e.g. "extract")
   */
  void addIndexedOperator(Kind tKind,
                          api::Kind opKind,
                          const std::string& name);

  Kind getOperatorKind(const std::string& name) const;

  bool isOperatorEnabled(const std::string& name) const;

  bool isTheoryEnabled(Theory theory) const;

  bool logicIsSet() override;

  /**
   * Creates an indexed constant, e.g. (_ +oo 8 24) (positive infinity
   * as a 32-bit floating-point constant).
   *
   * @param name The name of the constant (e.g. "+oo")
   * @param numerals The parameters for the constant (e.g. [8, 24])
   * @return The term corresponding to the constant or a parse error if name is
   *         not valid.
   */
  api::Term mkIndexedConstant(const std::string& name,
                              const std::vector<uint64_t>& numerals);

  /**
   * Creates an indexed operator term, e.g. (_ extract 5 0).
   *
   * @param name The name of the operator (e.g. "extract")
   * @param numerals The parameters for the operator (e.g. [5, 0])
   * @return The operator term corresponding to the indexed operator or a parse
   *         error if the name is not valid.
   */
  api::OpTerm mkIndexedOp(const std::string& name,
                          const std::vector<uint64_t>& numerals);

  /**
   * Returns the expression that name should be interpreted as.
   */
  Expr getExpressionForNameAndType(const std::string& name, Type t) override;

  /** Make function defined by a define-fun(s)-rec command.
   *
   * fname : the name of the function.
   * sortedVarNames : the list of variable arguments for the function.
   * t : the range type of the function we are defining.
   *
   * This function will create a bind a new function term to name fname.
   * The type of this function is
   * Parser::mkFlatFunctionType(sorts,t,flattenVars),
   * where sorts are the types in the second components of sortedVarNames.
   * As descibed in Parser::mkFlatFunctionType, new bound variables may be
   * added to flattenVars in this function if the function is given a function
   * range type.
   */
  Expr mkDefineFunRec(
      const std::string& fname,
      const std::vector<std::pair<std::string, Type> >& sortedVarNames,
      Type t,
      std::vector<Expr>& flattenVars);

  /** Push scope for define-fun-rec
   *
   * This calls Parser::pushScope(bindingLevel) and sets up
   * initial information for reading a body of a function definition
   * in the define-fun-rec and define-funs-rec command.
   * The input parameters func/flattenVars are the result
   * of a call to mkDefineRec above.
   *
   * func : the function whose body we are defining.
   * sortedVarNames : the list of variable arguments for the function.
   * flattenVars : the implicit variables introduced when defining func.
   *
   * This function:
   * (1) Calls Parser::pushScope(bindingLevel).
   * (2) Computes the bound variable list for the quantified formula
   *     that defined this definition and stores it in bvs.
   */
  void pushDefineFunRecScope(
      const std::vector<std::pair<std::string, Type> >& sortedVarNames,
      Expr func,
      const std::vector<Expr>& flattenVars,
      std::vector<Expr>& bvs,
      bool bindingLevel = false);

  void reset() override;

  void resetAssertions();

  /**
   * Sets the logic for the current benchmark. Declares any logic and
   * theory symbols.
   *
   * @param name the name of the logic (e.g., QF_UF, AUFLIA)
   * @param fromCommand should be set to true if the request originates from a
   *                    set-logic command and false otherwise
   * @return the command corresponding to setting the logic
   */
  Command* setLogic(std::string name, bool fromCommand = true);

  /**
   * Get the logic.
   */
  const LogicInfo& getLogic() const { return d_logic; }

  bool v2_0() const
  {
    return getLanguage() == language::input::LANG_SMTLIB_V2_0;
  }
  /**
   * Are we using smtlib 2.5 or above? If exact=true, then this method returns
   * false if the input language is not exactly SMT-LIB 2.5.
   */
  bool v2_5(bool exact = false) const
  {
    return language::isInputLang_smt2_5(getLanguage(), exact);
  }
  /**
   * Are we using smtlib 2.6 or above? If exact=true, then this method returns
   * false if the input language is not exactly SMT-LIB 2.6.
   */
  bool v2_6(bool exact = false) const
  {
    return language::isInputLang_smt2_6(getLanguage(), exact);
  }
  /** Are we using a sygus language? */
  bool sygus() const;
  /** Are we using the sygus version 1.0 format? */
  bool sygus_v1() const;

  /**
   * Returns true if the language that we are parsing (SMT-LIB version >=2.5
   * and SyGuS) treats duplicate double quotes ("") as an escape sequence
   * denoting a single double quote (").
   */
  bool escapeDupDblQuote() const { return v2_5() || sygus(); }

  void setInfo(const std::string& flag, const SExpr& sexpr);

  void setOption(const std::string& flag, const SExpr& sexpr);

  void checkThatLogicIsSet();

  void checkUserSymbol(const std::string& name) {
    if(name.length() > 0 && (name[0] == '.' || name[0] == '@')) {
      std::stringstream ss;
      ss << "cannot declare or define symbol `" << name << "'; symbols starting with . and @ are reserved in SMT-LIB";
      parseError(ss.str());
    }
    else if (isOperatorEnabled(name))
    {
      std::stringstream ss;
      ss << "Symbol `" << name << "' is shadowing a theory function symbol";
      parseError(ss.str());
    }
  }

  void includeFile(const std::string& filename);

  void setLastNamedTerm(Expr e, std::string name) {
    d_lastNamedTerm = std::make_pair(e, name);
  }

  void clearLastNamedTerm() {
    d_lastNamedTerm = std::make_pair(Expr(), "");
  }

  std::pair<Expr, std::string> lastNamedTerm() {
    return d_lastNamedTerm;
  }

  bool isAbstractValue(const std::string& name) {
    return name.length() >= 2 && name[0] == '@' && name[1] != '0' &&
      name.find_first_not_of("0123456789", 1) == std::string::npos;
  }

  Expr mkAbstractValue(const std::string& name) {
    assert(isAbstractValue(name));
    return getExprManager()->mkConst(AbstractValue(Integer(name.substr(1))));
  }

  void mkSygusVar(const std::string& name,
                  const Type& type,
                  bool isPrimed = false);

  void mkSygusConstantsForType( const Type& type, std::vector<CVC4::Expr>& ops );

  void processSygusGTerm( CVC4::SygusGTerm& sgt, int index,
                          std::vector< CVC4::Datatype >& datatypes,
                          std::vector< CVC4::Type>& sorts,
                          std::vector< std::vector<CVC4::Expr> >& ops,
                          std::vector< std::vector<std::string> >& cnames,
                          std::vector< std::vector< std::vector< CVC4::Type > > >& cargs,
                          std::vector< bool >& allow_const,
                          std::vector< std::vector< std::string > >& unresolved_gterm_sym,
                          std::vector<CVC4::Expr>& sygus_vars,
                          std::map< CVC4::Type, CVC4::Type >& sygus_to_builtin, std::map< CVC4::Type, CVC4::Expr >& sygus_to_builtin_expr,
                          CVC4::Type& ret, bool isNested = false );

  static bool pushSygusDatatypeDef( Type t, std::string& dname,
                                    std::vector< CVC4::Datatype >& datatypes,
                                    std::vector< CVC4::Type>& sorts,
                                    std::vector< std::vector<CVC4::Expr> >& ops,
                                    std::vector< std::vector<std::string> >& cnames,
                                    std::vector< std::vector< std::vector< CVC4::Type > > >& cargs,
                                    std::vector< bool >& allow_const,
                                    std::vector< std::vector< std::string > >& unresolved_gterm_sym );

  static bool popSygusDatatypeDef( std::vector< CVC4::Datatype >& datatypes,
                                   std::vector< CVC4::Type>& sorts,
                                   std::vector< std::vector<CVC4::Expr> >& ops,
                                   std::vector< std::vector<std::string> >& cnames,
                                   std::vector< std::vector< std::vector< CVC4::Type > > >& cargs,
                                   std::vector< bool >& allow_const,
                                   std::vector< std::vector< std::string > >& unresolved_gterm_sym );

  void setSygusStartIndex( std::string& fun, int startIndex,
                           std::vector< CVC4::Datatype >& datatypes,
                           std::vector< CVC4::Type>& sorts,
                           std::vector< std::vector<CVC4::Expr> >& ops );

  void mkSygusDatatype( CVC4::Datatype& dt, std::vector<CVC4::Expr>& ops,
                        std::vector<std::string>& cnames, std::vector< std::vector< CVC4::Type > >& cargs,
                        std::vector<std::string>& unresolved_gterm_sym,
                        std::map< CVC4::Type, CVC4::Type >& sygus_to_builtin );

  /**
   * Adds a constructor to sygus datatype dt whose sygus operator is term.
   *
   * ntsToUnres contains a mapping from non-terminal symbols to the unresolved
   * types they correspond to. This map indicates how the argument term should
   * be interpreted (instances of symbols from the domain of ntsToUnres
   * correspond to constructor arguments).
   *
   * The sygus operator that is actually added to dt corresponds to replacing
   * each occurrence of non-terminal symbols from the domain of ntsToUnres
   * with bound variables via purifySygusGTerm, and binding these variables
   * via a lambda.
   */
  void addSygusConstructorTerm(Datatype& dt,
                               Expr term,
                               std::map<Expr, Type>& ntsToUnres) const;
  /**
   * This adds constructors to dt for sygus variables in sygusVars whose
   * type is argument type. This method should be called when the sygus grammar
   * term (Variable type) is encountered.
   */
  void addSygusConstructorVariables(Datatype& dt,
                                    std::vector<Expr>& sygusVars,
                                    Type type) const;

  /**
   * Smt2 parser provides its own checkDeclaration, which does the
   * same as the base, but with some more helpful errors.
   */
  void checkDeclaration(const std::string& name,
                        DeclarationCheck check,
                        SymbolType type = SYM_VARIABLE,
                        std::string notes = "")
  {
    // if the symbol is something like "-1", we'll give the user a helpful
    // syntax hint.  (-1 is a valid identifier in SMT-LIB, NOT unary minus.)
    if( check != CHECK_DECLARED ||
        name[0] != '-' ||
        name.find_first_not_of("0123456789", 1) != std::string::npos ) {
      this->Parser::checkDeclaration(name, check, type, notes);
      return;
    }else{
      //it is allowable in sygus
      if (sygus_v1() && name[0] == '-')
      {
        //do not check anything
        return;
      }
    }

    std::stringstream ss;
    ss << notes
       << "You may have intended to apply unary minus: `(- "
       << name.substr(1)
       << ")'\n";
    this->Parser::checkDeclaration(name, check, type, ss.str());
  }

  void checkOperator(Kind kind, unsigned numArgs)
  {
    Parser::checkOperator(kind, numArgs);
    // strict SMT-LIB mode enables extra checks for some bitvector operators
    // that CVC4 permits as N-ary but the standard requires is binary
    if(strictModeEnabled()) {
      switch(kind) {
      case kind::BITVECTOR_AND:
      case kind::BITVECTOR_MULT:
      case kind::BITVECTOR_OR:
      case kind::BITVECTOR_PLUS:
      case kind::BITVECTOR_XOR:
        if (numArgs != 2 && !v2_6())
        {
          parseError(
              "Operator requires exactly 2 arguments in strict SMT-LIB "
              "compliance mode (for versions <2.6): "
              + kindToString(kind));
        }
        break;
      case kind::BITVECTOR_CONCAT:
        if(numArgs != 2) {
          parseError(
              "Operator requires exactly 2 arguments in strict SMT-LIB "
              "compliance mode: "
              + kindToString(kind));
        }
        break;
      default:
        break; /* no problem */
      }
    }
  }
  /** Set named attribute
   *
   * This is called when expression expr is annotated with a name, i.e.
   * (! expr :named sexpr). It sets up the necessary information to process
   * this naming, including marking that expr is the last named term.
   *
   * We construct an expression symbol whose name is the name of s-expression
   * which is used later for tracking assertions in unsat cores. This
   * symbol is returned by this method.
   */
  Expr setNamedAttribute(Expr& expr, const SExpr& sexpr);

  // Throw a ParserException with msg appended with the current logic.
  inline void parseErrorLogic(const std::string& msg)
  {
    const std::string withLogic = msg + getLogic().getLogicString();
    parseError(withLogic);
  }

  //------------------------- processing parse operators
  /**
   * Given a parse operator p, apply a type ascription to it. This method is run
   * when we encounter "(as t type)" and information regarding t has been stored
   * in p.
   *
   * This updates p to take into account the ascription. This may include:
   * - Converting an (pre-ascribed) array constant specification "const" to
   * an ascribed array constant specification (as const type) where type is
   * (Array T1 T2) for some T1, T2.
   * - Converting a (nullary or non-nullary) parametric datatype constructor to
   * the specialized constructor for the given type.
   * - Converting an empty set, universe set, or separation nil reference to
   * the respective term of the given type.
   * - If p's expression field is set, then we leave p unchanged, check if
   * that expression has the given type and throw a parse error otherwise.
   */
  void applyTypeAscription(ParseOp& p, Type type);
  /**
   * This converts a ParseOp to expression, assuming it is a standalone term.
   *
   * In particular:
   * - If p's expression field is set, then that expression is returned.
   * - If p's name field is set, then we look up that name in the symbol table
   * of this class.
   * In other cases, a parse error is thrown.
   */
  Expr parseOpToExpr(ParseOp& p);
  /**
   * Apply parse operator to list of arguments, and return the resulting
   * expression.
   *
   * This method involves two phases.
   * (1) Processing the operator represented by p,
   * (2) Applying that operator to the set of arguments.
   *
   * For (1), this involves determining the kind of the overall expression. We
   * may be in one the following cases:
   * - If p's expression field is set, we may choose to prepend it to args, or
   * otherwise determine the appropriate kind of the overall expression based on
   * this expression.
   * - If p's name field is set, then we get the appropriate symbol for that
   * name, which may involve disambiguating that name if it is overloaded based
   * on the types of args. We then determine the overall kind of the return
   * expression based on that symbol.
   * - p's kind field may be already set.
   *
   * For (2), we construct the overall expression, which may involve the
   * following:
   * - If p is an array constant specification (as const (Array T1 T2)), then
   * we return the appropriate array constant based on args[0].
   * - If p represents a tuple selector, then we infer the appropriate tuple
   * selector expression based on the type of args[0].
   * - If the overall kind of the expression is chainable, we may convert it
   * to a left- or right-associative chain.
   * - If the overall kind is MINUS and args has size 1, then we return an
   * application of UMINUS.
   * - If the overall expression is a partial application, then we process this
   * as a chain of HO_APPLY terms.
   */
  Expr applyParseOp(ParseOp& p, std::vector<Expr>& args);
  //------------------------- end processing parse operators
 private:
  std::map< CVC4::Expr, CVC4::Type > d_sygus_bound_var_type;
  std::map< CVC4::Expr, std::vector< CVC4::Expr > > d_sygus_let_func_to_vars;
  std::map< CVC4::Expr, CVC4::Expr > d_sygus_let_func_to_body;
  std::map< CVC4::Expr, unsigned > d_sygus_let_func_to_num_input_vars;
  //auxiliary define-fun functions introduced for production rules
  std::vector< CVC4::Expr > d_sygus_defined_funs;

  void collectSygusLetArgs( CVC4::Expr e, std::vector< CVC4::Type >& sygusArgs, std::vector< CVC4::Expr >& builtinArgs );

  Type processSygusNestedGTerm( int sub_dt_index, std::string& sub_dname, std::vector< CVC4::Datatype >& datatypes,
                                std::vector< CVC4::Type>& sorts,
                                std::vector< std::vector<CVC4::Expr> >& ops,
                                std::vector< std::vector<std::string> >& cnames,
                                std::vector< std::vector< std::vector< CVC4::Type > > >& cargs,
                                std::vector< bool >& allow_const,
                                std::vector< std::vector< std::string > >& unresolved_gterm_sym,
                                std::map< CVC4::Type, CVC4::Type >& sygus_to_builtin,
                                std::map< CVC4::Type, CVC4::Expr >& sygus_to_builtin_expr, Type sub_ret );

  void processSygusLetConstructor( std::vector< CVC4::Expr >& let_vars, int index,
                                   std::vector< CVC4::Datatype >& datatypes,
                                   std::vector< CVC4::Type>& sorts,
                                   std::vector< std::vector<CVC4::Expr> >& ops,
                                   std::vector< std::vector<std::string> >& cnames,
                                   std::vector< std::vector< std::vector< CVC4::Type > > >& cargs,
                                   std::vector<CVC4::Expr>& sygus_vars,
                                   std::map< CVC4::Type, CVC4::Type >& sygus_to_builtin,
                                   std::map< CVC4::Type, CVC4::Expr >& sygus_to_builtin_expr );

  /** make sygus bound var list
   *
   * This is used for converting non-builtin sygus operators to lambda
   * expressions. It takes as input a datatype and constructor index (for
   * naming) and a vector of type ltypes.
   * It appends a bound variable to lvars for each type in ltypes, and returns
   * a bound variable list whose children are lvars.
   */
  Expr makeSygusBoundVarList(Datatype& dt,
                             unsigned i,
                             const std::vector<Type>& ltypes,
                             std::vector<Expr>& lvars);

  /** Purify sygus grammar term
   *
   * This returns a term where all occurrences of non-terminal symbols (those
   * in the domain of ntsToUnres) are replaced by fresh variables. For each
   * variable replaced in this way, we add the fresh variable it is replaced
   * with to args, and the unresolved type corresponding to the non-terminal
   * symbol to cargs (constructor args). In other words, args contains the
   * free variables in the term returned by this method (which should be bound
   * by a lambda), and cargs contains the types of the arguments of the
   * sygus constructor.
   */
  Expr purifySygusGTerm(Expr term,
                        std::map<Expr, Type>& ntsToUnres,
                        std::vector<Expr>& args,
                        std::vector<Type>& cargs) const;

  void addArithmeticOperators();

  void addTranscendentalOperators();

  void addQuantifiersOperators();

  void addBitvectorOperators();

  void addDatatypesOperators();

  void addStringOperators();

  void addFloatingPointOperators();

  void addSepOperators();

  InputLanguage getLanguage() const;
}; /* class Smt2 */

}/* CVC4::parser namespace */
}/* CVC4 namespace */

#endif /* CVC4__PARSER__SMT2_H */