/*
 Basic expression visitor

 Copyright (C) 2014 AMPL Optimization Inc

 Permission to use, copy, modify, and distribute this software and its
 documentation for any purpose and without fee is hereby granted,
 provided that the above copyright notice appear in all copies and that
 both that the copyright notice and this permission notice and warranty
 disclaimer appear in supporting documentation.

 The author and AMPL Optimization Inc disclaim all warranties with
 regard to this software, including all implied warranties of
 merchantability and fitness.  In no event shall the author be liable
 for any special, indirect or consequential damages or any damages
 whatsoever resulting from loss of use, data or profits, whether in an
 action of contract, negligence or other tortious action, arising out
 of or in connection with the use or performance of this software.

 Author: Victor Zverovich
 */

#ifndef MP_BASIC_EXPR_VISITOR_H_
#define MP_BASIC_EXPR_VISITOR_H_

#include "mp/common.h"
#include "mp/error.h"

#define MP_DEFINE_EXPR_TYPES(ExprTypes)                                                                                \
    typedef typename ExprTypes::Expr Expr;                                                                             \
    typedef typename ExprTypes::NumericExpr NumericExpr;                                                               \
    typedef typename ExprTypes::LogicalExpr LogicalExpr;                                                               \
    typedef typename ExprTypes::NumericConstant NumericConstant;                                                       \
    typedef typename ExprTypes::Variable Variable;                                                                     \
    typedef typename ExprTypes::CommonExpr CommonExpr;                                                                 \
    typedef typename ExprTypes::UnaryExpr UnaryExpr;                                                                   \
    typedef typename ExprTypes::BinaryExpr BinaryExpr;                                                                 \
    typedef typename ExprTypes::IfExpr IfExpr;                                                                         \
    typedef typename ExprTypes::PLTerm PLTerm;                                                                         \
    typedef typename ExprTypes::CallExpr CallExpr;                                                                     \
    typedef typename ExprTypes::VarArgExpr VarArgExpr;                                                                 \
    typedef typename ExprTypes::SumExpr SumExpr;                                                                       \
    typedef typename ExprTypes::CountExpr CountExpr;                                                                   \
    typedef typename ExprTypes::NumberOfExpr NumberOfExpr;                                                             \
    typedef typename ExprTypes::SymbolicNumberOfExpr SymbolicNumberOfExpr;                                             \
    typedef typename ExprTypes::LogicalConstant LogicalConstant;                                                       \
    typedef typename ExprTypes::NotExpr NotExpr;                                                                       \
    typedef typename ExprTypes::BinaryLogicalExpr BinaryLogicalExpr;                                                   \
    typedef typename ExprTypes::RelationalExpr RelationalExpr;                                                         \
    typedef typename ExprTypes::LogicalCountExpr LogicalCountExpr;                                                     \
    typedef typename ExprTypes::ImplicationExpr ImplicationExpr;                                                       \
    typedef typename ExprTypes::IteratedLogicalExpr IteratedLogicalExpr;                                               \
    typedef typename ExprTypes::PairwiseExpr PairwiseExpr;                                                             \
    typedef typename ExprTypes::StringLiteral StringLiteral;                                                           \
    typedef typename ExprTypes::SymbolicIfExpr SymbolicIfExpr

namespace mp
{

// A basic expression visitor that can be used with different expression
// hierarchies described by ExprTypes.
//
// BasicExprVisitor uses the curiously recurring template pattern:
// http://en.wikipedia.org/wiki/Curiously_recurring_template_pattern
template <typename Impl, typename Result, typename ExprTypes> class BasicExprVisitor
{
public:
    MP_DEFINE_EXPR_TYPES(ExprTypes);

    Result Visit(Expr e);

    Result VisitUnsupported(Expr e) { throw MakeUnsupportedError(str(e.kind())); }

    Result VisitNumeric(NumericExpr e) { return VisitUnsupported(e); }

    Result VisitLogical(LogicalExpr e) { return VisitUnsupported(e); }

    Result VisitNumericConstant(NumericConstant c) { return MP_DISPATCH(VisitNumeric(c)); }

    Result VisitVariable(Variable v) { return MP_DISPATCH(VisitNumeric(v)); }

    Result VisitCommonExpr(CommonExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    // Visits a unary expression or a function taking one argument.
    Result VisitUnary(UnaryExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitMinus(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitAbs(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitFloor(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitCeil(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitSqrt(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitPow2(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitExp(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitLog(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitLog10(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitSin(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitSinh(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitCos(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitCosh(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitTan(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitTanh(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitAsin(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitAsinh(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitAcos(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitAcosh(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitAtan(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    Result VisitAtanh(UnaryExpr e) { return MP_DISPATCH(VisitUnary(e)); }

    // Visits a binary expression or a function taking two arguments.
    Result VisitBinary(BinaryExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitAdd(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitSub(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitLess(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitMul(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitDiv(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitTruncDiv(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitMod(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitPow(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitPowConstBase(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitPowConstExp(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    // Visits a function taking two arguments.
    Result VisitBinaryFunc(BinaryExpr e) { return MP_DISPATCH(VisitBinary(e)); }

    Result VisitAtan2(BinaryExpr e) { return MP_DISPATCH(VisitBinaryFunc(e)); }

    Result VisitPrecision(BinaryExpr e) { return MP_DISPATCH(VisitBinaryFunc(e)); }

    Result VisitRound(BinaryExpr e) { return MP_DISPATCH(VisitBinaryFunc(e)); }

    Result VisitTrunc(BinaryExpr e) { return MP_DISPATCH(VisitBinaryFunc(e)); }

    Result VisitIf(IfExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitPLTerm(PLTerm e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitCall(CallExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitVarArg(VarArgExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitMin(VarArgExpr e) { return MP_DISPATCH(VisitVarArg(e)); }

    Result VisitMax(VarArgExpr e) { return MP_DISPATCH(VisitVarArg(e)); }

    Result VisitSum(SumExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitNumberOf(NumberOfExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitNumberOfSym(SymbolicNumberOfExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitCount(CountExpr e) { return MP_DISPATCH(VisitNumeric(e)); }

    Result VisitLogicalConstant(LogicalConstant c) { return MP_DISPATCH(VisitLogical(c)); }

    Result VisitNot(NotExpr e) { return MP_DISPATCH(VisitLogical(e)); }

    Result VisitBinaryLogical(BinaryLogicalExpr e) { return MP_DISPATCH(VisitLogical(e)); }

    Result VisitOr(BinaryLogicalExpr e) { return MP_DISPATCH(VisitBinaryLogical(e)); }

    Result VisitAnd(BinaryLogicalExpr e) { return MP_DISPATCH(VisitBinaryLogical(e)); }

    Result VisitIff(BinaryLogicalExpr e) { return MP_DISPATCH(VisitBinaryLogical(e)); }

    Result VisitRelational(RelationalExpr e) { return MP_DISPATCH(VisitLogical(e)); }

    Result VisitLT(RelationalExpr e) { return MP_DISPATCH(VisitRelational(e)); }

    Result VisitLE(RelationalExpr e) { return MP_DISPATCH(VisitRelational(e)); }

    Result VisitEQ(RelationalExpr e) { return MP_DISPATCH(VisitRelational(e)); }

    Result VisitGE(RelationalExpr e) { return MP_DISPATCH(VisitRelational(e)); }

    Result VisitGT(RelationalExpr e) { return MP_DISPATCH(VisitRelational(e)); }

    Result VisitNE(RelationalExpr e) { return MP_DISPATCH(VisitRelational(e)); }

    Result VisitLogicalCount(LogicalCountExpr e) { return MP_DISPATCH(VisitLogical(e)); }

    Result VisitAtLeast(LogicalCountExpr e) { return MP_DISPATCH(VisitLogicalCount(e)); }

    Result VisitAtMost(LogicalCountExpr e) { return MP_DISPATCH(VisitLogicalCount(e)); }

    Result VisitExactly(LogicalCountExpr e) { return MP_DISPATCH(VisitLogicalCount(e)); }

    Result VisitNotAtLeast(LogicalCountExpr e) { return MP_DISPATCH(VisitLogicalCount(e)); }

    Result VisitNotAtMost(LogicalCountExpr e) { return MP_DISPATCH(VisitLogicalCount(e)); }

    Result VisitNotExactly(LogicalCountExpr e) { return MP_DISPATCH(VisitLogicalCount(e)); }

    Result VisitImplication(ImplicationExpr e) { return MP_DISPATCH(VisitLogical(e)); }

    Result VisitIteratedLogical(IteratedLogicalExpr e) { return MP_DISPATCH(VisitLogical(e)); }

    Result VisitExists(IteratedLogicalExpr e) { return MP_DISPATCH(VisitIteratedLogical(e)); }

    Result VisitForAll(IteratedLogicalExpr e) { return MP_DISPATCH(VisitIteratedLogical(e)); }

    Result VisitAllDiff(PairwiseExpr e) { return MP_DISPATCH(VisitLogical(e)); }

    Result VisitNotAllDiff(PairwiseExpr e) { return MP_DISPATCH(VisitLogical(e)); }

    Result VisitStringLiteral(StringLiteral e) { return VisitUnsupported(e); }

    Result VisitSymbolicIf(SymbolicIfExpr e) { return VisitUnsupported(e); }
};

template <typename Impl, typename Result, typename ET> Result BasicExprVisitor<Impl, Result, ET>::Visit(Expr e)
{
    // All expressions except OPNUMBEROFs and OPIFSYM are supported.
    switch(e.kind())
    {
    default:
        MP_ASSERT(false, "invalid expression");
        // Fall through.
    case expr::NUMBER:
        return MP_DISPATCH(VisitNumericConstant(ET::template UncheckedCast<NumericConstant>(e)));
    case expr::VARIABLE:
        return MP_DISPATCH(VisitVariable(ET::template UncheckedCast<Variable>(e)));
    case expr::COMMON_EXPR:
        return MP_DISPATCH(VisitCommonExpr(ET::template UncheckedCast<CommonExpr>(e)));

    // Unary expressions.
    case expr::MINUS:
        return MP_DISPATCH(VisitMinus(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::ABS:
        return MP_DISPATCH(VisitAbs(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::FLOOR:
        return MP_DISPATCH(VisitFloor(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::CEIL:
        return MP_DISPATCH(VisitCeil(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::SQRT:
        return MP_DISPATCH(VisitSqrt(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::POW2:
        return MP_DISPATCH(VisitPow2(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::EXP:
        return MP_DISPATCH(VisitExp(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::LOG:
        return MP_DISPATCH(VisitLog(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::LOG10:
        return MP_DISPATCH(VisitLog10(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::SIN:
        return MP_DISPATCH(VisitSin(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::SINH:
        return MP_DISPATCH(VisitSinh(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::COS:
        return MP_DISPATCH(VisitCos(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::COSH:
        return MP_DISPATCH(VisitCosh(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::TAN:
        return MP_DISPATCH(VisitTan(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::TANH:
        return MP_DISPATCH(VisitTanh(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::ASIN:
        return MP_DISPATCH(VisitAsin(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::ASINH:
        return MP_DISPATCH(VisitAsinh(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::ACOS:
        return MP_DISPATCH(VisitAcos(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::ACOSH:
        return MP_DISPATCH(VisitAcosh(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::ATAN:
        return MP_DISPATCH(VisitAtan(ET::template UncheckedCast<UnaryExpr>(e)));
    case expr::ATANH:
        return MP_DISPATCH(VisitAtanh(ET::template UncheckedCast<UnaryExpr>(e)));

    // Binary expressions.
    case expr::ADD:
        return MP_DISPATCH(VisitAdd(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::SUB:
        return MP_DISPATCH(VisitSub(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::LESS:
        return MP_DISPATCH(VisitLess(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::MUL:
        return MP_DISPATCH(VisitMul(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::DIV:
        return MP_DISPATCH(VisitDiv(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::TRUNC_DIV:
        return MP_DISPATCH(VisitTruncDiv(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::MOD:
        return MP_DISPATCH(VisitMod(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::POW:
        return MP_DISPATCH(VisitPow(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::POW_CONST_BASE:
        return MP_DISPATCH(VisitPowConstBase(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::POW_CONST_EXP:
        return MP_DISPATCH(VisitPowConstExp(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::ATAN2:
        return MP_DISPATCH(VisitAtan2(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::PRECISION:
        return MP_DISPATCH(VisitPrecision(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::ROUND:
        return MP_DISPATCH(VisitRound(ET::template UncheckedCast<BinaryExpr>(e)));
    case expr::TRUNC:
        return MP_DISPATCH(VisitTrunc(ET::template UncheckedCast<BinaryExpr>(e)));

    case expr::IF:
        return MP_DISPATCH(VisitIf(ET::template UncheckedCast<IfExpr>(e)));
    case expr::PLTERM:
        return MP_DISPATCH(VisitPLTerm(ET::template UncheckedCast<PLTerm>(e)));
    case expr::CALL:
        return MP_DISPATCH(VisitCall(ET::template UncheckedCast<CallExpr>(e)));
    case expr::MIN:
        return MP_DISPATCH(VisitMin(ET::template UncheckedCast<VarArgExpr>(e)));
    case expr::MAX:
        return MP_DISPATCH(VisitMax(ET::template UncheckedCast<VarArgExpr>(e)));
    case expr::SUM:
        return MP_DISPATCH(VisitSum(ET::template UncheckedCast<SumExpr>(e)));
    case expr::NUMBEROF:
        return MP_DISPATCH(VisitNumberOf(ET::template UncheckedCast<NumberOfExpr>(e)));
    case expr::NUMBEROF_SYM:
        return MP_DISPATCH(VisitNumberOfSym(ET::template UncheckedCast<SymbolicNumberOfExpr>(e)));
    case expr::COUNT:
        return MP_DISPATCH(VisitCount(ET::template UncheckedCast<CountExpr>(e)));

        // Logical expressions.
    case expr::BOOL:
        return MP_DISPATCH(VisitLogicalConstant(ET::template UncheckedCast<LogicalConstant>(e)));
    case expr::NOT:
        return MP_DISPATCH(VisitNot(ET::template UncheckedCast<NotExpr>(e)));
    case expr::OR:
        return MP_DISPATCH(VisitOr(ET::template UncheckedCast<BinaryLogicalExpr>(e)));
    case expr::AND:
        return MP_DISPATCH(VisitAnd(ET::template UncheckedCast<BinaryLogicalExpr>(e)));
    case expr::IFF:
        return MP_DISPATCH(VisitIff(ET::template UncheckedCast<BinaryLogicalExpr>(e)));
    case expr::LT:
        return MP_DISPATCH(VisitLT(ET::template UncheckedCast<RelationalExpr>(e)));
    case expr::LE:
        return MP_DISPATCH(VisitLE(ET::template UncheckedCast<RelationalExpr>(e)));
    case expr::EQ:
        return MP_DISPATCH(VisitEQ(ET::template UncheckedCast<RelationalExpr>(e)));
    case expr::GE:
        return MP_DISPATCH(VisitGE(ET::template UncheckedCast<RelationalExpr>(e)));
    case expr::GT:
        return MP_DISPATCH(VisitGT(ET::template UncheckedCast<RelationalExpr>(e)));
    case expr::NE:
        return MP_DISPATCH(VisitNE(ET::template UncheckedCast<RelationalExpr>(e)));
    case expr::ATLEAST:
        return MP_DISPATCH(VisitAtLeast(ET::template UncheckedCast<LogicalCountExpr>(e)));
    case expr::ATMOST:
        return MP_DISPATCH(VisitAtMost(ET::template UncheckedCast<LogicalCountExpr>(e)));
    case expr::EXACTLY:
        return MP_DISPATCH(VisitExactly(ET::template UncheckedCast<LogicalCountExpr>(e)));
    case expr::NOT_ATLEAST:
        return MP_DISPATCH(VisitNotAtLeast(ET::template UncheckedCast<LogicalCountExpr>(e)));
    case expr::NOT_ATMOST:
        return MP_DISPATCH(VisitNotAtMost(ET::template UncheckedCast<LogicalCountExpr>(e)));
    case expr::NOT_EXACTLY:
        return MP_DISPATCH(VisitNotExactly(ET::template UncheckedCast<LogicalCountExpr>(e)));
    case expr::IMPLICATION:
        return MP_DISPATCH(VisitImplication(ET::template UncheckedCast<ImplicationExpr>(e)));
    case expr::EXISTS:
        return MP_DISPATCH(VisitExists(ET::template UncheckedCast<IteratedLogicalExpr>(e)));
    case expr::FORALL:
        return MP_DISPATCH(VisitForAll(ET::template UncheckedCast<IteratedLogicalExpr>(e)));
    case expr::ALLDIFF:
        return MP_DISPATCH(VisitAllDiff(ET::template UncheckedCast<PairwiseExpr>(e)));
    case expr::NOT_ALLDIFF:
        return MP_DISPATCH(VisitNotAllDiff(ET::template UncheckedCast<PairwiseExpr>(e)));

        // String expressions.
    case expr::STRING:
        return MP_DISPATCH(VisitStringLiteral(ET::template UncheckedCast<StringLiteral>(e)));
    case expr::IFSYM:
        return MP_DISPATCH(VisitSymbolicIf(ET::template UncheckedCast<SymbolicIfExpr>(e)));
    }
}
} // namespace mp

#endif // MP_BASIC_EXPR_VISITOR_H_
