#ifndef _CONTEXT_H_
#define _CONTEXT_H_

#include <vector>


class evalcontext_t;
class evaltree_t {
public:
  virtual std::string Evaluate(evalcontext_t* context)=0;
};
typedef std::vector<evaltree_t *> evaltree_vector;

//------------
class eval_binary_operator_t : public evaltree_t {
public:
  eval_binary_operator_t(ushort itype, evaltree_t* left, evaltree_t* right);
  static evaltree_t* MakeNode(ushort itype, evaltree_t* left, evaltree_t* right);

  virtual std::string Evaluate(evalcontext_t* context);

  ushort GetOperation();
  evaltree_t*GetLeft();
  evaltree_t*GetRight();

  std::string GetOperatorString();

private:
    ushort m_itype;
    evaltree_t* m_left;
    evaltree_t* m_right;
};
//------------
class eval_unary_operator_t : public evaltree_t {
public:
  eval_unary_operator_t(ushort itype, evaltree_t* arg);
  static evaltree_t* MakeNode(ushort itype, evaltree_t* arg);

  virtual std::string Evaluate(evalcontext_t* context);

  ushort GetOperation();
  evaltree_t* GetArg();

  std::string GetOperatorString();

private:
    ushort m_itype;
    evaltree_t* m_arg;
};
//------------
class eval_constant_t : public evaltree_t {
public:
  eval_constant_t(ea_t ea);
  static evaltree_t* MakeNode(ea_t ea);

  virtual std::string Evaluate(evalcontext_t* context);

  ea_t GetConstant();

private:
    ea_t m_ea;
};
//------------
class eval_register_t : public evaltree_t {
public:
  eval_register_t(int reg);
  static evaltree_t* MakeNode(int reg);

  virtual std::string Evaluate(evalcontext_t* context);

  int GetRegister();

private:
    int m_reg;
};



//------------
class evalcontext_t {
public:
  evalcontext_t(ea_t ea);
  ~evalcontext_t();

  evaltree_t *GetRegisterExpression(int reg);
  evaltree_t *GetStackArgExpression(int stackarg);
  evaltree_t *GetStackVarExpression(int stackvar);

  std::string EvaluateExpression(evaltree_t *tree);

private:
    evaltree_vector m_registers;   // 0 = R0, .. 3 = R3
    evaltree_vector m_stackargs;   // 0 = [SP], 1 = [SP-4], etc
    evaltree_vector m_stackvars;   // either SP, or FP based.

    ea_t m_ea;
    func_t *m_pfn;

  void TraceBack();
  void Assign(evaltree_t *dst, evaltree_t *src);
  evaltree_t *GetOperandExpression(const op_t& op);
  evaltree_t *GetRegister(int reg);

};

#endif