/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */


#ifdef __GNUC__
#pragma interface			/* gcc class implementation */
#endif

struct st_table_list;
void item_init(void);				/* Init item functions */

class Item {
  Item(const Item &);				/* Prevent use of theese */
  void operator=(Item &);
public:
  static void *operator new(size_t size) {return (void*) sql_alloc((uint) size); }
  static void operator delete(void *ptr,size_t size) {} /*lint -e715 */

  enum Type {FIELD_ITEM,FUNC_ITEM,SUM_FUNC_ITEM,STRING_ITEM,
	     INT_ITEM,REAL_ITEM,NULL_ITEM,VARBIN_ITEM,
	     COPY_STR_ITEM,FIELD_AVG_ITEM,
	     PROC_ITEM,COND_ITEM,REF_ITEM,FIELD_STD_ITEM, CONST_ITEM};
  enum cond_result { COND_UNDEF,COND_OK,COND_TRUE,COND_FALSE };

  String str_value;			/* used to store value */
  my_string name;			/* Name from select */
  Item *next;
  uint32 max_length;
  uint8 marker,decimals;
  my_bool maybe_null;			/* If item may be null */
  my_bool null_value;			/* if item is null */
  my_bool binary;
  my_bool with_sum_func;


  // alloc & destruct is done as start of select using sql_alloc
  Item();
  virtual ~Item() { name=0; }		/*lint -e1509 */
  void set_name(char* str,uint length=0);
  void init_make_field(Send_field *tmp_field,enum enum_field_types type);
  virtual bool fix_fields(THD *,struct st_table_list *);
  virtual bool save_in_field(Field *field);
  virtual void save_org_in_field(Field *field)
    { (void) save_in_field(field); }
  virtual bool send(String *str);
  virtual bool eq(const Item *) const;
  virtual Item_result result_type () const { return REAL_RESULT; }
  virtual enum Type type() const =0;
  virtual double val()=0;
  virtual longlong val_int()=0;
  virtual String *val_str(String*)=0;
  virtual void make_field(Send_field *field)=0;
  virtual Field *tmp_table_field() { return 0; }
  virtual const char *full_name() const { return name ? name : "???"; }
  virtual double  val_result() { return val(); }
  virtual longlong val_int_result() { return val_int(); }
  virtual String *str_result(String* tmp) { return val_str(tmp); }
  virtual table_map used_tables() const { return (table_map) 0L; }
  virtual bool basic_const_item() const { return 0; }
  virtual Item *new_item() { return 0; }	/* Only for const items */
  virtual cond_result eq_cmp_result() const { return COND_OK; }
  inline uint float_length(uint decimals_par) const
  { return decimals != NOT_FIXED_DEC ? (DBL_DIG+2+decimals_par) : DBL_DIG+8;}
  virtual bool const_item() const { return used_tables() == 0; }
  virtual void print(String *str_arg) { str_arg->append(full_name()); }
  virtual void update_used_tables() {}
  virtual void split_sum_func(List<Item> &fields) {}
  virtual bool get_date(TIME *ltime,bool fuzzydate);
  virtual bool get_time(TIME *ltime);
};


class Item_ident :public Item
{
public:
  const char *db_name;
  const char *table_name;
  const char *field_name;
  Item_ident(const char *db_name_par,const char *table_name_par,
	     const char *field_name_par)
    :db_name(db_name_par),table_name(table_name_par),field_name(field_name_par)
    { name = (char*) field_name_par; }
  const char *full_name() const;
};

class Item_field :public Item_ident
{
  void set_field(Field *field);
public:
  Field *field,*result_field;
  // Item_field() {}

  Item_field(const char *db_par,const char *table_name_par,
	     const char *field_name_par)
    :Item_ident(db_par,table_name_par,field_name_par),field(0),result_field(0)
  {}
  Item_field(Field *field);
  enum Type type() const { return FIELD_ITEM; }
  bool eq(const Item *item) const;
  double val();
  longlong val_int();
  String *val_str(String*);
  double val_result();
  longlong val_int_result();
  String *str_result(String* tmp);
  bool send(String *str_arg) { return result_field->send(str_arg); }
  void make_field(Send_field *field);
  bool fix_fields(THD *,struct st_table_list *);
  bool save_in_field(Field *field);
  void save_org_in_field(Field *field);
  table_map used_tables() const;
  enum Item_result result_type () const
  {
    return field->result_type();
  }
  Field *tmp_table_field() { return result_field; }
  bool get_date(TIME *ltime,bool fuzzydate);  
  bool get_time(TIME *ltime);  
};


class Item_null :public Item
{
public:
  Item_null(char *name_par=0)
    { maybe_null=null_value=TRUE; name= name_par ? name_par : (char*) "NULL";}
  enum Type type() const { return NULL_ITEM; }
  bool eq(const Item *item) const;
  double val();
  longlong val_int();
  String *val_str(String *str);
  void make_field(Send_field *field);
  bool save_in_field(Field *field);
  enum Item_result result_type () const
  { return STRING_RESULT; }
  bool send(String *str);
  bool basic_const_item() const { return 1; }
  Item *new_item() { return new Item_null(name); }
};


class Item_int :public Item
{
public:
  const longlong value;
  Item_int(int32 i,uint length=11) :value((longlong) i)
    { max_length=length;}
#ifdef HAVE_LONG_LONG
  Item_int(longlong i,uint length=21) :value(i)
    { max_length=length;}
#endif
  Item_int(const char *str_arg,longlong i,uint length) :value(i)
    { max_length=length; name=(char*) str_arg;}
  Item_int(const char *str_arg) :
    value(str_arg[0] == '-' ? strtoll(str_arg,(char**) 0,10) :
	  (longlong) strtoull(str_arg,(char**) 0,10))
    { max_length= (uint) strlen(str_arg); name=(char*) str_arg;}
  enum Type type() const { return INT_ITEM; }
  virtual enum Item_result result_type () const { return INT_RESULT; }
  longlong val_int() { return value; }
  double val() { return (double) value; }
  String *val_str(String*);
  void make_field(Send_field *field);
  bool save_in_field(Field *field);
  bool basic_const_item() const { return 1; }
  Item *new_item() { return new Item_int(name,value,max_length); }
  void print(String *str);
};


class Item_real :public Item
{
public:
  const double value;
  // Item_real() :value(0) {}
  Item_real(const char *str_arg,uint length) :value(atof(str_arg))
  {
    name=(char*) str_arg;
    decimals=nr_of_decimals(str_arg);
    max_length=length;
  }
  Item_real(const char *str,double val_arg,uint decimal_par,uint length)
    :value(val_arg)
  {
    name=(char*) str;
    decimals=decimal_par;
    max_length=length;
  }
  Item_real(double value_par) :value(value_par) {}
  bool save_in_field(Field *field);
  enum Type type() const { return REAL_ITEM; }
  double val() { return value; }
  longlong val_int() { return (longlong) (value+(value > 0 ? 0.5 : -0.5));}
  String *val_str(String*);
  void make_field(Send_field *field);
  bool basic_const_item() const { return 1; }
  Item *new_item() { return new Item_real(name,value,decimals,max_length); }
};


class Item_float :public Item_real
{
public:
  Item_float(const char *str,uint length) :Item_real(str,length)
  {
    decimals=NOT_FIXED_DEC;
    max_length=DBL_DIG+8;
  }
};

class Item_string :public Item
{
public:
  Item_string(const char *str,uint length)
  {
    str_value.set(str,length);
    max_length=length;
    name=(char*) str_value.ptr();
    decimals=NOT_FIXED_DEC;
  }
  Item_string(const char *name_par,const char *str,uint length)
  {
    str_value.set(str,length);
    max_length=length;
    name=(char*) name_par;
    decimals=NOT_FIXED_DEC;
  }
  ~Item_string() {}
  enum Type type() const { return STRING_ITEM; }
  double val() { return atof(str_value.ptr()); }
  longlong val_int() { return strtoll(str_value.ptr(),(char**) 0,10); }
  String *val_str(String*) { return (String*) &str_value; }
  bool save_in_field(Field *field);
  void make_field(Send_field *field);
  enum Item_result result_type () const { return STRING_RESULT; }
  bool basic_const_item() const { return 1; }
  Item *new_item() { return new Item_string(name,str_value.ptr(),max_length); }
  String *const_string() { return &str_value; }
  inline void append(char *str,uint length) { str_value.append(str,length); }
  void print(String *str);
};

/* for show tables */

class Item_datetime :public Item_string
{
public:
  Item_datetime(const char *item_name): Item_string(item_name,"",0)
  { max_length=19;}
  void make_field(Send_field *field);
};

class Item_empty_string :public Item_string
{
public:
  Item_empty_string(const char *header,uint length) :Item_string("",0)
    { name=(char*) header; max_length=length;}
};

class Item_varbinary :public Item
{
public:
  Item_varbinary(const char *str,uint str_length);
  ~Item_varbinary() {}
  enum Type type() const { return VARBIN_ITEM; }
  double val() { return (double) Item_varbinary::val_int(); }
  longlong val_int();
  String *val_str(String*) { return &str_value; }
  bool save_in_field(Field *field);
  void make_field(Send_field *field);
  enum Item_result result_type () const { return INT_RESULT; }
};


class Item_result_field :public Item	/* Item with result field */
{
public:
  Field *result_field;				/* Save result here */
  Item_result_field() :result_field(0) {}
  ~Item_result_field() {}			/* Required with gcc 2.95 */
  Field *tmp_table_field() { return result_field; }
  virtual void fix_length_and_dec()=0;
};


class Item_ref :public Item_ident
{
  Item **ref;
public:
  Item_ref(char *db_par,char *table_name_par,char *field_name_par)
    :Item_ident(db_par,table_name_par,field_name_par),ref(0) {}
  Item_ref(Item **item, char *table_name_par,char *field_name_par)
    :Item_ident(NullS,table_name_par,field_name_par),ref(item) {}
  enum Type type() const		{ return REF_ITEM; }
  bool eq(const Item *item) const	{ return (*ref)->eq(item); }
  ~Item_ref() { if (ref) delete *ref; }
  double val()
  {
    double tmp=(*ref)->val_result();
    null_value=(*ref)->null_value;
    return tmp;
  }
  longlong val_int()
  {
    longlong tmp=(*ref)->val_int_result();
    null_value=(*ref)->null_value;
    return tmp;
  }
  String *val_str(String* tmp)
  {
    tmp=(*ref)->str_result(tmp);
    null_value=(*ref)->null_value;
    return tmp;
  }
  bool get_date(TIME *ltime,bool fuzzydate)
  {  
    return (null_value=(*ref)->get_date(ltime,fuzzydate));
  }
  bool send(String *tmp)		{ return (*ref)->send(tmp); }
  void make_field(Send_field *field)	{ (*ref)->make_field(field); }
  bool fix_fields(THD *,struct st_table_list *);
  bool save_in_field(Field *field)	{ return (*ref)->save_in_field(field); }
  void save_org_in_field(Field *field)	{ (*ref)->save_org_in_field(field); }
  enum Item_result result_type () const { return (*ref)->result_type(); }
  table_map used_tables() const		{ return (*ref)->used_tables(); }
};


#include "item_sum.h"
#include "item_func.h"
#include "item_cmpfunc.h"
#include "item_strfunc.h"
#include "item_timefunc.h"
#include "item_uniq.h"

class Item_copy_string :public Item
{
public:
  Item *item;
  Item_copy_string(Item *i) :item(i)
  {
    null_value=maybe_null=item->maybe_null;
    decimals=item->decimals;
    max_length=item->max_length;
    name=item->name;
  }
  ~Item_copy_string() { delete item; }
  enum Type type() const { return COPY_STR_ITEM; }
  enum Item_result result_type () const { return STRING_RESULT; }
  double val()
  { return null_value ? 0.0 : atof(str_value.c_ptr()); }
  longlong val_int()
  { return null_value ? LL(0) : strtoll(str_value.c_ptr(),(char**) 0,10); }
  String *val_str(String*);
  void make_field(Send_field *field) { item->make_field(field); }
  void copy();
  table_map used_tables() const { return (table_map) 1L; }
  bool const_item() const { return 0; }
};


class Item_buff :public Sql_alloc
{
public:
  my_bool null_value;
  Item_buff() :null_value(0) {}
  virtual bool cmp(void)=0;
  virtual ~Item_buff(); /*line -e1509 */
};

class Item_str_buff :public Item_buff
{
  Item *item;
  String value,tmp_value;
public:
  Item_str_buff(Item *arg) :item(arg),value(arg->max_length) {}
  bool cmp(void);
  ~Item_str_buff();				// Deallocate String:s
};


class Item_real_buff :public Item_buff
{
  Item *item;
  double value;
public:
  Item_real_buff(Item *item_par) :item(item_par),value(0.0) {}
  bool cmp(void);
};

class Item_int_buff :public Item_buff
{
  Item *item;
  longlong value;
public:
  Item_int_buff(Item *item_par) :item(item_par),value(0) {}
  bool cmp(void);
};


class Item_field_buff :public Item_buff
{
  char *buff;
  Field *field;
  uint length;

public:
  Item_field_buff(Item_field *item)
  {
    field=item->field;
    buff= (char*) sql_calloc(length=field->pack_length());
  }
  bool cmp(void);
};

extern Item_buff *new_Item_buff(Item *item);
extern Item_result item_cmp_type(Item_result a,Item_result b);
extern Item *resolve_const_item(Item *item,Item *cmp_item);
extern bool field_is_equal_to_item(Field *field,Item *item);
Item *get_system_var(LEX_STRING name);
