#ifdef STANDARD
#include <stdio.h>
#include <string.h>
#ifdef __WIN__
typedef unsigned __int64 ulonglong;	/* Microsofts 64 bit types */
typedef __int64 longlong;
#else
typedef unsigned long long ulonglong;
typedef long long longlong;
#endif /*__WIN__*/
#else
#include <my_global.h>
#include <my_sys.h>
#endif
#include <mysql.h>
#include <m_ctype.h>
#include <m_string.h>		// To get strmov()

#ifdef HAVE_DLOPEN

/* These must be right or mysqld will not find the symbol! */

extern "C" {
my_bool firstval_init( UDF_INIT* initid, UDF_ARGS* args, char* message );
void firstval_deinit( UDF_INIT* initid );
void firstval_reset( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error );
void firstval_add( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error );
double firstval( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error );

}

struct firstval_data {
  double value;
  longlong order;
  int inited;
  int is_null;
};

my_bool firstval_init( UDF_INIT* initid, UDF_ARGS* args, char* message ) {
  if (args->arg_count != 2) {
    strcpy(message, "wrong number of arguments: FIRSTVAL() requires 2 arguments");
    return 1;
  }
  if ((args->arg_type[0] != REAL_RESULT) || (args->arg_type[1] != INT_RESULT) ) {
    strcpy(message, "wrong argument type: FIRSTVAL() requires a REAL and an INT");
    return 1;
  }
  initid->maybe_null = 0;
  initid->decimals = 2; 
  initid->max_length = 20;

  struct firstval_data* data;
  data = new struct firstval_data;
  data->value = 0.0;
  data->order = 0;
  data->inited = 0;
  data->is_null = 1; 
  initid->ptr = (char*)data;
  return 0;
}
  
void firstval_deinit(UDF_INIT* initid) {
  delete initid->ptr;
}

void firstval_reset(UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* message) {
  struct firstval_data* data = (struct firstval_data*)initid->ptr;
  data->value = 0.0;
  data->order = -1;
  data->inited = 0;
  data->is_null = 1;
  *is_null = 0;
  firstval_add(initid, args, is_null, message);  
}

void firstval_add(UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* message) {
  if (args->args[0] && args->args[1]) {
    struct firstval_data* data = (struct firstval_data*)initid->ptr;
    double   val = *((double*)args->args[0]);
    longlong ord = *((longlong*)args->args[1]);
    if (args->args[0] != 0) {
      if (ord < data->order || data->inited == 0) {
        data->order = ord;
        data->inited = 1;
        data->value = val;
      } else if (ord == data->order && val < data->value) {
        data->value = val;
      }
    }
  } else {
    *is_null = 1;
  }
}

double firstval(UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* error) {
  struct firstval_data* data = (struct firstval_data*)initid->ptr;
  if (data->inited != 1) {
    *is_null = 1;
    return 0.0;
  }
  *is_null = 0;
  return data->value;
}
#endif /* HAVE_DLOPEN */