# include <ctype.h>
# include <stdbool.h>
# include <stdio.h>
# include <stdlib.h>

# include "byname.h"

/******************************************************************************/

double byname ( char *action, char *name, double *value_in )

/******************************************************************************/
/*
  Purpose:

    byname() controls a set of named persistent data.

  Discussion:

    Three values are stored, named ALPHA, BETA and GAMMA.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    07 May 2021

  Author:

    John Burkardt

  Input:

    char *ACTION (case insensitive, only first character important)
    "Get"     get the value;
    "Print"   print the value;
    "Reset"   reset value to default;
    "Set"     set the value;

    string NAME, the name of the parameter (case insensitive)
    "ALPHA"
    "BETA"
    "GAMMA"
    "*" (all variables)
    NAME is required for "Get" and "Set".  
    NAME, if omitted, is assumed "*" for "Print" and "Reset".

    double *VALUE_IN.
    Only used for "Set" command.

  Output:

    double *VALUE_OUT.
    If NAME was specified on input, and was not "*", then
    VALUE_OUT is the current value of the corresponding variable.
    Otherwise, VALUE_OUT is empty.
*/
{
  char action2;
  static double alpha = 1.0;
  static double alpha_default = 1.0;
  static double beta = 2.0;
  static double beta_default = 2.0;
  static double gamma = 3.0;
  static double gamma_default = 3.0;
  bool match;
  char name2;
  double value_out;
/*
  Check action.
*/
  if ( ! action )
  {
    action2 = 'p';
  }
  else
  {
    action2 = action[0];
    action2 = tolower ( action2 );
    match = 
      ( action2 == 'g' ) |
      ( action2 == 'p' ) |
      ( action2 == 'r' ) |
      ( action2 == 's' ) ;

    if ( ! match )
    {
      printf ( "\n" );
      printf ( "byname: Fatal error!\n" );
      printf ( "  Legal actions are 'g', 'p', 'r', 's', not '%s'\n", action );
      exit ( 1 );
    }
  }
/*
  Check name.
*/
  if ( ! name )
  {
    name2 = '*';
  }
  else
  {
    name2 = name[0];
    name2 = tolower ( name2 );

    match = 
      ( name2 == 'a' ) |
      ( name2 == 'b' ) |
      ( name2 == 'g' ) |
      ( name2 == '*' );

    if ( ! match )
    {
      printf ( "\n" );
      printf ( "byname: Fatal error!\n" );
      printf ( "  Legal names are 'alpha', 'beta', 'gamma', '*', not '%s'\n", name );
      exit ( 1 );
    }
  }
/*
  Check value.
*/
  if ( ( action2 == 's' ) & ( ! value_in ) )
  {
    printf ( "\n" );
    printf ( "byname: Fatal error!\n" );
    printf ( "  'set, name' command but no 'value'.\n" );
    exit ( 1 );
  }
/*
  Carry out requested action.
*/
  value_out = 0.0;

  if ( action2 == 'g' )
  {
    if ( name2 == 'a' )
    {
      value_out = alpha;
    }
    else if ( name2 == 'b' )
    {
      value_out = beta;
    }
    else if ( name2 == 'g' )
    {
      value_out = gamma;
    }
  }
  else if ( action2 == 'p' )
  {
    if ( ( name2 == 'a' ) | ( name2 == '*' ) )
    {
      printf ( "alpha = %g\n", alpha );
    }
    if ( name2 == 'a' )
    {
      value_out = alpha;
    }
    if ( ( name2 == 'b' ) | ( name2 == '*' ) )
    {
      printf ( "beta = %g\n", beta );
    }
    if ( name2 == 'b' )
    {
      value_out = beta;
    }
    if ( ( name2 == 'g' ) | ( name2 == '*' ) )
    {
      printf ( "gamma = %g\n", gamma );
    }
    if ( name2 == 'g' )
    {
      value_out = gamma;
    }
  }
  else if ( action2 == 'r' )
  {
    if ( ( name2 == 'a' ) | ( name2 == '*' ) )
    {
      alpha = alpha_default;
    }
    if ( name2 == 'a' )
    {
      value_out = alpha;
    }
    if ( ( name2 == 'b' ) | ( name2 == '*' ) )
    {
      beta = beta_default;
    }
    if ( name2 == 'b' )
    {
      value_out = beta;
    }
    if ( ( name2 == 'g' ) | ( name2 == '*' ) )
    {
      gamma = gamma_default;
    }
    if ( name2 == 'g' )
    {
      value_out = gamma;
    }
  }
  else if ( action2 == 's' )
  {
    if ( name2 == 'a' )
    {
      alpha = *value_in;
      value_out = alpha;
    }
    if ( name2 == 'b' )
    {
      beta = *value_in;
      value_out = beta;
    }
    if ( name2 == 'g' )
    {
      gamma = *value_in;
      value_out = gamma;
    }
  }

  return value_out;
}