// balst.cpp Implementation for the BALState class

/*******************************************************************************
// MODULE NAME: BALState
// INTERFACE FILE:      balst.h
// IMPLEMENTATION FILE: balst.cpp
//
// PURPOSE: To provide a state code storage type useful in implementing the BAL
// program which allows the user to create a new BALState, assign a value to it
// test the value to see if it is valid or contains a default, print the value
// or the default value, and reset the value to its default
//
// FUNCTIONS:    Name            Purpose
//              BALState        Parameterless Constructor
//              isValid         Test whether value could be a valid state code
//              isDefault       Test whether object contains default value
//              valueIs         Report current value of object
//              Print           Print, w/correct width, current value of object
//              Default         Print, w/correct width, default value of object
//              Limits          Report limits on a BALState object
//              Store           Change the value to a specified one
//              Reset           Change the value to the default value
//
//  AUTHOR: Amy Langill *2B  DATE: 3/22/199
*******************************************************************************/

#include "balst.h"

/********************************CONSTRUCTORS**********************************/

/*******************************************************************************
//  FUNCTION NAME: BALState
//
//  DESCRIPTION OF FUNCTION: Creates a default BALState object
//
//  DESCRIPTION OF ALGORITHM: assigns DEFAULT_STATE to value
//
//  CALLED BY: client
//  CALLS: none
//
//  PARAMETERS: none
//
//  PRECONDITIONS: none
//
//  POSTCONDITIONS: Object has been created w/default value
//
//  AUTHOR:  Amy Langill *2B  DATE: 3/22/1999
*******************************************************************************/
BALState::BALState()
{
  value=DEFAULT_STATE;
}

/*********************************OBSERVERS************************************/

/*******************************************************************************
//  FUNCTION NAME: isValid
//
//  DESCRIPTION OF FUNCTION: Determines whether object could hold a valid state
//  code or not
//
//  DESCRIPTION OF ALGORITHM: Tests each character in the value string to 
//  determine if it is alphabetic.
//
//  CALLED BY: client
//  CALLS: isDefault
//
//  PARAMETERS: none
//
//  PRECONDITIONS: none
//
//  POSTCONDITIONS: Returns true if object is default or is not more than 2
//  alphabetic characters long
//
//  AUTHOR:  Amy Langill *2B  DATE: 3/22/1999
*******************************************************************************/
bool BALState::isValid()
{
  if (this->isDefault())
    return true;

  return ((value.length()<=STATE_WIDTH)&&
          ((isalpha(value[FIRST_CHAR]))&&(isalpha(value[SECOND_CHAR]))));
}

/*******************************************************************************
//  FUNCTION NAME: isDefault
//
//  DESCRIPTION OF FUNCTION: Determines if the object contains the default value
//
//  DESCRIPTION OF ALGORITHM: Compares value for exact equality w/DEFAULT_STATE
//
//  CALLED BY: client
//  CALLS: none
//
//  PARAMETERS: none
//
//  PRECONDITIONS: none
//
//  POSTCONDITIONS: Returns true if the value string is exactly equal to 
//  DEFAULT_STATE
//
//  AUTHOR:  Amy Langill *2B  DATE: 3/22/1999
*******************************************************************************/
bool BALState::isDefault()
{
  return (value==DEFAULT_STATE);
}

/*******************************************************************************
//  FUNCTION NAME: valueIs
//
//  DESCRIPTION OF FUNCTION: Reports the current value of the object, without
//  any special formatting
//
//  DESCRIPTION OF ALGORITHM: Returns the value string
//
//  CALLED BY: client
//  CALLS: none
//
//  PARAMETERS: none
//
//  PRECONDITIONS: none
//
//  POSTCONDITIONS: Returns the value string
//
//  AUTHOR:  Amy Langill *2B  DATE: 3/22/1999
*******************************************************************************/
string BALState::valueIs()
{
  return value;
}

/*******************************************************************************
//  FUNCTION NAME: Print
//
//  DESCRIPTION OF FUNCTION: Creates a string of the appropriate length that 
//  holds the current value of the object
//
//  DESCRIPTION OF ALGORITHM: If the value string is not wide enough to fill the
//  field, pads it with spaces in front to make it wider, otherwise, prints out
//  the first STATE_WIDTH characters of the value string
//
//  CALLED BY: client
//  CALLS: none
//
//  PARAMETERS: none
//
//  PRECONDITIONS: none
//
//  POSTCONDITIONS: A string has been createc with length STATE_WIDTH that 
//  contains the current value of the object
//
//  AUTHOR:  Amy Langill *2B  DATE: 3/22/1999
*******************************************************************************/
string BALState::Print()
{
  int counter;        // for controlling loop
  string outputString;  // to hold resultant string

  if (value.length()<STATE_WIDTH) // if the state isn't long enough, pad it
    {
    for (counter=0;counter<(STATE_WIDTH-value.length());counter++)
      outputString += ST_STRING_FILLER;
    for (counter=0;counter<value.length();counter++)
      outputString += toupper(value[counter]);
    }
  else    // Otherwise, print out the first STATE_WIDTH chars in uppercase
    for (counter=0;counter<STATE_WIDTH;counter++)
      outputString += toupper(value[counter]);

  return outputString;
}

/*******************************************************************************
//  FUNCTION NAME: Default
//
//  DESCRIPTION OF FUNCTION: Creates a string of the appropriate length that 
//  holds the default value of the object
//
//  DESCRIPTION OF ALGORITHM: Creates a default BALState object and calls the 
//  Print member function to output the default string
//
//  CALLED BY: client
//  CALLS: BALState,Print
//
//  PARAMETERS: none
//
//  PRECONDITIONS: none
//
//  POSTCONDITIONS: A string is returned which contains the default value of the
//  object.
//
//  AUTHOR:  Amy Langill *2B  DATE: 3/22/1999
*******************************************************************************/
string BALState::Default()
{
  BALState defaultState;

  return (defaultState.Print());
}

/*******************************************************************************
//  FUNCTION NAME: Limits
//
//  DESCRIPTION OF FUNCTION: Report on the limits in effect for the field
//
//  DESCRIPTION OF ALGORITHM: Returns a string which contains a literal message
//
//  CALLED BY: client
//  CALLS: none
//
//  PARAMETERS: none
//
//  PRECONDITIONS: none
//
//  POSTCONDITIONS: Returns a string containing the message:
//  "Must contain 2 alphabetic characters (A-Z)"
//
//  AUTHOR:  Amy Langill *2B  DATE: 3/22/1999
*******************************************************************************/
string BALState::Limits()
{
  return "Must contain 2 alphabetic characters (A-Z)";
}


/********************************TRANSFORMERS**********************************/

/*******************************************************************************
//  FUNCTION NAME: Store
//
//  DESCRIPTION OF FUNCTION: Stores a new string into the state value
//
//  DESCRIPTION OF ALGORITHM: Assigns the string newValue to value
//
//  CALLED BY: client
//  CALLS: none
//
//  PARAMETERS: / in / newValue - string that value should be changed to 
//
//  PRECONDITIONS: none
//
//  POSTCONDITIONS: The value has been changed to whatever was in newValue
//
//  AUTHOR:  Amy Langill *2B  DATE: 3/22/1999
*******************************************************************************/
void BALState::Store(string newValue)
{
  value=newValue;
  return;
}

/*******************************************************************************
//  FUNCTION NAME: Reset
//
//  DESCRIPTION OF FUNCTION: Change the value of the object to its default
//
//  DESCRIPTION OF ALGORITHM: Assigns DEFAULT_STATE to value
//
//  CALLED BY: client
//  CALLS: none
//
//  PARAMETERS: none
//
//  PRECONDITIONS: none
//
//  POSTCONDITIONS: value has been changed to DEFAULT_STATE
//
//  AUTHOR:  Amy Langill *2B  DATE: 3/22/1999
*******************************************************************************/
void BALState::Reset()
{
  value=DEFAULT_STATE;
  return;
}