/****************************************************************************** 
 * 
 *  file:  ValueArg.h
 * 
 *  Copyright (c) 2003, Michael E. Smoot .
 *  Copyright (c) 2004, Michael E. Smoot, Daniel Aarno.
 *  All rights reverved.
 * 
 *  See the file COPYING in the top directory of this distribution for
 *  more information.
 *  
 *  THE SOFTWARE IS PROVIDED _AS IS_, WITHOUT WARRANTY OF ANY KIND, EXPRESS 
 *  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
 *  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
 *  DEALINGS IN THE SOFTWARE.  
 *  
 *****************************************************************************/ 


#ifndef TCLAP_VALUE_ARGUMENT_H
#define TCLAP_VALUE_ARGUMENT_H

#include <string>
#include <vector>

#include <tclap/Arg.h>
#include <tclap/Constraint.h>

namespace TCLAP {

/**
 * The basic labeled argument that parses a value.
 * This is a template class, which means the type T defines the type
 * that a given object will attempt to parse when the flag/name is matched
 * on the command line.  While there is nothing stopping you from creating
 * an unflagged ValueArg, it is unwise and would cause significant problems.
 * Instead use an UnlabeledValueArg.
 */
template<class T>
class ValueArg : public Arg 
{
    protected:

        /**
         * The value parsed from the command line.
         * Can be of any type, as long as the >> operator for the type
         * is defined.
         */
        T _value;

		/**
		 * Used to support the reset() method so that ValueArg can be
		 * reset to their constructed value.
		 */
        T _default;

        /**
         * A human readable description of the type to be parsed.
         * This is a hack, plain and simple.  Ideally we would use RTTI to
         * return the name of type T, but until there is some sort of
         * consistent support for human readable names, we are left to our
         * own devices.
         */
        std::string _typeDesc;

        /**
         * A Constraint this Arg must conform to. 
         */
        Constraint<T>* _constraint;

        /**
         * Extracts the value from the string.
         * Attempts to parse string as type T, if this fails an exception
         * is thrown.
         * \param val - value to be parsed. 
         */
        void _extractValue( const std::string& val );

	public:

        /**
         * Labeled ValueArg constructor.
         * You could conceivably call this constructor with a blank flag, 
         * but that would make you a bad person.  It would also cause
         * an exception to be thrown.   If you want an unlabeled argument, 
         * use the other constructor.
         * \param flag - The one character flag that identifies this
         * argument on the command line.
         * \param name - A one word name for the argument.  Can be
         * used as a long flag on the command line.
         * \param desc - A description of what the argument is for or
         * does.
         * \param req - Whether the argument is required on the command
         * line.
         * \param value - The default value assigned to this argument if it
         * is not present on the command line.
         * \param typeDesc - A short, human readable description of the
         * type that this object expects.  This is used in the generation
         * of the USAGE statement.  The goal is to be helpful to the end user
         * of the program.
         * \param v - An optional visitor.  You probably should not
         * use this unless you have a very good reason.
         */
        ValueArg( const std::string& flag, 
                  const std::string& name, 
                  const std::string& desc, 
                  bool req, 
                  T value,
                  const std::string& typeDesc,
                  Visitor* v = NULL);
				 
				 
        /**
         * Labeled ValueArg constructor.
         * You could conceivably call this constructor with a blank flag, 
         * but that would make you a bad person.  It would also cause
         * an exception to be thrown.   If you want an unlabeled argument, 
         * use the other constructor.
         * \param flag - The one character flag that identifies this
         * argument on the command line.
         * \param name - A one word name for the argument.  Can be
         * used as a long flag on the command line.
         * \param desc - A description of what the argument is for or
         * does.
         * \param req - Whether the argument is required on the command
         * line.
         * \param value - The default value assigned to this argument if it
         * is not present on the command line.
         * \param typeDesc - A short, human readable description of the
         * type that this object expects.  This is used in the generation
         * of the USAGE statement.  The goal is to be helpful to the end user
         * of the program.
         * \param parser - A CmdLine parser object to add this Arg to
         * \param v - An optional visitor.  You probably should not
         * use this unless you have a very good reason.
         */
        ValueArg( const std::string& flag, 
                  const std::string& name, 
                  const std::string& desc, 
                  bool req, 
                  T value,
                  const std::string& typeDesc,
                  CmdLineInterface& parser,
                  Visitor* v = NULL );
 
        /**
         * Labeled ValueArg constructor.
         * You could conceivably call this constructor with a blank flag, 
         * but that would make you a bad person.  It would also cause
         * an exception to be thrown.   If you want an unlabeled argument, 
         * use the other constructor.
         * \param flag - The one character flag that identifies this
         * argument on the command line.
         * \param name - A one word name for the argument.  Can be
         * used as a long flag on the command line.
         * \param desc - A description of what the argument is for or
         * does.
         * \param req - Whether the argument is required on the command
         * line.
         * \param value - The default value assigned to this argument if it
         * is not present on the command line.
         * \param constraint - A pointer to a Constraint object used
		 * to constrain this Arg.
         * \param parser - A CmdLine parser object to add this Arg to.
         * \param v - An optional visitor.  You probably should not
         * use this unless you have a very good reason.
         */
        ValueArg( const std::string& flag, 
                  const std::string& name, 
                  const std::string& desc, 
                  bool req, 
                  T value,
                  Constraint<T>* constraint,
                  CmdLineInterface& parser,
                  Visitor* v = NULL );
	  
        /**
         * Labeled ValueArg constructor.
         * You could conceivably call this constructor with a blank flag, 
         * but that would make you a bad person.  It would also cause
         * an exception to be thrown.   If you want an unlabeled argument, 
         * use the other constructor.
         * \param flag - The one character flag that identifies this
         * argument on the command line.
         * \param name - A one word name for the argument.  Can be
         * used as a long flag on the command line.
         * \param desc - A description of what the argument is for or
         * does.
         * \param req - Whether the argument is required on the command
         * line.
         * \param value - The default value assigned to this argument if it
         * is not present on the command line.
         * \param constraint - A pointer to a Constraint object used
		 * to constrain this Arg.
         * \param v - An optional visitor.  You probably should not
         * use this unless you have a very good reason.
         */
        ValueArg( const std::string& flag, 
                  const std::string& name, 
                  const std::string& desc, 
                  bool req, 
                  T value,
                  Constraint<T>* constraint,
                  Visitor* v = NULL );

        /**
         * Handles the processing of the argument.
         * This re-implements the Arg version of this method to set the
         * _value of the argument appropriately.  It knows the difference
         * between labeled and unlabeled.
         * \param i - Pointer the the current argument in the list.
         * \param args - Mutable list of strings. Passed 
         * in from main().
         */
        virtual bool processArg(int* i, std::vector<std::string>& args); 

        /**
         * Returns the value of the argument.
         */
        T& getValue() ;

        /**
         * Specialization of shortID.
         * \param val - value to be used.
         */
        virtual std::string shortID(const std::string& val = "val") const;

        /**
         * Specialization of longID.
         * \param val - value to be used.
         */
        virtual std::string longID(const std::string& val = "val") const;
        
        virtual void reset() ;

};


/**
 * Constructor implementation.
 */
template<class T>
ValueArg<T>::ValueArg(const std::string& flag, 
                      const std::string& name, 
                      const std::string& desc, 
                      bool req, 
                      T val,
                      const std::string& typeDesc,
                      Visitor* v)
: Arg(flag, name, desc, req, true, v),
  _value( val ),
  _default( val ),
  _typeDesc( typeDesc ),
  _constraint( NULL )
{ }

template<class T>
ValueArg<T>::ValueArg(const std::string& flag, 
                      const std::string& name, 
                      const std::string& desc, 
                      bool req, 
                      T val,
                      const std::string& typeDesc,
                      CmdLineInterface& parser,
                      Visitor* v)
: Arg(flag, name, desc, req, true, v),
  _value( val ),
  _default( val ),
  _typeDesc( typeDesc ),
  _constraint( NULL )
{ 
    parser.add( this );
}

template<class T>
ValueArg<T>::ValueArg(const std::string& flag, 
                      const std::string& name, 
                      const std::string& desc, 
                      bool req, 
                      T val,
                      Constraint<T>* constraint,
                      Visitor* v)
: Arg(flag, name, desc, req, true, v),
  _value( val ),
  _default( val ),
  _typeDesc( constraint->shortID() ),
  _constraint( constraint )
{ }

template<class T>
ValueArg<T>::ValueArg(const std::string& flag, 
                      const std::string& name, 
                      const std::string& desc, 
                      bool req, 
                      T val,
                      Constraint<T>* constraint,
                      CmdLineInterface& parser,
                      Visitor* v)
: Arg(flag, name, desc, req, true, v),
  _value( val ),
  _default( val ),
  _typeDesc( constraint->shortID() ),
  _constraint( constraint )
{ 
    parser.add( this );
}


/**
 * Implementation of getValue().
 */
template<class T>
T& ValueArg<T>::getValue() { return _value; }

/**
 * Implementation of processArg().
 */
template<class T>
bool ValueArg<T>::processArg(int *i, std::vector<std::string>& args)
{
    if ( _ignoreable && Arg::ignoreRest() )
		return false;

    if ( _hasBlanks( args[*i] ) )
		return false;

    std::string flag = args[*i];

    std::string value = "";
    trimFlag( flag, value );

    if ( argMatches( flag ) )
    {
        if ( _alreadySet )
			throw( CmdLineParseException("Argument already set!", toString()) );

        if ( Arg::delimiter() != ' ' && value == "" )
			throw( ArgParseException( 
							"Couldn't find delimiter for this argument!",
                             toString() ) );

        if ( value == "" )
        {
            (*i)++;
            if ( static_cast<unsigned int>(*i) < args.size() ) 
				_extractValue( args[*i] );
            else
				throw( ArgParseException("Missing a value for this argument!",
                                                    toString() ) );
        }
        else
			_extractValue( value );
				
        _alreadySet = true;
        _checkWithVisitor();
        return true;
    }	
    else
		return false;
}

/**
 * Implementation of shortID.
 */
template<class T>
std::string ValueArg<T>::shortID(const std::string& val) const
{
	static_cast<void>(val); // Ignore input, don't warn
	return Arg::shortID( _typeDesc ); 
}

/**
 * Implementation of longID.
 */
template<class T>
std::string ValueArg<T>::longID(const std::string& val) const
{
	static_cast<void>(val); // Ignore input, don't warn
	return Arg::longID( _typeDesc ); 
}

template<class T>
void ValueArg<T>::_extractValue( const std::string& val ) 
{
    try {
	ExtractValue(_value, val, typename ArgTraits<T>::ValueCategory());
    } catch( ArgParseException &e) {
	throw ArgParseException(e.error(), toString());
    }
    
    if ( _constraint != NULL )
	if ( ! _constraint->check( _value ) )
	    throw( CmdLineParseException( "Value '" + val + 
					  + "' does not meet constraint: " 
					  + _constraint->description(),
					  toString() ) );
}

template<class T>
void ValueArg<T>::reset()
{
	Arg::reset();
	_value = _default;
}

} // namespace TCLAP

#endif
