/******************************************************************************
 *
 *  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 "Arg.h"
#include "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() ;

  private:
    /**
     * Prevent accidental copying
     */
    ValueArg<T>(const ValueArg<T>& rhs);
    ValueArg<T>& operator=(const ValueArg<T>& rhs);
};


/**
 * 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 )
    {
      if ( _xorSet )
        throw( CmdLineParseException(
                 "Mutually exclusive argument already set!",
                 toString()) );
      else
        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