Arg.h

/*
  Copyright (C) 2006,2010 by Tommi Maekitalo
  Copyright (C) 2006-2016 by Marc Duerner
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
  
  As a special exception, you may use this file as part of a free
  software library without restriction. Specifically, if other files
  instantiate templates or use macros or inline functions from this
  file, or you compile this file and link it with other files to
  produce an executable, this file does not by itself cause the
  resulting executable to be covered by the GNU General Public
  License. This exception does not however invalidate any other
  reasons why the executable file might be covered by the GNU Library
  General Public License.
  
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
  
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  MA 02110-1301 USA
*/

#ifndef Pt_Arg_h
#define Pt_Arg_h

#include <Pt/Api.h>
#include <sstream>
#include <cstring>

namespace Pt {

class ArgBase
{
    public:
        ArgBase()
          : m_isset(false)
        { }

        bool isSet() const
        { return m_isset; }

    protected:
        bool m_isset;

        static void removeArg(int& argc, char* argv[], int pos, int n)
        {
          for ( ; pos < argc - n; ++pos)
              argv[pos] = argv[pos + n];
          
          argc -= n;
          argv[argc] = 0;
        }
};

template <typename T>
class ArgBaseT : public ArgBase
{
    protected:
        explicit ArgBaseT(const T& def)
        : m_value(def)
        { }

        bool extract(const char* str, int& argc, char* argv[], int i, int n)
        {
            std::istringstream s(str);
            s >> m_value;
            if( ! s.fail() )
            {
                m_isset = true;
                removeArg(argc, argv, i, n);
                return true;
            }
            
            return false;
        }

    public:
        const T& get() const
        { return m_value; }

    private:
       T m_value;
};

template <>
class ArgBaseT<const char*> : public ArgBase
{
    protected:
        explicit ArgBaseT(const char* def)
        : m_value(def)
        { }

        bool extract(const char* str, int& argc, char* argv[], int i, int n)
        {
            m_value = str;
            m_isset = true;
            removeArg(argc, argv, i, n);
            return true;
        }

    public:
        const char* get() const
        { return m_value; }

    private:
        const char* m_value;
};

template <>
class ArgBaseT<std::string> : public ArgBase
{
    protected:
        explicit ArgBaseT(const std::string& def)
        : m_value(def)
        { }

        bool extract(const char* str, int& argc, char* argv[], int i, int n)
        {
            m_value = str;
            m_isset = true;
            removeArg(argc, argv, i, n);
            return true;
        }

    public:
        const std::string& get() const
        { return m_value; }

    private:
        std::string m_value;
};

template <typename T>
class Arg : public ArgBaseT<T>
{
  public:
      Arg(const T& def = T())
      : ArgBaseT<T>(def)
      { }

      Arg(int& argc, char* argv[], char ch, const T& def = T())
      : ArgBaseT<T>(def)
      {
          set(argc, argv, ch);
      }

        Arg(int& argc, char* argv[], const char* str, const T& def = T())
        : ArgBaseT<T>(def)
        {
            this->m_isset = set(argc, argv, str);
        }

        Arg(int& argc, char* argv[])
        : ArgBaseT<T>(T())
        {
            this->m_isset = set(argc, argv);
        }

        bool set(int& argc, char* argv[], char ch)
        {
            // don't extract value, when already found
            if(this->m_isset)
                return false;

            for(int i = 1; i < argc; ++i)
            {
                if (argv[i] && argv[i][0] == '-' && argv[i][1] == ch)
                {
                    if(argv[i][2] == '\0' && i < argc - 1)
                    {
                      // -O foo
                      if (this->extract(argv[i + 1], argc, argv, i, 2))
                        return true;
                    }

                  // -Ofoo
                  if( this->extract(argv[i] + 2, argc, argv, i, 1) )
                      return true;
                }
            }

            return false;
        }

        bool set(int& argc, char* argv[], const char* str)
        {
            // don't extract value, when already found
            if (this->m_isset)
                return false;

            unsigned n = std::strlen(str);
            for (int i = 1; i < argc; ++i)
            {
                if(argv[i] && (std::strncmp(argv[i], str, n) == 0))
                {
                    if (i < argc - 1 && argv[i][n] == '\0')
                    {
                        // --option value
                        if (this->extract(argv[i + 1], argc, argv, i, 2))
                            return true;
                    }

                    if (argv[i][n] == '=')
                    {
                        // --option=value
                        if (this->extract(argv[i] + n + 1, argc, argv, i, 1))
                            return true;
                    }
                }
            }

            return false;
        }

        bool set(int& argc, char* argv[])
        {
            // don't extract value, when already found
            if (this->m_isset)
                return false;

            if (argc > 1)
                this->extract(argv[1], argc, argv, 1, 1);

            return this->m_isset;
        }
};

template <>
class Arg<bool> : public ArgBase
{
    public:
        Arg(bool def = false)
        : m_value(def)
        { }

        Arg(int& argc, char* argv[], char ch, bool def = false)
        : m_value(def)
        {
            m_isset = set(argc, argv, ch);
        }

        Arg(int& argc, char* argv[], const char* str, bool def = false)
        : m_value(def)
        {
            m_isset = set(argc, argv, str);
        }

        bool set(int& argc, char* argv[], char ch)
        {
            // don't extract value, when already found
            if (m_isset)
                return false;

            for (int i = 1; i < argc; ++i)
            {
                if (argv[i][0] == '-' && argv[i][1] != '-')
                {
                    // starts with a '-', but not with "--"
                    if (argv[i][1] == ch && argv[i][2] == '\0')
                    {
                        // single option found
                        m_value = true;
                        m_isset = true;
                        removeArg(argc, argv, i, 1);
                        return true;
                    }
                    else if(argv[i][1] == ch && 
                            argv[i][2] == '-' && 
                            argv[i][3] == '\0')
                    {
                        // Option was explicitly disabled with -x-
                        m_value = false;
                        m_isset = true;
                        removeArg(argc, argv, i, 1);
                        return true;
                    }
                    else
                    {
                        // check for optiongroup
                        for (char* p = argv[i] + 1; *p != '\0'; ++p)
                        {
                            if (*p == ch)
                            {
                                // here it is - extract it
                                m_value = true;
                                m_isset = true;
                                do
                                {
                                    *p = *(p + 1);
                                } 
                                while (*p++ != '\0');

                                return true;
                            }
                        }
                    }
                }
            }

            return false;
        }

        bool set(int& argc, char* argv[], const char* str)
        {
            // don't extract value, when already found
            if(m_isset)
                return false;

            for (int i = 1; i < argc; ++i)
            {
                if (std::strcmp(argv[i], str) == 0)
                {
                    m_value = true;
                    m_isset = true;
                    removeArg(argc, argv, i, 1);
                    return true;
                }
            }

            return false;
        }

        bool get() const
        { return m_value; }

        operator bool() const
        { return m_value; }

    private:
        bool m_value;
};

template <typename T>
inline std::ostream& operator<<(std::ostream& out, const Arg<T>& arg)
{
  return out << arg.get();
}

} // namespace Pt

#endif