#ifndef _theplu_yat_utility_commandline_
#define _theplu_yat_utility_commandline_

//$Id: CommandLine.h 2817 2012-08-29 00:38:17Z peter $

/*
	Copyright (C) 2007, 2008, 2009 Jari Häkkinen, Peter Johansson
	Copyright (C) 2010, 2011, 2012 Peter Johansson

	This file is part of the yat library, http://dev.thep.lu.se/yat

	The yat library is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License as
	published by the Free Software Foundation; either version 3 of the
	License, or (at your option) any later version.

	The yat 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
	General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with yat. If not, see <http://www.gnu.org/licenses/>.
*/

#include <algorithm>
#include <cctype>
#include <map>
#include <iosfwd>
#include <sstream>
#include <stdexcept>
#include <string>
#include <typeinfo>
#include <utility>
#include <vector>

namespace theplu {
namespace yat {
namespace utility {

	class Option;

	/**
		 @brief Class for parsing the command line.
		 
		 Provides parsing and storage of command line arguments. The class
		 is typically used by hooking a number of Option objects to
		 CommandLine, and then call the parse() function. Here is a short
		 example how the class may be used:
	
		 \code
	
     CommandLine cmd;
     OptionHelp help(cmd);
     OptionFile in(cmd, "i,in", 
                   "Read input from file (rather than standard input)",
                   false, true, "r");
     OptionFile out(cmd, "o,out", "Place the output to file", false, false, "w");
     OptionSwitch target(cmd, "T,target", "treat DEST as a normal file", true);
     OptionSwitch verbose(cmd, "v,verbose", "explain what is being done");
     OptionSwitch version(cmd, "version", "output version and exit");
		 std::stringstream copyright;
     copyright << "example 1.0\n"
               << "Copyright (C) 2007 Peter Johansson\n\n"
               << "This is free software see the source for copying "
               << "conditions. There is NO\nwarranty; not even for "
               << "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n";
     try {
       cmd.parse(argc, argv);
     }
     catch (cmd_error& e){
       if (version.present()){
         std::cout << copyright.str();	   
         return EXIT_SUCCESS;
       }
       std::cerr << e.what() << std::endl;
       return EXIT_FAILURE;
     }  
     if (version.present()){
       std::cout << copyright.str();	   
       return EXIT_SUCCESS;
     }
     StreamRedirect sr_out(std::cout, out.value(), out.present());
     StreamRedirect sr_in(std::cin, in.value(), in.present());
	   ...
	   \endcode

		 After creation a number of Option classes are hooked up to the
		 CommandLine object in their constructors. 

		 Each parameter is associated to a one-character flag and/or a
		 longer string flag. The longer flag expects to be preceded by
		 '--' as e.g. '--help' for help. The shorter flag expects to be
		 preceded by '-' as e.g. '-h', and can also be concatenated like
		 "program -vf", which is equivalent to "program -v -f". or
		 its sibblings for different types.
	*/
	class CommandLine
	{
	public:
		/**
			 \brief default constructor

			 \param str text preceeding the list of option in output
		*/
    CommandLine(std::string str="Available options are:");

		/**
			 \brief Destructor
		*/
		virtual ~CommandLine(void);

		/**
			 \brief Function to add an option. 
		*/
    void add(Option&);

		/**
			 \brief Allow at most \a n free arguments.

			 A free argument is an argument not associated with an Option,
			 allowing commandlines such as \code prog foo bar \endcode
		 */
		void allow_free_args(size_t n);

		/**
			 \brief Arguments not associated with an Option

			 \see allow_free_args(size_t n)
		*/
		const std::vector<std::string>& free_args(void) const;

		/**
			 \brief parse the commandline

			 First the commandline is parsed to detect which options are
			 present, then each Option parses the its relevant part of
			 commandline (Option::parse()), and finally each Option is
			 validated (Option::validate()).

			 throw cmd_error if an error is detected.
		*/
    void parse(int argc, char* argv[]);

		/**
			 \brief has the commandline been parsed already

			 \return true if parse function has already been called

			 \since New in yat 0.5
		*/
    bool parsed(void) const;

		/**
			 @return Name of more; more specifically argv[0] is
			 stripped so only string after the last '/' remains.
 		 */
		std::string program_name(void) const;

		/**
			 \brief Sort Options how they will appear in (help) output.

			 This function will sort the Options in alphabetical order. If
			 the Option has a long_name, it is used for the sorting;
			 otherwise, the short_name is used.

			 \since New in yat 0.7
		 */
		void sort(void);

		/**
			 Like sort(void) but using \a compare to sort Options.

			 The functor Compare must be a <a
			 href="http://www.sgi.com/tech/stl/BinaryPredicate.html">Binary
			 Predicate</a> with both argument types \c const \c Option*.

			 \since New in yat 0.7
		 */
		template<class Compare>
		void sort(Compare compare);

		/**
			 \return something like "Try `<program_name()> --help` for
			 more information."
		 */
	  std::string try_help(void) const;

	private:
		friend std::ostream& operator<<(std::ostream& os, const CommandLine& cl);
		bool is_long_option(std::string str) const;
		bool is_short_option(std::string str) const;
		void parse(std::vector<std::string>::iterator& first,
							 std::vector<std::string>::iterator& last);
		void parse_long(std::vector<std::string>::iterator& first,
										std::vector<std::string>::iterator& last);
		void parse_short(std::vector<std::string>::iterator& first,
										 std::vector<std::string>::iterator& last);
		void parse_free_arg(std::vector<std::string>::iterator& first,
												std::vector<std::string>::iterator& last);
		std::string description_;
		std::vector<std::string> free_arg_;
		size_t free_arg_max_;
		std::vector<Option*> options_;
		std::map<char, Option*> short_options_;
		std::map<std::string, Option*> long_options_;
		bool parsed_;
		std::string program_name_;

		// use cond to make doxygen ignore this privat class
		/// \cond yat_ignore_this
		struct OptionCompare
		{
			bool operator()(const Option*, const Option*) const;
		};
		/// \endcond

	};

	/**
		 \brief CommandLine output operator

		 A typical output may look like this
		 \verbatim
		 Available options are:
		 -h, --help      display this help and exit
		 -v, --verbose   explain what is being done
		 \endverbatim
		 The output starts with a descriptive line such as "Available
		 options are:" (default) that can be set in constructor. Then follows the
		 options described in the order they were added to
		 Commandline. Each Option is described according to
		 Option::print(void) function.
		 \see OptionHelp

		 \relates CommandLine
	*/
	std::ostream& operator<<(std::ostream&, const CommandLine&);

	template<class Compare>
	void CommandLine::sort(Compare compare)
	{
		std::sort(options_.begin(), options_.end(), compare);
	}

}}} // end of namespace utility, yat, and theplu

#endif