#ifndef CMDLINE_H // -*- c++ -*-
#define CMDLINE_H
///
// Copyright (C) 2003, 2004, Fredrik Arnerup & Rasmus Kaj, See COPYING
///

#include <string>
#include <vector>
#include <queue>
#include <stdexcept>
#include <iostream>

/** A general-purpose command line option parser. */ 
class CmdLine {
public:
  struct Error: public std::runtime_error {
    Error(const std::string &msg) : runtime_error(msg) {}
    ~Error() throw() {}
  };
  struct UnknownOptionError: public Error {
    UnknownOptionError(const std::string &option)
      : Error("Unknown option: \"" + option + "\""), opt(option)
    {}
    ~UnknownOptionError() throw() {}
    const std::string opt;
  };
  struct ArgumentError: public Error {
    ArgumentError(const std::string &option, bool not_allowed = false)
      : Error("Argument " + (not_allowed ? std::string("not allowed")
			     : std::string("missing"))
	      + " for : \"" + option + "\""), opt(option)
    {}
    ~ArgumentError() throw() {}
    const std::string opt;
  };

  //** Defines a possible option. */
  struct Option {
    enum ParameterMode { NO_PARAM, REQ_PARAM, OPT_PARAM };

    Option(char short_option, const std::string long_option = "",
	   ParameterMode parameter_mode = NO_PARAM,
	   const std::string &description = "", 
	   const std::string &p_name = "")
      : short_opt(short_option), long_opt(long_option),
	desc(description), param_name(p_name),
	param_mode(parameter_mode)
    {}
    
    /// Short option. Set to 0 to disable.
    char short_opt;

    /// Long option.
    std::string long_opt;

    /// Description. Used by print_usage().
    std::string desc;

    /// Name of parameter, if any. Used by print_usage().
    std::string param_name;

    /** Describes whether the option takes a parameter or not.
     * Only long options accept optional parameters. */
    ParameterMode param_mode;

    /** A unique identifier.
     * This is set by add_option.() */
    int id;
  };

  /// Initialize with command line arguments.
  CmdLine(int argc, char **argv);

  /** Register a possible option.
   * Returns a unique number (> 0) to identiy the option. */
  int add_option(Option option);

  typedef std::pair<int, std::string> Arg;
  typedef std::vector<Arg> ParsedOptions;

  /** Return a vector of option id/param pairs.
   * The id is zero for arguments that are not options. */
  ParsedOptions parse();

  /// Display help.
  void print_usage(std::ostream &out);
  
private:
  bool seen_double_dash; /// "--" turns off parsing
  typedef std::vector<Option> Options;
  Options options;
  typedef std::vector<std::string> Arguments;
  Arguments arguments;
  Arguments::const_iterator argi;
  typedef std::queue<Arg> ArgQueue;
  ArgQueue arg_queue;

  Arg parse_next();
};

#endif