/*! @file SimpleOpt.h

	@version 3.6

	@brief A cross-platform command line library which can parse almost any
	of the standard command line formats in use today. It is designed
	explicitly to be portable to any platform and has been tested on Windows
	and Linux. See CSimpleOptTempl for the class definition.

	@section features FEATURES
	-   MIT Licence allows free use in all software (including GPL
		and commercial)
	-   multi-platform (Windows 95/98/ME/NT/2K/XP, Linux, Unix)
	-   supports all lengths of option names:
		<table width="60%">
			<tr><td width="30%"> -
				<td>switch character only (e.g. use stdin for input)
			<tr><td> -o
				<td>short (single character)
			<tr><td> -long
				<td>long (multiple character, single switch character)
			<tr><td> --longer
				<td>long (multiple character, multiple switch characters)
		</table>
	-   supports all types of arguments for options:
		<table width="60%">
			<tr><td width="30%"> --option
				<td>short/long option flag (no argument)
			<tr><td> --option ARG
				<td>short/long option with separate required argument
			<tr><td> --option=ARG
				<td>short/long option with combined required argument
			<tr><td> --option[=ARG]
				<td>short/long option with combined optional argument
			<tr><td> -oARG
				<td>short option with combined required argument
			<tr><td> -o[ARG]
				<td>short option with combined optional argument
		</table>
	-   supports options with multiple or variable numbers of arguments:
		<table width="60%">
			<tr><td width="30%"> --multi ARG1 ARG2
				<td>Multiple arguments
			<tr><td> --multi N ARG-1 ARG-2 ... ARG-N
				<td>Variable number of arguments
		</table>
	-   supports case-insensitive option matching on short, long and/or
		word arguments.
	-   supports options which do not use a switch character. i.e. a special
		word which is construed as an option.
		e.g. "foo.exe open /directory/file.txt"
	-   supports clumping of multiple short options (no arguments) in a string
		e.g. "foo.exe -abcdef file1" <==> "foo.exe -a -b -c -d -e -f file1"
	-   automatic recognition of a single slash as equivalent to a single
		hyphen on Windows, e.g. "/f FILE" is equivalent to "-f FILE".
	-   file arguments can appear anywhere in the argument list:
		"foo.exe file1.txt -a ARG file2.txt --flag file3.txt file4.txt"
		files will be returned to the application in the same order they were
		supplied on the command line
	-   short-circuit option matching: "--man" will match "--mandate"
		invalid options can be handled while continuing to parse the command
		line valid options list can be changed dynamically during command line
		processing, i.e. accept different options depending on an option
		supplied earlier in the command line.
	-   implemented with only a single C++ header file
	-   optionally use no C runtime or OS functions
	-   char, wchar_t and Windows TCHAR in the same program
	-   complete working examples included
	-   compiles cleanly at warning level 4 (Windows/VC.NET 2003), warning
		level 3 (Windows/VC6) and -Wall (Linux/gcc)

	@section usage USAGE
	The SimpleOpt class is used by following these steps:
<ol>
	<li> Include the SimpleOpt.h header file
		<pre>
		\#include "SimpleOpt.h"
		</pre>
	<li> Define an array of valid options for your program.
<pre>
@link CSimpleOptTempl::SOption CSimpleOpt::SOption @endlink g_rgOptions[] = {
	{ OPT_FLAG, _T("-a"),     SO_NONE    }, // "-a"
	{ OPT_FLAG, _T("-b"),     SO_NONE    }, // "-b"
	{ OPT_ARG,  _T("-f"),     SO_REQ_SEP }, // "-f ARG"
	{ OPT_HELP, _T("-?"),     SO_NONE    }, // "-?"
	{ OPT_HELP, _T("--help"), SO_NONE    }, // "--help"
	SO_END_OF_OPTIONS                       // END
};
</pre>
		Note that all options must start with a hyphen even if the slash will
		be accepted. This is because the slash character is automatically
		converted into a hyphen to test against the list of options.
		For example, the following line matches both "-?" and "/?"
		(on Windows).
<pre>
	{ OPT_HELP, _T("-?"),     SO_NONE    }, // "-?"
</pre>
   <li> Instantiate a CSimpleOpt object supplying argc, argv and the option
		table
<pre>
@link CSimpleOptTempl CSimpleOpt @endlink args(argc, argv, g_rgOptions);
</pre>
   <li> Process the arguments by calling Next() until it returns false.
		On each call, first check for an error by calling LastError(), then
		either handle the error or process the argument.
<pre>
while (args.Next()) {
	if (args.LastError() == SO_SUCCESS) {
		handle option: use OptionId(), OptionText() and OptionArg()
	}
	else {
		handle error: see ESOError enums
	}
}
</pre>
   <li> Process all non-option arguments with File(), Files() and FileCount()
<pre>
ShowFiles(args.FileCount(), args.Files());
</pre>
	</ol>

	@section notes NOTES
	-   In MBCS mode, this library is guaranteed to work correctly only when
		all option names use only ASCII characters.
	-   Note that if case-insensitive matching is being used then the first
		matching option in the argument list will be returned.

	@section licence MIT LICENCE
<pre>
	The licence text below is the boilerplate "MIT Licence" used from:
	http://www.opensource.org/licenses/mit-license.php

	Copyright (c) 2006-2013, Brodie Thiesfield

	Permission is hereby granted, free of charge, to any person obtaining a
	copy of this software and associated documentation files (the "Software"),
	to deal in the Software without restriction, including without limitation
	the rights to use, copy, modify, merge, publish, distribute, sublicense,
	and/or sell copies of the Software, and to permit persons to whom the
	Software is furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included
	in all copies or substantial portions of the Software.

	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.
</pre>
*/

/*! @mainpage

	<table>
		<tr><th>Library     <td>SimpleOpt
		<tr><th>Author      <td>Brodie Thiesfield [code at jellycan dot com]
		<tr><th>Source      <td>http://code.jellycan.com/simpleopt/
	</table>

	@section SimpleOpt SimpleOpt

	A cross-platform library providing a simple method to parse almost any of
	the standard command-line formats in use today.

	See the @link SimpleOpt.h SimpleOpt @endlink documentation for full
	details.

	@section SimpleGlob SimpleGlob

	A cross-platform file globbing library providing the ability to
	expand wildcards in command-line arguments to a list of all matching
	files.

	See the @link SimpleGlob.h SimpleGlob @endlink documentation for full
	details.
*/

#ifndef INCLUDED_SimpleOpt
#define INCLUDED_SimpleOpt

// Default the max arguments to a fixed value. If you want to be able to
// handle any number of arguments, then predefine this to 0 and it will
// use an internal dynamically allocated buffer instead.
#ifdef SO_MAX_ARGS
# define SO_STATICBUF   SO_MAX_ARGS
#else
# include <stdlib.h>    // malloc, free
# include <string.h>    // memcpy
# define SO_STATICBUF   50
#endif

//! Error values
typedef enum _ESOError
{
	//! No error
	SO_SUCCESS          =  0,

	/*! It looks like an option (it starts with a switch character), but
		it isn't registered in the option table. */
	SO_OPT_INVALID      = -1,

	/*! Multiple options matched the supplied option text.
		Only returned when NOT using SO_O_EXACT. */
	SO_OPT_MULTIPLE     = -2,

	/*! Option doesn't take an argument, but a combined argument was
		supplied. */
	SO_ARG_INVALID      = -3,

	/*! SO_REQ_CMB style-argument was supplied to a SO_REQ_SEP option
		Only returned when using SO_O_PEDANTIC. */
	SO_ARG_INVALID_TYPE = -4,

	//! Required argument was not supplied
	SO_ARG_MISSING      = -5,

	/*! Option argument looks like another option.
		Only returned when NOT using SO_O_NOERR. */
	SO_ARG_INVALID_DATA = -6
} ESOError;

//! Option flags
enum _ESOFlags
{
	/*! Disallow partial matching of option names */
	SO_O_EXACT       = 0x0001,

	/*! Disallow use of slash as an option marker on Windows.
		Un*x only ever recognizes a hyphen. */
	SO_O_NOSLASH     = 0x0002,

	/*! Permit arguments on single letter options with no equals sign.
		e.g. -oARG or -o[ARG] */
	SO_O_SHORTARG    = 0x0004,

	/*! Permit single character options to be clumped into a single
		option string. e.g. "-a -b -c" <==> "-abc" */
	SO_O_CLUMP       = 0x0008,

	/*! Process the entire argv array for options, including the
		argv[0] entry. */
	SO_O_USEALL      = 0x0010,

	/*! Do not generate an error for invalid options. errors for missing
		arguments will still be generated. invalid options will be
		treated as files. invalid options in clumps will be silently
		ignored. */
	SO_O_NOERR       = 0x0020,

	/*! Validate argument type pedantically. Return an error when a
		separated argument "-opt arg" is supplied by the user as a
		combined argument "-opt=arg". By default this is not considered
		an error. */
	SO_O_PEDANTIC    = 0x0040,

	/*! Case-insensitive comparisons for short arguments */
	SO_O_ICASE_SHORT = 0x0100,

	/*! Case-insensitive comparisons for long arguments */
	SO_O_ICASE_LONG  = 0x0200,

	/*! Case-insensitive comparisons for word arguments
		i.e. arguments without any hyphens at the start. */
	SO_O_ICASE_WORD  = 0x0400,

	/*! Case-insensitive comparisons for all arg types */
	SO_O_ICASE       = 0x0700
};

/*! Types of arguments that options may have. Note that some of the _ESOFlags
	are not compatible with all argument types. SO_O_SHORTARG requires that
	relevant options use either SO_REQ_CMB or SO_OPT. SO_O_CLUMP requires
	that relevant options use only SO_NONE.
 */
typedef enum _ESOArgType {
	/*! No argument. Just the option flags.
		e.g. -o         --opt */
	SO_NONE,

	/*! Required separate argument.
		e.g. -o ARG     --opt ARG */
	SO_REQ_SEP,

	/*! Required combined argument.
		e.g. -oARG      -o=ARG      --opt=ARG  */
	SO_REQ_CMB,

	/*! Optional combined argument.
		e.g. -o[ARG]    -o[=ARG]    --opt[=ARG] */
	SO_OPT,

	/*! Multiple separate arguments. The actual number of arguments is
		determined programatically at the time the argument is processed.
		e.g. -o N ARG1 ARG2 ... ARGN    --opt N ARG1 ARG2 ... ARGN */
	SO_MULTI
} ESOArgType;

//! this option definition must be the last entry in the table
#define SO_END_OF_OPTIONS   { -1, nullptr, SO_NONE }

#ifdef _DEBUG
# ifdef _MSC_VER
#  include <crtdbg.h>
#  define SO_ASSERT(b)  _ASSERTE(b)
# else
#  include <assert.h>
#  define SO_ASSERT(b)  assert(b)
# endif
#else
# define SO_ASSERT(b)   //!< assertion used to test input data
#endif

// ---------------------------------------------------------------------------
//                              MAIN TEMPLATE CLASS
// ---------------------------------------------------------------------------

/*! @brief Implementation of the SimpleOpt class */
template<class SOCHAR>
class CSimpleOptTempl
{
public:
	/*! @brief Structure used to define all known options. */
	struct SOption {

		//SOption()//Added for compatibility with fractal flames.
		//{
		//	nId = 0;
		//	pszArg = nullptr;
		//	nArgType = SO_NONE;
		//}

		//SOption(int id, const SOCHAR* arg, ESOArgType argType)//Added for compatibility with fractal flames.
		//{
		//	nId = id;
		//	pszArg = arg;
		//	nArgType = argType;
		//}

		/*! ID to return for this flag. Optional but must be >= 0 */
		int nId;

		/*! arg string to search for, e.g.  "open", "-", "-f", "--file"
			Note that on Windows the slash option marker will be converted
			to a hyphen so that "-f" will also match "/f". */
		const SOCHAR * pszArg;

		/*! type of argument accepted by this option */
		ESOArgType nArgType;
	};

	/*! @brief Initialize the class. Init() must be called later. */
	CSimpleOptTempl()
		: m_rgShuffleBuf(nullptr)
	{
		Init(0, nullptr, nullptr, 0);
	}

	/*! @brief Initialize the class in preparation for use. */
	CSimpleOptTempl(
		int             argc,
		SOCHAR *        argv[],
		const SOption * a_rgOptions,
		int             a_nFlags = 0
		)
		: m_rgShuffleBuf(nullptr)
	{
		Init(argc, argv, a_rgOptions, a_nFlags);
	}

#ifndef SO_MAX_ARGS
	/*! @brief Deallocate any allocated memory. */
	~CSimpleOptTempl() { if (m_rgShuffleBuf) free(m_rgShuffleBuf); }
#endif

	/*! @brief Initialize the class in preparation for calling Next.

		The table of options pointed to by a_rgOptions does not need to be
		valid at the time that Init() is called. However on every call to
		Next() the table pointed to must be a valid options table with the
		last valid entry set to SO_END_OF_OPTIONS.

		NOTE: the array pointed to by a_argv will be modified by this
		class and must not be used or modified outside of member calls to
		this class.

		@param a_argc       Argument array size
		@param a_argv       Argument array
		@param a_rgOptions  Valid option array
		@param a_nFlags     Optional flags to modify the processing of
							the arguments

		@return true        Successful
		@return false       if SO_MAX_ARGC > 0:  Too many arguments
							if SO_MAX_ARGC == 0: Memory allocation failure
	*/
	bool Init(
		int             a_argc,
		SOCHAR *        a_argv[],
		const SOption * a_rgOptions,
		int             a_nFlags = 0
		);

	/*! @brief Change the current options table during option parsing.

		@param a_rgOptions  Valid option array
	 */
	inline void SetOptions(const SOption * a_rgOptions) {
		m_rgOptions = a_rgOptions;
	}

	/*! @brief Change the current flags during option parsing.

		Note that changing the SO_O_USEALL flag here will have no affect.
		It must be set using Init() or the constructor.

		@param a_nFlags     Flags to modify the processing of the arguments
	 */
	inline void SetFlags(int a_nFlags) { m_nFlags = a_nFlags; }

	/*! @brief Query if a particular flag is set */
	inline bool HasFlag(int a_nFlag) const {
		return (m_nFlags & a_nFlag) == a_nFlag;
	}

	/*! @brief Advance to the next option if available.

		When all options have been processed it will return false. When true
		has been returned, you must check for an invalid or unrecognized
		option using the LastError() method. This will be return an error
		value other than SO_SUCCESS on an error. All standard data
		(e.g. OptionText(), OptionArg(), OptionId(), etc) will be available
		depending on the error.

		After all options have been processed, the remaining files from the
		command line can be processed in same order as they were passed to
		the program.

		@return true    option or error available for processing
		@return false   all options have been processed
	*/
	bool Next();

	/*! Stops processing of the command line and returns all remaining
		arguments as files. The next call to Next() will return false.
	 */
	void Stop();

	/*! @brief Return the last error that occurred.

		This function must always be called before processing the current
		option. This function is available only when Next() has returned true.
	 */
	inline ESOError LastError() const  { return m_nLastError; }

	/*! @brief Return the nId value from the options array for the current
		option.

		This function is available only when Next() has returned true.
	 */
	inline int OptionId() const { return m_nOptionId; }

	/*! @brief Return the pszArg from the options array for the current
		option.

		This function is available only when Next() has returned true.
	 */
	inline const SOCHAR * OptionText() const { return m_pszOptionText; }

	/*! @brief Return the argument for the current option where one exists.

		If there is no argument for the option, this will return nullptr.
		This function is available only when Next() has returned true.
	 */
	inline SOCHAR * OptionArg() const { return m_pszOptionArg; }

	/*! @brief Validate and return the desired number of arguments.

		This is only valid when OptionId() has return the ID of an option
		that is registered as SO_MULTI. It may be called multiple times
		each time returning the desired number of arguments. Previously
		returned argument pointers are remain valid.

		If an error occurs during processing, nullptr will be returned and
		the error will be available via LastError().

		@param n    Number of arguments to return.
	 */
	SOCHAR ** MultiArg(int n);

	/*! @brief Returned the number of entries in the Files() array.

		After Next() has returned false, this will be the list of files (or
		otherwise unprocessed arguments).
	 */
	inline int FileCount() const { return m_argc - m_nLastArg; }

	/*! @brief Return the specified file argument.

		@param n    Index of the file to return. This must be between 0
					and FileCount() - 1;
	 */
	inline SOCHAR * File(int n) const {
		SO_ASSERT(n >= 0 && n < FileCount());
		return m_argv[m_nLastArg + n];
	}

	/*! @brief Return the array of files. */
	inline SOCHAR ** Files() const { return &m_argv[m_nLastArg]; }

private:
	CSimpleOptTempl(const CSimpleOptTempl &); // disabled
	CSimpleOptTempl & operator=(const CSimpleOptTempl &); // disabled

	SOCHAR PrepareArg(SOCHAR * a_pszString) const;
	bool NextClumped();
	void ShuffleArg(int a_nStartIdx, int a_nCount);
	int LookupOption(const SOCHAR * a_pszOption) const;
	int CalcMatch(const SOCHAR *a_pszSource, const SOCHAR *a_pszTest) const;

	// Find the '=' character within a string.
	inline SOCHAR * FindEquals(SOCHAR *s) const {
		while (*s && *s != SOCHAR('=')) ++s;
		return *s ? s : nullptr;
	}
	bool IsEqual(SOCHAR a_cLeft, SOCHAR a_cRight, int a_nArgType) const;

	inline void Copy(SOCHAR ** ppDst, SOCHAR ** ppSrc, int nCount) const {
#ifdef SO_MAX_ARGS
		// keep our promise of no CLIB usage
		while (nCount-- > 0) *ppDst++ = *ppSrc++;
#else
		memcpy(ppDst, ppSrc, nCount * sizeof(SOCHAR*));
#endif
	}

private:
	const SOption * m_rgOptions;     //!< pointer to options table
	int             m_nFlags;        //!< flags
	int             m_nOptionIdx;    //!< current argv option index
	int             m_nOptionId;     //!< id of current option (-1 = invalid)
	int             m_nNextOption;   //!< index of next option
	int             m_nLastArg;      //!< last argument, after this are files
	int             m_argc;          //!< argc to process
	SOCHAR **       m_argv;          //!< argv
	const SOCHAR *  m_pszOptionText; //!< curr option text, e.g. "-f"
	SOCHAR *        m_pszOptionArg;  //!< curr option arg, e.g. "c:\file.txt"
	SOCHAR *        m_pszClump;      //!< clumped single character options
	SOCHAR          m_szShort[3];    //!< temp for clump and combined args
	ESOError        m_nLastError;    //!< error status from the last call
	SOCHAR **       m_rgShuffleBuf;  //!< shuffle buffer for large argc
};

// ---------------------------------------------------------------------------
//                                  IMPLEMENTATION
// ---------------------------------------------------------------------------

template<class SOCHAR>
bool
CSimpleOptTempl<SOCHAR>::Init(
	int             a_argc,
	SOCHAR *        a_argv[],
	const SOption * a_rgOptions,
	int             a_nFlags
	)
{
	m_argc           = a_argc;
	m_nLastArg       = a_argc;
	m_argv           = a_argv;
	m_rgOptions      = a_rgOptions;
	m_nLastError     = SO_SUCCESS;
	m_nOptionIdx     = 0;
	m_nOptionId      = -1;
	m_pszOptionText  = nullptr;
	m_pszOptionArg   = nullptr;
	m_nNextOption    = (a_nFlags & SO_O_USEALL) ? 0 : 1;
	m_szShort[0]     = SOCHAR('-');
	m_szShort[2]     = SOCHAR('\0');
	m_nFlags         = a_nFlags;
	m_pszClump       = nullptr;

#ifdef SO_MAX_ARGS
	if (m_argc > SO_MAX_ARGS) {
		m_nLastError = SO_ARG_INVALID_DATA;
		m_nLastArg = 0;
		return false;
	}
#else
	if (m_rgShuffleBuf) {
		free(m_rgShuffleBuf);
	}
	if (m_argc > SO_STATICBUF) {
		m_rgShuffleBuf = reinterpret_cast<SOCHAR**>(malloc(sizeof(SOCHAR*) * m_argc));
		if (!m_rgShuffleBuf) {
			return false;
		}
	}
#endif

	return true;
}

template<class SOCHAR>
bool
CSimpleOptTempl<SOCHAR>::Next()
{
#ifdef SO_MAX_ARGS
	if (m_argc > SO_MAX_ARGS) {
		SO_ASSERT(!"Too many args! Check the return value of Init()!");
		return false;
	}
#endif

	// process a clumped option string if appropriate
	if (m_pszClump && *m_pszClump) {
		// silently discard invalid clumped option
		bool bIsValid = NextClumped();
		while (*m_pszClump && !bIsValid && HasFlag(SO_O_NOERR)) {
			bIsValid = NextClumped();
		}

		// return this option if valid or we are returning errors
		if (bIsValid || !HasFlag(SO_O_NOERR)) {
			return true;
		}
	}
	SO_ASSERT(!m_pszClump || !*m_pszClump);
	m_pszClump = nullptr;

	// init for the next option
	m_nOptionIdx    = m_nNextOption;
	m_nOptionId     = -1;
	m_pszOptionText = nullptr;
	m_pszOptionArg  = nullptr;
	m_nLastError    = SO_SUCCESS;

	// find the next option
	SOCHAR cFirst;
	int nTableIdx = -1;
	int nOptIdx = m_nOptionIdx;
	while (nTableIdx < 0 && nOptIdx < m_nLastArg) {
		SOCHAR * pszArg = m_argv[nOptIdx];
		m_pszOptionArg  = nullptr;

		// find this option in the options table
		cFirst = PrepareArg(pszArg);
		if (pszArg[0] == SOCHAR('-')) {
			// find any combined argument string and remove equals sign
			m_pszOptionArg = FindEquals(pszArg);
			if (m_pszOptionArg) {
				*m_pszOptionArg++ = SOCHAR('\0');
			}
		}
		nTableIdx = LookupOption(pszArg);

		// if we didn't find this option but if it is a short form
		// option then we try the alternative forms
		if (nTableIdx < 0
			&& !m_pszOptionArg
			&& pszArg[0] == SOCHAR('-')
			&& pszArg[1]
			&& pszArg[1] != SOCHAR('-')
			&& pszArg[2])
		{
			// test for a short-form with argument if appropriate
			if (HasFlag(SO_O_SHORTARG)) {
				m_szShort[1] = pszArg[1];
				int nIdx = LookupOption(m_szShort);
				if (nIdx >= 0
					&& (m_rgOptions[nIdx].nArgType == SO_REQ_CMB
						|| m_rgOptions[nIdx].nArgType == SO_OPT))
				{
					m_pszOptionArg = &pszArg[2];
					pszArg         = m_szShort;
					nTableIdx      = nIdx;
				}
			}

			// test for a clumped short-form option string and we didn't
			// match on the short-form argument above
			if (nTableIdx < 0 && HasFlag(SO_O_CLUMP))  {
				m_pszClump = &pszArg[1];
				++m_nNextOption;
				if (nOptIdx > m_nOptionIdx) {
					ShuffleArg(m_nOptionIdx, nOptIdx - m_nOptionIdx);
				}
				return Next();
			}
		}

		// The option wasn't found. If it starts with a switch character
		// and we are not suppressing errors for invalid options then it
		// is reported as an error, otherwise it is data.
		if (nTableIdx < 0) {
			if (!HasFlag(SO_O_NOERR) && pszArg[0] == SOCHAR('-')) {
				m_pszOptionText = pszArg;
				break;
			}

			pszArg[0] = cFirst;
			++nOptIdx;
			if (m_pszOptionArg) {
				*(--m_pszOptionArg) = SOCHAR('=');
			}
		}
	}

	// end of options
	if (nOptIdx >= m_nLastArg) {
		if (nOptIdx > m_nOptionIdx) {
			ShuffleArg(m_nOptionIdx, nOptIdx - m_nOptionIdx);
		}
		return false;
	}
	++m_nNextOption;

	// get the option id
	ESOArgType nArgType = SO_NONE;
	if (nTableIdx < 0) {
		m_nLastError    = ESOError(nTableIdx); // error code
	}
	else {
		m_nOptionId     = m_rgOptions[nTableIdx].nId;
		m_pszOptionText = m_rgOptions[nTableIdx].pszArg;

		// ensure that the arg type is valid
		nArgType = m_rgOptions[nTableIdx].nArgType;
		switch (nArgType) {
		case SO_NONE:
			if (m_pszOptionArg) {
				m_nLastError = SO_ARG_INVALID;
			}
			break;

		case SO_REQ_SEP:
			if (m_pszOptionArg) {
				// they wanted separate args, but we got a combined one,
				// unless we are pedantic, just accept it.
				if (HasFlag(SO_O_PEDANTIC)) {
					m_nLastError = SO_ARG_INVALID_TYPE;
				}
			}
			// more processing after we shuffle
			break;

		case SO_REQ_CMB:
			if (!m_pszOptionArg) {
				m_nLastError = SO_ARG_MISSING;
			}
			break;

		case SO_OPT:
			// nothing to do
			break;

		case SO_MULTI:
			// nothing to do. Caller must now check for valid arguments
			// using GetMultiArg()
			break;
		default:
			break;
		}
	}

	// shuffle the files out of the way
	if (nOptIdx > m_nOptionIdx) {
		ShuffleArg(m_nOptionIdx, nOptIdx - m_nOptionIdx);
	}

	// we need to return the separate arg if required, just re-use the
	// multi-arg code because it all does the same thing
	if (   nArgType == SO_REQ_SEP
		&& !m_pszOptionArg
		&& m_nLastError == SO_SUCCESS)
	{
		SOCHAR ** ppArgs = MultiArg(1);
		if (ppArgs) {
			m_pszOptionArg = *ppArgs;
		}
	}

	return true;
}

template<class SOCHAR>
void
CSimpleOptTempl<SOCHAR>::Stop()
{
	if (m_nNextOption < m_nLastArg) {
		ShuffleArg(m_nNextOption, m_nLastArg - m_nNextOption);
	}
}

template<class SOCHAR>
SOCHAR
CSimpleOptTempl<SOCHAR>::PrepareArg(
	SOCHAR * a_pszString
	) const
{
#ifdef _WIN32
	// On Windows we can accept the forward slash as a single character
	// option delimiter, but it cannot replace the '-' option used to
	// denote stdin. On Un*x paths may start with slash so it may not
	// be used to start an option.
	if (!HasFlag(SO_O_NOSLASH)
		&& a_pszString[0] == (SOCHAR)'/'
		&& a_pszString[1]
		&& a_pszString[1] != (SOCHAR)'-')
	{
		a_pszString[0] = (SOCHAR)'-';
		return (SOCHAR)'/';
	}
#endif
	return a_pszString[0];
}

template<class SOCHAR>
bool
CSimpleOptTempl<SOCHAR>::NextClumped()
{
	// prepare for the next clumped option
	m_szShort[1]    = *m_pszClump++;
	m_nOptionId     = -1;
	m_pszOptionText = nullptr;
	m_pszOptionArg  = nullptr;
	m_nLastError    = SO_SUCCESS;

	// lookup this option, ensure that we are using exact matching
	int nSavedFlags = m_nFlags;
	m_nFlags = SO_O_EXACT;
	int nTableIdx = LookupOption(m_szShort);
	m_nFlags = nSavedFlags;

	// unknown option
	if (nTableIdx < 0) {
		m_pszOptionText = m_szShort; // invalid option
		m_nLastError = ESOError(nTableIdx); // error code
		return false;
	}

	// valid option
	m_pszOptionText = m_rgOptions[nTableIdx].pszArg;
	ESOArgType nArgType = m_rgOptions[nTableIdx].nArgType;
	if (nArgType == SO_NONE) {
		m_nOptionId = m_rgOptions[nTableIdx].nId;
		return true;
	}

	if (nArgType == SO_REQ_CMB && *m_pszClump) {
		m_nOptionId = m_rgOptions[nTableIdx].nId;
		m_pszOptionArg = m_pszClump;
		while (*m_pszClump) ++m_pszClump; // must point to an empty string
		return true;
	}

	// invalid option as it requires an argument
	m_nLastError = SO_ARG_MISSING;
	return true;
}

// Shuffle arguments to the end of the argv array.
//
// For example:
//      argv[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8" };
//
//  ShuffleArg(1, 1) = { "0", "2", "3", "4", "5", "6", "7", "8", "1" };
//  ShuffleArg(5, 2) = { "0", "1", "2", "3", "4", "7", "8", "5", "6" };
//  ShuffleArg(2, 4) = { "0", "1", "6", "7", "8", "2", "3", "4", "5" };
template<class SOCHAR>
void
CSimpleOptTempl<SOCHAR>::ShuffleArg(
	int a_nStartIdx,
	int a_nCount
	)
{
	SOCHAR * staticBuf[SO_STATICBUF];
	SOCHAR ** buf = m_rgShuffleBuf ? m_rgShuffleBuf : staticBuf;
	int nTail = m_argc - a_nStartIdx - a_nCount;

	// make a copy of the elements to be moved
	Copy(buf, m_argv + a_nStartIdx, a_nCount);

	// move the tail down
	Copy(m_argv + a_nStartIdx, m_argv + a_nStartIdx + a_nCount, nTail);

	// append the moved elements to the tail
	Copy(m_argv + a_nStartIdx + nTail, buf, a_nCount);

	// update the index of the last unshuffled arg
	m_nLastArg -= a_nCount;
}

// match on the long format strings. partial matches will be
// accepted only if that feature is enabled.
template<class SOCHAR>
int
CSimpleOptTempl<SOCHAR>::LookupOption(
	const SOCHAR * a_pszOption
	) const
{
	int nBestMatch = -1;    // index of best match so far
	int nBestMatchLen = 0;  // matching characters of best match
	int nLastMatchLen = 0;  // matching characters of last best match

	for (int n = 0; m_rgOptions[n].nId >= 0; ++n) {
		// the option table must use hyphens as the option character,
		// the slash character is converted to a hyphen for testing.
		SO_ASSERT(m_rgOptions[n].pszArg[0] != (SOCHAR)'/');

		int nMatchLen = CalcMatch(m_rgOptions[n].pszArg, a_pszOption);
		if (nMatchLen == -1) {
			return n;
		}
		if (nMatchLen > 0 && nMatchLen >= nBestMatchLen) {
			nLastMatchLen = nBestMatchLen;
			nBestMatchLen = nMatchLen;
			nBestMatch = n;
		}
	}

	// only partial matches or no match gets to here, ensure that we
	// don't return a partial match unless it is a clear winner
	if (HasFlag(SO_O_EXACT) || nBestMatch == -1) {
		return SO_OPT_INVALID;
	}
	return (nBestMatchLen > nLastMatchLen) ? nBestMatch : SO_OPT_MULTIPLE;
}

// calculate the number of characters that match (case-sensitive)
// 0 = no match, > 0 == number of characters, -1 == perfect match
template<class SOCHAR>
int
CSimpleOptTempl<SOCHAR>::CalcMatch(
	const SOCHAR *  a_pszSource,
	const SOCHAR *  a_pszTest
	) const
{
	if (!a_pszSource || !a_pszTest) {
		return 0;
	}

	// determine the argument type
	int nArgType = SO_O_ICASE_LONG;
	if (a_pszSource[0] != '-') {
		nArgType = SO_O_ICASE_WORD;
	}
	else if (a_pszSource[1] != '-' && !a_pszSource[2]) {
		nArgType = SO_O_ICASE_SHORT;
	}

	// match and skip leading hyphens
	while (*a_pszSource == SOCHAR('-') && *a_pszSource == *a_pszTest) {
		++a_pszSource;
		++a_pszTest;
	}
	if (*a_pszSource == SOCHAR('-') || *a_pszTest == SOCHAR('-')) {
		return 0;
	}

	// find matching number of characters in the strings
	int nLen = 0;
	while (*a_pszSource && IsEqual(*a_pszSource, *a_pszTest, nArgType)) {
		++a_pszSource;
		++a_pszTest;
		++nLen;
	}

	// if we have exhausted the source...
	if (!*a_pszSource) {
		// and the test strings, then it's a perfect match
		if (!*a_pszTest) {
			return -1;
		}

		// otherwise the match failed as the test is longer than
		// the source. i.e. "--mant" will not match the option "--man".
		return 0;
	}

	// if we haven't exhausted the test string then it is not a match
	// i.e. "--mantle" will not best-fit match to "--mandate" at all.
	if (*a_pszTest) {
		return 0;
	}

	// partial match to the current length of the test string
	return nLen;
}

template<class SOCHAR>
bool
CSimpleOptTempl<SOCHAR>::IsEqual(
	SOCHAR  a_cLeft,
	SOCHAR  a_cRight,
	int     a_nArgType
	) const
{
	// if this matches then we are doing case-insensitive matching
	if (m_nFlags & a_nArgType) {
		if (a_cLeft  >= 'A' && a_cLeft  <= 'Z') a_cLeft  += 'a' - 'A';
		if (a_cRight >= 'A' && a_cRight <= 'Z') a_cRight += 'a' - 'A';
	}
	return a_cLeft == a_cRight;
}

// calculate the number of characters that match (case-sensitive)
// 0 = no match, > 0 == number of characters, -1 == perfect match
template<class SOCHAR>
SOCHAR **
CSimpleOptTempl<SOCHAR>::MultiArg(
	int a_nCount
	)
{
	// ensure we have enough arguments
	if (m_nNextOption + a_nCount > m_nLastArg) {
		m_nLastError = SO_ARG_MISSING;
		return nullptr;
	}

	// our argument array
	SOCHAR ** rgpszArg = &m_argv[m_nNextOption];

	// Ensure that each of the following don't start with an switch character.
	// Only make this check if we are returning errors for unknown arguments.
	if (!HasFlag(SO_O_NOERR)) {
		for (int n = 0; n < a_nCount; ++n) {
			SOCHAR ch = PrepareArg(rgpszArg[n]);
			if (rgpszArg[n][0] == SOCHAR('-')) {
				rgpszArg[n][0] = ch;
				m_nLastError = SO_ARG_INVALID_DATA;
				return nullptr;
			}
			rgpszArg[n][0] = ch;
		}
	}

	// all good
	m_nNextOption += a_nCount;
	return rgpszArg;
}


// ---------------------------------------------------------------------------
//                                  TYPE DEFINITIONS
// ---------------------------------------------------------------------------

/*! @brief ASCII/MBCS version of CSimpleOpt */
typedef CSimpleOptTempl<char>    CSimpleOptA;

/*! @brief wchar_t version of CSimpleOpt */
typedef CSimpleOptTempl<wchar_t> CSimpleOptW;

#if defined(_UNICODE)
/*! @brief TCHAR version dependent on if _UNICODE is defined */
# define CSimpleOpt CSimpleOptW
# define CharT wchar_t
#else
/*! @brief TCHAR version dependent on if _UNICODE is defined */
# define CSimpleOpt CSimpleOptA
# define CharT char
#endif

#endif // INCLUDED_SimpleOpt