/**

 * vim: set ts=4 :

 * =============================================================================

 * SourceMod

 * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.

 * =============================================================================

 *

 * This program is free software; you can redistribute it and/or modify it under

 * the terms of the GNU General Public License, version 3.0, as published by the

 * Free Software Foundation.

 * 

 * This program 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

 * this program.  If not, see <http://www.gnu.org/licenses/>.

 *

 * As a special exception, AlliedModders LLC gives you permission to link the

 * code of this program (as well as its derivative works) to "Half-Life 2," the

 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

 * by the Valve Corporation.  You must obey the GNU General Public License in

 * all respects for all other code used.  Additionally, AlliedModders LLC grants

 * this exception to all derivative works.  AlliedModders LLC defines further

 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

 * or <http://www.sourcemod.net/license.php>.

 *

 * Version: $Id$

 */

#ifndef _INCLUDE_SOURCEMOD_TEXTPARSERS_INTERFACE_H_

#define _INCLUDE_SOURCEMOD_TEXTPARSERS_INTERFACE_H_

/**

 * @file ITextParsers.h

 * @brief Defines various text/file parsing functions, as well as UTF-8 support code.

 */

#include <IShareSys.h>

namespace SourceMod

{

	#define SMINTERFACE_TEXTPARSERS_NAME		"ITextParsers"

	#define SMINTERFACE_TEXTPARSERS_VERSION		3

	/**

	 * The INI file format is defined as:

	 * WHITESPACE: 0x20, \n, \t, \r

	 * IDENTIFIER: A-Z a-z 0-9 _ - , + . $ ? / 

	 * STRING: Any set of symbols

	 * 

	 * Basic syntax is comprised of SECTIONs.

	 * A SECTION is defined as:

	 * [SECTIONNAME]

	 * OPTION

	 * OPTION

	 * OPTION...

	 *

	 * SECTIONNAME is an IDENTIFIER.

	 * OPTION can be repeated any number of times, once per line.

	 * OPTION is defined as one of:

	 *  KEY = "VALUE"

	 *  KEY = VALUE

	 *  KEY

	 * Where KEY is an IDENTIFIER and VALUE is a STRING.

	 * 

	 * WHITESPACE should always be omitted.

	 * COMMENTS should be stripped, and are defined as text occurring in:

	 * ;<TEXT>

	 * 

	 * Example file below.  Note that

	 * The second line is technically invalid.  The event handler

	 * must decide whether this should be allowed.

	 * --FILE BELOW--

	 * [gaben]

	 * hi = clams

	 * bye = "NO CLAMS"

	 *

	 * [valve]

	 * cannot

	 * maintain

	 * products

	 */

	/**

	 * @brief Contains parse events for INI files.

	 */

	class ITextListener_INI

	{

	public:

		/** 

		 * @brief Returns version number.

		 */

		virtual unsigned int GetTextParserVersion1()

		{

			return SMINTERFACE_TEXTPARSERS_VERSION;

		}

	public:

		/**

		 * @brief Called when a new section is encountered in an INI file.

		 * 

		 * @param section		Name of section in between the [ and ] characters.

		 * @param invalid_tokens True if invalid tokens were detected in the name.

		 * @param close_bracket	True if a closing bracket was detected, false otherwise.

		 * @param extra_tokens	True if extra tokens were detected on the line.

		 * @param curtok		Contains current token in the line where the section name starts.

		 *						You can add to this offset when failing to point to a token.

		 * @return				True to keep parsing, false otherwise.

		 */

		virtual bool ReadINI_NewSection(const char *section,

										bool invalid_tokens,

										bool close_bracket,

										bool extra_tokens,

										unsigned int *curtok)

		{

			return true;

		}

		/**

		 * @brief Called when encountering a key/value pair in an INI file.

		 * 

		 * @param key			Name of key.

		 * @param value			String containing value (with quotes stripped, if any).

		 * @param invalid_tokens Whether or not the key contained invalid tokens.

		 * @param equal_token	There was an '=' sign present (in case the value is missing).

		 * @param quotes		Whether value was enclosed in quotes.

		 * @param curtok		Contains the token index of the start of the value string.  

		 *						This can be changed when returning false.

		 * @return				True to keep parsing, false otherwise.

		 */

		virtual bool ReadINI_KeyValue(const char *key, 

									  const char *value, 

									  bool invalid_tokens,

									  bool equal_token,

									  bool quotes,

									  unsigned int *curtok)

		{

			return true;

		}

		/**

		 * @brief Called after a line has been preprocessed, if it has text.

		 *

		 * @param line			Contents of line.

		 * @param curtok		Pointer to optionally store failed position in string.

		 * @return				True to keep parsing, false otherwise.

		 */

		virtual bool ReadINI_RawLine(const char *line, unsigned int *curtok)

		{

			return true;

		}

	};

	/**

	 * :TODO: write this in CFG (context free grammar) format so it makes sense

	 * 

	 * The SMC file format is defined as:

	 * WHITESPACE: 0x20, \n, \t, \r

	 * IDENTIFIER: Any ASCII character EXCLUDING ", {, }, ;, //, / *, or WHITESPACE.

	 * STRING: Any set of symbols enclosed in quotes.

	 * Note: if a STRING does not have quotes, it is parsed as an IDENTIFIER.

	 *

	 * Basic syntax is comprised of SECTIONBLOCKs.

	 * A SECTIONBLOCK defined as:

	 *

	 * SECTIONNAME

	 * {

	 *    OPTION

	 * }

	 * 

	 * OPTION can be repeated any number of times inside a SECTIONBLOCK.

	 * A new line will terminate an OPTION, but there can be more than one OPTION per line.

	 * OPTION is defined any of:

	 * 	  "KEY"  "VALUE"

	 *    SECTIONBLOCK

	 *

	 * SECTIONNAME, KEY, VALUE, and SINGLEKEY are strings

	 * SECTIONNAME cannot have trailing characters if quoted, but the quotes can be optionally removed.

	 * If SECTIONNAME is not enclosed in quotes, the entire sectionname string is used (minus surrounding whitespace).

	 * If KEY is not enclosed in quotes, the key is terminated at first whitespace.

	 * If VALUE is not properly enclosed in quotes, the entire value string is used (minus surrounding whitespace).

	 * The VALUE may have inner quotes, but the key string may not.

	 *

	 * For an example, see configs/permissions.cfg

	 *

	 * WHITESPACE should be ignored.

	 * Comments are text occurring inside the following tokens, and should be stripped

	 * unless they are inside literal strings:

	 *  ;<TEXT>

	 *  //<TEXT>

	 *  / *<TEXT> */

	/**

	 * @brief Lists actions to take when an SMC parse hook is done.

	 */

	enum SMCResult

	{

		SMCResult_Continue,		/**< Continue parsing */

		SMCResult_Halt,			/**< Stop parsing here */

		SMCResult_HaltFail		/**< Stop parsing and return SMCError_Custom */

	};

	/**

	 * @brief Lists error codes possible from parsing an SMC file.

	 */

	enum SMCError

	{

		SMCError_Okay = 0,			/**< No error */

		SMCError_StreamOpen,		/**< Stream failed to open */

		SMCError_StreamError,		/**< The stream died... somehow */

		SMCError_Custom,			/**< A custom handler threw an error */

		SMCError_InvalidSection1,	/**< A section was declared without quotes, and had extra tokens */

		SMCError_InvalidSection2,	/**< A section was declared without any header */

		SMCError_InvalidSection3,	/**< A section ending was declared with too many unknown tokens */

		SMCError_InvalidSection4,	/**< A section ending has no matching beginning */

		SMCError_InvalidSection5,	/**< A section beginning has no matching ending */

		SMCError_InvalidTokens,		/**< There were too many unidentifiable strings on one line */

		SMCError_TokenOverflow,		/**< The token buffer overflowed */

		SMCError_InvalidProperty1,	/**< A property was declared outside of any section */

	};

	/**

	 * @brief States for line/column

	 */

	struct SMCStates

	{

		unsigned int line;			/**< Current line */

		unsigned int col;			/**< Current col */

	};

	/**

	 * @brief Describes the events available for reading an SMC stream.

	 */

	class ITextListener_SMC

	{

	public:

		/** 

		 * @brief Returns version number.

		 */

		virtual unsigned int GetTextParserVersion2()

		{

			return SMINTERFACE_TEXTPARSERS_VERSION;

		}

	public:

		/**

		 * @brief Called when starting parsing.

		 */

		virtual void ReadSMC_ParseStart()

		{

		};

		/**

		 * @brief Called when ending parsing.

		 *

		 * @param halted			True if abnormally halted, false otherwise.

		 * @param failed			True if parsing failed, false otherwise.

		 */

		virtual void ReadSMC_ParseEnd(bool halted, bool failed)

		{

		}

		/**

		 * @brief Called when entering a new section

		 *

		 * @param states		Parsing states.

		 * @param name			Name of section, with the colon omitted.

		 * @return				SMCResult directive.

		 */

		virtual SMCResult ReadSMC_NewSection(const SMCStates *states, const char *name)

		{

			return SMCResult_Continue;

		}

		/**

		 * @brief Called when encountering a key/value pair in a section.

		 * 

		 * @param states		Parsing states.

		 * @param key			Key string.

		 * @param value			Value string.  If no quotes were specified, this will be NULL, 

		 *						and key will contain the entire string.

		 * @return				SMCResult directive.

		 */

		virtual SMCResult ReadSMC_KeyValue(const SMCStates *states, const char *key, const char *value)

		{

			return SMCResult_Continue;

		}

		/**

		 * @brief Called when leaving the current section.

		 *

		 * @param states		Parsing states.

		 * @return				SMCResult directive.

		 */

		virtual SMCResult ReadSMC_LeavingSection(const SMCStates *states)

		{

			return SMCResult_Continue;

		}

		/**

		 * @brief Called after an input line has been preprocessed.

		 *

		 * @param states		Parsing states.

		 * @param line			Contents of the line, null terminated at the position 

		 * 						of the newline character (thus, no newline will exist).

		 * @return				SMCResult directive.

		 */

		virtual SMCResult ReadSMC_RawLine(const SMCStates *states, const char *line)

		{

			return SMCResult_Continue;

		}

	};	

	/**

	 * @brief Contains various text stream parsing functions.

	 */

	class ITextParsers : public SMInterface

	{

	public:

		virtual const char *GetInterfaceName()

		{

			return SMINTERFACE_TEXTPARSERS_NAME;

		}

		virtual unsigned int GetInterfaceVersion()

		{

			return SMINTERFACE_TEXTPARSERS_VERSION;

		}

		virtual bool IsVersionCompatible(unsigned int version)

		{

			if (version < 2)

			{

				return false;

			}

			return SMInterface::IsVersionCompatible(version);

		}

	public:

		/**

		 * @brief Parses an INI-format file.

		 *

		 * @param file			Path to file.

		 * @param ini_listener	Event handler for reading file.

		 * @param line			If non-NULL, will contain last line parsed (0 if file could not be opened).

		 * @param col			If non-NULL, will contain last column parsed (undefined if file could not be opened).

		 * @return				True if parsing succeeded, false if file couldn't be opened or there was a syntax error.

		 */

		virtual bool ParseFile_INI(const char *file, 

									ITextListener_INI *ini_listener,

									unsigned int *line,

									unsigned int *col) =0;

		/**

		 * @brief Parses an SMC-format text file.

		 * Note that the parser makes every effort to obey broken syntax.

		 * For example, if an open brace is missing, but the section name has a colon,

		 * it will let you know.  It is up to the event handlers to decide whether to be strict or not.

		 *

		 * @param file			Path to file.

		 * @param smc_listener	Event handler for reading file.

		 * @param states		Optional pointer to store last known states.

		 * @return				An SMCError result code.

		 */

		virtual SMCError ParseFile_SMC(const char *file, 

									ITextListener_SMC *smc_listener, 

									SMCStates *states) =0;

		/**

		 * @brief Converts an SMCError to a string.

		 *

		 * @param err			SMCError.

		 * @return				String error message, or NULL if none.

		 */

		virtual const char *GetSMCErrorString(SMCError err) =0;

	public:

		/**

		 * @brief Returns the number of bytes that a multi-byte character contains in a UTF-8 stream.

		 * If the current character is not multi-byte, the function returns 1.

		 *

		 * @param stream		Pointer to multi-byte ANSI character string.

		 * @return				Number of bytes in current character.

		 */

		virtual unsigned int GetUTF8CharBytes(const char *stream) =0;

		/**

		 * @brief Returns whether the first multi-byte character in the given stream

		 * is a whitespace character.

		 *

		 * @param stream		Pointer to multi-byte character string.

		 * @return				True if first character is whitespace, false otherwise.

		 */

		virtual bool IsWhitespace(const char *stream) =0;

		/**

		 * @brief Same as ParseFile_SMC, but with an extended error buffer.

		 *

		 * @param file			Path to file.

		 * @param smc_listener	Event handler for reading file.

		 * @param states		Optional pointer to store last known states.

		 * @param buffer		Error message buffer.

		 * @param maxsize		Maximum size of the error buffer.

		 */

		virtual SMCError ParseSMCFile(const char *file,

			ITextListener_SMC *smc_listener,

			SMCStates *states,

			char *buffer,

			size_t maxsize) =0;

	};

	inline unsigned int _GetUTF8CharBytes(const char *stream)

	{

		unsigned char c = *(unsigned char *)stream;

		if (c & (1<<7))

		{

			if (c & (1<<5))

			{

				if (c & (1<<4))

				{

					return 4;

				}

				return 3;

			}

			return 2;

		}

		return 1;

	}

}

extern SourceMod::ITextParsers *textparsers;

#endif //_INCLUDE_SOURCEMOD_TEXTPARSERS_INTERFACE_H_