/*
  * Standalone Configuration File Parser
  *
  * Copyright (C) 2008 iptelorg GmbH
  * Written by Jan Janak <jan@iptel.org>
  *

  * This file is part of Kamailio, a free SIP server.

  *

  * Kamailio 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 2 of the License, or (at your option) any later
  * version.
  *

  * Kamailio 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, write to the Free Software Foundation, Inc., 

  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */

 /*!
  * \file

  * \brief Kamailio core :: Standalone Configuration File Parser

  * Written by Jan Janak <jan@iptel.org>

  *
  * \ingroup core
  * Module: \ref core
  *
  * See \ref ConfigEngine
  */

 
 #ifndef _CFG_PARSER_H
 #define _CFG_PARSER_H
 
 #include "str.h"
 #include <stdio.h>
 

 #define MAX_TOKEN_LEN 512 /*!< Token names cannot be longer than this value */

 /*! \brief Configuration flags */

 typedef enum cfg_flags {

 	/*! \brief Extended tokens can contain also delimiters, in addition to

 	 * alpha-numeric characters, this is used on the righ side of assignments
 	 * where no quotes are used.
 	 */
 	CFG_EXTENDED_ALPHA = (1 << 0),
 

 	/*! \brief The parser performs case-insensitive comparisons of token strings by

 	 * default. The parser will use case-sensitive comparison instead if this
 	 * flag is set.
 	 */
 	CFG_CASE_SENSITIVE = (1 << 1), 
 

 	/*! \brief This is a flag that can be set in the last element of cfg_option

 	 * arrays (this is the one with 0 as token name). When this flag is set
 	 * then the value or parsing function of the element will be used for
 	 * options that do not match any other element in the array.
 	 */
 	CFG_DEFAULT = (1 << 2),
 
 

 	/*! \brief When this flag is set then the name of the options is a prefix and all

 	 * options that have the same prefix will be matched by this entry.
 	 */
 	CFG_PREFIX = (1 << 3),
 

 	/*! \brief The result of cfg_parse_str_val will be in a buffer allocated by

 	 * pkg_malloc, if the destination varaiable contains a pointer to a buffer
 	 * already then it will be freed with pkg_free first.
 	 */
 	CFG_STR_PKGMEM = (1 << 4),
 

 	/*! \brief The result of cfg_parse_str_val will be in a buffer allocated by

 	 * shm_malloc, if the destination variable contains a pointer to a buffer
 	 * already then it will be freed with shm_free first.
 	 */
 	CFG_STR_SHMMEM = (1 << 5),
 

 	/*! \brief The result of cfg_parse_str_val will be in a buffer allocated by

 	 * malloc, if the destination variable contains a pointer to a buffer
 	 * already then it will be freed with free first.
 	 */
 	CFG_STR_MALLOC = (1 << 6),
 

 	/*! \brief The result of cfg_parse_str_val will be copied into a pre-allocated

 	 * buffer with a fixed size, a pointer to str variable which contains the
 	 * buffer and its size is passed to the function in parameter 'param'.
 	 */
 	CFG_STR_STATIC = (1 << 7),
 
 } cfg_flags_t;
 
 
 enum cfg_token_type {
 	CFG_TOKEN_EOF    = -1,
 	CFG_TOKEN_ALPHA  = -2,
 	CFG_TOKEN_STRING = -3
 };
 
 

 /*! \brief Structure representing a lexical token */

 typedef struct cfg_token {
 	char buf [MAX_TOKEN_LEN];

 	int type;  /*!< Token type */
 	str val;   /*!< Token value */
 	struct {   /*!< Position of first and last character of token in file */
 		int line; /*!< The starting/ending line of the token */
 		int col;  /*!< The starting/ending column of the token */

 	} start, end;
 } cfg_token_t;
 
 
 struct cfg_parser;
 
 typedef int (*cfg_func_f)(void* param, struct cfg_parser* st,
 						  unsigned int flags);
 
 

 /*! \brief Token mapping structure.
  *

  * This structure is used to map tokens to values or function calls. Arrays of
  * such structures are typically provided by the caller of the parser.
  */
 typedef struct cfg_option {

 	char* name;    /*!< Token name */

 	unsigned int flags;

 	void* param;   /*!< Pointer to the destination variable */
 	int val;       /*!< Value */
 	cfg_func_f f;  /*!< Parser function to be called */

 } cfg_option_t;
 
 

 /*! \brief Parser state */

 typedef struct cfg_parser {

 	FILE* f;                 /*!< Handle of the currently open file */
 	char* file;              /*!< Current file name */
 	int line;                /*!< Current line */
 	int col;                 /*!< Column index */
 	struct cfg_option* options; /*!< Array of supported options */

 	struct {

 		cfg_func_f parser;   /*!< Section parser function */
 		void* param;         /*!< Parameter value for the parser function */

 	} section;

 	struct cfg_token* cur_opt; /*!< Current option */

 } cfg_parser_t;
 
 
 extern struct cfg_option cfg_bool_values[];
 

 struct cfg_parser* cfg_parser_init(str* basedir, str* filename);

 
 void cfg_section_parser(struct cfg_parser* st, cfg_func_f parser, void* param);
 
 void cfg_set_options(struct cfg_parser* st, struct cfg_option* options);
 

 int sr_cfg_parse(struct cfg_parser* st);

 
 void cfg_parser_close(struct cfg_parser* st);
 
 struct cfg_option* cfg_lookup_token(struct cfg_option* options, str* token);
 

 /*! ! \brief Interface to the lexical scanner */

 int cfg_get_token(struct cfg_token* token, struct cfg_parser* st, unsigned int flags);
 
 /* Commonly needed parser functions */
 

 int cfg_eat_equal(struct cfg_parser* st, unsigned int flags);
 
 int cfg_eat_eol(struct cfg_parser* st, unsigned int flags);

 /*! \brief Parse section identifier of form [section]. The function expects parameter

  * param to be of type (str*). The result string is allocated using pkg_malloc
  * and is zero terminated. To free the memory use pkg_free(((str*)param)->s)
  */
 int cfg_parse_section(void* param, struct cfg_parser* st, unsigned int flags);
 

 /*! \brief Parse string parameter value, either quoted or unquoted */

 int cfg_parse_str_opt(void* param, struct cfg_parser* st, unsigned int flags);
 
 int cfg_parse_str(void* param, struct cfg_parser* st, unsigned int flags);
 
 int cfg_parse_enum_opt(void* param, struct cfg_parser* st, unsigned int flags);

 int cfg_parse_enum(void* param, struct cfg_parser* st, unsigned int flags);

 /*! \brief Parser integer parameter value */

 int cfg_parse_int_opt(void* param, struct cfg_parser* st, unsigned int flags);
 
 int cfg_parse_int(void* param, struct cfg_parser* st, unsigned int flags);

 /*! \brief Parse boolean parameter value */

 int cfg_parse_bool_opt(void* param, struct cfg_parser* st, unsigned int flags);
 
 int cfg_parse_bool(void* param, struct cfg_parser* st, unsigned int flags);

 
 #endif /* _CFG_PARSER_H */