/*********************************************************************************************************
* Software License Agreement (BSD License)                                                               *
* Author: Sebastien Decugis <sdecugis@freediameter.net>							 *
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* Copyright (c) 2013, WIDE Project and NICT								 *
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/* Yacc extension's configuration parser.
 */

/* For development only : */
%debug
%error-verbose

/* The parser receives the configuration file filename as parameter */
%parse-param {char * conffile}

/* Keep track of location */
%locations
%pure-parser

%{
#include "rtereg.h"
#include "rtereg_conf.tab.h"	/* bison is not smart enough to define the YYLTYPE before including this code, so... */

/* Forward declaration */
int yyparse(char * conffile);
void rtereg_confrestart(FILE *input_file);

/* Parse the configuration file */
int rtereg_conf_handle(char * conffile)
{
	extern FILE * rtereg_confin;
	int ret;

	LOG_D("[rt_ereg] parsing configuration file '%s'", conffile);

	rtereg_confin = fopen(conffile, "r");
	if (rtereg_confin == NULL) {
		ret = errno;
		fd_log_debug("Unable to open extension configuration file %s for reading: %s", conffile, strerror(ret));
		LOG_E("[rt_ereg] error occurred, message logged -- configuration file.");
		return ret;
	}

	rtereg_confrestart(rtereg_confin);
	ret = yyparse(conffile);

	fclose(rtereg_confin);

	if (rtereg_conf[rtereg_conf_size-1].finished == 0) {
		LOG_E("[rt_ereg] configuration invalid, AVP ended without OCTETSTRING AVP");
		return EINVAL;
	}

	if (ret != 0) {
		LOG_E("[rt_ereg] unable to parse the configuration file.");
		return EINVAL;
	} else {
		int i, sum = 0;
		for (i=0; i<rtereg_conf_size; i++) {
			sum += rtereg_conf[i].rules_nb;
		}
		LOG_D("[rt-ereg] Added %d rules successfully.", sum);
	}

	return 0;
}

int avp_add(const char *name)
{
	void *ret;
	int level;

	if (rtereg_conf[rtereg_conf_size-1].finished) {
		if ((ret = realloc(rtereg_conf, sizeof(*rtereg_conf)*(rtereg_conf_size+1))) == NULL) {
			LOG_E("[rt_ereg] realloc failed");
			return -1;
		}
		rtereg_conf_size++;
		rtereg_conf = ret;
		memset(&rtereg_conf[rtereg_conf_size-1], 0, sizeof(*rtereg_conf));
		LOG_D("[rt_ereg] New AVP group found starting with %s", name);
	}
	level = rtereg_conf[rtereg_conf_size-1].level + 1;

	if ((ret = realloc(rtereg_conf[rtereg_conf_size-1].avps, sizeof(*rtereg_conf[rtereg_conf_size-1].avps)*level)) == NULL) {
		LOG_E("[rt_ereg] realloc failed");
		return -1;
	}
	rtereg_conf[rtereg_conf_size-1].avps = ret;

	CHECK_FCT_DO( fd_dict_search ( fd_g_config->cnf_dict, DICT_AVP, AVP_BY_NAME_ALL_VENDORS, name, &rtereg_conf[rtereg_conf_size-1].avps[level-1], ENOENT ),
		      {
			      LOG_E("[rt_ereg] Unable to find '%s' AVP in the loaded dictionaries.", name);
			      return -1;
		      } );

	/* Now check the type */
	{
		struct dict_avp_data data;
		CHECK_FCT( fd_dict_getval( rtereg_conf[rtereg_conf_size-1].avps[level-1], &data) );
		if (data.avp_basetype == AVP_TYPE_OCTETSTRING) {
			rtereg_conf[rtereg_conf_size-1].finished = 1;
		} else if (data.avp_basetype != AVP_TYPE_GROUPED) {
			LOG_E("[rt_ereg] '%s' AVP is not an OCTETSTRING nor GROUPED AVP (%d).", name, data.avp_basetype);
			return -1;
		}
	}
	rtereg_conf[rtereg_conf_size-1].level = level;
	return 0;
}

/* The Lex parser prototype */
int rtereg_conflex(YYSTYPE *lvalp, YYLTYPE *llocp);

/* Function to report the errors */
void yyerror (YYLTYPE *ploc, char * conffile, char const *s)
{
	LOG_E("[rt_ereg] error in configuration parsing");

	if (ploc->first_line != ploc->last_line)
		fd_log_debug("%s:%d.%d-%d.%d : %s", conffile, ploc->first_line, ploc->first_column, ploc->last_line, ploc->last_column, s);
	else if (ploc->first_column != ploc->last_column)
		fd_log_debug("%s:%d.%d-%d : %s", conffile, ploc->first_line, ploc->first_column, ploc->last_column, s);
	else
		fd_log_debug("%s:%d.%d : %s", conffile, ploc->first_line, ploc->first_column, s);
}

%}

/* Values returned by lex for token */
%union {
	char 		*string;	/* The string is allocated by strdup in lex.*/
	int		integer;
}

/* In case of error in the lexical analysis */
%token 		LEX_ERROR

/* A (de)quoted string (malloc'd in lex parser; it must be freed after use) */
%token <string>	 QSTRING
%token <integer> INTEGER

/* Tokens */
%token 		AVP


/* -------------------------------------- */
%%

	/* The grammar definition */
conffile:		avp rules
			| conffile avp rules
			;

	/* a server entry */
avp:			AVP '=' avp_part ';'
			;

avp_part: 		avp_part ':' QSTRING { if (avp_add($3) < 0) { YYERROR; } }
			| QSTRING { if (avp_add($1) < 0) { YYERROR; } }
			;

rules:			/* empty OK */
			| rules rule
			;

rule:			QSTRING ':' QSTRING '+' '=' INTEGER ';'
			{
				struct rtereg_rule * new;
				int err;

				/* Add new rule in the array */
				rtereg_conf[rtereg_conf_size-1].rules_nb += 1;
				CHECK_MALLOC_DO(rtereg_conf[rtereg_conf_size-1].rules = realloc(rtereg_conf[rtereg_conf_size-1].rules, rtereg_conf[rtereg_conf_size-1].rules_nb * sizeof(struct rtereg_rule)),
					{
						yyerror (&yylloc, conffile, "Not enough memory to store the configuration...");
						YYERROR;
					} );

				new = &rtereg_conf[rtereg_conf_size-1].rules[rtereg_conf[rtereg_conf_size-1].rules_nb - 1];

				new->pattern = $1;
				new->server  = $3;
				new->score   = $6;

				/* Attempt to compile the regex */
				CHECK_FCT_DO( err=regcomp(&new->preg, new->pattern, REG_EXTENDED | REG_NOSUB),
					{
						char * buf;
						size_t bl;

						/* Error while compiling the regex */
						LOG_E("[rt_ereg] error while compiling the regular expression '%s':", new->pattern);

						/* Get the error message size */
						bl = regerror(err, &new->preg, NULL, 0);

						/* Alloc the buffer for error message */
						CHECK_MALLOC( buf = malloc(bl) );

						/* Get the error message content */
						regerror(err, &new->preg, buf, bl);
						LOG_E("\t%s", buf);

						/* Free the buffer, return the error */
						free(buf);

						yyerror (&yylloc, conffile, "Invalid regular expression.");
						YYERROR;
					} );
			}
			;