/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* ====================================================================
 * Copyright (c) 2007 Carnegie Mellon University.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * This work was supported in part by funding from the Defense Advanced 
 * Research Projects Agency and the National Science Foundation of the 
 * United States of America, and the CMU Sphinx Speech Consortium.
 *
 * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND 
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY
 * NOR ITS EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 * ====================================================================
 *
 */

#ifndef __JSGF_H__
#define __JSGF_H__

/**
 * @file jsgf.h JSGF grammar compiler
 *
 * This file defines the data structures for parsing JSGF grammars
 * into Sphinx finite-state grammars.
 **/

#include <stdio.h>

#include <soundswallower/hash_table.h>
#include <soundswallower/fsg_model.h>
#include <soundswallower/logmath.h>

#ifdef __cplusplus
extern "C" {
#endif
#if 0
/* Fool Emacs. */
}
#endif

typedef struct jsgf_s jsgf_t;
typedef struct jsgf_rule_s jsgf_rule_t;

/**
 * Create a new JSGF grammar.
 *
 * @param parent optional parent grammar for this one (NULL, usually).
 * @return new JSGF grammar object, or NULL on failure.
 */
jsgf_t *jsgf_grammar_new(jsgf_t *parent);

/**
 * Parse a JSGF grammar from a file.
 *
 * @param filename the name of the file to parse.
 * @param parent optional parent grammar for this one (NULL, usually).
 * @return new JSGF grammar object, or NULL on failure.
 */
jsgf_t *jsgf_parse_file(const char *filename, jsgf_t *parent);

/**
 * Parse a JSGF grammar from a string.
 *
 * @param 0-terminated string with grammar.
 * @param parent optional parent grammar for this one (NULL, usually).
 * @return new JSGF grammar object, or NULL on failure.
 */
jsgf_t *jsgf_parse_string(const char *string, jsgf_t *parent);

/**
 * Get the grammar name from the file.
 */
char const *jsgf_grammar_name(jsgf_t *jsgf);

/**
 * Free a JSGF grammar.
 */
void jsgf_grammar_free(jsgf_t *jsgf);

/**
 * Iterator over rules in a grammar.
 */
typedef hash_iter_t jsgf_rule_iter_t;

/**
 * Get an iterator over all rules in a grammar.
 */
jsgf_rule_iter_t *jsgf_rule_iter(jsgf_t *grammar);

/**
 * Advance an iterator to the next rule in the grammar.
 */
#define jsgf_rule_iter_next(itor) hash_table_iter_next(itor)

/**
 * Get the current rule in a rule iterator.
 */
#define jsgf_rule_iter_rule(itor) ((jsgf_rule_t *)(itor)->ent->val)

/**
 * Free a rule iterator (if the end hasn't been reached).
 */
#define jsgf_rule_iter_free(itor) hash_table_iter_free(itor)

/**
 * Get a rule by name from a grammar. Name should not contain brackets.
 */
jsgf_rule_t *jsgf_get_rule(jsgf_t *grammar, const char *name);

/**
 * Returns the first public rule of the grammar
 */ 
jsgf_rule_t *jsgf_get_public_rule(jsgf_t *grammar);

/**
 * Get the rule name from a rule.
 */
char const *jsgf_rule_name(jsgf_rule_t *rule);

/**
 * Test if a rule is public or not.
 */
int jsgf_rule_public(jsgf_rule_t *rule);

/**
 * Build a Sphinx FSG object from a JSGF rule.
 */
fsg_model_t *jsgf_build_fsg(jsgf_t *grammar, jsgf_rule_t *rule,
                            logmath_t *lmath, float32 lw);

/**
 * Build a Sphinx FSG object from a JSGF rule.
 *
 * This differs from jsgf_build_fsg() in that it does not do closure
 * on epsilon transitions or any other postprocessing.  For the time
 * being this is necessary in order to write it to a file - the FSG
 * code will be fixed soon.
 */
fsg_model_t *jsgf_build_fsg_raw(jsgf_t *grammar, jsgf_rule_t *rule,
                                logmath_t *lmath, float32 lw);


/**
 * Read JSGF from file and return FSG object from it.
 *
 * This function looks for a first public rule in jsgf and constructs JSGF from it.
 */
fsg_model_t *jsgf_read_file(const char *file, logmath_t * lmath, float32 lw);

/**
 * Read JSGF from string and return FSG object from it.
 *
 * This function looks for a first public rule in jsgf and constructs JSGF from it.
 */
fsg_model_t *jsgf_read_string(const char *string, logmath_t * lmath, float32 lw);


/**
 * Convert a JSGF rule to Sphinx FSG text form.
 *
 * This does a direct conversion without doing transitive closure on
 * null transitions and so forth.
 */
int jsgf_write_fsg(jsgf_t *grammar, jsgf_rule_t *rule, FILE *outfh);

#ifdef __cplusplus
}
#endif


#endif /* __JSGF_H__ */
