#ifndef PARCEL_GRAMMAR_PARSER_H
#define PARCEL_GRAMMAR_PARSER_H

#include <parcel/utility/utility.h>
#include <logger.h>

typedef struct pac_grammar              pac_grammar_s;
typedef struct pac_rule                 pac_rule_s;
typedef struct pac_variant              pac_variant_s;
typedef struct pac_literal              pac_literal_s;
typedef struct pac_item                 pac_item_s;

// pac_item_e: The type of an item of a rule variant.
//
//  A rule (-variant) is made up of multiple items which
//  can have one of the types that are listed in this enum.
typedef enum
{
    PAC_ITEM_INVALID                = 0x00,
    PAC_ITEM_REFERENCE,
    PAC_ITEM_LITERAL,
    PAC_ITEM_SET,

} pac_item_e;

typedef enum
{
    PAC_SET_INVALID                 = 0x00,
    PAC_SET_RUNE,
    PAC_SET_WORD,
    PAC_SET_INTEGER,
    PAC_SET_FLOAT
} pac_set_e;

struct pac_literal
{
    usz_t                       length;
    char                       *string;
};

struct pac_item
{
    pac_item_e                  type;
    union pac_item_data
    {
        pac_literal_s               literal;
        pac_set_e                   set;
        pac_rule_s                 *reference;

    } data;
};

struct pac_variant
{
    usz_t                       num_items;
    pac_item_s                 *items;
};

struct pac_rule
{
    char                       *name;
    
    usz_t                       num_variants;
    pac_variant_s              *variants;
};

struct pac_grammar
{
    usz_t                       len_source;
    char                       *source;

    usz_t                       num_rules;
    pac_rule_s                 *rules;

    pac_logger_s                log;
    pac_arena_s                 result_arena;
};



pac_grammar_s               pac_convert_grammar         (char *source, usz_t len_source);
void                        pac_delete_grammar          (pac_grammar_s grammar);

void                        pac_display_log             (pac_logger_s *logger);
void                        pac_display_grammar         (pac_grammar_s grammar);

#endif // PARCEL_GRAMMAR_PARSER_H