#ifndef CARROT_DEFINITION_H
#define CARROT_DEFINITION_H

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <tokenizer.h>


typedef enum
{
    CARROT_PATTERN_ELEMENT_VARIABLE_TERMINAL,
    CARROT_PATTERN_ELEMENT_LITERAL_TERMINAL,
    CARROT_PATTERN_ELEMENT_RULE
} carrot_pattern_element_e;

typedef enum
{
    CARROT_VARIABLE_TERMINAL_ALPHABETICAL_WORD,
    CARROT_VARIABLE_TERMINAL_ALPHANUMERIC_WORD,         // 
    CARROT_VARIABLE_TERMINAL_KEYWORD,                   // Subtype of CARROT_VARIABLE_TERMINAL_ALPHANUMERIC_WORD; from a list of user-specified keywords.
    CARROT_VARIABLE_TERMINAL_OPERATOR,
    CARROT_VARIABLE_TERMINAL_NUMBER,
    CARROT_VARIABLE_TERMINAL_FLOAT,                     // Subtype of CARROT_VARIABLE_TERMINAL_NUMBER; all numbers, including those with digits after the number.
    CARROT_VARIABLE_TERMINAL_INTEGER                    // Subtype of CARROT_VARIABLE_TERMINAL_NUMBER; only means full numbers without digits after the number.
} carrot__variable_terminal_e;


// carrot_definition_unit_s: A whole file (with possible included sub-files) of rules.
//  A definition unit describes a single format or language.
typedef struct      carrot_definition_unit              carrot_definition_unit_s;

// carrot_rule_definition_s: The definition of a rule with all of the patterns it contains.
//  A rule definition starts with the name of the rule inside of a pair of arrow brackets ( < > ),
//  followed by an equals sign and some patterns, until a semicolon ends the rule definition.
typedef struct      carrot_rule_definition              carrot_rule_definition_s;

// carrot_pattern_s: A pattern consisting of a sequence of pattern elements. These elements
//  can be terminal or the names of whole other rules themselves.
typedef struct      carrot_pattern_sequence             carrot_pattern_sequence_s;

// carrot_pattern_element_s: An element of a pattern; this can be a terminal symbol or the name
//  of another rule in arrow brackets ( < > ). It denotes a piece of data, one or multiple tokens,
//  which have to exist for the pattern to begin (which are static, defined literals)
//  or can be extracted (like variable terminals).
typedef struct      carrot_pattern_element              carrot_pattern_element_s;

// carrot_terminal_s: An ending symbol of the parsing tree. This can be the name of a variable terminal
//  or a static, defined literal.
//
//  A variable terminal could be "[word]", "[keyword]" or one of some others (as they are defined in
//  docs/variable_terminals.md)
//
//  A static, defined literal is a literal piece of data which must exist at that position in a rule
//  in exactly the way as it was stated in the definition.
typedef struct      carrot_terminal                     carrot_terminal_s;

struct carrot_definition_unit
{
    uint32_t                                                    num_rules;
    carrot_rule_definition_s                                   *rules;

    carrot_token_stream_s                                      *token_stream;
};

struct carrot_rule_definition
{
    carrot_definition_unit_s                                   *syntax_definition;

    uint32_t                                                    num_applying_patterns;
    carrot_pattern_sequence_s                                  *applying_patterns;
};

struct carrot_pattern_sequence
{
    // rule: The rule that this pattern sequence belongs to.
    carrot_rule_definition_s                                   *rule;

    uint32_t                                                    num_items;
    carrot_pattern_element_s                                   *items;
};

struct carrot_pattern_element
{
    carrot_pattern_element_e                                    type;
    carrot__variable_terminal_e                                 variable_terminal;
    char                                                       *referenced_rule_name;
    char                                                       *literal_terminal;

};

#endif