json.h

/*
 * json - A simple JSON library using only the standard C library.
 * Copyright (C) 2022 Hasan Zahra
 *
 * This program 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 3 of the License, or
 * (at your option) any later version.
 * 
 * This program 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, see <https://www.gnu.org/licenses/>.
 */

#ifndef JSON_H
#define JSON_H

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

/* hashmap */
#define JSONLIB_MAX(a, b) ((a) > (b)) ? (a) : (b)

typedef struct HMItem HMItem;

struct HMItem {
	char *key;
	void *val;

	void (*k_free_func)(void *);
	void (*v_free_func)(void *);
};

#define hashmap_item_free_func(a) (void (*)(void *))a

typedef struct {
	HMItem **items;  /* buckets */

	size_t can_store;
	size_t stored;
} HashMap;

HMItem *new_item(char *key, void *val,
                void (*k_free_func)(void *), void (*v_free_func)(void *));
void free_item(HMItem *item);
HashMap *new_hashmap(size_t capacity);
void free_hashmap(HashMap *map);
int check_hashmap_capacity(HashMap *map, size_t n);
int hashmap_set(HashMap *map, HMItem *item);

/*
 * 64-bit FNV-1a hash:
 * https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function
 * https://github.com/benhoyt/ht/blob/master/ht.c
 */
#define FNV_OFFSET 14695981039346656037UL
#define FNV_PRIME 1099511628211UL
uint64_t hashmap_hash_func(char *key);

void *hashmap_index(HashMap *map, char *key);
void hashmap_remove(HashMap *map, char *key);

/* Begin JSON implementation */

typedef enum json_t {
	json_bool,
	json_string,
	json_array,
	json_dict,
	json_number,
	json_null
} json_t;

typedef union {
	double number;
	char *string;
	bool boolean;
	struct json *json_data;
        struct json **json_data_array;
        HashMap *json_data_dict;  
} json_data;

struct json {
	json_t type;
	char *key;
        int n_data_items;  /* length of array or dict (if present) */
        size_t data_list_capacity;  /* capacity of array/dict */
	json_data data;
};

struct json *new_json(void);
void free_json_item(struct json *j);
void print_json(struct json *j);
HMItem *json_parse_dict_tuple(char *str, int *idx);
struct json *json_parse_dict(char *str, int *idx);
struct json *json_parse_string(char *str, int *idx);
struct json *json_parse_array(char *str, int *idx);
struct json *json_parse_number(char *str, int *idx);
struct json *json_parse_bool(char *str, int *idx);
struct json *json_parse_null(char *str, int *idx);
struct json *json_parse_item(char *str, int *idx);

#define json_parse(str) json_parse_item(str, NULL)

struct json *json_get_array_item(struct json *arr, int idx);
struct json *json_get_dict_item(struct json *dict, char *key);
int json_get_size(struct json *arr);
int json_get_capacity(struct json *arr);

struct json *json_access(struct json *j, ...);
struct json *json_safe_access(struct json *j, char *fmt, ...);

char *json_read_file(char *path);

#define json_get_string(j) (j->data.string)
#define json_get_bool(j) (j->data.boolean)
#define json_get_number(j) (j->data.number)
#define json_get_data(j) (j->data.json_data)
#define json_get_array(j) (j->data.json_data_array)
#define json_get_dict(j) (j->data.json_data_dict)

#define json_get_array_string(arr, i) (json_get_string(\
                        json_get_array_item(arr, i)))

#define json_get_array_bool(arr, i) (json_get_bool(\
                        json_get_array_item(arr, i)))

#define json_get_array_number(arr, i) (json_get_number(\
                        json_get_array_item(arr, i)))

#define json_get_array_data(arr, i) (json_get_data(\
                        json_get_array_item(arr, i)))

#define json_get_array_array(arr, i) (json_get_array(\
                        json_get_array_item(arr, i)))

#define json_get_array_dict(arr, i) (json_get_dict(\
                        json_get_array_item(arr, i)))

#define json_get_dict_string(dict, str) (json_get_string(\
                        json_get_dict_item(dict, str)))

#define json_get_dict_bool(dict, str) (json_get_bool(\
                        json_get_dict_item(dict, str)))

#define json_get_dict_number(dict, str) (json_get_number(\
                        json_get_dict_item(dict, str)))

#define json_get_dict_data(dict, str) (json_get_data(\
                        json_get_dict_item(dict, str)))

#define json_get_dict_array(dict, str) (json_get_array(\
                        json_get_dict_item(dict, str)))

#define json_get_dict_dict(dict, str) (json_get_dict(\
                        json_get_dict_item(dict, str)))

#endif  /* JSON_H */