#ifndef JSON_H
#define JSON_H

enum json_type {
    JSON_TYPE_INVALID,

    JSON_TYPE_STRING,
    JSON_TYPE_NULL,
    JSON_TYPE_BOOL,
    JSON_TYPE_ARRAY,
    JSON_TYPE_OBJECT,
    JSON_TYPE_NUMBER
};

struct json_object_entry;

struct json_ir_parent_data {
    u32 child_count;
    struct json_ir *child_first;
    struct json_ir *child_last;
};

/* Intermediate representation of JSON hierarchy tree in memory. Used for mutating
 * JSON in parsing stage or for creating new objects. Should be manipulated via the
 * API. */
struct json_ir {
    enum json_type type;
    struct json_ir *next_child;
    struct string key;
    union {
        struct json_ir_parent_data children;
        b32 boolean;
        struct string string;
        f64 number;
    } val;
};

/* Final representation of JSON hierarchy. Should be manipulated via the API. */
struct json_val {
    enum json_type type;
    u32 child_count;
    union {
        void *object_table;
        struct json_val *array_children;
        b32 boolean;
        struct string *string;
        f64 number;
    } val;
};

struct json_object_entry {
    struct string key;
    struct json_val value;
};

/* Parse */
const struct json_ir *json_parse(struct arena *arena, struct buffer bytes, struct string **error);

/* Format */
const struct json_val *json_format(struct arena *arena, const struct json_ir *ir);
const struct json_val *json_parse_and_format(struct arena *arena, struct buffer bytes, struct string **error);

/* Index */
const struct json_val *json_array_get(const struct json_val *a, u32 index);
const struct json_val *json_object_get(const struct json_val *obj, struct string key);
const struct json_object_entry *json_object_get_index(const struct json_val *obj, u32 index);

/* Dump */
struct string json_dump_to_string(struct arena *arena, const struct json_val *val, u32 indent);

/* Write */
struct json_ir *json_ir_object(struct arena *arena);
struct json_ir *json_ir_number(struct arena *arena, f64 n);
struct json_ir *json_ir_bool(struct arena *arena, b32 b);
struct json_ir *json_ir_object_set(struct json_ir *obj, struct string key, struct json_ir *value);

/* ========================== *
 * Type util
 * ========================== */

INLINE b32 json_is_object(const struct json_val *v)
{
    return v && v->type == JSON_TYPE_OBJECT;
}

INLINE b32 json_is_string(const struct json_val *v)
{
    return v && v->type == JSON_TYPE_STRING;
}

INLINE b32 json_is_number(const struct json_val *v)
{
    return v && v->type == JSON_TYPE_NUMBER;
}

INLINE b32 json_is_array(const struct json_val *v)
{
    return v && v->type == JSON_TYPE_ARRAY;
}

INLINE b32 json_is_bool(const struct json_val *v)
{
    return v && v->type == JSON_TYPE_BOOL;
}

INLINE b32 json_is_null(const struct json_val *v)
{
    return v && v->type == JSON_TYPE_NULL;
}

/* ========================== *
 * Val util
 * ========================== */

INLINE struct string json_string(const struct json_val *v)
{
    ASSERT(json_is_string(v));
    return *v->val.string;
}

INLINE f64 json_number(const struct json_val *v)
{
    ASSERT(json_is_number(v));
    return v->val.number;
}

INLINE b32 json_bool(const struct json_val *v)
{
    ASSERT(json_is_bool(v));
    return v->val.boolean;
}

/* ========================== *
 * Parent util
 * ========================== */

INLINE u32 json_child_count(const struct json_val *v)
{
    ASSERT(json_is_object(v) || json_is_array(v));
    return v->child_count;
}

#endif