/*
 * This is free and unencumbered software released into the public domain.
 *
 * Anyone is free to copy, modify, publish, use, compile, sell, or
 * distribute this software, either in source code form or as a compiled
 * binary, for any purpose, commercial or non-commercial, and by any
 * means.
 *
 * In jurisdictions that recognize copyright laws, the author or authors
 * of this software dedicate any and all copyright interest in the
 * software to the public domain. We make this dedication for the benefit
 * of the public at large and to the detriment of our heirs and
 * successors. We intend this dedication to be an overt act of
 * relinquishment in perpetuity of all present and future rights to this
 * software under copyright law.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * For more information, please refer to <http://unlicense.org/>
 */

#ifndef PDJSON_H
#define PDJSON_H

#include <stdio.h>
#include "util.h"

#define PDJSON_STACK_MAX	20

enum json_type {
	JSON_ERROR = 1, JSON_DONE,
	JSON_OBJECT, JSON_OBJECT_END, JSON_ARRAY, JSON_ARRAY_END,
	JSON_STRING, JSON_NUMBER, JSON_TRUE, JSON_FALSE, JSON_NULL
};

extern const char *json_typename[];

struct json_allocator {
	void *(*malloc)(size_t);
	void *(*realloc)(void *, size_t);
	void (*free)(void *);
};

typedef short (*json_user_io)(void *user);

typedef struct json_stream json_stream;
typedef struct json_allocator json_allocator;

void json_open_buffer(json_stream *json, const void *buffer, size_t size);
void json_open_string(json_stream *json, const char *string);
void json_open_stream(json_stream *json, FILE *stream);
void json_open_user(json_stream *json, json_user_io get, json_user_io peek,
  void *user);
void json_close(json_stream *json);

void json_set_allocator(json_stream *json, json_allocator *a);
void json_set_streaming(json_stream *json, bool mode);

enum json_type json_next(json_stream *json);
enum json_type json_peek(json_stream *json);
void json_reset(json_stream *json);
const char *json_get_string(json_stream *json, size_t *length);
double json_get_number(json_stream *json);

enum json_type json_skip(json_stream *json);
enum json_type json_skip_until(json_stream *json, enum json_type type);

size_t json_get_lineno(json_stream *json);
size_t json_get_position(json_stream *json);
size_t json_get_depth(json_stream *json);
enum json_type json_get_context(json_stream *json, size_t *count);
const char *json_get_error(json_stream *json);

short json_source_get(json_stream *json);
short json_source_peek(json_stream *json);
bool json_isspace(short c);

/* internal */

struct json_source {
	short (*get)(struct json_source *);
	short (*peek)(struct json_source *);
	size_t position;
	union {
		struct {
			FILE *stream;
		} stream;
		struct {
			const char *buffer;
			size_t length;
		} buffer;
		struct {
			void *ptr;
			json_user_io get;
			json_user_io peek;
		} user;
	} source;
};

struct json_stream {
	size_t lineno;

	struct json_stack *stack;
	size_t stack_top;
	size_t stack_size;
	enum json_type next;
	unsigned flags;

	struct {
		char *string;
		size_t string_fill;
		size_t string_size;
	} data;

	size_t ntokens;

	struct json_source source;
	struct json_allocator alloc;
	char errmsg[128];
};

#endif