/*
 * Copyright (c) 2023 Egor Tensin <egor@tensin.name>
 * This file is part of the "cimple" project.
 * For details, see https://github.com/egor-tensin/cimple.
 * Distributed under the MIT License.
 */

#include "json.h"

#include "buf.h"
#include "log.h"
#include "net.h"

#include <json-c/json_object.h>
#include <json-c/json_tokener.h>

#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#define libjson_errno(fn)                         \
	do {                                      \
		log_err("JSON: %s failed\n", fn); \
	} while (0)

void libjson_free(struct json_object* obj) {
	json_object_put(obj);
}

static const char* libjson_to_string_internal(struct json_object* obj, int flags) {
	const char* result = json_object_to_json_string_ext(obj, flags);
	if (!result) {
		libjson_errno("json_object_to_json_string");
		return NULL;
	}
	return result;
}

const char* libjson_to_string(struct json_object* obj) {
	return libjson_to_string_internal(obj, JSON_C_TO_STRING_SPACED);
}

const char* libjson_to_string_pretty(struct json_object* obj) {
	return libjson_to_string_internal(obj, JSON_C_TO_STRING_SPACED | JSON_C_TO_STRING_PRETTY);
}

struct json_object* libjson_from_string(const char* src) {
	enum json_tokener_error error;

	struct json_object* result = json_tokener_parse_verbose(src, &error);
	if (!result) {
		libjson_errno("json_tokener_parse_verbose");
		log_err("JSON: parsing failed: %s\n", json_tokener_error_desc(error));
		return NULL;
	}

	return result;
}

int libjson_clone(const struct json_object* obj, const char* key, struct json_object** _value) {
	int ret = 0;

	struct json_object* old_value = NULL;
	ret = libjson_get(obj, key, &old_value);
	if (ret < 0)
		return ret;

	struct json_object* new_value = NULL;
	ret = json_object_deep_copy(old_value, &new_value, NULL);
	if (ret < 0)
		return ret;

	*_value = new_value;
	return ret;
}

int libjson_send(struct json_object* obj, int fd) {
	int ret = 0;

	const char* str = libjson_to_string(obj);
	if (!str)
		return -1;

	struct buf* buf = NULL;
	ret = buf_create_from_string(&buf, str);
	if (ret < 0)
		return ret;

	ret = net_send_buf(fd, buf);
	buf_destroy(buf);
	return ret;
}

struct json_object* libjson_recv(int fd) {
	struct json_object* result = NULL;
	int ret = 0;

	struct buf* buf = NULL;
	ret = net_recv_buf(fd, &buf);
	if (ret < 0)
		return NULL;

	result = libjson_from_string((const char*)buf_get_data(buf));
	if (!result)
		goto destroy_buf;

destroy_buf:
	free((void*)buf_get_data(buf));
	buf_destroy(buf);

	return result;
}

int libjson_new_object(struct json_object** _obj) {
	struct json_object* obj = json_object_new_object();
	if (!obj) {
		libjson_errno("json_object_new_object");
		return -1;
	}
	*_obj = obj;
	return 0;
}

int libjson_new_array(struct json_object** _arr) {
	struct json_object* arr = json_object_new_array();
	if (!arr) {
		libjson_errno("json_object_new_array");
		return -1;
	}
	*_arr = arr;
	return 0;
}

int libjson_has(const struct json_object* obj, const char* key) {
	return json_object_object_get_ex(obj, key, NULL);
}

int libjson_get(const struct json_object* obj, const char* key, struct json_object** value) {
	if (!libjson_has(obj, key)) {
		log_err("JSON: key is missing: %s\n", key);
		return -1;
	}

	return json_object_object_get_ex(obj, key, value);
}

int libjson_get_string(const struct json_object* obj, const char* key, const char** _value) {
	struct json_object* value = NULL;

	int ret = libjson_get(obj, key, &value);
	if (ret < 0)
		return ret;

	if (!json_object_is_type(value, json_type_string)) {
		log_err("JSON: key is not a string: %s\n", key);
		return -1;
	}

	*_value = json_object_get_string(value);
	return 0;
}

int libjson_get_int(const struct json_object* obj, const char* key, int64_t* _value) {
	struct json_object* value = NULL;

	int ret = libjson_get(obj, key, &value);
	if (ret < 0)
		return ret;

	if (!json_object_is_type(value, json_type_int)) {
		log_err("JSON: key is not an integer: %s\n", key);
		return -1;
	}

	errno = 0;
	int64_t tmp = json_object_get_int64(value);
	if (errno) {
		log_err("JSON: failed to parse integer from key: %s\n", key);
		return -1;
	}

	*_value = tmp;
	return 0;
}

static int libjson_set_internal(struct json_object* obj,
                                const char* key,
                                struct json_object* value,
                                unsigned flags) {
	int ret = 0;

	ret = json_object_object_add_ex(obj, key, value, flags);
	if (ret < 0) {
		libjson_errno("json_object_object_add_ex");
		return ret;
	}

	return 0;
}

static int libjson_set_string_internal(struct json_object* obj,
                                       const char* key,
                                       const char* _value,
                                       unsigned flags) {
	struct json_object* value = json_object_new_string(_value);
	if (!value) {
		libjson_errno("json_object_new_string");
		return -1;
	}

	int ret = libjson_set_internal(obj, key, value, flags);
	if (ret < 0)
		goto free_value;

	return ret;

free_value:
	json_object_put(value);

	return ret;
}

static int libjson_set_int_internal(struct json_object* obj,
                                    const char* key,
                                    int64_t _value,
                                    unsigned flags) {
	struct json_object* value = json_object_new_int64(_value);
	if (!value) {
		libjson_errno("json_object_new_int");
		return -1;
	}

	int ret = libjson_set_internal(obj, key, value, flags);
	if (ret < 0)
		goto free_value;

	return ret;

free_value:
	json_object_put(value);

	return ret;
}

int libjson_set(struct json_object* obj, const char* key, struct json_object* value) {
	return libjson_set_internal(obj, key, value, 0);
}

int libjson_set_string(struct json_object* obj, const char* key, const char* value) {
	return libjson_set_string_internal(obj, key, value, 0);
}

int libjson_set_int(struct json_object* obj, const char* key, int64_t value) {
	return libjson_set_int_internal(obj, key, value, 0);
}

#ifndef JSON_C_OBJECT_ADD_CONSTANT_KEY
#define JSON_C_OBJECT_ADD_CONSTANT_KEY JSON_C_OBJECT_KEY_IS_CONSTANT
#endif
static const unsigned json_const_key_flags = JSON_C_OBJECT_ADD_CONSTANT_KEY;

int libjson_set_const_key(struct json_object* obj, const char* key, struct json_object* value) {
	return libjson_set_internal(obj, key, value, json_const_key_flags);
}

int libjson_set_string_const_key(struct json_object* obj, const char* key, const char* value) {
	return libjson_set_string_internal(obj, key, value, json_const_key_flags);
}

int libjson_set_int_const_key(struct json_object* obj, const char* key, int64_t value) {
	return libjson_set_int_internal(obj, key, value, json_const_key_flags);
}

int libjson_append(struct json_object* arr, struct json_object* elem) {
	int ret = json_object_array_add(arr, elem);
	if (ret < 0) {
		libjson_errno("json_object_array_add");
		return ret;
	}
	return ret;
}