jsonrpc.cpp

/**************************************************************************/
/*  jsonrpc.cpp                                                           */
/**************************************************************************/
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#include "jsonrpc.h"
#include "jsonrpc.compat.inc"

#include "core/io/json.h"

JSONRPC::JSONRPC() {
}

JSONRPC::~JSONRPC() {
}

void JSONRPC::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_method", "name", "callback"), &JSONRPC::set_method);
	ClassDB::bind_method(D_METHOD("process_action", "action", "recurse"), &JSONRPC::process_action, DEFVAL(false));
	ClassDB::bind_method(D_METHOD("process_string", "action"), &JSONRPC::process_string);

	ClassDB::bind_method(D_METHOD("make_request", "method", "params", "id"), &JSONRPC::make_request);
	ClassDB::bind_method(D_METHOD("make_response", "result", "id"), &JSONRPC::make_response);
	ClassDB::bind_method(D_METHOD("make_notification", "method", "params"), &JSONRPC::make_notification);
	ClassDB::bind_method(D_METHOD("make_response_error", "code", "message", "id"), &JSONRPC::make_response_error, DEFVAL(Variant()));

	BIND_ENUM_CONSTANT(PARSE_ERROR);
	BIND_ENUM_CONSTANT(INVALID_REQUEST);
	BIND_ENUM_CONSTANT(METHOD_NOT_FOUND);
	BIND_ENUM_CONSTANT(INVALID_PARAMS);
	BIND_ENUM_CONSTANT(INTERNAL_ERROR);
}

Dictionary JSONRPC::make_response_error(int p_code, const String &p_message, const Variant &p_id) const {
	Dictionary dict;
	dict["jsonrpc"] = "2.0";

	Dictionary err;
	err["code"] = p_code;
	err["message"] = p_message;

	dict["error"] = err;
	dict["id"] = p_id;

	return dict;
}

Dictionary JSONRPC::make_response(const Variant &p_value, const Variant &p_id) {
	Dictionary dict;
	dict["jsonrpc"] = "2.0";
	dict["id"] = p_id;
	dict["result"] = p_value;
	return dict;
}

Dictionary JSONRPC::make_notification(const String &p_method, const Variant &p_params) {
	Dictionary dict;
	dict["jsonrpc"] = "2.0";
	dict["method"] = p_method;
	dict["params"] = p_params;
	return dict;
}

Dictionary JSONRPC::make_request(const String &p_method, const Variant &p_params, const Variant &p_id) {
	Dictionary dict;
	dict["jsonrpc"] = "2.0";
	dict["method"] = p_method;
	dict["params"] = p_params;
	dict["id"] = p_id;
	return dict;
}

Variant JSONRPC::process_action(const Variant &p_action, bool p_process_arr_elements) {
	Variant ret;
	if (p_action.get_type() == Variant::DICTIONARY) {
		Dictionary dict = p_action;
		String method = dict.get("method", "");

		Array args;
		if (dict.has("params")) {
			Variant params = dict.get("params", Variant());
			if (params.get_type() == Variant::ARRAY) {
				args = params;
			} else {
				args.push_back(params);
			}
		}

		/// A Notification is a Request object without an "id" member.
		bool is_notification = !dict.has("id");

		Variant id;
		if (!is_notification) {
			id = dict["id"];

			// Account for implementations that discern between int and float on the json serialization level, by using an int if there is a .0 fraction. See #100914
			if (id.get_type() == Variant::FLOAT && id.operator float() == (float)(id.operator int())) {
				id = id.operator int();
			}
		}

		if (methods.has(method)) {
			Variant call_ret = methods[method].callv(args);
			ret = make_response(call_ret, id);
		} else {
			ret = make_response_error(JSONRPC::METHOD_NOT_FOUND, "Method not found: " + method, id);
		}

		/// The Server MUST NOT reply to a Notification
		if (is_notification) {
			ret = Variant();
		}
	} else if (p_action.get_type() == Variant::ARRAY && p_process_arr_elements) {
		Array arr = p_action;
		if (!arr.is_empty()) {
			Array arr_ret;
			for (const Variant &var : arr) {
				Variant res = process_action(var);

				if (res.get_type() != Variant::NIL) {
					arr_ret.push_back(res);
				}
			}

			/// If there are no Response objects contained within the Response array as it is to be sent to the client, the server MUST NOT return an empty Array and should return nothing at all.
			if (!arr_ret.is_empty()) {
				ret = arr_ret;
			}
		} else {
			/// If the batch rpc call itself fails to be recognized ... as an Array with at least one value, the response from the Server MUST be a single Response object.
			ret = make_response_error(JSONRPC::INVALID_REQUEST, "Invalid Request");
		}
	} else {
		ret = make_response_error(JSONRPC::INVALID_REQUEST, "Invalid Request");
	}
	return ret;
}

String JSONRPC::process_string(const String &p_input) {
	if (p_input.is_empty()) {
		return String();
	}

	Variant ret;
	JSON json;
	if (json.parse(p_input) == OK) {
		ret = process_action(json.get_data(), true);
	} else {
		ret = make_response_error(JSONRPC::PARSE_ERROR, "Parse error");
	}

	if (ret.get_type() == Variant::NIL) {
		return "";
	}
	return ret.to_json_string();
}

void JSONRPC::set_method(const String &p_name, const Callable &p_callback) {
	methods[p_name] = p_callback;
}