/*************************************************************************/
/*  jsonrpc.cpp                                                          */
/*************************************************************************/
/*                         This file is part of:                         */
/*                          PANDEMONIUM ENGINE                           */
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/* Copyright (c) 2022-present Péter Magyar.                              */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
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#include "jsonrpc.h"
#include "core/io/json.h"

JSONRPC::JSONRPC() {
}

JSONRPC::~JSONRPC() {
}

void JSONRPC::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_scope", "scope", "target"), &JSONRPC::set_scope);
	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", "");
		if (method.begins_with("$/")) {
			return ret;
		}

		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);
			}
		}

		Object *object = this;
		if (method_scopes.has(method.get_base_dir())) {
			object = method_scopes[method.get_base_dir()];
			method = method.get_file();
		}

		Variant id;
		if (dict.has("id")) {
			id = dict["id"];
		}

		if (object == nullptr || !object->has_method(method)) {
			ret = make_response_error(JSONRPC::METHOD_NOT_FOUND, "Method not found: " + method, id);
		} else {
			Variant call_ret = object->callv(method, args);
			if (id.get_type() != Variant::NIL) {
				ret = make_response(call_ret, id);
			}
		}
	} else if (p_action.get_type() == Variant::ARRAY && p_process_arr_elements) {
		Array arr = p_action;
		int size = arr.size();
		if (size) {
			Array arr_ret;
			for (int i = 0; i < size; i++) {
				const Variant &var = arr.get(i);
				arr_ret.push_back(process_action(var));
			}
			ret = arr_ret;
		} else {
			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.empty()) {
		return String();
	}

	Variant ret;
	Variant input;
	String err_message;
	int err_line;
	if (OK != JSON::parse(p_input, input, err_message, err_line)) {
		ret = make_response_error(JSONRPC::PARSE_ERROR, "Parse error");
	} else {
		ret = process_action(input, true);
	}

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

void JSONRPC::set_scope(const String &p_scope, Object *p_obj) {
	method_scopes[p_scope] = p_obj;
}