001//
002// MIT License
003//
004// Copyright (c) 2021 Alexander Söderberg & Contributors
005//
006// Permission is hereby granted, free of charge, to any person obtaining a copy
007// of this software and associated documentation files (the "Software"), to deal
008// in the Software without restriction, including without limitation the rights
009// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
010// copies of the Software, and to permit persons to whom the Software is
011// furnished to do so, subject to the following conditions:
012//
013// The above copyright notice and this permission notice shall be included in all
014// copies or substantial portions of the Software.
015//
016// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
017// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
018// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
019// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
020// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
021// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
022// SOFTWARE.
023//
024package cloud.commandframework.services.types;
025
026import cloud.commandframework.services.State;
027import org.checkerframework.checker.nullness.qual.NonNull;
028
029/**
030 * Service implementation that alters the state of the owning application in some way. A
031 * SideEffectService does not return a generated result, instead it returns a response, indicating
032 * whether or not the context was consumed
033 *
034 * @param <Context> Context type.
035 */
036@FunctionalInterface
037public interface SideEffectService<Context> extends Service<Context, State> {
038
039    /**
040     * Consumes the context, if possible. Returns {@link State#ACCEPTED} if the input was consumed,
041     * else {@link State#REJECTED}
042     *
043     * @param context context used in the generation of the response
044     * @return Response. If the response isn't {@link State#ACCEPTED}, the next service in the service
045     *         chain will get to act on the context. Otherwise the execution halts, and the provided response
046     *         is the final response.
047     * @throws Exception Any exception that occurs during the handling can be thrown, and will be
048     *                   wrapped by a {@link cloud.commandframework.services.PipelineException}
049     */
050    @Override
051    @NonNull State handle(@NonNull Context context) throws Exception;
052
053}