/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.streaming.tests;

import org.apache.flink.api.common.JobID;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.core.fs.CloseableRegistry;
import org.apache.flink.metrics.MetricGroup;
import org.apache.flink.runtime.execution.Environment;
import org.apache.flink.runtime.query.TaskKvStateRegistry;
import org.apache.flink.runtime.state.CheckpointableKeyedStateBackend;
import org.apache.flink.runtime.state.KeyGroupRange;
import org.apache.flink.runtime.state.KeyedStateHandle;
import org.apache.flink.runtime.state.OperatorStateBackend;
import org.apache.flink.runtime.state.OperatorStateHandle;
import org.apache.flink.runtime.state.StateBackend;
import org.apache.flink.runtime.state.ttl.TtlTimeProvider;

import javax.annotation.Nonnull;

import java.util.Collection;

import static org.apache.flink.util.Preconditions.checkNotNull;

/**
 * A stub implementation of the {@link StateBackend} that allows the use of a custom {@link
 * TtlTimeProvider}.
 */
final class StubStateBackend implements StateBackend {

    private static final long serialVersionUID = 1L;

    private final TtlTimeProvider ttlTimeProvider;

    private final StateBackend backend;

    StubStateBackend(final StateBackend wrappedBackend, final TtlTimeProvider ttlTimeProvider) {
        this.backend = checkNotNull(wrappedBackend);
        this.ttlTimeProvider = checkNotNull(ttlTimeProvider);
    }

    @Override
    public <K> CheckpointableKeyedStateBackend<K> createKeyedStateBackend(
            Environment env,
            JobID jobID,
            String operatorIdentifier,
            TypeSerializer<K> keySerializer,
            int numberOfKeyGroups,
            KeyGroupRange keyGroupRange,
            TaskKvStateRegistry kvStateRegistry,
            TtlTimeProvider ttlTimeProvider,
            MetricGroup metricGroup,
            @Nonnull Collection<KeyedStateHandle> stateHandles,
            CloseableRegistry cancelStreamRegistry)
            throws Exception {

        return backend.createKeyedStateBackend(
                env,
                jobID,
                operatorIdentifier,
                keySerializer,
                numberOfKeyGroups,
                keyGroupRange,
                kvStateRegistry,
                this.ttlTimeProvider,
                metricGroup,
                stateHandles,
                cancelStreamRegistry);
    }

    @Override
    public OperatorStateBackend createOperatorStateBackend(
            Environment env,
            String operatorIdentifier,
            @Nonnull Collection<OperatorStateHandle> stateHandles,
            CloseableRegistry cancelStreamRegistry)
            throws Exception {
        return backend.createOperatorStateBackend(
                env, operatorIdentifier, stateHandles, cancelStreamRegistry);
    }
}