/*
* 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.samza.sql.system;

import java.util.Collections;
import java.util.Map;
import java.util.Set;
import java.util.function.Function;
import java.util.stream.Collectors;
import org.apache.samza.Partition;
import org.apache.samza.config.Config;
import org.apache.samza.system.StreamSpec;
import org.apache.samza.system.SystemAdmin;
import org.apache.samza.system.SystemStreamMetadata;
import org.apache.samza.system.SystemStreamPartition;

import static org.apache.samza.system.IncomingMessageEnvelope.*;


public class SimpleSystemAdmin implements SystemAdmin {

  public SimpleSystemAdmin(Config config) {
  }

  @Override
  public Map<SystemStreamPartition, String> getOffsetsAfter(Map<SystemStreamPartition, String> offsets) {
    return offsets.entrySet().stream().collect(Collectors.toMap(Map.Entry::getKey, null));
  }

  @Override
  public Map<String, SystemStreamMetadata> getSystemStreamMetadata(Set<String> streamNames) {
    return streamNames.stream()
        .collect(Collectors.toMap(Function.identity(), streamName -> new SystemStreamMetadata(streamName,
            Collections.singletonMap(new Partition(0),
                new SystemStreamMetadata.SystemStreamPartitionMetadata(null, END_OF_STREAM_OFFSET, null)))));
  }

  @Override
  public Integer offsetComparator(String offset1, String offset2) {
    if (offset1 == null) {
      return offset2 == null ? 0 : -1;
    } else if (offset2 == null) {
      return 1;
    }
    return offset1.compareTo(offset2);
  }

  @Override
  public boolean createStream(StreamSpec streamSpec) {
    // Do nothing.
    return true;
  }
}