content: /*
   * 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.cassandra.repair.consistent.admin;
  
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  
  import com.google.common.base.Preconditions;
  import com.google.common.collect.Iterables;
  import com.google.common.collect.Lists;
  
  import org.apache.cassandra.db.ColumnFamilyStore;
  import org.apache.cassandra.db.Keyspace;
  import org.apache.cassandra.schema.Schema;
  import org.apache.cassandra.utils.AbstractIterator;
  
  public class SchemaArgsParser implements Iterable<ColumnFamilyStore>
  {
  
      private final List<String> schemaArgs;
  
      private SchemaArgsParser(List<String> schemaArgs)
      {
          this.schemaArgs = schemaArgs;
      }
  
      private static class TableIterator extends AbstractIterator<ColumnFamilyStore>
      {
          private final Iterator<ColumnFamilyStore> tables;
  
          public TableIterator(String ksName, List<String> tableNames)
          {
              Preconditions.checkArgument(Schema.instance.getKeyspaceMetadata(ksName) != null);
              Keyspace keyspace = Keyspace.open(ksName);
  
              if (tableNames.isEmpty())
              {
                  tables = keyspace.getColumnFamilyStores().iterator();
              }
              else
              {
                  tables = Lists.newArrayList(Iterables.transform(tableNames, tn -> keyspace.getColumnFamilyStore(tn))).iterator();
              }
          }
  
          @Override
          protected ColumnFamilyStore computeNext()
          {
              return tables.hasNext() ? tables.next() : endOfData();
          }
      }
  
      @Override
      public Iterator<ColumnFamilyStore> iterator()
      {
          if (schemaArgs.isEmpty())
          {
              // iterate over everything
              Iterator<String> ksNames = Schema.instance.distributedKeyspaces().names().iterator();
  
              return new AbstractIterator<ColumnFamilyStore>()
              {
                  TableIterator current = null;
                  protected ColumnFamilyStore computeNext()
                  {
                      for (;;)
                      {
                          if (current != null && current.hasNext())
                          {
                              return current.next();
                          }
  
                          if (ksNames.hasNext())
                          {
                              current = new TableIterator(ksNames.next(), Collections.emptyList());
                              continue;
                          }
  
                          return endOfData();
                      }
                  }
              };
  
          }
          else
          {
              return new TableIterator(schemaArgs.get(0), schemaArgs.subList(1, schemaArgs.size()));
          }
      }
  
      public static Iterable<ColumnFamilyStore> parse(List<String> schemaArgs)
      {
          return new SchemaArgsParser(schemaArgs);
      }
  
      public static Iterable<ColumnFamilyStore> parse(String... schemaArgs)
      {
          return parse(Lists.newArrayList(schemaArgs));
      }
  }
  