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.cql3.statements.schema;
  
  import org.apache.cassandra.audit.AuditLogContext;
  import org.apache.cassandra.audit.AuditLogEntryType;
  import org.apache.cassandra.auth.Permission;
  import org.apache.cassandra.cql3.CQLStatement;
  import org.apache.cassandra.cql3.QualifiedName;
  import org.apache.cassandra.schema.*;
  import org.apache.cassandra.schema.KeyspaceMetadata.KeyspaceDiff;
  import org.apache.cassandra.schema.Keyspaces.KeyspacesDiff;
  import org.apache.cassandra.service.ClientState;
  import org.apache.cassandra.tcm.ClusterMetadata;
  import org.apache.cassandra.transport.Event.SchemaChange;
  import org.apache.cassandra.transport.Event.SchemaChange.Change;
  import org.apache.cassandra.transport.Event.SchemaChange.Target;
  
  public final class DropIndexStatement extends AlterSchemaStatement
  {
      private final String indexName;
      private final boolean ifExists;
  
      public DropIndexStatement(String keyspaceName, String indexName, boolean ifExists)
      {
          super(keyspaceName);
          this.indexName = indexName;
          this.ifExists = ifExists;
      }
  
      @Override
      public Keyspaces apply(ClusterMetadata metadata)
      {
          Keyspaces schema = metadata.schema.getKeyspaces();
          KeyspaceMetadata keyspace = schema.getNullable(keyspaceName);
  
          TableMetadata table = null == keyspace
                              ? null
                              : keyspace.findIndexedTable(indexName).orElse(null);
  
          if (null == table)
          {
              if (ifExists)
                  return schema;
  
              throw ire("Index '%s.%s' doesn't exist'", keyspaceName, indexName);
          }
  
          TableMetadata newTable = table.withSwapped(table.indexes.without(indexName));
          return schema.withAddedOrUpdated(keyspace.withSwapped(keyspace.tables.withSwapped(newTable)));
      }
  
      SchemaChange schemaChangeEvent(KeyspacesDiff diff)
      {
          assert diff.altered.size() == 1;
          KeyspaceDiff ksDiff = diff.altered.get(0);
  
          assert ksDiff.tables.altered.size() == 1;
          Diff.Altered<TableMetadata> tableDiff = ksDiff.tables.altered.iterator().next();
  
          return new SchemaChange(Change.UPDATED, Target.TABLE, keyspaceName, tableDiff.after.name);
      }
  
      public void authorize(ClientState client)
      {
          KeyspaceMetadata keyspace = Schema.instance.getKeyspaceMetadata(keyspaceName);
          if (null == keyspace)
              return;
  
          keyspace.findIndexedTable(indexName)
                  .ifPresent(t -> client.ensureTablePermission(keyspaceName, t.name, Permission.ALTER));
      }
  
      @Override
      public AuditLogContext getAuditLogContext()
      {
          return new AuditLogContext(AuditLogEntryType.DROP_INDEX, keyspaceName, indexName);
      }
  
      public String toString()
      {
          return String.format("%s (%s, %s)", getClass().getSimpleName(), keyspaceName, indexName);
      }
  
      public static final class Raw extends CQLStatement.Raw
      {
          private final QualifiedName name;
          private final boolean ifExists;
  
          public Raw(QualifiedName name, boolean ifExists)
          {
              this.name = name;
              this.ifExists = ifExists;
          }
  
          public DropIndexStatement prepare(ClientState state)
          {
              String keyspaceName = name.hasKeyspace() ? name.getKeyspace() : state.getKeyspace();
              return new DropIndexStatement(keyspaceName, name.getName(), ifExists);
          }
      }
  }
  