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;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import com.google.common.base.Preconditions;
  import com.google.common.collect.Iterators;
  
  import org.apache.cassandra.cql3.functions.Function;
  import org.apache.cassandra.cql3.statements.StatementType;
  import org.apache.cassandra.cql3.transactions.ReferenceOperation;
  import org.apache.cassandra.schema.ColumnMetadata;
  import org.apache.cassandra.schema.TableMetadata;
  
  /**
   * A set of <code>Operation</code>s.
   *
   */
  public final class Operations implements Iterable<Operation>
  {
      /**
       * The type of statement.
       */
      private final StatementType type;
      /**
       * If this operation is for a Transaction; this causes Operations to "migrate" when they require-read
       */
      private final boolean isForTxn;
  
      /**
       * The operations on regular columns.
       */
      private final List<Operation> regularOperations = new ArrayList<>();
  
      /**
       * The operations on static columns.
       */
      private final List<Operation> staticOperations = new ArrayList<>();
  
      private final List<ReferenceOperation> regularSubstitutions = new ArrayList<>();
      private final List<ReferenceOperation> staticSubstitutions = new ArrayList<>();
  
      public Operations(StatementType type, boolean isForTxn)
      {
          this.type = type;
          this.isForTxn = isForTxn;
      }
  
      private Operations(Operations other, TableMetadata tableMetadata)
      {
          Preconditions.checkState(!other.isForTxn, "Unable to migrate from txn to txn");
          Preconditions.checkState(other.regularSubstitutions.isEmpty() && other.staticSubstitutions.isEmpty(), "Transaction substitutions are defined for a non-transaction operations! regular=%s, static=%s", other.regularSubstitutions, other.staticSubstitutions);
  
          type = other.type;
          isForTxn = true;
          for (Operation opt : other)
              add(opt, tableMetadata);
      }
  
      public Operations forTxn(TableMetadata tableMetadata)
      {
          return new Operations(this, tableMetadata);
      }
  
      /**
       * Checks if some of the operations apply to static columns.
       *
       * @return <code>true</code> if some of the operations apply to static columns, <code>false</code> otherwise.
       */
      public boolean appliesToStaticColumns()
      {
          return !staticIsEmpty();
      }
  
      /**
       * Checks if some of the operations apply to regular columns.
       *
       * @return <code>true</code> if some of the operations apply to regular columns, <code>false</code> otherwise.
       */
      public boolean appliesToRegularColumns()
      {
          // If we have regular operations, this applies to regular columns.
          // Otherwise, if the statement is a DELETE and staticOperations is also empty, this means we have no operations,
          // which for a DELETE means a full row deletion. Which means the operation applies to all columns and regular ones in particular.
          return !regularIsEmpty() || (type.isDelete() && staticIsEmpty());
      }
  
      /**
       * Returns the operation on regular columns.
       * @return the operation on regular columns
       */
      public List<Operation> regularOperations()
      {
          return regularOperations;
      }
  
      /**
       * Returns the operation on static columns.
       * @return the operation on static columns
       */
      public List<Operation> staticOperations()
      {
          return staticOperations;
      }
  
      /**
       * Adds the specified <code>Operation</code> to this set of operations.
       *
       * @param operation     the operation to add
       * @param tableMetadata
       */
      public void add(Operation operation, TableMetadata tableMetadata)
      {
          if (isForTxn && (operation.requiresRead() || operation.requiresTimestamp()))
          {
              add(operation.column, ReferenceOperation.create(operation, tableMetadata));
              return;
          }
          if (operation.column.isStatic())
              staticOperations.add(operation);
          else
              regularOperations.add(operation);
      }
  
      public void add(ColumnMetadata column, ReferenceOperation operation)
      {
          Preconditions.checkState(isForTxn, "Unable to add a transaction reference to a non-transaction operation");
          if (column.isStatic())
              staticSubstitutions.add(operation);
          else
              regularSubstitutions.add(operation);
      }
  
      /**
       * Checks if one of the operations requires a read.
       *
       * @return <code>true</code> if one of the operations requires a read, <code>false</code> otherwise.
       */
      public boolean requiresRead()
      {
          // Lists SET operation incurs a read.
          for (Operation operation : this)
              if (operation.requiresRead())
                  return true;
  
          return false;
      }
  
      /**
       * Checks if this <code>Operations</code> is empty.
       * @return <code>true</code> if this <code>Operations</code> is empty, <code>false</code> otherwise.
       */
      public boolean isEmpty()
      {
          return staticIsEmpty() && regularIsEmpty();
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public Iterator<Operation> iterator()
      {
          return Iterators.concat(staticOperations.iterator(), regularOperations.iterator());
      }
  
      public void addFunctionsTo(List<Function> functions)
      {
          regularOperations.forEach(p -> p.addFunctionsTo(functions));
          staticOperations.forEach(p -> p.addFunctionsTo(functions));
          //TODO substitutions as well?
      }
  
      public List<ReferenceOperation> allSubstitutions()
      {
          if (staticSubstitutions.isEmpty())
              return regularSubstitutions;
          
          if (regularSubstitutions.isEmpty())
              return staticSubstitutions;
  
          // Only create a new list if we actually have something to combine
          List<ReferenceOperation> list = new ArrayList<>(staticSubstitutions.size() + regularSubstitutions.size());
          list.addAll(staticSubstitutions);
          list.addAll(regularSubstitutions);
          return list;
      }
  
      public List<ReferenceOperation> regularSubstitutions()
      {
          return regularSubstitutions;
      }
  
      public List<ReferenceOperation> staticSubstitutions()
      {
          return staticSubstitutions;
      }
  
      private boolean regularIsEmpty()
      {
          return regularOperations.isEmpty() && regularSubstitutions.isEmpty();
      }
  
      private boolean staticIsEmpty()
      {
          return staticOperations.isEmpty() && staticSubstitutions.isEmpty();
      }
  }
  