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.terms;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Objects;
  import java.util.Optional;
  import java.util.Set;
  import java.util.stream.Collectors;
  
  import org.apache.cassandra.cql3.AssignmentTestable;
  import org.apache.cassandra.cql3.ColumnIdentifier;
  import org.apache.cassandra.cql3.ColumnSpecification;
  import org.apache.cassandra.cql3.QueryOptions;
  import org.apache.cassandra.db.marshal.AbstractType;
  import org.apache.cassandra.db.marshal.VectorType;
  import org.apache.cassandra.exceptions.InvalidRequestException;
  
  public final class Vectors
  {
      private Vectors() {}
  
      private static AbstractType<?> elementsType(AbstractType<?> type)
      {
          return ((VectorType<?>) type.unwrap()).getElementsType();
      }
  
      private static ColumnSpecification valueSpecOf(ColumnSpecification column)
      {
          return new ColumnSpecification(column.ksName, column.cfName, new ColumnIdentifier("value(" + column.name + ')', true), elementsType(column.type));
      }
  
      /**
       * Tests that the vector with the specified elements can be assigned to the specified column.
       *
       * @param receiver the receiving column
       * @param elements the vector elements
       */
      public static AssignmentTestable.TestResult testVectorAssignment(ColumnSpecification receiver,
                                                                       List<? extends AssignmentTestable> elements)
      {
          if (!receiver.type.isVector())
              return AssignmentTestable.TestResult.NOT_ASSIGNABLE;
  
          // If there is no elements, we can't say it's an exact match (an empty vector if fundamentally polymorphic).
          if (elements.isEmpty())
              return AssignmentTestable.TestResult.WEAKLY_ASSIGNABLE;
  
          ColumnSpecification valueSpec = valueSpecOf(receiver);
          return AssignmentTestable.TestResult.testAll(receiver.ksName, valueSpec, elements);
      }
  
      /**
       * Returns the exact VectorType from the items if it can be known.
       *
       * @param items the items mapped to the vector elements
       * @param mapper the mapper used to retrieve the element types from the items
       * @return the exact VectorType from the items if it can be known or <code>null</code>
       */
      public static <T> VectorType<?> getExactVectorTypeIfKnown(List<T> items,
                                                                java.util.function.Function<T, AbstractType<?>> mapper)
      {
          // TODO - this doesn't feel right... if you are dealing with a literal then the value is `null`, so we will ignore
          // if there are multiple times, we randomly select the first?  This logic matches Lists.getExactListTypeIfKnown but feels flawed
          Optional<AbstractType<?>> type = items.stream().map(mapper).filter(Objects::nonNull).findFirst();
          return type.isPresent() ? VectorType.getInstance(type.get(), items.size()) : null;
      }
  
      public static <T> VectorType<?> getPreferredCompatibleType(List<T> items,
                                                                 java.util.function.Function<T, AbstractType<?>> mapper)
      {
          Set<AbstractType<?>> types = items.stream().map(mapper).filter(Objects::nonNull).collect(Collectors.toSet());
          AbstractType<?> type = AssignmentTestable.getCompatibleTypeIfKnown(types);
          return type == null ? null : VectorType.getInstance(type, items.size());
      }
  
      public static class Literal extends Term.Raw
      {
          private final List<Term.Raw> elements;
  
          public Literal(List<Term.Raw> elements)
          {
              this.elements = elements;
          }
  
          @Override
          public TestResult testAssignment(String keyspace, ColumnSpecification receiver)
          {
              if (!receiver.type.isVector())
                  return AssignmentTestable.TestResult.NOT_ASSIGNABLE;
              VectorType<?> type = (VectorType<?>) receiver.type;
              if (elements.size() != type.dimension)
                  return AssignmentTestable.TestResult.NOT_ASSIGNABLE;
              ColumnSpecification valueSpec = valueSpecOf(receiver);
              return AssignmentTestable.TestResult.testAll(receiver.ksName, valueSpec, elements);
          }
  
          @Override
          public Term prepare(String keyspace, ColumnSpecification receiver) throws InvalidRequestException
          {
              AbstractType<?> unwrapped = receiver.type.unwrap();
  
              if (!unwrapped.isVector())
                  throw new InvalidRequestException(String.format("Invalid vector literal for %s of type %s", receiver.name, receiver.type.asCQL3Type()));
              VectorType<?> type = (VectorType<?>) unwrapped;
              if (elements.size() != type.dimension)
                  throw new InvalidRequestException(String.format("Invalid vector literal for %s of type %s; expected %d elements, but given %d", receiver.name, receiver.type.asCQL3Type(), type.dimension, elements.size()));
  
              ColumnSpecification valueSpec = valueSpecOf(receiver);
              List<Term> values = new ArrayList<>(elements.size());
              boolean allTerminal = true;
              for (Term.Raw rt : elements)
              {
                  if (!rt.testAssignment(keyspace, valueSpec).isAssignable())
                      throw new InvalidRequestException(String.format("Invalid vector literal for %s: value %s is not of type %s", receiver.name, rt, valueSpec.type.asCQL3Type()));
  
                  Term t = rt.prepare(keyspace, valueSpec);
  
                  if (t instanceof Term.NonTerminal)
                      allTerminal = false;
  
                  values.add(t);
              }
              MultiElements.DelayedValue value = new MultiElements.DelayedValue(type, values);
              return allTerminal ? value.bind(QueryOptions.DEFAULT) : value;
          }
  
          @Override
          public String getText()
          {
              return Lists.listToString(elements, Term.Raw::getText);
          }
  
          @Override
          public AbstractType<?> getExactTypeIfKnown(String keyspace)
          {
              return getExactVectorTypeIfKnown(elements, e -> e.getExactTypeIfKnown(keyspace));
          }
  
          @Override
          public AbstractType<?> getCompatibleTypeIfKnown(String keyspace)
          {
              return getPreferredCompatibleType(elements, e -> e.getCompatibleTypeIfKnown(keyspace));
          }
      }
  }
  