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.calcite.sql.validate;
  
  import org.apache.calcite.linq4j.Ord;
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.rel.type.RelDataTypeFactory;
  import org.apache.calcite.schema.Function;
  import org.apache.calcite.schema.FunctionParameter;
  import org.apache.calcite.schema.TableMacro;
  import org.apache.calcite.schema.TranslatableTable;
  import org.apache.calcite.sql.SqlFunction;
  import org.apache.calcite.sql.SqlFunctionCategory;
  import org.apache.calcite.sql.SqlIdentifier;
  import org.apache.calcite.sql.SqlKind;
  import org.apache.calcite.sql.SqlOperatorBinding;
  import org.apache.calcite.sql.SqlTableFunction;
  import org.apache.calcite.sql.type.SqlOperandMetadata;
  import org.apache.calcite.sql.type.SqlOperandTypeChecker;
  import org.apache.calcite.sql.type.SqlOperandTypeInference;
  import org.apache.calcite.sql.type.SqlReturnTypeInference;
  import org.apache.calcite.util.Util;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * User-defined table macro.
   *
   * <p>Created by the validator, after resolving a function call to a function
   * defined in a Calcite schema.
  */
  public class SqlUserDefinedTableMacro extends SqlFunction
      implements SqlTableFunction {
    private final TableMacro tableMacro;
  
    @Deprecated // to be removed before 2.0
    public SqlUserDefinedTableMacro(SqlIdentifier opName,
        SqlReturnTypeInference returnTypeInference,
        SqlOperandTypeInference operandTypeInference,
        @Nullable SqlOperandTypeChecker operandTypeChecker, List<RelDataType> paramTypes,
        TableMacro tableMacro) {
      this(opName, SqlKind.OTHER_FUNCTION, returnTypeInference,
          operandTypeInference,
          operandTypeChecker instanceof SqlOperandMetadata
              ? (SqlOperandMetadata) operandTypeChecker : null, tableMacro);
      Util.discard(paramTypes); // no longer used
    }
  
    /** Creates a user-defined table macro. */
    public SqlUserDefinedTableMacro(SqlIdentifier opName, SqlKind kind,
        SqlReturnTypeInference returnTypeInference,
        SqlOperandTypeInference operandTypeInference,
        @Nullable SqlOperandMetadata operandMetadata,
        TableMacro tableMacro) {
      super(Util.last(opName.names), opName, kind,
          returnTypeInference, operandTypeInference, operandMetadata,
          SqlFunctionCategory.USER_DEFINED_TABLE_FUNCTION);
      this.tableMacro = tableMacro;
    }
  
    @Override public @Nullable SqlOperandMetadata getOperandTypeChecker() {
      return (@Nullable SqlOperandMetadata) super.getOperandTypeChecker();
    }
  
    @SuppressWarnings("deprecation")
    @Override public List<String> getParamNames() {
      return Util.transform(tableMacro.getParameters(), FunctionParameter::getName);
    }
  
    /** Returns the table in this UDF, or null if there is no table. */
    public TranslatableTable getTable(SqlOperatorBinding callBinding) {
      List<@Nullable Object> arguments =
          convertArguments(callBinding, tableMacro, getNameAsId(), true);
      return tableMacro.apply(arguments);
    }
  
    /**
     * Converts arguments from {@link org.apache.calcite.sql.SqlNode} to
     * java object format.
     *
     * @param callBinding Operator bound to arguments
     * @param function target function to get parameter types from
     * @param opName name of the operator to use in error message
     * @param failOnNonLiteral true when conversion should fail on non-literal
     * @return converted list of arguments
     */
    static List<@Nullable Object> convertArguments(SqlOperatorBinding callBinding,
        Function function, SqlIdentifier opName, boolean failOnNonLiteral) {
      RelDataTypeFactory typeFactory = callBinding.getTypeFactory();
      List<@Nullable Object> arguments = new ArrayList<>(callBinding.getOperandCount());
      Ord.forEach(function.getParameters(), (parameter, i) -> {
        final RelDataType type = parameter.getType(typeFactory);
        final Object value;
        if (callBinding.isOperandLiteral(i, true)) {
          value = callBinding.getOperandLiteralValue(i, type);
        } else {
          if (failOnNonLiteral) {
            throw new IllegalArgumentException("All arguments of call to macro "
                + opName + " should be literal. Actual argument #"
                + parameter.getOrdinal() + " (" + parameter.getName()
                + ") is not literal");
          }
          if (type.isNullable()) {
            value = null;
          } else {
            value = 0L;
          }
        }
        arguments.add(value);
      });
      return arguments;
    }
  
    @Override public SqlReturnTypeInference getRowTypeInference() {
      return this::inferRowType;
    }
  
    private RelDataType inferRowType(SqlOperatorBinding callBinding) {
      final RelDataTypeFactory typeFactory = callBinding.getTypeFactory();
      final TranslatableTable table = getTable(callBinding);
      return table.getRowType(typeFactory);
    }
  }
  