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.fun;
  
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.sql.SqlFunction;
  import org.apache.calcite.sql.SqlFunctionCategory;
  import org.apache.calcite.sql.SqlKind;
  import org.apache.calcite.sql.SqlOperatorBinding;
  import org.apache.calcite.sql.SqlSyntax;
  import org.apache.calcite.sql.type.OperandTypes;
  import org.apache.calcite.sql.type.SqlOperandTypeChecker;
  import org.apache.calcite.sql.type.SqlTypeName;
  import org.apache.calcite.sql.type.SqlTypeUtil;
  import org.apache.calcite.sql.validate.SqlMonotonicity;
  
  import static org.apache.calcite.sql.validate.SqlNonNullableAccessors.getOperandLiteralValueOrThrow;
  import static org.apache.calcite.util.Static.RESOURCE;
  
  /**
   * Base class for time functions such as "LOCALTIME", "LOCALTIME(n)".
   */
  public class SqlAbstractTimeFunction extends SqlFunction {
    //~ Static fields/initializers ---------------------------------------------
  
    private static final SqlOperandTypeChecker OTC_CUSTOM =
        OperandTypes.POSITIVE_INTEGER_LITERAL.or(OperandTypes.NILADIC);
  
    //~ Instance fields --------------------------------------------------------
  
    private final SqlTypeName typeName;
  
    //~ Constructors -----------------------------------------------------------
  
    protected SqlAbstractTimeFunction(String name, SqlTypeName typeName) {
      super(name, SqlKind.OTHER_FUNCTION, null, null, OTC_CUSTOM,
          SqlFunctionCategory.TIMEDATE);
      this.typeName = typeName;
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @Override public SqlSyntax getSyntax() {
      return SqlSyntax.FUNCTION_ID;
    }
  
    @Override public RelDataType inferReturnType(
        SqlOperatorBinding opBinding) {
      // REVIEW jvs 20-Feb-2005: Need to take care of time zones.
      int precision = 0;
      if (opBinding.getOperandCount() == 1) {
        RelDataType type = opBinding.getOperandType(0);
        if (SqlTypeUtil.isNumeric(type)) {
          precision = getOperandLiteralValueOrThrow(opBinding, 0, Integer.class);
        }
      }
      assert precision >= 0;
      final int maxPrecision = opBinding.getTypeFactory().getTypeSystem().getMaxPrecision(typeName);
      if (precision > maxPrecision) {
        throw opBinding.newError(
            RESOURCE.argumentMustBeValidPrecision(
                opBinding.getOperator().getName(), 0,
                maxPrecision));
      }
      return opBinding.getTypeFactory().createSqlType(typeName, precision);
    }
  
    // All of the time functions are increasing. Not strictly increasing.
    @Override public SqlMonotonicity getMonotonicity(SqlOperatorBinding call) {
      return SqlMonotonicity.INCREASING;
    }
  
    // Plans referencing context variables should never be cached
    @Override public boolean isDynamicFunction() {
      return true;
    }
  }
  