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.SqlCall;
  import org.apache.calcite.sql.SqlCallBinding;
  import org.apache.calcite.sql.SqlFunction;
  import org.apache.calcite.sql.SqlFunctionCategory;
  import org.apache.calcite.sql.SqlKind;
  import org.apache.calcite.sql.SqlOperandCountRange;
  import org.apache.calcite.sql.type.OperandTypes;
  import org.apache.calcite.sql.type.ReturnTypes;
  import org.apache.calcite.sql.type.SqlOperandCountRanges;
  import org.apache.calcite.sql.type.SqlOperandTypeChecker;
  import org.apache.calcite.sql.type.SqlTypeTransforms;
  import org.apache.calcite.sql.type.SqlTypeUtil;
  import org.apache.calcite.sql.validate.SqlValidator;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.Locale;
  
  import static org.apache.calcite.util.Static.RESOURCE;
  
  /**
   * Definition of the <code>JSON_INSERT</code>, <code>JSON_REPLACE</code>
   * and <code>JSON_SET</code> JSON Modify functions.
   */
  public class SqlJsonModifyFunction extends SqlFunction {
    public SqlJsonModifyFunction(String name) {
      super(name,
          SqlKind.OTHER_FUNCTION,
          ReturnTypes.cascade(ReturnTypes.VARCHAR_2000,
              SqlTypeTransforms.FORCE_NULLABLE),
          null,
          OperandTypes.ANY,
          SqlFunctionCategory.SYSTEM);
    }
  
    @Override public SqlOperandCountRange getOperandCountRange() {
      return SqlOperandCountRanges.from(3);
    }
  
    @Override protected void checkOperandCount(SqlValidator validator,
        @Nullable SqlOperandTypeChecker argType, SqlCall call) {
      assert (call.operandCount() >= 3) && (call.operandCount() % 2 == 1);
    }
  
    @Override public boolean checkOperandTypes(SqlCallBinding callBinding,
        boolean throwOnFailure) {
      final int count = callBinding.getOperandCount();
      for (int i = 1; i < count; i += 2) {
        RelDataType nameType = callBinding.getOperandType(i);
        if (!SqlTypeUtil.isCharacter(nameType)) {
          if (throwOnFailure) {
            throw callBinding.newError(RESOURCE.expectedCharacter());
          }
          return false;
        }
        if (nameType.isNullable()) {
          if (throwOnFailure) {
            throw callBinding.newError(
                RESOURCE.argumentMustNotBeNull(
                    callBinding.operand(i).toString()));
          }
          return false;
        }
      }
      return true;
    }
  
    @Override public String getSignatureTemplate(int operandsCount) {
      assert operandsCount % 2 == 1;
      StringBuilder sb = new StringBuilder();
      sb.append("{0}(");
      for (int i = 1; i < operandsCount; i++) {
        sb.append(String.format(Locale.ROOT, "{%d} ", i + 1));
      }
      sb.append("{1})");
      return sb.toString();
    }
  }
  