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.dialect;
  
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.rel.type.RelDataTypeSystem;
  import org.apache.calcite.rel.type.RelDataTypeSystemImpl;
  import org.apache.calcite.sql.SqlAlienSystemTypeNameSpec;
  import org.apache.calcite.sql.SqlDataTypeSpec;
  import org.apache.calcite.sql.SqlDialect;
  import org.apache.calcite.sql.SqlNode;
  import org.apache.calcite.sql.parser.SqlParserPos;
  import org.apache.calcite.sql.type.AbstractSqlType;
  import org.apache.calcite.sql.type.SqlTypeName;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  /**
   * A <code>SqlDialect</code> implementation for the Apache Phoenix database.
   */
  public class PhoenixSqlDialect extends SqlDialect {
    public static final RelDataTypeSystem TYPE_SYSTEM =
        new RelDataTypeSystemImpl() {
  
          // We can refer to document of Phoenix 5.x:
          // https://phoenix.apache.org/language/datatypes.html#decimal_type
          @Override public int getMaxPrecision(SqlTypeName typeName) {
            switch (typeName) {
            case DECIMAL:
              return 38;
            default:
              return super.getMaxPrecision(typeName);
            }
          }
  
          @Override public int getMaxScale(SqlTypeName typeName) {
            switch (typeName) {
            case DECIMAL:
              return 38;
            default:
              return super.getMaxScale(typeName);
            }
          }
  
          @Override public int getMaxNumericScale() {
            return getMaxScale(SqlTypeName.DECIMAL);
          }
        };
  
    public static final SqlDialect.Context DEFAULT_CONTEXT = SqlDialect.EMPTY_CONTEXT
        .withDatabaseProduct(SqlDialect.DatabaseProduct.PHOENIX)
        .withIdentifierQuoteString("\"")
        .withDataTypeSystem(TYPE_SYSTEM);
  
    public static final SqlDialect DEFAULT = new PhoenixSqlDialect(DEFAULT_CONTEXT);
  
    /** Creates a PhoenixSqlDialect. */
    public PhoenixSqlDialect(Context context) {
      super(context);
    }
  
    @Override public boolean supportsApproxCountDistinct() {
      return true;
    }
  
    @Override public boolean supportsCharSet() {
      return false;
    }
  
    @Override public @Nullable SqlNode getCastSpec(RelDataType type) {
      switch (type.getSqlTypeName()) {
      case REAL:
        return new SqlDataTypeSpec(
            new SqlAlienSystemTypeNameSpec(
                "FLOAT",
                type.getSqlTypeName(),
                SqlParserPos.ZERO),
            SqlParserPos.ZERO);
      default:
        break;
      }
  
      if (type instanceof AbstractSqlType) {
        switch (type.getSqlTypeName()) {
        case ARRAY:
        case MAP:
        case MULTISET:
          throw new UnsupportedOperationException("Phoenix dialect does not support cast to "
              + type.getSqlTypeName());
        default:
          break;
        }
      }
  
      return super.getCastSpec(type);
    }
  }
  