/*
* Licensed 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 com.facebook.presto.sql.planner;
import com.facebook.presto.spi.type.Type;
import com.facebook.presto.sql.tree.AtTimeZone;
import com.facebook.presto.sql.tree.Cast;
import com.facebook.presto.sql.tree.Expression;
import com.facebook.presto.sql.tree.ExpressionRewriter;
import com.facebook.presto.sql.tree.ExpressionTreeRewriter;
import com.facebook.presto.sql.tree.FunctionCall;
import com.facebook.presto.sql.tree.QualifiedName;
import com.facebook.presto.util.maps.IdentityLinkedHashMap;
import com.google.common.collect.ImmutableList;
import static com.facebook.presto.spi.type.TimeType.TIME;
import static com.facebook.presto.spi.type.TimeWithTimeZoneType.TIME_WITH_TIME_ZONE;
import static com.facebook.presto.spi.type.TimestampType.TIMESTAMP;
import static com.facebook.presto.spi.type.TimestampWithTimeZoneType.TIMESTAMP_WITH_TIME_ZONE;
import static java.util.Objects.requireNonNull;
public class DesugaringRewriter
extends ExpressionRewriter<Void>
{
private final IdentityLinkedHashMap<Expression, Type> expressionTypes;
public DesugaringRewriter(IdentityLinkedHashMap<Expression, Type> expressionTypes)
{
this.expressionTypes = requireNonNull(expressionTypes, "expressionTypes is null");
}
@Override
public Expression rewriteAtTimeZone(AtTimeZone node, Void context, ExpressionTreeRewriter<Void> treeRewriter)
{
Expression value = treeRewriter.rewrite(node.getValue(), context);
Type type = expressionTypes.get(node.getValue());
if (type.equals(TIME)) {
value = new Cast(value, TIME_WITH_TIME_ZONE.getDisplayName());
}
else if (type.equals(TIMESTAMP)) {
value = new Cast(value, TIMESTAMP_WITH_TIME_ZONE.getDisplayName());
}
return new FunctionCall(QualifiedName.of("at_timezone"), ImmutableList.of(
value,
treeRewriter.rewrite(node.getTimeZone(), context)));
}
}