/*
* Copyright 2004-2023 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.expression;
import org.h2.engine.SessionLocal;
import org.h2.message.DbException;
import org.h2.util.DateTimeUtils;
import org.h2.util.TimeZoneProvider;
import org.h2.value.DataType;
import org.h2.value.TypeInfo;
import org.h2.value.Value;
import org.h2.value.ValueInterval;
import org.h2.value.ValueNull;
import org.h2.value.ValueTimeTimeZone;
import org.h2.value.ValueTimestamp;
import org.h2.value.ValueTimestampTimeZone;
/**
* A time zone specification (AT { TIME ZONE | LOCAL }).
*/
public final class TimeZoneOperation extends Operation1_2 {
public TimeZoneOperation(Expression left, Expression right) {
super(left, right);
}
@Override
public StringBuilder getUnenclosedSQL(StringBuilder builder, int sqlFlags) {
left.getSQL(builder, sqlFlags, AUTO_PARENTHESES).append(" AT ");
if (right != null) {
right.getSQL(builder.append("TIME ZONE "), sqlFlags, AUTO_PARENTHESES);
} else {
builder.append("LOCAL");
}
return builder;
}
@Override
public Value getValue(SessionLocal session) {
Value l = left.getValue(session);
Value a = l.convertTo(type, session);
if (a == ValueNull.INSTANCE) {
return ValueNull.INSTANCE;
}
Value b;
if (right == null) {
int t = l.getValueType();
if (t == Value.TIME || t == Value.TIMESTAMP) {
// Already in time zone of the session
return a;
}
b = null;
} else {
b = right.getValue(session);
if (b == ValueNull.INSTANCE) {
return ValueNull.INSTANCE;
}
}
if (a.getValueType() == Value.TIMESTAMP_TZ) {
ValueTimestampTimeZone v = (ValueTimestampTimeZone) a;
long dateValue = v.getDateValue();
long timeNanos = v.getTimeNanos();
int offsetSeconds = v.getTimeZoneOffsetSeconds();
int newOffset = b != null //
? parseTimeZone(b, dateValue, timeNanos, offsetSeconds, true)
: session.currentTimeZone()
.getTimeZoneOffsetUTC(DateTimeUtils.getEpochSeconds(dateValue, timeNanos, offsetSeconds));
if (offsetSeconds != newOffset) {
a = DateTimeUtils.timestampTimeZoneAtOffset(dateValue, timeNanos, offsetSeconds, newOffset);
}
} else {
ValueTimeTimeZone v = (ValueTimeTimeZone) a;
long timeNanos = v.getNanos();
int offsetSeconds = v.getTimeZoneOffsetSeconds();
int newOffset = b != null
? parseTimeZone(b, DateTimeUtils.EPOCH_DATE_VALUE, timeNanos, offsetSeconds, false)
: session.currentTimeZone().getTimeZoneOffsetUTC(DateTimeUtils
.getEpochSeconds(session.currentTimestamp().getDateValue(), timeNanos, offsetSeconds));
if (offsetSeconds != newOffset) {
timeNanos += (newOffset - offsetSeconds) * DateTimeUtils.NANOS_PER_SECOND;
a = ValueTimeTimeZone.fromNanos(DateTimeUtils.normalizeNanosOfDay(timeNanos), newOffset);
}
}
return a;
}
private static int parseTimeZone(Value b, long dateValue, long timeNanos, int offsetSeconds,
boolean allowTimeZoneName) {
if (DataType.isCharacterStringType(b.getValueType())) {
TimeZoneProvider timeZone;
try {
timeZone = TimeZoneProvider.ofId(b.getString());
} catch (RuntimeException ex) {
throw DbException.getInvalidValueException("time zone", b.getTraceSQL());
}
if (!allowTimeZoneName && !timeZone.hasFixedOffset()) {
throw DbException.getInvalidValueException("time zone", b.getTraceSQL());
}
return timeZone.getTimeZoneOffsetUTC(DateTimeUtils.getEpochSeconds(dateValue, timeNanos, offsetSeconds));
}
return parseInterval(b);
}
/**
* Parses a daytime interval as time zone offset.
*
* @param interval the interval
* @return the time zone offset in seconds
*/
public static int parseInterval(Value interval) {
ValueInterval i = (ValueInterval) interval.convertTo(TypeInfo.TYPE_INTERVAL_HOUR_TO_SECOND);
long h = i.getLeading(), seconds = i.getRemaining();
if (h > 18 || h == 18 && seconds != 0 || seconds % DateTimeUtils.NANOS_PER_SECOND != 0) {
throw DbException.getInvalidValueException("time zone", i.getTraceSQL());
}
int newOffset = (int) (h * 3_600 + seconds / DateTimeUtils.NANOS_PER_SECOND);
if (i.isNegative()) {
newOffset = -newOffset;
}
return newOffset;
}
@Override
public Expression optimize(SessionLocal session) {
left = left.optimize(session);
if (right != null) {
right = right.optimize(session);
}
TypeInfo type = left.getType();
int valueType = Value.TIMESTAMP_TZ, scale = ValueTimestamp.MAXIMUM_SCALE;
int lType = type.getValueType();
switch (lType) {
case Value.TIMESTAMP:
case Value.TIMESTAMP_TZ:
scale = type.getScale();
break;
case Value.TIME:
case Value.TIME_TZ:
valueType = Value.TIME_TZ;
scale = type.getScale();
break;
default:
StringBuilder builder = left.getSQL(new StringBuilder(), TRACE_SQL_FLAGS, AUTO_PARENTHESES);
int offset = builder.length();
builder.append(" AT ");
if (right != null) {
right.getSQL(builder.append("TIME ZONE "), TRACE_SQL_FLAGS, AUTO_PARENTHESES);
} else {
builder.append("LOCAL");
}
throw DbException.getSyntaxError(builder.toString(), offset, "time, timestamp");
}
this.type = TypeInfo.getTypeInfo(valueType, -1, scale, null);
if (left.isConstant() && (lType == Value.TIME_TZ || lType == Value.TIMESTAMP_TZ) && right != null
&& right.isConstant()) {
return ValueExpression.get(getValue(session));
}
return this;
}
@Override
public boolean isEverything(ExpressionVisitor visitor) {
if (visitor.getType() == ExpressionVisitor.DETERMINISTIC) {
if (right == null) {
return false;
}
int lType = left.getType().getValueType();
if (lType == Value.TIME || lType == Value.TIMESTAMP) {
return false;
}
}
return left.isEverything(visitor) && (right == null || right.isEverything(visitor));
}
}