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package org.babyfish.jimmer.sql.ast.query;
import org.babyfish.jimmer.lang.NewChain;
import org.babyfish.jimmer.meta.EmbeddedLevel;
import org.babyfish.jimmer.meta.ImmutableProp;
import org.babyfish.jimmer.meta.ImmutableType;
import org.babyfish.jimmer.meta.TargetLevel;
import org.babyfish.jimmer.sql.JoinType;
import org.babyfish.jimmer.sql.ast.Expression;
import org.babyfish.jimmer.sql.ast.PropExpression;
import org.babyfish.jimmer.sql.ast.table.Props;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.regex.Pattern;
public class Order {
private static final Pattern SEPARATOR_PATTERN = Pattern.compile("[,;]");
private static final Pattern WHITESPACE_PATTERN = Pattern.compile("\\s+");
private final Expression expression;
private final OrderMode orderMode;
private final NullOrderMode nullOrderMode;
public Order(Expression expression, OrderMode orderMode, NullOrderMode nullOrderMode) {
this.expression = Objects.requireNonNull(expression);
this.orderMode = Objects.requireNonNull(orderMode);
this.nullOrderMode = Objects.requireNonNull(nullOrderMode);
}
public Expression getExpression() {
return expression;
}
public OrderMode getOrderMode() {
return orderMode;
}
public NullOrderMode getNullOrderMode() {
return nullOrderMode;
}
@NewChain
public Order nullsFirst() {
return new Order(expression, orderMode, NullOrderMode.NULLS_FIRST);
}
@NewChain
public Order nullsLast() {
return new Order(expression, orderMode, NullOrderMode.NULLS_LAST);
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Order order = (Order) o;
return expression.equals(order.expression) && orderMode == order.orderMode && nullOrderMode == order.nullOrderMode;
}
@Override
public int hashCode() {
return Objects.hash(expression, orderMode, nullOrderMode);
}
@Override
public String toString() {
return "Order{" +
"expression=" + expression +
", orderMode=" + orderMode +
", nullOrderMode=" + nullOrderMode +
'}';
}
/**
* Parse dynamic code to jimmer order list,
*
* For example:
*
*
* q.makeOrders(
* Order.orders(
* table,
* "name asc, parent.name desc nulls last"
* "edition desc",
* "region.segment.size; region.segment.cost desc"
* )
* )
*
*/
public static List makeOrders(Props table, String ... codes) {
CustomOrderCreator creator = (path, orderMode, nullOrderMode) ->
new Order(
orderedExpression(table, path),
orderMode,
nullOrderMode
);
return makeCustomOrders(creator, codes);
}
/**
* Parse dynamic code to order list of third-party library, such as `Sort.Order` of spring-data,
*
* For example: cast to list whose element type is `Sort.Order` of spring data
*
*
* List<Sort.Order> orders =
* Order.makeCustomOrders(
* (path, orderMode, nullOrderMode) -> {
* NullHandling nullHandling;
* switch (nullOrderMode) {
* case NullOrderMode.NULLS_FIRST:
* nullHandling = NullHandling.NULLS_FIRST;
* break;
* case NullOrderMode.NULLS_LAST:
* nullHandling = NullHandling.NULLS_LAST;
* break;
* default:
* nullHandling = NullHandling.NATIVE;
* break;
* }
* return new Sort.Order(
* path,
* orderMode == OrderMode.DESC ? Direction.DESC : Direction.ASC,
* nullHandling
* );
* },
* "name asc, parent.name desc nulls last"
* "edition desc",
* "region.segment.size; region.segment.cost desc"
* )
* );
*
*/
public static List makeCustomOrders(
CustomOrderCreator creator,
String... codes
) {
List orders = new ArrayList<>();
for (String code : codes) {
for (String part : SEPARATOR_PATTERN.split(code)) {
part = part.trim();
if (!part.isEmpty()) {
orders.add(makeCustomOrder(part, creator));
}
}
}
return orders;
}
private static O makeCustomOrder(String code, CustomOrderCreator creator) {
String[] parts = WHITESPACE_PATTERN.split(code);
OrderMode orderMode = OrderMode.ASC;
NullOrderMode nullOrderMode = NullOrderMode.UNSPECIFIED;
// 0: asc | desc, 1: nulls, 2: first | last, 3: end
int channel = 0;
for (int i = 1; i < parts.length; i++) {
String rest = parts[i].toLowerCase();
switch (channel) {
case 0:
switch (rest) {
case "asc":
channel = 1;
break;
case "desc":
channel = 1;
orderMode = OrderMode.DESC;
break;
case "nulls":
channel = 2;
break;
default:
throw new IllegalArgumentException(
"Illegal order code \"" + code + "\"," +
"\"asc\", \"desc\" or \"nulls\" is expected after property path"
);
}
break;
case 1:
if ("nulls".equals(rest)) {
channel = 2;
} else {
throw new IllegalArgumentException(
"Illegal order code \"" + code + "\"" +
"\"nulls\" is expected but \"" + rest + "\" is found"
);
}
break;
case 2:
switch (rest) {
case "first":
channel = 3;
nullOrderMode = NullOrderMode.NULLS_FIRST;
break;
case "last":
channel = 3;
nullOrderMode = NullOrderMode.NULLS_LAST;
break;
default:
throw new IllegalArgumentException(
"Illegal order code \"" + code + "\"," +
"\"asc\", \"desc\" or \"nulls\" is expected after property path"
);
}
break;
case 3:
throw new IllegalArgumentException(
"Illegal order code \"" + code + "\"," +
"unexpected token \"" + rest + "\""
);
}
}
if (channel == 2) {
throw new IllegalArgumentException(
"Illegal order code \"" + code + "\", " +
"\"first\" or \"last\" is expected after \"nulls\""
);
}
return creator.create(parts[0], orderMode, nullOrderMode);
}
public static Expression orderedExpression(Props table, String path) {
List props = orderedPropChain(table.getImmutableType(), path);
JoinType joinType = JoinType.INNER;
Props source = table;
Expression expr = null;
for (ImmutableProp prop : props) {
if (prop.isReference(TargetLevel.PERSISTENT)) {
if (prop.isNullable()) {
joinType = JoinType.LEFT;
}
source = source.join(prop.getName(), joinType);
} else if (expr != null) {
expr = ((PropExpression.Embedded)expr).get(prop.getName());
} else {
expr = source.get(prop.getName());
}
}
if (expr == null) {
throw new AssertionError("Internal bug, illegal path \"" + path + "\"");
}
return expr;
}
public static List orderedPropChain(ImmutableType type, String path) {
List props = new ArrayList<>();
while (!path.isEmpty()) {
int dotIndex = path.indexOf('.');
String propName = dotIndex == -1 ? path : path.substring(0, dotIndex);
String restPath = dotIndex == -1 ? "" : path.substring(dotIndex + 1);
ImmutableProp prop = type.getProps().get(propName);
if (prop == null) {
throw new IllegalArgumentException(
"Cannot resolve ordered property path \"" +
path +
"\" from \"" +
type +
"\", there is no property \"" +
propName +
"\" in \"" +
type +
"\""
);
}
if (prop.isReferenceList(TargetLevel.OBJECT) || prop.isScalarList()) {
throw new IllegalArgumentException(
"Cannot resolve ordered property path \"" +
path +
"\" from \"" +
type +
"\", the property \"" +
prop +
"\" cannot be list"
);
}
if (restPath.isEmpty() && !prop.isScalar(TargetLevel.OBJECT)) {
throw new IllegalArgumentException(
"Cannot resolve ordered property path \"" +
path +
"\" from \"" +
type +
"\", \"" +
prop +
"\" is the last property of the path but it is not scalar"
);
}
if (!restPath.isEmpty() && !prop.isReference(TargetLevel.PERSISTENT) && !prop.isEmbedded(EmbeddedLevel.BOTH)) {
throw new IllegalArgumentException(
"Cannot resolve ordered property path \"" +
path +
"\" from \"" +
type +
"\", \"" +
prop +
"\" is not the last property of path but it is neither reference nor embedded"
);
}
props.add(prop);
path = restPath;
if (prop.getTargetType() != null) {
type = prop.getTargetType();
}
}
return props;
}
public interface CustomOrderCreator {
O create(String path, OrderMode orderMode, NullOrderMode nullOrderMode);
}
}