package sqlancer.postgres.ast;

import sqlancer.Randomly;

import sqlancer.postgres.PostgresSchema.PostgresDataType;

public class PostgresOrderByTerm implements PostgresExpression {

private final PostgresExpression expr;

private final PostgresOrder order;

public enum PostgresOrder {

ASC, DESC;

public static PostgresOrder getRandomOrder() {

return Randomly.fromOptions(PostgresOrder.values());

}

}

public PostgresOrderByTerm(PostgresExpression expr, PostgresOrder order) {

if (expr == null) {

throw new IllegalArgumentException("Expression cannot be null");

}

this.expr = expr;

this.order = order;

}

// Constructor for window functions, might be removed in the future to have only one constructor

public PostgresOrderByTerm(PostgresExpression expr, boolean ascending) {

if (expr == null) {

throw new IllegalArgumentException("Expression cannot be null");

}

this.expr = expr;

this.order = ascending ? PostgresOrder.ASC : PostgresOrder.DESC;

}

public PostgresExpression getExpr() {

return expr;

}

public PostgresOrder getOrder() {

return order;

}

public boolean isAscending() {

return order == PostgresOrder.ASC;

}

@Override

public PostgresConstant getExpectedValue() {

throw new AssertionError(this);

}

@Override

public PostgresDataType getExpressionType() {

return null;

}

@Override

public String toString() {

return String.format("%s %s", expr, order);

}

}