package sqlancer.presto.gen;

import java.util.List;

import sqlancer.Randomly;

import sqlancer.common.gen.AbstractIndexGenerator;

import sqlancer.common.query.SQLQueryAdapter;

import sqlancer.presto.PrestoGlobalState;

import sqlancer.presto.PrestoSchema;

import sqlancer.presto.PrestoSchema.PrestoColumn;

import sqlancer.presto.PrestoSchema.PrestoTable;

import sqlancer.presto.PrestoToStringVisitor;

import sqlancer.presto.ast.PrestoExpression;

public class PrestoIndexGenerator extends AbstractIndexGenerator<PrestoColumn> {

private final PrestoGlobalState globalState;

public PrestoIndexGenerator(PrestoGlobalState globalState) {

this.globalState = globalState;

this.canAffectSchema = true;

this.canonicalizeString = false;

}

public static SQLQueryAdapter getQuery(PrestoGlobalState globalState) {

return new PrestoIndexGenerator(globalState).getStatement();

}

@Override

public void buildStatement() {

boolean unique = Randomly.getBoolean();

if (unique) {

errors.add("Cant create unique index, table contains duplicate data on indexed column(s)");

}

appendCreateIndex(unique);

sb.append(Randomly.fromOptions("i0", "i1", "i2", "i3", "i4")); // cannot query this information

sb.append(" ON ");

PrestoTable table = globalState.getSchema().getRandomTable(t -> !t.isView());

sb.append(table.getName());

sb.append("(");

List<PrestoColumn> columns = table.getRandomNonEmptyColumnSubset();

for (int i = 0; i < columns.size(); i++) {

if (i != 0) {

sb.append(", ");

}

sb.append(columns.get(i).getName());

sb.append(" ");

if (Randomly.getBooleanWithRatherLowProbability()) {

sb.append(Randomly.fromOptions("ASC", "DESC"));

}

}

sb.append(")");

if (Randomly.getBoolean()) {

PrestoExpression expr = new PrestoTypedExpressionGenerator(globalState).setColumns(table.getColumns())

.generateExpression(PrestoSchema.PrestoCompositeDataType.getRandomWithoutNull());

appendWhereClause(PrestoToStringVisitor.asString(expr));

}

errors.add("already exists!");

}

}