/*
 * 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.sanity;

import com.facebook.presto.Session;
import com.facebook.presto.metadata.Metadata;
import com.facebook.presto.spi.type.Type;
import com.facebook.presto.sql.parser.SqlParser;
import com.facebook.presto.sql.planner.SimplePlanVisitor;
import com.facebook.presto.sql.planner.Symbol;
import com.facebook.presto.sql.planner.plan.PlanNode;
import com.facebook.presto.sql.planner.plan.PlanNodeId;

import java.util.HashMap;
import java.util.Map;

import static com.google.common.base.Preconditions.checkArgument;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;

public class NoDuplicatePlanNodeIdsChecker
        implements PlanSanityChecker.Checker
{
    @Override
    public void validate(PlanNode planNode, Session session, Metadata metadata, SqlParser sqlParser, Map<Symbol, Type> types)
    {
        planNode.accept(new Visitor(), new HashMap<>());
    }

    private static class Visitor
            extends SimplePlanVisitor<Map<PlanNodeId, PlanNode>>
    {
        @Override
        protected Void visitPlan(PlanNode node, Map<PlanNodeId, PlanNode> context)
        {
            context.merge(node.getId(), node, this::reportDuplicateId);

            return super.visitPlan(node, context);
        }

        private PlanNode reportDuplicateId(PlanNode first, PlanNode second)
        {
            requireNonNull(first, "first is null");
            requireNonNull(second, "second is null");
            checkArgument(first.getId().equals(second.getId()));

            throw new IllegalStateException(format(
                    "Generated plan contains nodes with duplicated id %s: %s and %s",
                    first.getId(),
                    first,
                    second));
        }
    }
}