/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.iotdb.db.queryengine.plan.relational.planner.iterative;

import org.apache.iotdb.db.queryengine.common.QueryId;
import org.apache.iotdb.db.queryengine.common.SessionInfo;
import org.apache.iotdb.db.queryengine.execution.warnings.WarningCollector;
import org.apache.iotdb.db.queryengine.plan.planner.plan.node.PlanNode;
import org.apache.iotdb.db.queryengine.plan.relational.planner.SymbolAllocator;
import org.apache.iotdb.db.queryengine.plan.relational.utils.matching.Captures;
import org.apache.iotdb.db.queryengine.plan.relational.utils.matching.Pattern;

import java.util.Optional;

import static java.util.Objects.requireNonNull;

public interface Rule<T> {
  /** Returns a pattern to which plan nodes this rule applies. */
  Pattern<T> getPattern();

  default boolean isEnabled(SessionInfo sessionInfo) {
    return true;
  }

  Result apply(T node, Captures captures, Context context);

  interface Context {
    Lookup getLookup();

    QueryId getIdAllocator();

    SymbolAllocator getSymbolAllocator();

    SessionInfo getSessionInfo();

    // StatsProvider getStatsProvider();

    // CostProvider getCostProvider();

    void checkTimeoutNotExhausted();

    WarningCollector getWarningCollector();
  }

  final class Result {
    private static final Result EMPTY = new Result(Optional.empty());

    public static Result empty() {
      return EMPTY;
    }

    public static Result ofPlanNode(PlanNode transformedPlan) {
      return new Result(Optional.of(transformedPlan));
    }

    private final Optional<PlanNode> transformedPlan;

    private Result(Optional<PlanNode> transformedPlan) {
      this.transformedPlan = requireNonNull(transformedPlan, "transformedPlan is null");
    }

    public Optional<PlanNode> getTransformedPlan() {
      return transformedPlan;
    }

    public boolean isEmpty() {
      return !transformedPlan.isPresent();
    }
  }
}
