// Copyright 2010-2018 Google LLC
// 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.

import static java.lang.Math.abs;
import java.util.logging.Logger;
import com.google.ortools.constraintsolver.Assignment;
import com.google.ortools.constraintsolver.FirstSolutionStrategy;
import com.google.ortools.constraintsolver.RoutingIndexManager;
import com.google.ortools.constraintsolver.RoutingModel;
import com.google.ortools.constraintsolver.RoutingSearchParameters;
import com.google.ortools.constraintsolver.main;

/** Tests the Routing java interface. */
public class TestRouting {
  static {
    System.loadLibrary("jniortools");
  }

  private static final Logger logger = Logger.getLogger(TestRouting.class.getName());

  static void testRoutingTransitCallback(boolean enableGC) {
    logger.info("testRoutingTransitCallback (enable gc:" + enableGC + ")...");
    // Create Routing Index Manager
    RoutingIndexManager manager =
      new RoutingIndexManager(5/*location*/, 1/*vehicle*/, 0/*depot*/);
    // Create Routing Model.
    RoutingModel routing = new RoutingModel(manager);
    // Define cost of each arc.
    int transitCallbackIndex;
    if (true) {
      transitCallbackIndex = routing.registerTransitCallback(
          (long fromIndex, long toIndex) -> {
            // Convert from routing variable Index to user NodeIndex.
            int fromNode = manager.indexToNode(fromIndex);
            int toNode = manager.indexToNode(toIndex);
            return abs(toNode - fromNode);
          });
    }
    if (enableGC) {
      System.gc();
    }
    routing.setArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
    // Setting first solution heuristic.
    RoutingSearchParameters searchParameters =
        main.defaultRoutingSearchParameters()
            .toBuilder()
            .setFirstSolutionStrategy(FirstSolutionStrategy.Value.PATH_CHEAPEST_ARC)
            .build();
    // Solve the problem.
    Assignment solution = routing.solveWithParameters(searchParameters);
    if (null == solution) throw new AssertionError("null == solution");
    if (8 != solution.objectiveValue()) throw new AssertionError("5 != objective");
    logger.info("testRoutingTransitCallback (enable gc:" + enableGC + ")...DONE");
  }

  static void testRoutingUnaryTransitCallback(boolean enableGC) {
    logger.info("testRoutingUnaryTransitCallback (enable gc:" + enableGC + ")...");
    // Create Routing Index Manager
    RoutingIndexManager manager =
      new RoutingIndexManager(5/*location*/, 1/*vehicle*/, 0/*depot*/);
    // Create Routing Model.
    RoutingModel routing = new RoutingModel(manager);
    // Define cost of each arc.
    int transitCallbackIndex;
    if (true) {
      transitCallbackIndex = routing.registerUnaryTransitCallback(
          (long fromIndex) -> {
            // Convert from routing variable Index to user NodeIndex.
            int fromNode = manager.indexToNode(fromIndex);
            return abs(fromNode);
          });
    }
    if (enableGC) {
      System.gc();
    }
    routing.setArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
    // Setting first solution heuristic.
    RoutingSearchParameters searchParameters =
        main.defaultRoutingSearchParameters()
            .toBuilder()
            .setFirstSolutionStrategy(FirstSolutionStrategy.Value.PATH_CHEAPEST_ARC)
            .build();
    // Solve the problem.
    Assignment solution = routing.solveWithParameters(searchParameters);
    if (null == solution) throw new AssertionError("null == solution");
    if (10 != solution.objectiveValue()) throw new AssertionError("5 != objective");
    logger.info("testRoutingUnaryTransitCallback (enable gc:" + enableGC + ")...DONE");
  }

  public static void main(String[] args) throws Exception {
    testRoutingTransitCallback(/*enable_gc=*/false);
    testRoutingTransitCallback(/*enable_gc=*/true);
    testRoutingUnaryTransitCallback(/*enable_gc=*/false);
    testRoutingUnaryTransitCallback(/*enable_gc=*/true);
  }
}