content: /*
   * Copyright 2017 The Android Open Source Project
   *
   * 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.android.server.wifi;
  
  import android.net.wifi.ScanResult;
  
  import java.util.Collection;
  
  /**
   * Evaluates ScanResults for Wifi Wake.
   */
  public class WakeupEvaluator {
  
      private final ScoringParams mScoringParams;
  
      WakeupEvaluator(ScoringParams scoringParams) {
          mScoringParams = scoringParams;
      }
  
      /**
       * Searches ScanResults to find a connectable network.
       *
       * <p>This method searches the given ScanResults for one that is present in the given
       * ScanResultMatchInfos and has a sufficiently high RSSI. If there is no such ScanResult, it
       * returns null. If there are multiple, it returns the one with the highest RSSI.
       *
       * @param scanResults ScanResults to search
       * @param networks Network list to compare against
       * @return The {@link ScanResult} representing an in-range connectable network, or {@code null}
       *         signifying there is no viable network
       */
      public ScanResult findViableNetwork(Collection<ScanResult> scanResults,
                                          Collection<ScanResultMatchInfo> networks) {
          ScanResult selectedScanResult = null;
  
          for (ScanResult scanResult : scanResults) {
              if (isBelowThreshold(scanResult)) {
                  continue;
              }
              if (networks.contains(ScanResultMatchInfo.fromScanResult(scanResult))) {
                  if (selectedScanResult == null || selectedScanResult.level < scanResult.level) {
                      selectedScanResult = scanResult;
                  }
              }
          }
  
          return selectedScanResult;
      }
  
      /**
       * Returns whether the given ScanResult's signal strength is below the selection threshold.
       */
      public boolean isBelowThreshold(ScanResult scanResult) {
          return scanResult.level < mScoringParams.getEntryRssi(scanResult.frequency);
      }
  }
  