DefaultFilterEvaluator.java

/*
 * Copyright 2014-2016 CyberVision, Inc.
 *
 * 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 org.kaaproject.kaa.server.operations.service.filter;

import org.apache.avro.Schema;
import org.apache.avro.generic.GenericRecord;
import org.kaaproject.kaa.common.avro.GenericAvroConverter;
import org.kaaproject.kaa.common.dto.EndpointProfileDto;
import org.kaaproject.kaa.common.dto.ProfileFilterDto;
import org.kaaproject.kaa.server.common.Base64Util;
import org.kaaproject.kaa.server.operations.service.filter.el.GenericRecordPropertyAccessor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.expression.Expression;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.expression.spel.support.StandardEvaluationContext;

import java.io.IOException;

/**
 * The Class DefaultFilter.
 */
public class DefaultFilterEvaluator implements FilterEvaluator {

  public static final String EP_KEYHASH_VARIABLE_NAME = "ekh";
  public static final String SERVER_PROFILE_VARIABLE_NAME = "sp";
  public static final String CLIENT_PROFILE_VARIABLE_NAME = "cp";

  /**
   * The Constant LOG.
   */
  private static final Logger LOG = LoggerFactory.getLogger(DefaultFilterEvaluator.class);

  private String epKey;
  private GenericRecord serverProfileGenericRecord;
  private GenericRecord clientProfileGenericRecord;

  /**
   * Instantiates a new default filter.
   */
  public DefaultFilterEvaluator() {
    super();
  }

  @Override
  public void init(EndpointProfileDto profile,
                   String profileSchemaBody,
                   String serverProfileSchemaBody) {
    GenericAvroConverter<GenericRecord> endpointProfileConverter = new GenericAvroConverter<>(
        new Schema.Parser().parse(profileSchemaBody));
    GenericAvroConverter<GenericRecord> serverProfileConverter = new GenericAvroConverter<>(
        new Schema.Parser().parse(serverProfileSchemaBody));
    this.epKey = Base64Util.encode(profile.getEndpointKeyHash());
    try {
      if (profile.getServerProfileBody() != null) {
        serverProfileGenericRecord = serverProfileConverter.decodeJson(
            profile.getServerProfileBody());
      }
      if (profile.getClientProfileBody() != null) {
        clientProfileGenericRecord = endpointProfileConverter.decodeJson(
            profile.getClientProfileBody());
      }
    } catch (IOException ioe) {
      LOG.error("Error decoding avro object from Json string", ioe);
    }
  }

  /*
   * (non-Javadoc)
   *
   * @see
   * org.kaaproject.kaa.server.operations.service.filter.Filter#matches(java
   * .lang.String)
   */
  @Override
  public boolean matches(ProfileFilterDto filter) {
    final Expression expression = new SpelExpressionParser().parseExpression(filter.getBody());
    StandardEvaluationContext evaluationContext;
    if (filter.getEndpointProfileSchemaVersion() != null) {
      evaluationContext = new StandardEvaluationContext(clientProfileGenericRecord);
      evaluationContext.setVariable(CLIENT_PROFILE_VARIABLE_NAME, clientProfileGenericRecord);
    } else {
      evaluationContext = new StandardEvaluationContext();
    }
    evaluationContext.addPropertyAccessor(new GenericRecordPropertyAccessor());
    evaluationContext.setVariable(EP_KEYHASH_VARIABLE_NAME, epKey);
    if (filter.getServerProfileSchemaVersion() != null) {
      evaluationContext.setVariable(SERVER_PROFILE_VARIABLE_NAME, serverProfileGenericRecord);
    }

    return expression.getValue(evaluationContext, Boolean.class);
  }

}