/*
 * 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.servicecomb.edge.core;

import java.util.concurrent.CompletableFuture;

import javax.annotation.Nonnull;

import org.apache.servicecomb.common.rest.filter.inner.RestServerCodecFilter;
import org.apache.servicecomb.core.Invocation;
import org.apache.servicecomb.core.filter.Filter;
import org.apache.servicecomb.core.filter.FilterNode;
import org.apache.servicecomb.swagger.invocation.InvocationType;
import org.apache.servicecomb.swagger.invocation.Response;
import org.apache.servicecomb.swagger.invocation.context.TransportContext;

public class EdgeServerCodecFilter extends RestServerCodecFilter {
  public static final String NAME = "edge-server-codec";

  @Nonnull
  @Override
  public String getName() {
    return NAME;
  }

  @Nonnull
  @Override
  public boolean enabledForInvocationType(InvocationType invocationType) {
    return invocationType == InvocationType.CONSUMER;
  }

  @Override
  public boolean enabledForTransport(String transport) {
    // For edge service, this filter executed before load balancer and transport is always null.
    return true;
  }

  @Override
  public int getOrder(InvocationType invocationType, String application, String serviceName) {
    return Filter.CONSUMER_LOAD_BALANCE_ORDER - 2000;
  }

  @Override
  public CompletableFuture<Response> onFilter(Invocation invocation, FilterNode nextNode) {
    if (invocation.getRequestEx() == null) {
      // to support normal consumer invocation in edge process
      return nextNode.onFilter(invocation);
    }

    return super.onFilter(invocation, nextNode);
  }

  // save and restore transportContext to support edge invocation
  @Override
  protected CompletableFuture<Response> invokeNext(Invocation invocation, FilterNode nextNode) {
    TransportContext transportContext = invocation.getTransportContext();
    return nextNode.onFilter(invocation)
        .whenComplete((r, e) -> invocation.setTransportContext(transportContext));
  }
}
