/*
 * Copyright 2017 The Cartographer Authors
 *
 * 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.
 */

#include "cartographer_grpc/framework/server.h"

#include "glog/logging.h"
#include "grpc++/impl/codegen/proto_utils.h"

namespace cartographer_grpc {
namespace framework {

Service::Service(const std::string& service_name,
                 const std::map<std::string, RpcHandlerInfo>& rpc_handler_infos)
    : rpc_handler_infos_(rpc_handler_infos) {
  for (const auto& rpc_handler_info : rpc_handler_infos_) {
    std::string fully_qualified_method_name =
        "/" + service_name + "/" + rpc_handler_info.first;
    // The 'handler' below is set to 'nullptr' indicating that we want to
    // handle this method asynchronously.
    this->AddMethod(new grpc::internal::RpcServiceMethod(
        fully_qualified_method_name.c_str(), rpc_handler_info.second.rpc_type,
        nullptr /* handler */));
  }
}

void Service::StartServing(
    const std::vector<::grpc::ServerCompletionQueue*>& completion_queues) {
  int i = 0;
  for (const auto& rpc_handler_info : rpc_handler_infos_) {
    for (auto completion_queue : completion_queues) {
      Rpc* rpc = active_rpcs_.Add(
          cartographer::common::make_unique<Rpc>(rpc_handler_info.second));
      RequestNextMethodInvocation(i, rpc, completion_queue);
    }
    ++i;
  }
}

void Service::RequestNextMethodInvocation(
    int method_index, Rpc* rpc,
    ::grpc::ServerCompletionQueue* completion_queue) {
  switch (rpc->rpc_type()) {
    case ::grpc::internal::RpcMethod::CLIENT_STREAMING:
      RequestAsyncClientStreaming(method_index, rpc->server_context(),
                                  rpc->responder(), completion_queue,
                                  completion_queue,
                                  rpc->GetState(Rpc::State::NEW_CONNECTION));
      break;
    default:
      LOG(FATAL) << "RPC type not implemented.";
  }
}

}  // namespace framework
}  // namespace cartographer_grpc