// Copyright (c) 2014 Baidu, 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.

// A server to receive EchoRequest and send back EchoResponse.

#include <gflags/gflags.h>
#include <butil/logging.h>
#include <brpc/server.h>
#include <brpc/policy/hulu_pbrpc_controller.h>
#include "echo.pb.h"

DEFINE_bool(echo_attachment, true, "Echo attachment as well");
DEFINE_int32(port, 8000, "TCP Port of this server");
DEFINE_int32(idle_timeout_s, -1, "Connection will be closed if there is no "
             "read/write operations during the last `idle_timeout_s'");
DEFINE_int32(logoff_ms, 2000, "Maximum duration of server's LOGOFF state "
             "(waiting for client to close connection before server stops)");

// Your implementation of example::EchoService
// Notice that implementing brpc::Describable grants the ability to put
// additional information in /status.
namespace example {
class EchoServiceImpl : public EchoService {
public:
    EchoServiceImpl() {};
    virtual ~EchoServiceImpl() {};
    virtual void Echo(google::protobuf::RpcController* cntl_base,
                      const EchoRequest* request,
                      EchoResponse* response,
                      google::protobuf::Closure* done) {
        // This object helps you to call done->Run() in RAII style. If you need
        // to process the request asynchronously, pass done_guard.release().
        brpc::ClosureGuard done_guard(done);

        brpc::Controller* cntl =
            static_cast<brpc::Controller*>(cntl_base);

        // The purpose of following logs is to help you to understand
        // how clients interact with servers more intuitively. You should 
        // remove these logs in performance-sensitive servers.
        LOG(INFO) << "Received request[log_id=" << cntl->log_id() 
                  << "] from " << cntl->remote_side() 
                  << " to " << cntl->local_side()
                  << ": " << request->message()
                  << " (attached=" << cntl->request_attachment() << ")";
        brpc::policy::HuluController* hulu_controller
                = dynamic_cast<brpc::policy::HuluController*>(cntl);
        if (hulu_controller) {
            LOG(INFO) << "source_addr="
                      << hulu_controller->request_source_addr()
                      << " user_data=\"" << hulu_controller->request_user_data()
                      << '\"';
        }

        // Fill response.
        response->set_message(request->message());

        // You can compress the response by setting Controller, but be aware
        // that compression may be costly, evaluate before turning on.
        // cntl->set_response_compress_type(brpc::COMPRESS_TYPE_GZIP);

        if (FLAGS_echo_attachment) {
            // Set attachment which is wired to network directly instead of
            // being serialized into protobuf messages.
            cntl->response_attachment().append(cntl->request_attachment());
        }
        if (hulu_controller) {
            hulu_controller->set_response_source_addr(
                    hulu_controller->request_source_addr() + 1);
            hulu_controller->set_response_user_data("server user data");
        }
    }
};
}  // namespace example

int main(int argc, char* argv[]) {
    // Parse gflags. We recommend you to use gflags as well.
    GFLAGS_NS::ParseCommandLineFlags(&argc, &argv, true);

    // Generally you only need one Server.
    brpc::Server server;

    // Instance of your service.
    example::EchoServiceImpl echo_service_impl;

    // Add the service into server. Notice the second parameter, because the
    // service is put on stack, we don't want server to delete it, otherwise
    // use brpc::SERVER_OWNS_SERVICE.
    if (server.AddService(&echo_service_impl, 
                          brpc::SERVER_DOESNT_OWN_SERVICE) != 0) {
        LOG(ERROR) << "Fail to add service";
        return -1;
    }

    // Start the server.
    brpc::ServerOptions options;
    options.idle_timeout_sec = FLAGS_idle_timeout_s;
    if (server.Start(FLAGS_port, &options) != 0) {
        LOG(ERROR) << "Fail to start EchoServer";
        return -1;
    }

    // Wait until Ctrl-C is pressed, then Stop() and Join() the server.
    server.RunUntilAskedToQuit();
    return 0;
}
