// rpc_service.hpp
inline std::string_view echo(std::string_view str) { return str; }

#include "rpc_service.hpp"
#include <ylt/coro_rpc/coro_rpc_server.hpp>

using namespace coro_rpc;

int main() {

  // 初始化服务器
  coro_rpc_server server(/*thread_num =*/10, /*port =*/9000);

  server.register_handler<echo>(); // 注册rpc函数

  server.start(); // 启动server并阻塞等待
}

#include "rpc_service.hpp"
#include <ylt/coro_rpc/coro_rpc_client.hpp>

using namespace coro_rpc;
using namespace async_simple::coro;

Lazy<void> test_client() {
  coro_rpc_client client;
  co_await client.connect("localhost", /*port =*/"9000");
  auto r = co_await client.call<echo>("hello coro_rpc"); //传参数调用rpc函数
  std::cout << r.result.value() << "\n"; //will print "hello coro_rpc"
}

int main() {
  syncAwait(test_client());
}

//<https://github.com/grpc/grpc/blob/master/examples/cpp/helloworld/greeter_callback_client.cc>
std::string SayHello(const std::string& user) {
    // Data we are sending to the server.
    HelloRequest request;
    request.set_name(user);

    // Container for the data we expect from the server.
    HelloReply reply;

    // Context for the client. It could be used to convey extra information to
    // the server and/or tweak certain RPC behaviors.
    ClientContext context;

    // The actual RPC.
    std::mutex mu;
    std::condition_variable cv;
    bool done = false;
    Status status;
    stub_->async()->SayHello(&context, &request, &reply,
                             [&mu, &cv, &done, &status](Status s) {
                               status = std::move(s);
                               std::lock_guard<std::mutex> lock(mu);
                               done = true;
                               cv.notify_one();
                             });

    std::unique_lock<std::mutex> lock(mu);
    while (!done) {
      cv.wait(lock);
    }

    // Act upon its status.
    if (status.ok()) {
      return reply.message();
    } else {
      std::cout << status.error_code() << ": " << status.error_message()
                << std::endl;
      return "RPC failed";
    }
  }

brpc异步回调
// <https://github.com/apache/incubator-brpc/blob/master/example/asynchronous_echo_c%2B%2B/client.cpp>
void HandleEchoResponse(
        brpc::Controller*cntl,
        example::EchoResponse* response) {
    // std::unique_ptr makes sure cntl/response will be deleted before returning.
    std::unique_ptr<brpc::Controller> cntl_guard(cntl);
    std::unique_ptr<example::EchoResponse> response_guard(response);

    if (cntl->Failed()) {
        LOG(WARNING) << "Fail to send EchoRequest, " << cntl->ErrorText();
        return;
    }
    LOG(INFO) << "Received response from " << cntl->remote_side()
        << ": " << response->message() << " (attached="
        << cntl->response_attachment() << ")"
        << " latency=" << cntl->latency_us() << "us";
}

int main() {
example::EchoService_Stub stub(&channel);

    // Send a request and wait for the response every 1 second.
    int log_id = 0;
    while (!brpc::IsAskedToQuit()) {
        // Since we are sending asynchronous RPC (`done' is not NULL),
        // these objects MUST remain valid until `done' is called.
        // As a result, we allocate these objects on heap
        example::EchoResponse* response = new example::EchoResponse();
        brpc::Controller* cntl = new brpc::Controller();

        // Notice that you don't have to new request, which can be modified
        // or destroyed just after stub.Echo is called.
        example::EchoRequest request;
        request.set_message("hello world");

        cntl->set_log_id(log_id ++);  // set by user
        if (FLAGS_send_attachment) {
            // Set attachment which is wired to network directly instead of 
            // being serialized into protobuf messages.
            cntl->request_attachment().append("foo");
        }

        // We use protobuf utility `NewCallback' to create a closure object
        // that will call our callback `HandleEchoResponse'. This closure
        // will automatically delete itself after being called once
        google::protobuf::Closure* done = brpc::NewCallback(
            &HandleEchoResponse, cntl, response);
        stub.Echo(cntl, &request, response, done);

        // This is an asynchronous RPC, so we can only fetch the result
        // inside the callback
        sleep(1);
    }
}

std::string_view echo(std::string_view);
#include <coro_rpc/coro_rpc_client.hpp>
Lazy<void> say_hello(){
  coro_rpc_client client;
  co_await client.connect("localhost", /*port =*/"9000");
  while (true){
    auto r = co_await client.call<echo>("hello coro_rpc");
    assert(r.result.value() == "hello coro_rpc");
  }
}

std::string_view echo(std::string_view sv) {
  return sv;
}
void start() {
  coro_rpc_server server(/*thread num = */10,/* listen port = */9000);
  server.register_handler<echo>();
  server.start();
}