// Copyright 2022 The Pigweed 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
//
//     https://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 <array>

#include "pw_rpc/nanopb/client_server_testing.h"
#include "pw_rpc_test_protos/test.rpc.pb.h"
#include "pw_sync/mutex.h"
#include "pw_unit_test/framework.h"

namespace pw::rpc {
namespace {

using GeneratedService = ::pw::rpc::test::pw_rpc::nanopb::TestService;

class TestService final : public GeneratedService::Service<TestService> {
 public:
  Status TestUnaryRpc(const pw_rpc_test_TestRequest& request,
                      pw_rpc_test_TestResponse& response) {
    response.value = request.integer + 1;
    return static_cast<Status::Code>(request.status_code);
  }

  Status TestAnotherUnaryRpc(const pw_rpc_test_TestRequest& request,
                             pw_rpc_test_TestResponse& response) {
    using ArgType = std::array<uint32_t, 3>;
    // The values array needs to be kept in memory until after this method call
    // returns since the response is not encoded until after returning from this
    // method.
    static const ArgType values = {7, 8, 9};
    response.repeated_field.funcs.encode = +[](pb_ostream_t* stream,
                                               const pb_field_t* field,
                                               void* const* arg) -> bool {
      // Note: nanopb passes the pointer to the repeated_filed.arg member as
      // arg, not its contents.
      for (auto elem : *static_cast<const ArgType*>(*arg)) {
        if (!pb_encode_tag_for_field(stream, field) ||
            !pb_encode_varint(stream, elem))
          return false;
      }
      return true;
    };
    response.repeated_field.arg = const_cast<ArgType*>(&values);
    return static_cast<Status::Code>(request.status_code);
  }

  static void TestServerStreamRpc(
      const pw_rpc_test_TestRequest&,
      ServerWriter<pw_rpc_test_TestStreamResponse>&) {}

  void TestClientStreamRpc(
      ServerReader<pw_rpc_test_TestRequest, pw_rpc_test_TestStreamResponse>&) {}

  void TestBidirectionalStreamRpc(
      ServerReaderWriter<pw_rpc_test_TestRequest,
                         pw_rpc_test_TestStreamResponse>&) {}
};

TEST(NanopbClientServerTestContext, ReceivesUnaryRpcResponse) {
  NanopbClientServerTestContext<> ctx;
  TestService service;
  ctx.server().RegisterService(service);

  pw_rpc_test_TestResponse response pw_rpc_test_TestResponse_init_default;
  auto handler = [&response](const pw_rpc_test_TestResponse& server_response,
                             pw::Status) { response = server_response; };

  pw_rpc_test_TestRequest request{.integer = 1,
                                  .status_code = OkStatus().code()};
  auto call = GeneratedService::TestUnaryRpc(
      ctx.client(), ctx.channel().id(), request, handler);
  // Force manual forwarding of packets as context is not threaded
  ctx.ForwardNewPackets();

  const auto sent_request =
      ctx.request<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(0);
  const auto sent_response =
      ctx.response<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(0);

  EXPECT_EQ(response.value, sent_response.value);
  EXPECT_EQ(response.value, request.integer + 1);
  EXPECT_EQ(request.integer, sent_request.integer);
}

TEST(NanopbClientServerTestContext, ReceivesMultipleResponses) {
  NanopbClientServerTestContext<> ctx;
  TestService service;
  ctx.server().RegisterService(service);

  pw_rpc_test_TestResponse response1 pw_rpc_test_TestResponse_init_default;
  pw_rpc_test_TestResponse response2 pw_rpc_test_TestResponse_init_default;
  auto handler1 = [&response1](const pw_rpc_test_TestResponse& server_response,
                               pw::Status) { response1 = server_response; };
  auto handler2 = [&response2](const pw_rpc_test_TestResponse& server_response,
                               pw::Status) { response2 = server_response; };

  pw_rpc_test_TestRequest request1{.integer = 1,
                                   .status_code = OkStatus().code()};
  pw_rpc_test_TestRequest request2{.integer = 2,
                                   .status_code = OkStatus().code()};
  const auto call1 = GeneratedService::TestUnaryRpc(
      ctx.client(), ctx.channel().id(), request1, handler1);
  // Force manual forwarding of packets as context is not threaded
  ctx.ForwardNewPackets();
  const auto call2 = GeneratedService::TestUnaryRpc(
      ctx.client(), ctx.channel().id(), request2, handler2);
  // Force manual forwarding of packets as context is not threaded
  ctx.ForwardNewPackets();

  const auto sent_request1 =
      ctx.request<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(0);
  const auto sent_request2 =
      ctx.request<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(1);
  const auto sent_response1 =
      ctx.response<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(0);
  const auto sent_response2 =
      ctx.response<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(1);

  EXPECT_EQ(response1.value, request1.integer + 1);
  EXPECT_EQ(response2.value, request2.integer + 1);
  EXPECT_EQ(response1.value, sent_response1.value);
  EXPECT_EQ(response2.value, sent_response2.value);
  EXPECT_EQ(request1.integer, sent_request1.integer);
  EXPECT_EQ(request2.integer, sent_request2.integer);
}

TEST(NanopbClientServerTestContext,
     ReceivesMultipleResponsesWithPacketProcessor) {
  using ProtectedInt = std::pair<int, pw::sync::Mutex>;
  ProtectedInt server_counter{};
  auto server_processor = [&server_counter](
                              ClientServer& client_server,
                              pw::ConstByteSpan packet) -> pw::Status {
    server_counter.second.lock();
    ++server_counter.first;
    server_counter.second.unlock();
    return client_server.ProcessPacket(packet);
  };

  ProtectedInt client_counter{};
  auto client_processor = [&client_counter](
                              ClientServer& client_server,
                              pw::ConstByteSpan packet) -> pw::Status {
    client_counter.second.lock();
    ++client_counter.first;
    client_counter.second.unlock();
    return client_server.ProcessPacket(packet);
  };

  NanopbClientServerTestContext<> ctx(server_processor, client_processor);
  TestService service;
  ctx.server().RegisterService(service);

  pw_rpc_test_TestResponse response1 pw_rpc_test_TestResponse_init_default;
  pw_rpc_test_TestResponse response2 pw_rpc_test_TestResponse_init_default;
  auto handler1 = [&response1](const pw_rpc_test_TestResponse& server_response,
                               pw::Status) { response1 = server_response; };
  auto handler2 = [&response2](const pw_rpc_test_TestResponse& server_response,
                               pw::Status) { response2 = server_response; };

  pw_rpc_test_TestRequest request1{.integer = 1,
                                   .status_code = OkStatus().code()};
  pw_rpc_test_TestRequest request2{.integer = 2,
                                   .status_code = OkStatus().code()};
  const auto call1 = GeneratedService::TestUnaryRpc(
      ctx.client(), ctx.channel().id(), request1, handler1);
  // Force manual forwarding of packets as context is not threaded
  ctx.ForwardNewPackets();
  const auto call2 = GeneratedService::TestUnaryRpc(
      ctx.client(), ctx.channel().id(), request2, handler2);
  // Force manual forwarding of packets as context is not threaded
  ctx.ForwardNewPackets();

  const auto sent_request1 =
      ctx.request<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(0);
  const auto sent_request2 =
      ctx.request<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(1);
  const auto sent_response1 =
      ctx.response<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(0);
  const auto sent_response2 =
      ctx.response<test::pw_rpc::nanopb::TestService::TestUnaryRpc>(1);

  EXPECT_EQ(response1.value, request1.integer + 1);
  EXPECT_EQ(response2.value, request2.integer + 1);
  EXPECT_EQ(response1.value, sent_response1.value);
  EXPECT_EQ(response2.value, sent_response2.value);
  EXPECT_EQ(request1.integer, sent_request1.integer);
  EXPECT_EQ(request2.integer, sent_request2.integer);

  server_counter.second.lock();
  EXPECT_EQ(server_counter.first, 2);
  server_counter.second.unlock();
  client_counter.second.lock();
  EXPECT_EQ(client_counter.first, 2);
  client_counter.second.unlock();
}

TEST(NanopbClientServerTestContext, ResponseWithCallbacks) {
  NanopbClientServerTestContext<> ctx;
  TestService service;
  ctx.server().RegisterService(service);

  const auto call = GeneratedService::TestAnotherUnaryRpc(
      ctx.client(), ctx.channel().id(), pw_rpc_test_TestRequest_init_default);
  // Force manual forwarding of packets as context is not threaded
  ctx.ForwardNewPackets();

  // To decode a response object that requires to set pb_callback_t members,
  // pass it to the response() method as a parameter.
  constexpr size_t kMaxNumValues = 4;
  struct DecoderContext {
    uint32_t num_calls = 0;
    uint32_t values[kMaxNumValues];
    bool failed = false;
  } decoder_context;

  pw_rpc_test_TestResponse response = pw_rpc_test_TestResponse_init_default;
  response.repeated_field.funcs.decode = +[](pb_istream_t* stream,
                                             const pb_field_t* /* field */,
                                             void** arg) -> bool {
    DecoderContext* dec_ctx = static_cast<DecoderContext*>(*arg);
    uint64_t value;
    if (!pb_decode_varint(stream, &value)) {
      dec_ctx->failed = true;
      return false;
    }
    if (dec_ctx->num_calls < kMaxNumValues) {
      dec_ctx->values[dec_ctx->num_calls] = value;
    }
    dec_ctx->num_calls++;
    return true;
  };
  response.repeated_field.arg = &decoder_context;
  ctx.response<GeneratedService::TestAnotherUnaryRpc>(0, response);

  EXPECT_FALSE(decoder_context.failed);
  EXPECT_EQ(3u, decoder_context.num_calls);
  EXPECT_EQ(7u, decoder_context.values[0]);
  EXPECT_EQ(8u, decoder_context.values[1]);
  EXPECT_EQ(9u, decoder_context.values[2]);
}

}  // namespace
}  // namespace pw::rpc