// Copyright 2020 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 "pw_rpc/internal/base_client_call.h"

#include "gtest/gtest.h"
#include "pw_rpc/internal/test_utils.h"

namespace pw::rpc::internal {
namespace {

TEST(BaseClientCall, RegistersAndRemovesItselfFromClient) {
  ClientContextForTest context;
  EXPECT_EQ(context.client().active_calls(), 0u);

  {
    BaseClientCall call(&context.client(),
                        context.channel().id(),
                        context.service_id(),
                        context.method_id(),
                        [](BaseClientCall&, const Packet&) {});
    EXPECT_EQ(context.client().active_calls(), 1u);
  }

  EXPECT_EQ(context.client().active_calls(), 0u);
}

TEST(BaseClientCall, Register_ReplacesExistingCall) {
  ClientContextForTest context;
  EXPECT_EQ(context.client().active_calls(), 0u);

  BaseClientCall first(&context.client(),
                       context.channel().id(),
                       context.service_id(),
                       context.method_id(),
                       [](BaseClientCall&, const Packet&) {});
  EXPECT_TRUE(first.active());
  EXPECT_EQ(context.client().active_calls(), 1u);

  BaseClientCall second(&context.client(),
                        context.channel().id(),
                        context.service_id(),
                        context.method_id(),
                        [](BaseClientCall&, const Packet&) {});
  EXPECT_TRUE(second.active());
  EXPECT_EQ(context.client().active_calls(), 1u);
  EXPECT_FALSE(first.active());
}

TEST(BaseClientCall, Move_UnregistersOriginal) {
  ClientContextForTest context;
  EXPECT_EQ(context.client().active_calls(), 0u);

  BaseClientCall moved(&context.client(),
                       context.channel().id(),
                       context.service_id(),
                       context.method_id(),
                       [](BaseClientCall&, const Packet&) {});
  EXPECT_EQ(context.client().active_calls(), 1u);

  BaseClientCall call(std::move(moved));
  EXPECT_EQ(context.client().active_calls(), 1u);

// Ignore use-after-move.
#ifndef __clang_analyzer__
  EXPECT_FALSE(moved.active());
#endif  // __clang_analyzer__
  EXPECT_TRUE(call.active());
}

TEST(BaseClientCall, TwoConcurrentClientCallsAssigned) {
  // Mostly null/placeholder data to exercise the call registration path.
  constexpr uint32_t kServiceId = 16;
  constexpr uint32_t kMethodId = 111;
  std::array<pw::rpc::Channel, 2> channels = {
      Channel::Create<1>(nullptr),
      Channel::Create<2>(nullptr),
  };
  Client client(channels);

  // Specifically testing the assignment operator.
  BaseClientCall call1;
  BaseClientCall call2;
  call1 = BaseClientCall(&channels[0], kServiceId, kMethodId, nullptr);
  call2 = BaseClientCall(&channels[1], kServiceId, kMethodId, nullptr);

  EXPECT_EQ(client.active_calls(), 2u);
}

class FakeClientCall : public BaseClientCall {
 public:
  constexpr FakeClientCall(Client* client,
                           uint32_t channel_id,
                           uint32_t service_id,
                           uint32_t method_id,
                           ResponseHandler handler)
      : BaseClientCall(client, channel_id, service_id, method_id, handler) {}

  Status SendPacket(std::span<const std::byte> payload) {
    std::span buffer = AcquirePayloadBuffer();
    std::memcpy(buffer.data(), payload.data(), payload.size());
    return ReleasePayloadBuffer(buffer.first(payload.size()));
  }
};

TEST(BaseClientCall, SendsPacketWithPayload) {
  ClientContextForTest context;
  FakeClientCall call(&context.client(),
                      context.channel().id(),
                      context.service_id(),
                      context.method_id(),
                      [](BaseClientCall&, const Packet&) {});

  constexpr std::byte payload[]{std::byte{0x08}, std::byte{0x39}};
  call.SendPacket(payload).IgnoreError();

  EXPECT_EQ(context.output().packet_count(), 1u);
  Packet packet = context.output().sent_packet();
  EXPECT_EQ(packet.channel_id(), context.channel().id());
  EXPECT_EQ(packet.service_id(), context.service_id());
  EXPECT_EQ(packet.method_id(), context.method_id());
  EXPECT_EQ(std::memcmp(packet.payload().data(), payload, sizeof(payload)), 0);
}

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