// Copyright 2021 Google LLC
//
// 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 "connections/implementation/pcp_manager.h"

#include <array>
#include <string>
#include <vector>

#include "gmock/gmock.h"
#include "protobuf-matchers/protocol-buffer-matchers.h"
#include "gtest/gtest.h"
#include "absl/time/time.h"
#include "connections/implementation/endpoint_channel_manager.h"
#include "connections/implementation/mock_device.h"
#include "connections/implementation/simulation_user.h"
#include "connections/medium_selector.h"
#include "connections/out_of_band_connection_metadata.h"
#include "connections/status.h"
#include "connections/strategy.h"
#include "connections/v3/connection_listening_options.h"
#include "internal/platform/byte_array.h"
#include "internal/platform/count_down_latch.h"
#include "internal/platform/medium_environment.h"

namespace nearby {
namespace connections {
namespace {

using ::testing::Return;

constexpr std::array<char, 6> kFakeMacAddress = {'a', 'b', 'c', 'd', 'e', 'f'};
constexpr char kServiceId[] = "service-id";
constexpr char kDeviceA[] = "device-A";
constexpr char kDeviceB[] = "device-B";

constexpr BooleanMediumSelector kTestCases[] = {
    BooleanMediumSelector{
        .ble = true,
    },
    BooleanMediumSelector{
        .bluetooth = true,
    },
    BooleanMediumSelector{
        .wifi_lan = true,
    },
    BooleanMediumSelector{
        .bluetooth = true,
        .ble = true,
    },
    BooleanMediumSelector{
        .bluetooth = true,
        .wifi_lan = true,
    },
    BooleanMediumSelector{
        .ble = true,
        .wifi_lan = true,
    },
    BooleanMediumSelector{
        .bluetooth = true,
        .ble = true,
        .wifi_lan = true,
    },
};

class PcpManagerTest : public ::testing::TestWithParam<BooleanMediumSelector> {
 protected:
  MediumEnvironment& env_{MediumEnvironment::Instance()};
};

TEST_P(PcpManagerTest, CanCreateOne) {
  env_.Start();
  SimulationUser user(kDeviceA, GetParam());
  env_.Stop();
}

TEST_P(PcpManagerTest, CanCreateMany) {
  env_.Start();
  SimulationUser user_a(kDeviceA, GetParam());
  SimulationUser user_b(kDeviceB, GetParam());
  env_.Stop();
}

TEST_P(PcpManagerTest, CanAdvertise) {
  env_.Start();
  SimulationUser user_a(kDeviceA, GetParam());
  SimulationUser user_b(kDeviceB, GetParam());
  user_a.StartAdvertising(kServiceId, nullptr);
  env_.Stop();
}

TEST_P(PcpManagerTest, CanDiscover) {
  env_.Start();
  SimulationUser user_a("device-a", GetParam());
  SimulationUser user_b("device-b", GetParam());
  user_a.StartAdvertising(kServiceId, nullptr);
  CountDownLatch latch(1);
  user_b.StartDiscovery(kServiceId, &latch);
  EXPECT_TRUE(latch.Await(absl::Milliseconds(1000)).result());
  EXPECT_EQ(user_b.GetDiscovered().service_id, kServiceId);
  EXPECT_EQ(user_b.GetDiscovered().endpoint_info, user_a.GetInfo());
  user_b.StopDiscovery();
  env_.Stop();
}

TEST_P(PcpManagerTest, CanConnect) {
  env_.Start();
  SimulationUser user_a("device-a", GetParam());
  SimulationUser user_b("device-b", GetParam());
  CountDownLatch discovery_latch(1);
  CountDownLatch connection_latch(2);
  user_a.StartAdvertising(kServiceId, &connection_latch);
  user_b.StartDiscovery(kServiceId, &discovery_latch);
  EXPECT_TRUE(discovery_latch.Await(absl::Milliseconds(1000)).result());
  EXPECT_EQ(user_b.GetDiscovered().service_id, kServiceId);
  EXPECT_EQ(user_b.GetDiscovered().endpoint_info, user_a.GetInfo());
  user_b.RequestConnection(&connection_latch);
  EXPECT_TRUE(connection_latch.Await(absl::Milliseconds(1000)).result());
  user_a.Stop();
  user_b.Stop();
  env_.Stop();
}

TEST_P(PcpManagerTest, CanAccept) {
  env_.Start();
  SimulationUser user_a("device-a", GetParam());
  SimulationUser user_b("device-b", GetParam());
  CountDownLatch discovery_latch(1);
  CountDownLatch connection_latch(2);
  CountDownLatch accept_latch(2);
  user_a.StartAdvertising(kServiceId, &connection_latch);
  user_b.StartDiscovery(kServiceId, &discovery_latch);
  EXPECT_TRUE(discovery_latch.Await(absl::Milliseconds(1000)).result());
  EXPECT_EQ(user_b.GetDiscovered().service_id, kServiceId);
  EXPECT_EQ(user_b.GetDiscovered().endpoint_info, user_a.GetInfo());
  user_b.RequestConnection(&connection_latch);
  EXPECT_TRUE(connection_latch.Await(absl::Milliseconds(1000)).result());
  user_a.AcceptConnection(&accept_latch);
  user_b.AcceptConnection(&accept_latch);
  EXPECT_TRUE(accept_latch.Await(absl::Milliseconds(1000)).result());
  user_a.Stop();
  user_b.Stop();
  env_.Stop();
}

TEST_P(PcpManagerTest, CanReject) {
  env_.Start();
  SimulationUser user_a("device-a", GetParam());
  SimulationUser user_b("device-b", GetParam());
  CountDownLatch discovery_latch(1);
  CountDownLatch connection_latch(2);
  CountDownLatch reject_latch(1);
  user_a.StartAdvertising(kServiceId, &connection_latch);
  user_b.StartDiscovery(kServiceId, &discovery_latch);
  EXPECT_TRUE(discovery_latch.Await(absl::Milliseconds(1000)).result());
  EXPECT_EQ(user_b.GetDiscovered().service_id, kServiceId);
  EXPECT_EQ(user_b.GetDiscovered().endpoint_info, user_a.GetInfo());
  user_b.RequestConnection(&connection_latch);
  EXPECT_TRUE(connection_latch.Await(absl::Milliseconds(1000)).result());
  user_b.ExpectRejectedConnection(reject_latch);
  user_a.RejectConnection(nullptr);
  EXPECT_TRUE(reject_latch.Await(absl::Milliseconds(1000)).result());
  user_a.Stop();
  user_b.Stop();
  env_.Stop();
}

TEST_P(PcpManagerTest, CanStartListeningForIncomingConnections) {
  env_.Start();
  BooleanMediumSelector selector = GetParam();
  SimulationUser user_a(kDeviceA, selector);
  CountDownLatch start_latch(1);
  v3::ConnectionListeningOptions options;
  options.enable_ble_listening = selector.ble;
  options.enable_bluetooth_listening = selector.bluetooth;
  options.enable_wlan_listening = selector.wifi_lan;
  options.listening_mediums = selector.GetMediums(true);
  options.upgrade_mediums = selector.GetMediums(true);
  options.strategy = Strategy::kP2pCluster;
  user_a.StartListeningForIncomingConnections(&start_latch, "service", options,
                                              {Status::kSuccess});
  user_a.Stop();
  env_.Stop();
}

TEST_P(PcpManagerTest, StartListeningForIncomingConnectionsFailsNoStrategy) {
  env_.Start();
  BooleanMediumSelector selector = GetParam();
  SimulationUser user_a(kDeviceA, selector);
  CountDownLatch start_latch(1);
  v3::ConnectionListeningOptions options;
  options.enable_ble_listening = selector.ble;
  options.enable_bluetooth_listening = selector.bluetooth;
  options.enable_wlan_listening = selector.wifi_lan;
  options.listening_mediums = selector.GetMediums(true);
  options.upgrade_mediums = selector.GetMediums(true);
  user_a.StartListeningForIncomingConnections(&start_latch, "service", options,
                                              {Status::kError});
  user_a.Stop();
  env_.Stop();
}

TEST_P(PcpManagerTest, CanConnectV3) {
  env_.Start();
  SimulationUser user_a("device-a", GetParam());
  SimulationUser user_b("device-b", GetParam());
  CountDownLatch discovery_latch(1);
  CountDownLatch connection_latch(2);
  user_a.StartAdvertising(kServiceId, &connection_latch);
  user_b.StartDiscovery(kServiceId, &discovery_latch);
  EXPECT_TRUE(discovery_latch.Await(absl::Milliseconds(1000)).result());
  EXPECT_EQ(user_b.GetDiscovered().service_id, kServiceId);
  EXPECT_EQ(user_b.GetDiscovered().endpoint_info, user_a.GetInfo());
  auto remote_device = MockNearbyDevice();
  EXPECT_CALL(remote_device, GetEndpointId)
      .WillRepeatedly(Return(std::string(user_b.GetDiscovered().endpoint_id)));
  user_b.RequestConnectionV3(&connection_latch, remote_device);
  EXPECT_TRUE(connection_latch.Await(absl::Milliseconds(1000)).result());
  user_a.Stop();
  user_b.Stop();
  env_.Stop();
}

INSTANTIATE_TEST_SUITE_P(ParametrisedPcpManagerTest, PcpManagerTest,
                         ::testing::ValuesIn(kTestCases));

// Verifies that InjectEndpoint() can be run successfully; does not test the
// full connection flow given that normal discovery/advertisement is skipped.
// Note: Not parameterized because InjectEndpoint only works over Bluetooth.
TEST_F(PcpManagerTest, InjectEndpoint) {
  env_.Start();
  SimulationUser user_a(kDeviceA, BooleanMediumSelector{.bluetooth = true});
  user_a.StartDiscovery(kServiceId, /*latch=*/nullptr);
  user_a.InjectEndpoint(kServiceId, OutOfBandConnectionMetadata{
                                        .medium = Medium::BLUETOOTH,
                                        .remote_bluetooth_mac_address =
                                            ByteArray(kFakeMacAddress),
                                    });
  user_a.StopDiscovery();
  user_a.Stop();
  env_.Stop();
}

TEST_F(PcpManagerTest, TestUpdateDiscoveryFailsWithoutPcpHandler) {
  BooleanMediumSelector selector;
  selector.SetAll(true);
  env_.Start();
  SimulationUser user_a(kDeviceA, selector);
  EXPECT_EQ(user_a.UpdateDiscoveryOptions(kServiceId).value,
            Status::Value::kOutOfOrderApiCall);
  env_.Stop();
}

}  // namespace
}  // namespace connections
}  // namespace nearby