// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "security_request_phase.h"

#include <memory>

#include <fbl/macros.h>
#include <gtest/gtest.h>

#include "lib/async/cpp/task.h"
#include "lib/fpromise/result.h"
#include "src/connectivity/bluetooth/core/bt-host/common/byte_buffer.h"
#include "src/connectivity/bluetooth/core/bt-host/common/test_helpers.h"
#include "src/connectivity/bluetooth/core/bt-host/hci/connection.h"
#include "src/connectivity/bluetooth/core/bt-host/l2cap/fake_channel_test.h"
#include "src/connectivity/bluetooth/core/bt-host/sm/fake_phase_listener.h"
#include "src/connectivity/bluetooth/core/bt-host/sm/packet.h"
#include "src/connectivity/bluetooth/core/bt-host/sm/smp.h"
#include "src/connectivity/bluetooth/core/bt-host/sm/types.h"
#include "src/connectivity/bluetooth/core/bt-host/sm/util.h"
#include "src/lib/fxl/memory/weak_ptr.h"

namespace bt::sm {
namespace {
struct SecurityRequestOptions {
  SecurityLevel requested_level = SecurityLevel::kEncrypted;
  BondableMode bondable = BondableMode::Bondable;
};

class SecurityRequestPhaseTest : public l2cap::testing::FakeChannelTest {
 public:
  SecurityRequestPhaseTest() = default;
  ~SecurityRequestPhaseTest() override = default;

 protected:
  void SetUp() override { NewSecurityRequestPhase(); }

  void TearDown() override { security_request_phase_ = nullptr; }

  void NewSecurityRequestPhase(SecurityRequestOptions opts = SecurityRequestOptions(),
                               bt::LinkType ll_type = bt::LinkType::kLE) {
    l2cap::ChannelId cid =
        ll_type == bt::LinkType::kLE ? l2cap::kLESMPChannelId : l2cap::kSMPChannelId;
    ChannelOptions options(cid);
    options.link_type = ll_type;

    fake_chan_ = CreateFakeChannel(options);
    sm_chan_ = std::make_unique<PairingChannel>(fake_chan_);
    fake_listener_ = std::make_unique<FakeListener>();
    security_request_phase_ = std::make_unique<SecurityRequestPhase>(
        sm_chan_->GetWeakPtr(), fake_listener_->as_weak_ptr(), opts.requested_level, opts.bondable,
        [this](PairingRequestParams preq) { last_pairing_req_ = preq; });
  }

  l2cap::testing::FakeChannel* fake_chan() const { return fake_chan_.get(); }
  SecurityRequestPhase* security_request_phase() { return security_request_phase_.get(); }

  std::optional<PairingRequestParams> last_pairing_req() { return last_pairing_req_; }

 private:
  fbl::RefPtr<l2cap::testing::FakeChannel> fake_chan_;
  std::unique_ptr<PairingChannel> sm_chan_;
  std::unique_ptr<FakeListener> fake_listener_;
  std::unique_ptr<SecurityRequestPhase> security_request_phase_;

  std::optional<PairingRequestParams> last_pairing_req_;

  DISALLOW_COPY_AND_ASSIGN_ALLOW_MOVE(SecurityRequestPhaseTest);
};

using SMP_SecurityRequestPhaseDeathTest = SecurityRequestPhaseTest;

TEST_F(SecurityRequestPhaseTest, MakeEncryptedBondableSecurityRequest) {
  NewSecurityRequestPhase(SecurityRequestOptions{.requested_level = SecurityLevel::kEncrypted,
                                                 .bondable = BondableMode::Bondable});
  StaticByteBuffer kExpectedReq(kSecurityRequest, AuthReq::kBondingFlag);
  async::PostTask(dispatcher(), [this] { security_request_phase()->Start(); });
  ASSERT_TRUE(Expect(kExpectedReq));
  EXPECT_EQ(SecurityLevel::kEncrypted, security_request_phase()->pending_security_request());
}

TEST_F(SecurityRequestPhaseTest, MakeAuthenticatedNonBondableSecurityRequest) {
  NewSecurityRequestPhase(SecurityRequestOptions{.requested_level = SecurityLevel::kAuthenticated,
                                                 .bondable = BondableMode::NonBondable});
  StaticByteBuffer kExpectedReq(kSecurityRequest, AuthReq::kMITM);
  async::PostTask(dispatcher(), [this] { security_request_phase()->Start(); });
  ASSERT_TRUE(Expect(kExpectedReq));
  EXPECT_EQ(SecurityLevel::kAuthenticated, security_request_phase()->pending_security_request());
}

TEST_F(SecurityRequestPhaseTest, MakeSecureAuthenticatedBondableSecurityRequest) {
  NewSecurityRequestPhase(
      SecurityRequestOptions{.requested_level = SecurityLevel::kSecureAuthenticated});
  StaticByteBuffer kExpectedReq(kSecurityRequest,
                                AuthReq::kBondingFlag | AuthReq::kMITM | AuthReq::kSC);
  async::PostTask(dispatcher(), [this] {
    security_request_phase()->Start();
    ;
  });
  ASSERT_TRUE(Expect(kExpectedReq));
  EXPECT_EQ(SecurityLevel::kSecureAuthenticated,
            security_request_phase()->pending_security_request());
}

TEST_F(SecurityRequestPhaseTest, HandlesChannelClosedGracefully) {
  fake_chan()->Close();
  RunLoopUntilIdle();
}

TEST_F(SecurityRequestPhaseTest, PairingRequestAsResponderPassedThrough) {
  StaticByteBuffer<util::PacketSize<PairingRequestParams>()> preq_packet;
  PacketWriter writer(kPairingRequest, &preq_packet);
  PairingRequestParams generic_preq{.auth_req = AuthReq::kBondingFlag};
  *writer.mutable_payload<PairingRequestParams>() = generic_preq;
  ASSERT_FALSE(last_pairing_req().has_value());
  fake_chan()->Receive(preq_packet);
  RunLoopUntilIdle();
  ASSERT_TRUE(last_pairing_req().has_value());
  PairingRequestParams last_preq = last_pairing_req().value();
  ASSERT_EQ(0, memcmp(&last_preq, &generic_preq, sizeof(PairingRequestParams)));
}

TEST_F(SecurityRequestPhaseTest, InboundSecurityRequestFails) {
  StaticByteBuffer<util::PacketSize<PairingResponseParams>()> pres_packet;
  PacketWriter writer(kPairingResponse, &pres_packet);
  *writer.mutable_payload<PairingResponseParams>() = PairingResponseParams();

  bool message_sent = false;
  fake_chan()->SetSendCallback(
      [&message_sent](ByteBufferPtr sdu) {
        ValidPacketReader reader = ValidPacketReader::ParseSdu(sdu).value();
        ASSERT_EQ(reader.code(), kPairingFailed);
        message_sent = true;
      },
      dispatcher());

  fake_chan()->Receive(pres_packet);
  RunLoopUntilIdle();
  ASSERT_FALSE(last_pairing_req().has_value());
  ASSERT_TRUE(message_sent);
}

TEST_F(SecurityRequestPhaseTest, DropsInvalidPacket) {
  StaticByteBuffer bad_packet(0xFF);  // 0xFF is not a valid SMP header code

  bool message_sent = false;
  fake_chan()->SetSendCallback(
      [&message_sent](ByteBufferPtr sdu) {
        ValidPacketReader reader = ValidPacketReader::ParseSdu(sdu).value();
        ASSERT_EQ(reader.code(), kPairingFailed);
        message_sent = true;
      },
      dispatcher());

  fake_chan()->Receive(bad_packet);
  RunLoopUntilIdle();
  ASSERT_FALSE(last_pairing_req().has_value());
  ASSERT_TRUE(message_sent);
}

}  // namespace
}  // namespace bt::sm