// Copyright 2023 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_bluetooth_sapphire/internal/host/sdp/service_discoverer.h"

#include "pw_bluetooth_sapphire/internal/host/l2cap/fake_channel.h"
#include "pw_bluetooth_sapphire/internal/host/l2cap/fake_channel_test.h"
#include "pw_bluetooth_sapphire/internal/host/testing/gtest_helpers.h"

namespace bt::sdp {
namespace {

constexpr PeerId kDeviceOne(1), kDeviceTwo(2), kDeviceThree(3);

class FakeClient : public Client {
 public:
  // |destroyed_cb| will be called when this client is destroyed, with true if
  // there are outstanding expected requests.
  FakeClient(fit::closure destroyed_cb)
      : destroyed_cb_(std::move(destroyed_cb)) {}

  virtual ~FakeClient() override { destroyed_cb_(); }

  virtual void ServiceSearchAttributes(
      std::unordered_set<UUID> search_pattern,
      const std::unordered_set<AttributeId>& req_attributes,
      SearchResultFunction result_cb) override {
    if (!service_search_attributes_cb_) {
      FAIL() << "ServiceSearchAttributes with no callback set";
    }

    service_search_attributes_cb_(std::move(search_pattern),
                                  std::move(req_attributes),
                                  std::move(result_cb));
  }

  using ServiceSearchAttributesCallback =
      fit::function<void(std::unordered_set<UUID>,
                         std::unordered_set<AttributeId>,
                         SearchResultFunction)>;
  void SetServiceSearchAttributesCallback(
      ServiceSearchAttributesCallback callback) {
    service_search_attributes_cb_ = std::move(callback);
  }

 private:
  ServiceSearchAttributesCallback service_search_attributes_cb_;
  fit::closure destroyed_cb_;
};

class ServiceDiscovererTest : public pw::async::test::FakeDispatcherFixture {
 public:
  ServiceDiscovererTest() = default;
  ~ServiceDiscovererTest() = default;

  pw::async::HeapDispatcher& heap_dispatcher() { return heap_dispatcher_; }

 protected:
  void SetUp() override {
    clients_created_ = 0;
    clients_destroyed_ = 0;
  }

  void TearDown() override {}

  // Connect an SDP client to a fake channel, which is available in channel_
  std::unique_ptr<FakeClient> GetFakeClient() {
    SCOPED_TRACE("Connect Client");
    clients_created_++;
    return std::make_unique<FakeClient>([this]() { clients_destroyed_++; });
  }

  size_t clients_created() const { return clients_created_; }
  size_t clients_destroyed() const { return clients_destroyed_; }

 private:
  size_t clients_created_, clients_destroyed_;
  pw::async::HeapDispatcher heap_dispatcher_{dispatcher()};
};

// When there are no searches registered, it just disconnects the client.
TEST_F(ServiceDiscovererTest, NoSearches) {
  ServiceDiscoverer discoverer;
  EXPECT_EQ(0u, discoverer.search_count());

  discoverer.StartServiceDiscovery(kDeviceOne, GetFakeClient());

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1u, clients_destroyed());
}

// Happy path test with one registered service and no results.
TEST_F(ServiceDiscovererTest, NoResults) {
  ServiceDiscoverer discoverer;

  size_t cb_count = 0;

  auto result_cb = [&cb_count](auto, const auto&) { cb_count++; };

  ServiceDiscoverer::SearchId id = discoverer.AddSearch(
      profile::kSerialPort,
      {kServiceId, kProtocolDescriptorList, kBluetoothProfileDescriptorList},
      std::move(result_cb));
  ASSERT_NE(ServiceDiscoverer::kInvalidSearchId, id);
  EXPECT_EQ(1u, discoverer.search_count());

  auto client = GetFakeClient();

  std::vector<std::unordered_set<UUID>> searches;

  client->SetServiceSearchAttributesCallback(
      [dispatcher = heap_dispatcher(), &searches](
          auto pattern, auto /*attributes*/, auto callback) mutable {
        searches.emplace_back(std::move(pattern));
        (void)dispatcher.Post(
            [cb = std::move(callback)](pw::async::Context /*ctx*/,
                                       pw::Status status) {
              if (status.ok()) {
                cb(fit::error(Error(HostError::kNotFound)));
              }
            });
      });

  discoverer.StartServiceDiscovery(kDeviceOne, std::move(client));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1u, searches.size());
  ASSERT_EQ(0u, cb_count);
  ASSERT_EQ(1u, clients_destroyed());
}

TEST_F(ServiceDiscovererTest, SynchronousErrorResult) {
  ServiceDiscoverer discoverer;

  size_t cb_count = 0;
  auto result_cb = [&cb_count](auto, const auto&) { cb_count++; };
  ServiceDiscoverer::SearchId id = discoverer.AddSearch(
      profile::kSerialPort,
      {kServiceId, kProtocolDescriptorList, kBluetoothProfileDescriptorList},
      std::move(result_cb));
  ASSERT_NE(ServiceDiscoverer::kInvalidSearchId, id);
  EXPECT_EQ(1u, discoverer.search_count());

  auto client = GetFakeClient();
  std::vector<std::unordered_set<UUID>> searches;
  client->SetServiceSearchAttributesCallback(
      [&searches](auto pattern, auto /*attributes*/, auto callback) {
        searches.emplace_back(std::move(pattern));
        callback(fit::error(Error(HostError::kLinkDisconnected)));
      });

  discoverer.StartServiceDiscovery(kDeviceOne, std::move(client));
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_EQ(1u, searches.size());
  ASSERT_EQ(0u, cb_count);
  ASSERT_EQ(1u, clients_destroyed());
}

// Happy path test with two registered searches.
// No results, then two results.
// Unregister one search.
// Then one result are searched for and two returned.
TEST_F(ServiceDiscovererTest, SomeResults) {
  ServiceDiscoverer discoverer;

  std::vector<std::pair<PeerId, std::map<AttributeId, DataElement>>> results;

  ServiceDiscoverer::ResultCallback result_cb =
      [&results](PeerId id, const auto& attributes) {
        std::map<AttributeId, DataElement> attributes_clone;
        for (const auto& it : attributes) {
          auto [inserted_it, added] =
              attributes_clone.try_emplace(it.first, it.second.Clone());
          ASSERT_TRUE(added);
        }
        results.emplace_back(id, std::move(attributes_clone));
      };

  ServiceDiscoverer::SearchId one = discoverer.AddSearch(
      profile::kSerialPort,
      {kServiceId, kProtocolDescriptorList, kBluetoothProfileDescriptorList},
      result_cb.share());
  ASSERT_NE(ServiceDiscoverer::kInvalidSearchId, one);
  EXPECT_EQ(1u, discoverer.search_count());
  ServiceDiscoverer::SearchId two = discoverer.AddSearch(
      profile::kAudioSink,
      {kProtocolDescriptorList, kBluetoothProfileDescriptorList},
      result_cb.share());
  ASSERT_NE(ServiceDiscoverer::kInvalidSearchId, two);
  EXPECT_EQ(2u, discoverer.search_count());

  auto client = GetFakeClient();

  std::vector<std::unordered_set<UUID>> searches;

  client->SetServiceSearchAttributesCallback(
      [dispatcher = heap_dispatcher(), &searches](
          auto pattern, auto /*attributes*/, auto callback) mutable {
        searches.emplace_back(std::move(pattern));
        (void)dispatcher.Post(
            [cb = std::move(callback)](pw::async::Context /*ctx*/,
                                       pw::Status status) {
              if (status.ok()) {
                cb(fit::error(Error(HostError::kNotFound)));
              }
            });
      });

  discoverer.StartServiceDiscovery(kDeviceOne, std::move(client));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(2u, searches.size());
  ASSERT_EQ(0u, results.size());
  ASSERT_EQ(1u, clients_destroyed());

  client = GetFakeClient();

  searches.clear();

  client->SetServiceSearchAttributesCallback(
      [cb_dispatcher = heap_dispatcher(), &searches](
          auto pattern, auto /*attributes*/, auto callback) mutable {
        searches.emplace_back(pattern);
        if (pattern.count(profile::kSerialPort)) {
          (void)cb_dispatcher.Post([cb = std::move(callback)](
                                       pw::async::Context /*ctx*/,
                                       pw::Status status) {
            if (!status.ok()) {
              return;
            }
            ServiceSearchAttributeResponse rsp;
            rsp.SetAttribute(0, kServiceId, DataElement(UUID(uint16_t{1})));
            // This would normally be a element list. uint32_t for Testing.
            rsp.SetAttribute(
                0, kBluetoothProfileDescriptorList, DataElement(uint32_t{1}));

            if (!cb(fit::ok(std::cref(rsp.attributes(0))))) {
              return;
            }
            cb(fit::error(Error(HostError::kNotFound)));
          });
        } else if (pattern.count(profile::kAudioSink)) {
          (void)cb_dispatcher.Post([cb = std::move(callback)](
                                       pw::async::Context /*ctx*/,
                                       pw::Status status) {
            if (!status.ok()) {
              return;
            }
            ServiceSearchAttributeResponse rsp;
            // This would normally be a element list. uint32_t for Testing.
            rsp.SetAttribute(
                0, kBluetoothProfileDescriptorList, DataElement(uint32_t{1}));

            if (!cb(fit::ok(std::cref(rsp.attributes(0))))) {
              return;
            }
            cb(fit::error(Error(HostError::kNotFound)));
          });
        } else {
          std::cerr << "Searched for " << pattern.size() << std::endl;
          for (auto it : pattern) {
            std::cerr << it.ToString() << std::endl;
          }
          FAIL() << "Unexpected search called";
        }
      });

  discoverer.StartServiceDiscovery(kDeviceTwo, std::move(client));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(2u, searches.size());
  ASSERT_EQ(2u, results.size());
  ASSERT_EQ(2u, clients_destroyed());

  results.clear();
  searches.clear();

  ASSERT_TRUE(discoverer.RemoveSearch(one));
  ASSERT_FALSE(discoverer.RemoveSearch(one));
  EXPECT_EQ(1u, discoverer.search_count());

  client = GetFakeClient();

  client->SetServiceSearchAttributesCallback(
      [cb_dispatcher = heap_dispatcher(), &searches](
          auto pattern, auto /*attributes*/, auto callback) mutable {
        searches.emplace_back(pattern);
        if (pattern.count(profile::kAudioSink)) {
          (void)cb_dispatcher.Post([cb = std::move(callback)](
                                       pw::async::Context /*ctx*/,
                                       pw::Status status) {
            if (!status.ok()) {
              return;
            }
            ServiceSearchAttributeResponse rsp;
            // This would normally be a element list. uint32_t for Testing.
            rsp.SetAttribute(
                0, kBluetoothProfileDescriptorList, DataElement(uint32_t{1}));
            rsp.SetAttribute(
                1, kProtocolDescriptorList, DataElement(uint32_t{2}));

            if (!cb(fit::ok(std::cref(rsp.attributes(0))))) {
              return;
            }
            if (!cb(fit::ok(std::cref(rsp.attributes(1))))) {
              return;
            }
            cb(fit::error(Error(HostError::kNotFound)));
          });
        } else {
          std::cerr << "Searched for " << pattern.size() << std::endl;
          for (auto it : pattern) {
            std::cerr << it.ToString() << std::endl;
          }
          FAIL() << "Unexpected search called";
        }
      });

  discoverer.StartServiceDiscovery(kDeviceThree, std::move(client));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1u, searches.size());
  ASSERT_EQ(2u, results.size());
  ASSERT_EQ(3u, clients_destroyed());
}

// Single search behavior when there is a discovery not running (2 clients
// simultaneously)
TEST_F(ServiceDiscovererTest, SingleSearchDifferentPeers) {
  ServiceDiscoverer discoverer;

  size_t cb_count = 0;

  auto result_cb = [&cb_count](auto, const auto&) { cb_count++; };

  ServiceDiscoverer::SearchId search_id = discoverer.AddSearch(
      profile::kSerialPort, {kServiceId}, std::move(result_cb));
  ASSERT_NE(ServiceDiscoverer::kInvalidSearchId, search_id);
  EXPECT_EQ(1u, discoverer.search_count());

  auto client = GetFakeClient();
  auto client2 = GetFakeClient();

  std::vector<std::unordered_set<UUID>> searches;

  auto search_attributes_cb =
      [cb_dispatcher = heap_dispatcher(), &searches](
          auto pattern, auto /*attributes*/, auto callback) mutable {
        searches.emplace_back(pattern);
        if (pattern.count(profile::kSerialPort)) {
          (void)cb_dispatcher.Post(
              [cb = std::move(callback)](pw::async::Context /*ctx*/,
                                         pw::Status status) {
                if (!status.ok()) {
                  return;
                }
                ServiceSearchAttributeResponse rsp;
                rsp.SetAttribute(0, kServiceId, DataElement(UUID(uint16_t{1})));
                if (!cb(fit::ok(std::cref(rsp.attributes(0))))) {
                  return;
                }
                cb(fit::error(Error(HostError::kNotFound)));
              });
        } else {
          std::cerr << "Searched for " << pattern.size() << std::endl;
          for (auto it : pattern) {
            std::cerr << it.ToString() << std::endl;
          }
          FAIL() << "Unexpected search called";
        }
      };

  client->SetServiceSearchAttributesCallback(search_attributes_cb);
  client2->SetServiceSearchAttributesCallback(search_attributes_cb);

  discoverer.SingleSearch(search_id, PeerId(1), std::move(client));
  discoverer.SingleSearch(search_id, PeerId(2), std::move(client2));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(2u, searches.size());
  ASSERT_EQ(2u, cb_count);
  ASSERT_EQ(2u, clients_destroyed());
}

// Single search behavior when there is a discovery running (2 searches
// simultaneously)
TEST_F(ServiceDiscovererTest, SingleSearchSamePeer) {
  ServiceDiscoverer discoverer;

  size_t cb_count = 0;

  auto result_cb = [&cb_count](auto, const auto&) { cb_count++; };

  ServiceDiscoverer::SearchId search_id = discoverer.AddSearch(
      profile::kSerialPort, {kServiceId}, std::move(result_cb));
  ASSERT_NE(ServiceDiscoverer::kInvalidSearchId, search_id);
  EXPECT_EQ(1u, discoverer.search_count());

  auto client = GetFakeClient();
  std::vector<std::unordered_set<UUID>> searches;

  auto search_attributes_cb =
      [cb_dispatcher = heap_dispatcher(), &searches](
          auto pattern, auto /*attributes*/, auto callback) mutable {
        searches.emplace_back(pattern);
        if (pattern.count(profile::kSerialPort)) {
          (void)cb_dispatcher.Post(
              [cb = std::move(callback)](pw::async::Context /*ctx*/,
                                         pw::Status status) {
                if (!status.ok()) {
                  return;
                }
                ServiceSearchAttributeResponse rsp;
                rsp.SetAttribute(0, kServiceId, DataElement(UUID(uint16_t{1})));
                if (!cb(fit::ok(std::cref(rsp.attributes(0))))) {
                  return;
                }
                cb(fit::error(Error(HostError::kNotFound)));
              });
        } else {
          std::cerr << "Searched for " << pattern.size() << std::endl;
          for (auto it : pattern) {
            std::cerr << it.ToString() << std::endl;
          }
          FAIL() << "Unexpected search called";
        }
      };

  client->SetServiceSearchAttributesCallback(search_attributes_cb);

  discoverer.SingleSearch(search_id, PeerId(1), std::move(client));
  discoverer.SingleSearch(search_id, PeerId(1), nullptr);

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(2u, searches.size());
  ASSERT_EQ(2u, cb_count);
  ASSERT_EQ(1u, clients_destroyed());
}

// Disconnected on the other end before the discovery completes
TEST_F(ServiceDiscovererTest, Disconnected) {
  ServiceDiscoverer discoverer;

  size_t cb_count = 0;

  auto result_cb = [&cb_count](auto, const auto&) { cb_count++; };

  ServiceDiscoverer::SearchId id = discoverer.AddSearch(
      profile::kSerialPort,
      {kServiceId, kProtocolDescriptorList, kBluetoothProfileDescriptorList},
      std::move(result_cb));
  ASSERT_NE(ServiceDiscoverer::kInvalidSearchId, id);
  EXPECT_EQ(1u, discoverer.search_count());

  auto client = GetFakeClient();

  std::vector<std::unordered_set<UUID>> searches;

  client->SetServiceSearchAttributesCallback(
      [cb_dispatcher = heap_dispatcher(), &searches](
          auto pattern, auto /*attributes*/, auto callback) mutable {
        searches.emplace_back(pattern);
        if (pattern.count(profile::kSerialPort)) {
          (void)cb_dispatcher.Post(
              [cb = std::move(callback)](pw::async::Context /*ctx*/,
                                         pw::Status status) {
                if (status.ok()) {
                  cb(fit::error(Error(HostError::kLinkDisconnected)));
                }
              });
        } else {
          std::cerr << "Searched for " << pattern.size() << std::endl;
          for (auto it : pattern) {
            std::cerr << it.ToString() << std::endl;
          }
          FAIL() << "Unexpected search called";
        }
      });

  discoverer.StartServiceDiscovery(kDeviceOne, std::move(client));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1u, searches.size());
  ASSERT_EQ(0u, cb_count);
  ASSERT_EQ(1u, clients_destroyed());
}

// Unregistered Search when partway through the discovery
TEST_F(ServiceDiscovererTest, UnregisterInProgress) {
  ServiceDiscoverer discoverer;

  std::optional<std::pair<PeerId, std::map<AttributeId, DataElement>>> result;

  ServiceDiscoverer::SearchId id = ServiceDiscoverer::kInvalidSearchId;

  ServiceDiscoverer::ResultCallback one_result_cb =
      [&discoverer, &result, &id](auto peer_id, const auto& attributes) {
        // We should only be called once
        ASSERT_TRUE(!result.has_value());
        std::map<AttributeId, DataElement> attributes_clone;
        for (const auto& it : attributes) {
          auto [inserted_it, added] =
              attributes_clone.try_emplace(it.first, it.second.Clone());
          ASSERT_TRUE(added);
        }
        result.emplace(peer_id, std::move(attributes_clone));
        discoverer.RemoveSearch(id);
      };

  id = discoverer.AddSearch(
      profile::kAudioSink,
      {kProtocolDescriptorList, kBluetoothProfileDescriptorList},
      one_result_cb.share());
  ASSERT_NE(ServiceDiscoverer::kInvalidSearchId, id);
  EXPECT_EQ(1u, discoverer.search_count());

  auto client = GetFakeClient();

  std::vector<std::unordered_set<UUID>> searches;

  client->SetServiceSearchAttributesCallback(
      [cb_dispatcher = heap_dispatcher(), &searches](
          auto pattern, auto /*attributes*/, auto callback) mutable {
        searches.emplace_back(pattern);
        if (pattern.count(profile::kAudioSink)) {
          (void)cb_dispatcher.Post([cb = std::move(callback)](
                                       pw::async::Context /*ctx*/,
                                       pw::Status status) {
            if (!status.ok()) {
              return;
            }
            ServiceSearchAttributeResponse rsp;
            // This would normally be a element list. uint32_t for Testing.
            rsp.SetAttribute(
                0, kBluetoothProfileDescriptorList, DataElement(uint32_t{1}));
            rsp.SetAttribute(
                1, kProtocolDescriptorList, DataElement(uint32_t{2}));

            if (!cb(fit::ok(std::cref(rsp.attributes(0))))) {
              return;
            }
            if (!cb(fit::ok(std::cref(rsp.attributes(1))))) {
              return;
            }
            cb(fit::error(Error(HostError::kNotFound)));
          });
        } else {
          std::cerr << "Searched for " << pattern.size() << std::endl;
          for (auto it : pattern) {
            std::cerr << it.ToString() << std::endl;
          }
          FAIL() << "Unexpected search called";
        }
      });

  discoverer.StartServiceDiscovery(kDeviceOne, std::move(client));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1u, searches.size());

  ASSERT_TRUE(result.has_value());
  ASSERT_EQ(kDeviceOne, result->first);
  auto value = result->second[kBluetoothProfileDescriptorList].Get<uint32_t>();
  ASSERT_TRUE(value);
  ASSERT_EQ(1u, *value);

  ASSERT_EQ(1u, clients_destroyed());
  EXPECT_EQ(0u, discoverer.search_count());
}

}  // namespace
}  // namespace bt::sdp