// Copyright 2014 The Chromium 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 "media/midi/midi_manager.h"

#include <stddef.h>
#include <stdint.h>

#include <memory>
#include <vector>

#include "base/bind.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/run_loop.h"
#include "base/system/system_monitor.h"
#include "base/test/scoped_task_environment.h"
#include "build/build_config.h"
#include "media/midi/midi_service.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace midi {

namespace {

using mojom::PortState;
using mojom::Result;

class FakeMidiManager : public MidiManager {
 public:
  explicit FakeMidiManager(MidiService* service)
      : MidiManager(service), weak_factory_(this) {}

  ~FakeMidiManager() override = default;

  base::WeakPtr<FakeMidiManager> GetWeakPtr() {
    return weak_factory_.GetWeakPtr();
  }

  // MidiManager implementation.
  void StartInitialization() override {
    DCHECK(!initialized_);
    initialized_ = true;
  }
  void DispatchSendMidiData(MidiManagerClient* client,
                            uint32_t port_index,
                            const std::vector<uint8_t>& data,
                            base::TimeTicks timestamp) override {}

  // Utility functions for testing.
  void CallCompleteInitialization(Result result) {
    CompleteInitialization(result);
  }

  size_t GetClientCount() { return GetClientCountForTesting(); }

  size_t GetPendingClientCount() { return GetPendingClientCountForTesting(); }

  bool IsInitialized() const { return initialized_; }

 private:
  bool initialized_ = false;

  base::WeakPtrFactory<FakeMidiManager> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(FakeMidiManager);
};

class FakeMidiManagerFactory : public MidiService::ManagerFactory {
 public:
  FakeMidiManagerFactory() : weak_factory_(this) {}
  ~FakeMidiManagerFactory() override = default;

  std::unique_ptr<MidiManager> Create(MidiService* service) override {
    std::unique_ptr<FakeMidiManager> manager =
        std::make_unique<FakeMidiManager>(service);
    manager_ = manager->GetWeakPtr();
    return manager;
  }

  base::WeakPtr<FakeMidiManagerFactory> GetWeakPtr() {
    return weak_factory_.GetWeakPtr();
  }

  base::WeakPtr<FakeMidiManager> manager() {
#if defined(OS_MACOSX)
    // To avoid Core MIDI issues, MidiManager won't be destructed on macOS.
    // See https://crbug.com/718140.
    if (!manager_ ||
        (!manager_->GetClientCount() && !manager_->GetPendingClientCount())) {
      return nullptr;
    }
#endif
    return manager_;
  }

 private:
  base::WeakPtr<FakeMidiManager> manager_ = nullptr;
  base::WeakPtrFactory<FakeMidiManagerFactory> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(FakeMidiManagerFactory);
};

class FakeMidiManagerClient : public MidiManagerClient {
 public:
  FakeMidiManagerClient() = default;
  ~FakeMidiManagerClient() override = default;

  // MidiManagerClient implementation.
  void AddInputPort(const mojom::PortInfo& info) override {}
  void AddOutputPort(const mojom::PortInfo& info) override {}
  void SetInputPortState(uint32_t port_index, PortState state) override {}
  void SetOutputPortState(uint32_t port_index, PortState state) override {}
  void CompleteStartSession(Result result) override {
    EXPECT_TRUE(wait_for_result_);
    result_ = result;
    wait_for_result_ = false;
  }
  void ReceiveMidiData(uint32_t port_index,
                       const uint8_t* data,
                       size_t size,
                       base::TimeTicks timestamp) override {}
  void AccumulateMidiBytesSent(size_t size) override {}
  void Detach() override {}

  Result result() const { return result_; }

  Result WaitForResult() {
    while (wait_for_result_) {
      base::RunLoop run_loop;
      run_loop.RunUntilIdle();
    }
    return result();
  }

 private:
  Result result_ = Result::NOT_SUPPORTED;
  bool wait_for_result_ = true;

  DISALLOW_COPY_AND_ASSIGN(FakeMidiManagerClient);
};

class MidiManagerTest : public ::testing::Test {
 public:
  MidiManagerTest() {
    std::unique_ptr<FakeMidiManagerFactory> factory =
        std::make_unique<FakeMidiManagerFactory>();
    factory_ = factory->GetWeakPtr();
    service_ = std::make_unique<MidiService>(std::move(factory));
  }

  ~MidiManagerTest() override {
    service_->Shutdown();
    base::RunLoop run_loop;
    run_loop.RunUntilIdle();
  }

 protected:
  void StartTheFirstSession(FakeMidiManagerClient* client) {
    DCHECK(factory_);

    EXPECT_FALSE(factory_->manager());
    service_->StartSession(client);
    ASSERT_TRUE(factory_->manager());
    EXPECT_TRUE(factory_->manager()->IsInitialized());
    EXPECT_EQ(0U, factory_->manager()->GetClientCount());
    EXPECT_EQ(1U, factory_->manager()->GetPendingClientCount());
  }

  void StartTheNthSession(FakeMidiManagerClient* client, size_t nth) {
    DCHECK(factory_);
    DCHECK_NE(1U, nth);

    ASSERT_TRUE(factory_->manager());
    EXPECT_TRUE(factory_->manager()->IsInitialized());
    EXPECT_EQ(0U, factory_->manager()->GetClientCount());
    EXPECT_EQ(nth - 1U, factory_->manager()->GetPendingClientCount());
    service_->StartSession(client);
    EXPECT_EQ(nth, factory_->manager()->GetPendingClientCount());
  }

  void StartSession(FakeMidiManagerClient* client) {
    service_->StartSession(client);
  }

  void EndSession(FakeMidiManagerClient* client, size_t before, size_t after) {
    DCHECK(factory_);

    ASSERT_TRUE(factory_->manager());
    EXPECT_EQ(before, factory_->manager()->GetClientCount());
    EXPECT_TRUE(service_->EndSession(client));
    if (after) {
      ASSERT_TRUE(factory_->manager());
      EXPECT_EQ(after, factory_->manager()->GetClientCount());
    } else {
      EXPECT_FALSE(factory_->manager());
    }
  }

  bool CompleteInitialization(Result result) {
    DCHECK(factory_);

    if (!factory_->manager())
      return false;

    factory_->manager()->CallCompleteInitialization(result);
    return true;
  }

  void RunLoopUntilIdle() {
    base::RunLoop run_loop;
    run_loop.RunUntilIdle();
  }

  base::WeakPtr<FakeMidiManagerFactory> factory() { return factory_; }

 private:
  base::test::ScopedTaskEnvironment env_;
  base::WeakPtr<FakeMidiManagerFactory> factory_;
  std::unique_ptr<MidiService> service_;

  DISALLOW_COPY_AND_ASSIGN(MidiManagerTest);
};

TEST_F(MidiManagerTest, StartAndEndSession) {
  std::unique_ptr<FakeMidiManagerClient> client =
      std::make_unique<FakeMidiManagerClient>();

  StartTheFirstSession(client.get());
  EXPECT_TRUE(CompleteInitialization(Result::OK));
  EXPECT_EQ(Result::OK, client->WaitForResult());
  EndSession(client.get(), 1U, 0U);
}

TEST_F(MidiManagerTest, StartAndEndSessionWithError) {
  std::unique_ptr<FakeMidiManagerClient> client =
      std::make_unique<FakeMidiManagerClient>();

  StartTheFirstSession(client.get());
  EXPECT_TRUE(CompleteInitialization(Result::INITIALIZATION_ERROR));
  EXPECT_EQ(Result::INITIALIZATION_ERROR, client->WaitForResult());
  EndSession(client.get(), 1U, 0U);
}

TEST_F(MidiManagerTest, StartMultipleSessions) {
  std::unique_ptr<FakeMidiManagerClient> client1 =
      std::make_unique<FakeMidiManagerClient>();
  std::unique_ptr<FakeMidiManagerClient> client2 =
      std::make_unique<FakeMidiManagerClient>();
  std::unique_ptr<FakeMidiManagerClient> client3 =
      std::make_unique<FakeMidiManagerClient>();

  StartTheFirstSession(client1.get());
  StartTheNthSession(client2.get(), 2);
  StartTheNthSession(client3.get(), 3);
  EXPECT_TRUE(CompleteInitialization(Result::OK));
  EXPECT_EQ(Result::OK, client1->WaitForResult());
  EXPECT_EQ(Result::OK, client2->WaitForResult());
  EXPECT_EQ(Result::OK, client3->WaitForResult());
  EndSession(client1.get(), 3U, 2U);
  EndSession(client2.get(), 2U, 1U);
  EndSession(client3.get(), 1U, 0U);
}

TEST_F(MidiManagerTest, TooManyPendingSessions) {
  // Push as many client requests for starting session as possible.
  std::vector<std::unique_ptr<FakeMidiManagerClient>> many_existing_clients;
  many_existing_clients.resize(MidiManager::kMaxPendingClientCount);
  many_existing_clients[0] = std::make_unique<FakeMidiManagerClient>();
  StartTheFirstSession(many_existing_clients[0].get());
  for (size_t i = 1; i < MidiManager::kMaxPendingClientCount; ++i) {
    many_existing_clients[i] = std::make_unique<FakeMidiManagerClient>();
    StartTheNthSession(many_existing_clients[i].get(), i + 1);
  }
  ASSERT_TRUE(factory()->manager());
  EXPECT_TRUE(factory()->manager()->IsInitialized());

  // Push the last client that should be rejected for too many pending requests.
  std::unique_ptr<FakeMidiManagerClient> additional_client =
      std::make_unique<FakeMidiManagerClient>();
  StartSession(additional_client.get());
  EXPECT_EQ(Result::INITIALIZATION_ERROR, additional_client->result());

  // Other clients still should not receive a result.
  RunLoopUntilIdle();
  for (size_t i = 0; i < many_existing_clients.size(); ++i)
    EXPECT_EQ(Result::NOT_SUPPORTED, many_existing_clients[i]->result());

  // The Result::OK should be distributed to other clients.
  EXPECT_TRUE(CompleteInitialization(Result::OK));
  for (size_t i = 0; i < many_existing_clients.size(); ++i)
    EXPECT_EQ(Result::OK, many_existing_clients[i]->WaitForResult());

  // Close all successful sessions in FIFO order.
  size_t sessions = many_existing_clients.size();
  for (size_t i = 0; i < many_existing_clients.size(); ++i, --sessions)
    EndSession(many_existing_clients[i].get(), sessions, sessions - 1);
}

TEST_F(MidiManagerTest, AbortSession) {
  // A client starting a session can be destructed while an asynchronous
  // initialization is performed.
  std::unique_ptr<FakeMidiManagerClient> client =
      std::make_unique<FakeMidiManagerClient>();

  StartTheFirstSession(client.get());
  EndSession(client.get(), 0, 0);
  client.reset();

  // Following function should not call the destructed |client| function.
  EXPECT_FALSE(CompleteInitialization(Result::OK));
  base::RunLoop run_loop;
  run_loop.RunUntilIdle();
}

#if defined(OS_ANDROID)
// The test sometimes fails on Android. https://crbug.com/844027
#define MAYBE_CreatePlatformMidiManager DISABLED_CreatePlatformMidiManager
#else
#define MAYBE_CreatePlatformMidiManager CreatePlatformMidiManager
#endif
TEST_F(MidiManagerTest, MAYBE_CreatePlatformMidiManager) {
  // SystemMonitor is needed on Windows.
  base::SystemMonitor system_monitor;

  std::unique_ptr<FakeMidiManagerClient> client =
      std::make_unique<FakeMidiManagerClient>();

  // Use own MidiService instance to construct a real platform dependent
  // MidiManager instance.
  std::unique_ptr<MidiService> service = std::make_unique<MidiService>();
  service->StartSession(client.get());

  Result result = client->WaitForResult();
  // This #ifdef needs to be identical to the one in media/midi/midi_manager.cc.
  // Do not change the condition for disabling this test.
#if !defined(OS_MACOSX) && !defined(OS_WIN) && \
    !(defined(USE_ALSA) && defined(USE_UDEV)) && !defined(OS_ANDROID)
  EXPECT_EQ(Result::NOT_SUPPORTED, result);
#elif defined(USE_ALSA)
  // Temporary until http://crbug.com/371230 is resolved.
  EXPECT_TRUE(result == Result::OK || result == Result::INITIALIZATION_ERROR);
#else
  EXPECT_EQ(Result::OK, result);
#endif

  service->Shutdown();
  base::RunLoop run_loop;
  run_loop.RunUntilIdle();
}

}  // namespace

}  // namespace midi