/*
 * Copyright 2019 The Android Open Source Project
 *
 * 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
 *
 *      http://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 "module.h"
#include "module_unittest_generated.h"
#include "os/handler.h"
#include "os/thread.h"

#include "gtest/gtest.h"

#include <functional>
#include <future>

using ::bluetooth::os::Thread;

namespace bluetooth {
namespace {

class ModuleTest : public ::testing::Test {
 protected:
  void SetUp() override {
    thread_ = new Thread("test_thread", Thread::Priority::NORMAL);
    registry_ = new ModuleRegistry();
  }

  void TearDown() override {
    delete registry_;
    delete thread_;
  }

  ModuleRegistry* registry_;
  Thread* thread_;
};

os::Handler* test_module_no_dependency_handler = nullptr;

class TestModuleNoDependency : public Module {
 public:
  static const ModuleFactory Factory;

 protected:
  void ListDependencies(ModuleList* list) override {
  }

  void Start() override {
    // A module is not considered started until Start() finishes
    EXPECT_FALSE(GetModuleRegistry()->IsStarted<TestModuleNoDependency>());
    test_module_no_dependency_handler = GetHandler();
  }

  void Stop() override {
    // A module is not considered stopped until after Stop() finishes
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleNoDependency>());
  }
};

const ModuleFactory TestModuleNoDependency::Factory = ModuleFactory([]() {
  return new TestModuleNoDependency();
});

os::Handler* test_module_one_dependency_handler = nullptr;

class TestModuleOneDependency : public Module {
 public:
  static const ModuleFactory Factory;

 protected:
  void ListDependencies(ModuleList* list) override {
    list->add<TestModuleNoDependency>();
  }

  void Start() override {
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleNoDependency>());

    // A module is not considered started until Start() finishes
    EXPECT_FALSE(GetModuleRegistry()->IsStarted<TestModuleOneDependency>());
    test_module_one_dependency_handler = GetHandler();
  }

  void Stop() override {
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleNoDependency>());

    // A module is not considered stopped until after Stop() finishes
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleOneDependency>());
  }
};

const ModuleFactory TestModuleOneDependency::Factory = ModuleFactory([]() {
  return new TestModuleOneDependency();
});


class TestModuleNoDependencyTwo : public Module {
 public:
  static const ModuleFactory Factory;

 protected:
  void ListDependencies(ModuleList* list) override {
  }

  void Start() override {
    // A module is not considered started until Start() finishes
    EXPECT_FALSE(GetModuleRegistry()->IsStarted<TestModuleNoDependencyTwo>());
  }

  void Stop() override {
    // A module is not considered stopped until after Stop() finishes
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleNoDependencyTwo>());
  }
};

const ModuleFactory TestModuleNoDependencyTwo::Factory = ModuleFactory([]() {
  return new TestModuleNoDependencyTwo();
});

class TestModuleTwoDependencies : public Module {
 public:
  static const ModuleFactory Factory;

 protected:
  void ListDependencies(ModuleList* list) override {
    list->add<TestModuleOneDependency>();
    list->add<TestModuleNoDependencyTwo>();
  }

  void Start() override {
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleOneDependency>());
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleNoDependencyTwo>());

    // A module is not considered started until Start() finishes
    EXPECT_FALSE(GetModuleRegistry()->IsStarted<TestModuleTwoDependencies>());
  }

  void Stop() override {
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleOneDependency>());
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleNoDependencyTwo>());

    // A module is not considered stopped until after Stop() finishes
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleTwoDependencies>());
  }
};

const ModuleFactory TestModuleTwoDependencies::Factory = ModuleFactory([]() {
  return new TestModuleTwoDependencies();
});

// To generate module unittest flatbuffer headers:
// $ flatc --cpp module_unittest.fbs
class TestModuleDumpState : public Module {
 public:
  static const ModuleFactory Factory;

  std::string test_string_{"Initial Test String"};

 protected:
  void ListDependencies(ModuleList* list) override {
    list->add<TestModuleNoDependency>();
  }

  void Start() override {
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleNoDependency>());

    // A module is not considered started until Start() finishes
    EXPECT_FALSE(GetModuleRegistry()->IsStarted<TestModuleDumpState>());
    test_module_one_dependency_handler = GetHandler();
  }

  void Stop() override {
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleNoDependency>());

    // A module is not considered stopped until after Stop() finishes
    EXPECT_TRUE(GetModuleRegistry()->IsStarted<TestModuleDumpState>());
  }

  DumpsysDataFinisher GetDumpsysData(flatbuffers::FlatBufferBuilder* fb_builder) const override {
    auto string = fb_builder->CreateString(test_string_.c_str());

    auto builder = ModuleUnitTestDataBuilder(*fb_builder);
    builder.add_title(string);
    auto table = builder.Finish();

    return [table](DumpsysDataBuilder* builder) { builder->add_module_unittest_data(table); };
  }
};

const ModuleFactory TestModuleDumpState::Factory = ModuleFactory([]() { return new TestModuleDumpState(); });

TEST_F(ModuleTest, no_dependency) {
  ModuleList list;
  list.add<TestModuleNoDependency>();
  registry_->Start(&list, thread_);

  EXPECT_TRUE(registry_->IsStarted<TestModuleNoDependency>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleOneDependency>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleNoDependencyTwo>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleTwoDependencies>());

  registry_->StopAll();

  EXPECT_FALSE(registry_->IsStarted<TestModuleNoDependency>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleOneDependency>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleNoDependencyTwo>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleTwoDependencies>());
}

TEST_F(ModuleTest, one_dependency) {
  ModuleList list;
  list.add<TestModuleOneDependency>();
  registry_->Start(&list, thread_);

  EXPECT_TRUE(registry_->IsStarted<TestModuleNoDependency>());
  EXPECT_TRUE(registry_->IsStarted<TestModuleOneDependency>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleNoDependencyTwo>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleTwoDependencies>());

  registry_->StopAll();

  EXPECT_FALSE(registry_->IsStarted<TestModuleNoDependency>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleOneDependency>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleNoDependencyTwo>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleTwoDependencies>());
}

TEST_F(ModuleTest, two_dependencies) {
  ModuleList list;
  list.add<TestModuleTwoDependencies>();
  registry_->Start(&list, thread_);

  EXPECT_TRUE(registry_->IsStarted<TestModuleNoDependency>());
  EXPECT_TRUE(registry_->IsStarted<TestModuleOneDependency>());
  EXPECT_TRUE(registry_->IsStarted<TestModuleNoDependencyTwo>());
  EXPECT_TRUE(registry_->IsStarted<TestModuleTwoDependencies>());

  registry_->StopAll();

  EXPECT_FALSE(registry_->IsStarted<TestModuleNoDependency>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleOneDependency>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleNoDependencyTwo>());
  EXPECT_FALSE(registry_->IsStarted<TestModuleTwoDependencies>());
}

void post_to_module_one_handler() {
  std::this_thread::sleep_for(std::chrono::milliseconds(100));
  test_module_one_dependency_handler->Post(common::BindOnce([] { FAIL(); }));
}

TEST_F(ModuleTest, shutdown_with_unhandled_callback) {
  ModuleList list;
  list.add<TestModuleOneDependency>();
  registry_->Start(&list, thread_);
  test_module_no_dependency_handler->Post(common::BindOnce(&post_to_module_one_handler));
  registry_->StopAll();
}

TEST_F(ModuleTest, dump_state) {
  static const char* title = "Test Dump Title";
  ModuleList list;
  list.add<TestModuleDumpState>();
  registry_->Start(&list, thread_);

  ModuleDumper dumper(*registry_, title);

  std::string output;
  dumper.DumpState(&output);

  auto data = flatbuffers::GetRoot<DumpsysData>(output.data());
  EXPECT_STREQ(title, data->title()->c_str());

  auto test_data = data->module_unittest_data();
  EXPECT_STREQ("Initial Test String", test_data->title()->c_str());

  TestModuleDumpState* test_module =
      static_cast<TestModuleDumpState*>(registry_->Start(&TestModuleDumpState::Factory, nullptr));
  test_module->test_string_ = "A Second Test String";

  dumper.DumpState(&output);

  data = flatbuffers::GetRoot<DumpsysData>(output.data());
  test_data = data->module_unittest_data();
  EXPECT_STREQ("A Second Test String", test_data->title()->c_str());

  registry_->StopAll();
}

}  // namespace
}  // namespace bluetooth