// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <algorithm>
#include <optional>

#include "base/files/file_util.h"
#include "base/files/scoped_temp_dir.h"
#include "base/functional/bind.h"
#include "base/functional/callback.h"
#include "base/functional/callback_helpers.h"
#include "base/task/single_thread_task_runner.h"
#include "base/test/test_simple_task_runner.h"
#include "base/uuid.h"
#include "components/download/internal/background_service/driver_entry.h"
#include "components/download/internal/background_service/entry.h"
#include "components/download/internal/background_service/file_monitor_impl.h"
#include "components/download/internal/background_service/test/entry_utils.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"

using testing::_;

namespace download {

class FileMonitorTest : public testing::Test {
 public:
  FileMonitorTest()
      : task_runner_(new base::TestSimpleTaskRunner),
        current_default_handle_(task_runner_),
        completion_callback_called_(false) {}

  FileMonitorTest(const FileMonitorTest&) = delete;
  FileMonitorTest& operator=(const FileMonitorTest&) = delete;

  ~FileMonitorTest() override = default;

  void HardRecoveryResponse(bool result);
  void CompletionCallback() { completion_callback_called_ = true; }

  void SetUp() override {
    EXPECT_TRUE(scoped_temp_dir_.CreateUniqueTempDir());
    download_dir_ = scoped_temp_dir_.GetPath();
    monitor_ = std::make_unique<FileMonitorImpl>(download_dir_, task_runner_);
  }

  void TearDown() override { ASSERT_TRUE(scoped_temp_dir_.Delete()); }

 protected:
  base::FilePath CreateTemporaryFile(std::string file_name);

  base::ScopedTempDir scoped_temp_dir_;
  scoped_refptr<base::TestSimpleTaskRunner> task_runner_;
  base::SingleThreadTaskRunner::CurrentDefaultHandle current_default_handle_;
  base::FilePath download_dir_;
  bool completion_callback_called_;
  std::unique_ptr<FileMonitor> monitor_;

  std::optional<bool> hard_recovery_result_;
};

base::FilePath FileMonitorTest::CreateTemporaryFile(std::string file_name) {
  base::FilePath file_path = download_dir_.AppendASCII(file_name);
  base::File file(file_path, base::File::FLAG_CREATE | base::File::FLAG_WRITE);
  EXPECT_TRUE(file.IsValid());
  file.Close();

  return file_path;
}

void FileMonitorTest::HardRecoveryResponse(bool result) {
  hard_recovery_result_ = result;
}

TEST_F(FileMonitorTest, TestDeleteUnknownFiles) {
  Entry entry1 = test::BuildEntry(
      DownloadClient::TEST, base::Uuid::GenerateRandomV4().AsLowercaseString());
  entry1.target_file_path = CreateTemporaryFile(entry1.guid);

  Entry entry2 = test::BuildEntry(
      DownloadClient::TEST, base::Uuid::GenerateRandomV4().AsLowercaseString());
  entry2.target_file_path = CreateTemporaryFile(entry2.guid);

  DriverEntry driver_entry1;
  driver_entry1.guid = entry1.guid;
  driver_entry1.current_file_path = entry1.target_file_path;

  DriverEntry driver_entry2;
  driver_entry2.guid = base::Uuid::GenerateRandomV4().AsLowercaseString();
  driver_entry2.current_file_path = CreateTemporaryFile(driver_entry2.guid);

  base::FilePath temp_file1 = CreateTemporaryFile("temp1");
  base::FilePath temp_file2 = CreateTemporaryFile("temp2");

  auto check_file_existence = [&](bool e1, bool e2, bool de1, bool de2, bool t1,
                                  bool t2) {
    EXPECT_EQ(e1, base::PathExists(entry1.target_file_path));
    EXPECT_EQ(e2, base::PathExists(entry2.target_file_path));
    EXPECT_EQ(de1, base::PathExists(driver_entry1.current_file_path));
    EXPECT_EQ(de2, base::PathExists(driver_entry2.current_file_path));
    EXPECT_EQ(t1, base::PathExists(temp_file1));
    EXPECT_EQ(t2, base::PathExists(temp_file2));
  };

  check_file_existence(true, true, true, true, true, true);

  std::vector<Entry*> entries = {&entry1, &entry2};
  std::vector<DriverEntry> driver_entries = {driver_entry1, driver_entry2};

  monitor_->DeleteUnknownFiles(entries, driver_entries, base::DoNothing());
  task_runner_->RunUntilIdle();
  check_file_existence(true, true, true, true, false, false);

  entries = {&entry2};
  driver_entries = {driver_entry1, driver_entry2};
  monitor_->DeleteUnknownFiles(entries, driver_entries, base::DoNothing());
  task_runner_->RunUntilIdle();
  check_file_existence(true, true, true, true, false, false);

  entries = {&entry2};
  driver_entries = {driver_entry2};
  monitor_->DeleteUnknownFiles(entries, driver_entries, base::DoNothing());
  task_runner_->RunUntilIdle();
  check_file_existence(false, true, false, true, false, false);

  entries.clear();
  driver_entries.clear();
  monitor_->DeleteUnknownFiles(entries, driver_entries, base::DoNothing());
  task_runner_->RunUntilIdle();
  check_file_existence(false, false, false, false, false, false);
}

TEST_F(FileMonitorTest, TestCleanupFilesForCompletedEntries) {
  Entry entry1 = test::BuildEntry(
      DownloadClient::TEST, base::Uuid::GenerateRandomV4().AsLowercaseString());
  EXPECT_TRUE(
      base::CreateTemporaryFileInDir(download_dir_, &entry1.target_file_path));

  Entry entry2 = test::BuildEntry(
      DownloadClient::TEST, base::Uuid::GenerateRandomV4().AsLowercaseString());
  EXPECT_TRUE(
      base::CreateTemporaryFileInDir(download_dir_, &entry2.target_file_path));

  std::vector<Entry*> entries = {&entry1, &entry2};
  monitor_->CleanupFilesForCompletedEntries(
      entries, base::BindOnce(&FileMonitorTest::CompletionCallback,
                              base::Unretained(this)));
  task_runner_->RunUntilIdle();

  EXPECT_FALSE(base::PathExists(entry1.target_file_path));
  EXPECT_FALSE(base::PathExists(entry2.target_file_path));
  EXPECT_TRUE(completion_callback_called_);
}

TEST_F(FileMonitorTest, TestHardRecovery) {
  base::FilePath temp_file1 = CreateTemporaryFile("temp1");
  base::FilePath temp_file2 = CreateTemporaryFile("temp2");

  auto callback = base::BindOnce(&FileMonitorTest::HardRecoveryResponse,
                                 base::Unretained(this));

  EXPECT_TRUE(base::PathExists(temp_file1));
  EXPECT_TRUE(base::PathExists(temp_file2));

  monitor_->HardRecover(std::move(callback));
  task_runner_->RunUntilIdle();

  EXPECT_TRUE(hard_recovery_result_.has_value());
  EXPECT_TRUE(hard_recovery_result_.value());
  EXPECT_FALSE(base::PathExists(temp_file1));
  EXPECT_FALSE(base::PathExists(temp_file2));
}

}  // namespace download