// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "chrome/installer/util/delete_after_reboot_helper.h"

#include <windows.h>

#include <shlobj.h>
#include <stddef.h>

#include <memory>

#include "base/files/file_util.h"
#include "base/logging.h"
#include "base/strings/string_util.h"
#include "base/win/registry.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {

// These tests exercise the Delete-After-Reboot code which requires
// modifications to HKLM. This will fail on Vista and above if the user
// is not an admin or if UAC is on.
// I tried using RegOverridePredefKey to test, but MoveFileEx ignore this
// even on 32 bit machines :-( As such, running this test may pollute
// your PendingFileRenameOperations value.
class DeleteAfterRebootHelperTest : public testing::Test {
 protected:
  void SetUp() override {
    // Create a temporary directory for testing and fill it with some files.
    base::CreateNewTempDirectory(base::FilePath::StringType(), &temp_dir_);
    base::CreateTemporaryFileInDir(temp_dir_, &temp_file_);

    temp_subdir_ = temp_dir_.Append(L"subdir");
    base::CreateDirectory(temp_subdir_);
    base::CreateTemporaryFileInDir(temp_subdir_, &temp_subdir_file_);

    // Copy the current pending moves and then clear it if we can:
    if (IsUserAnAdmin()) {
      GetPendingMovesValue(&original_pending_moves_);
    }
  }
  void TearDown() override {
    // Delete the temporary directory if it's still there.
    base::DeletePathRecursively(temp_dir_);

    // Try and restore the pending moves value, if we have one.
    if (IsUserAnAdmin() && original_pending_moves_.size() > 1) {
      base::win::RegKey session_manager_key(HKEY_LOCAL_MACHINE,
                                            kSessionManagerKey,
                                            KEY_CREATE_SUB_KEY | KEY_SET_VALUE);
      if (!session_manager_key.Handle()) {
        // Couldn't open / create the key.
        DLOG(ERROR) << "Failed to open session manager key for writing.";
      }

      std::vector<char> buffer;
      StringArrayToMultiSZBytes(original_pending_moves_, &buffer);
      session_manager_key.WriteValue(kPendingFileRenameOps, &buffer[0],
                                     static_cast<int>(buffer.size()),
                                     REG_MULTI_SZ);
    }
  }

  // Compares two buffers of size len. Returns true if they are equal,
  // false otherwise. Standard warnings about making sure the buffers
  // are at least len chars long apply.
  template <class Type>
  bool CompareBuffers(Type* buf1, Type* buf2, int len) {
    Type* comp1 = buf1;
    Type* comp2 = buf2;
    for (int i = 0; i < len; i++) {
      if (*comp1 != *comp2)
        return false;
      comp1++;
      comp2++;
    }
    return true;
  }

  // Returns the size of the given list of wstrings in bytes, including
  // null chars, plus an additional terminating null char.
  // e.g. the length of all the strings * sizeof(wchar_t).
  virtual size_t WStringPairListSize(
      const std::vector<PendingMove>& string_list) {
    size_t length = 0;
    std::vector<PendingMove>::const_iterator iter(string_list.begin());
    for (; iter != string_list.end(); ++iter) {
      length += iter->first.size() + 1;   // +1 for the null char.
      length += iter->second.size() + 1;  // +1 for the null char.
    }
    length++;  // for the additional null char.
    return length * sizeof(wchar_t);
  }

  std::vector<PendingMove> original_pending_moves_;

  base::FilePath temp_dir_;
  base::FilePath temp_file_;
  base::FilePath temp_subdir_;
  base::FilePath temp_subdir_file_;
};

}  // namespace

TEST_F(DeleteAfterRebootHelperTest, TestStringListToMultiSZConversions) {
  struct StringTest {
    const wchar_t* test_name;
    const wchar_t* str;
    DWORD length;
    size_t count;
  } tests[] = {
      {L"basic", L"foo\0bar\0fee\0bee\0boo\0bong\0\0", 26 * sizeof(wchar_t), 3},
      {L"empty", L"\0\0", 2 * sizeof(wchar_t), 1},
      {L"deletes", L"foo\0\0bar\0\0bizz\0\0", 16 * sizeof(wchar_t), 3},
  };

  for (size_t i = 0; i < std::size(tests); i++) {
    std::vector<PendingMove> string_list;
    EXPECT_TRUE(SUCCEEDED(
        MultiSZBytesToStringArray(reinterpret_cast<const char*>(tests[i].str),
                                  tests[i].length, &string_list)))
        << tests[i].test_name;
    EXPECT_EQ(tests[i].count, string_list.size()) << tests[i].test_name;
    std::vector<char> buffer;
    buffer.resize(WStringPairListSize(string_list));
    StringArrayToMultiSZBytes(string_list, &buffer);
    EXPECT_TRUE(CompareBuffers(const_cast<const char*>(&buffer[0]),
                               reinterpret_cast<const char*>(tests[i].str),
                               tests[i].length))
        << tests[i].test_name;
  }

  StringTest failures[] = {
      {L"malformed", reinterpret_cast<const wchar_t*>("oddnumb\0\0"), 9, 1},
  };

  for (size_t i = 0; i < std::size(failures); i++) {
    std::vector<PendingMove> string_list;
    EXPECT_FALSE(SUCCEEDED(MultiSZBytesToStringArray(
        reinterpret_cast<const char*>(failures[i].str), failures[i].length,
        &string_list)))
        << failures[i].test_name;
  }
}

TEST_F(DeleteAfterRebootHelperTest, TestFileDeleteScheduleAndUnschedule) {
  if (!IsUserAnAdmin()) {
    return;
  }

  EXPECT_TRUE(ScheduleDirectoryForDeletion(temp_dir_));

  std::vector<PendingMove> pending_moves;
  EXPECT_TRUE(SUCCEEDED(GetPendingMovesValue(&pending_moves)));

  // We should see, somewhere in this key, deletion writs for
  // temp_file_, temp_subdir_file_, temp_subdir_ and temp_dir_ in that order.
  EXPECT_GT(pending_moves.size(), 3U);

  // Get the short form of temp_file_ and use that to match.
  base::FilePath short_temp_file(GetShortPathName(temp_file_));

  // Scan for the first expected delete.
  std::vector<PendingMove>::const_iterator iter(pending_moves.begin());
  for (; iter != pending_moves.end(); iter++) {
    base::FilePath move_path(iter->first);
    if (MatchPendingDeletePath(short_temp_file, move_path))
      break;
  }

  // Check that each of the deletes we expect are there in order.
  base::FilePath expected_paths[] = {temp_file_, temp_subdir_file_,
                                     temp_subdir_, temp_dir_};
  for (size_t i = 0; i < std::size(expected_paths); ++i) {
    EXPECT_FALSE(iter == pending_moves.end());
    if (iter != pending_moves.end()) {
      base::FilePath short_path_name(GetShortPathName(expected_paths[i]));
      base::FilePath move_path(iter->first);
      EXPECT_TRUE(MatchPendingDeletePath(short_path_name, move_path));
      ++iter;
    }
  }

  // Test that we can remove the pending deletes.
  EXPECT_TRUE(RemoveFromMovesPendingReboot(temp_dir_));
  HRESULT hr = GetPendingMovesValue(&pending_moves);
  EXPECT_TRUE(hr == S_OK || hr == HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND));

  std::vector<PendingMove>::const_iterator check_iter(pending_moves.begin());
  for (; check_iter != pending_moves.end(); ++check_iter) {
    base::FilePath move_path(check_iter->first);
    EXPECT_FALSE(MatchPendingDeletePath(short_temp_file, move_path));
  }
}

TEST_F(DeleteAfterRebootHelperTest, TestFileDeleteSchedulingWithActualDeletes) {
  if (!IsUserAnAdmin()) {
    return;
  }

  std::vector<PendingMove> initial_pending_moves;
  GetPendingMovesValue(&initial_pending_moves);
  size_t initial_pending_moves_size = initial_pending_moves.size();

  EXPECT_TRUE(ScheduleDirectoryForDeletion(temp_dir_));

  std::vector<PendingMove> pending_moves;
  EXPECT_TRUE(SUCCEEDED(GetPendingMovesValue(&pending_moves)));

  // We should see, somewhere in this key, deletion writs for
  // temp_file_, temp_subdir_file_, temp_subdir_ and temp_dir_ in that order.
  EXPECT_TRUE(pending_moves.size() > 3);

  // Get the short form of temp_file_ and use that to match.
  base::FilePath short_temp_file(GetShortPathName(temp_file_));

  // Scan for the first expected delete.
  std::vector<PendingMove>::const_iterator iter(pending_moves.begin());
  for (; iter != pending_moves.end(); iter++) {
    base::FilePath move_path(iter->first);
    if (MatchPendingDeletePath(short_temp_file, move_path))
      break;
  }

  // Check that each of the deletes we expect are there in order.
  base::FilePath expected_paths[] = {temp_file_, temp_subdir_file_,
                                     temp_subdir_, temp_dir_};
  for (size_t i = 0; i < std::size(expected_paths); ++i) {
    EXPECT_FALSE(iter == pending_moves.end());
    if (iter != pending_moves.end()) {
      base::FilePath short_path_name(GetShortPathName(expected_paths[i]));
      base::FilePath move_path(iter->first);
      EXPECT_TRUE(MatchPendingDeletePath(short_path_name, move_path));
      ++iter;
    }
  }

  // Delete the temporary directory.
  base::DeletePathRecursively(temp_dir_);

  // Test that we can remove the pending deletes.
  EXPECT_TRUE(RemoveFromMovesPendingReboot(temp_dir_));
  HRESULT hr = GetPendingMovesValue(&pending_moves);
  EXPECT_TRUE(hr == S_OK || hr == HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND));

  EXPECT_EQ(initial_pending_moves_size, pending_moves.size());

  std::vector<PendingMove>::const_iterator check_iter(pending_moves.begin());
  for (; check_iter != pending_moves.end(); ++check_iter) {
    base::FilePath move_path(check_iter->first);
    EXPECT_FALSE(MatchPendingDeletePath(short_temp_file, move_path));
  }
}