// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

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

#include <stdint.h>

#include <string>

#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/notreached.h"
#include "base/path_service.h"
#include "base/strings/strcat.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/utf_string_conversions.h"
#include "base/win/win_util.h"
#include "chrome/common/chrome_constants.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/installer/util/util_constants.h"
#include "components/app_launch_prefetch/app_launch_prefetch.h"
#include "crypto/hash.h"

namespace auto_launch_util {

// The prefix of the Chrome Auto-launch key under the Run key.
constexpr wchar_t kAutolaunchKeyValue[] = L"GoogleChromeAutoLaunch";

// Builds a registry key name to use when deciding where to read/write the auto-
// launch value to/from. It takes into account the path of the profile so that
// different installations of Chrome don't conflict. Returns an empty string if
// the key name cannot be determined.
std::wstring GetAutoLaunchKeyName() {
  base::FilePath path;
  if (!base::PathService::Get(chrome::DIR_USER_DATA, &path)) {
    return {};
  }
  // Background auto-launch is only supported for the Default profile at the
  // moment, but keep the door opened to a multi-profile implementation by
  // encoding the Default profile in the hash.
  path = path.AppendASCII(chrome::kInitialProfile);

  const auto hash = crypto::hash::Sha256(path.AsUTF8Unsafe());

  // This code has historically used the first 16 bytes of the SHA-256 of the
  // path, primarily to keep the registry key name shorter since we do not need
  // cryptographic collision resistance.
  const auto truncated_hash = base::span<const uint8_t>(hash).first<16>();
  return base::StrCat({kAutolaunchKeyValue, L"_",
                       base::ASCIIToWide(base::HexEncode(truncated_hash))});
}

void EnableStartAtLogin(StartupLaunchMode startup_launch_mode) {
  base::FilePath application_dir;
  if (!base::PathService::Get(base::DIR_EXE, &application_dir)) {
    return;
  }

  base::CommandLine cmd_line(application_dir.Append(installer::kChromeExe));

  switch (startup_launch_mode) {
    case StartupLaunchMode::kBackground:
      cmd_line.AppendSwitch(switches::kNoStartupWindow);
      cmd_line.AppendArgNative(app_launch_prefetch::GetPrefetchSwitch(
          app_launch_prefetch::SubprocessType::kBrowserBackground));
      break;
    default:
      NOTREACHED();
  }
  if (auto key_name = GetAutoLaunchKeyName(); !key_name.empty()) {
    base::win::AddCommandToAutoRun(HKEY_CURRENT_USER, key_name,
                                   cmd_line.GetCommandLineString());
  }
}

void DisableStartAtLogin() {
  if (auto key_name = GetAutoLaunchKeyName(); !key_name.empty()) {
    base::win::RemoveCommandFromAutoRun(HKEY_CURRENT_USER, key_name);
  }
}

}  // namespace auto_launch_util