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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "win32/base/omaha_util.h"

#include <atlbase.h>
#include <windows.h>

#include <string>

#include "base/system_util.h"

namespace mozc {
namespace win32 {
#if defined(GOOGLE_JAPANESE_INPUT_BUILD)
namespace {
using ATL::CRegKey;

const wchar_t kClientStateKey[] =
    L"Software\\Google\\Update\\ClientState\\"
    L"{DDCCD2A9-025E-4142-BCEB-F467B88CF830}";
const wchar_t kChannelKeyName[] = L"ap";

LONG OpenClientStateKey(CRegKey *key, REGSAM base_sam) {
  const REGSAM sam_desired = base_sam | KEY_WOW64_32KEY;
  return key->Create(HKEY_LOCAL_MACHINE, kClientStateKey, REG_NONE,
                     REG_OPTION_NON_VOLATILE, sam_desired);
}
}  // namespace

// Writes a REG_SZ channel name into "ap" in Mozc's client state key.
bool OmahaUtil::WriteChannel(const std::wstring &value) {
  CRegKey key;
  LONG result = OpenClientStateKey(&key, KEY_READ | KEY_WRITE);
  if (ERROR_SUCCESS != result) {
    return false;
  }
  result = key.SetStringValue(kChannelKeyName, value.c_str());
  if (ERROR_SUCCESS != result) {
    return false;
  }
  return true;
}

// Reads a REG_SZ channel name from "ap" in Mozc's client state key.
std::wstring OmahaUtil::ReadChannel() {
  CRegKey key;
  LONG result = OpenClientStateKey(&key, KEY_READ);
  if (ERROR_SUCCESS != result) {
    return L"";
  }
  wchar_t buf[512];
  ULONG buf_size = std::size(buf);
  result = key.QueryStringValue(kChannelKeyName, buf, &buf_size);
  if (ERROR_SUCCESS != result) {
    return L"";
  }
  return std::wstring(buf);
}

bool OmahaUtil::ClearOmahaError() {
  CRegKey key;
  LONG result = OpenClientStateKey(&key, KEY_READ | KEY_WRITE);
  if (ERROR_SUCCESS != result) {
    return false;
  }
  result = key.SetDWORDValue(L"InstallerResult", 0);
  if (ERROR_SUCCESS != result) {
    return false;
  }
  result = key.SetStringValue(L"InstallerResultUIString", L"");
  if (ERROR_SUCCESS != result) {
    return false;
  }
  return true;
}

bool OmahaUtil::WriteOmahaError(const std::wstring &ui_message,
                                const std::wstring &header) {
  CRegKey key;
  LONG result = OpenClientStateKey(&key, KEY_READ | KEY_WRITE);
  if (ERROR_SUCCESS != result) {
    return false;
  }
  result = key.SetDWORDValue(L"InstallerResult", 1);
  if (ERROR_SUCCESS != result) {
    return false;
  }

  // Leaves Mozc version in addition to UI message for customer support.
  const std::wstring &message =
      header.length() > 0 ? header + L"\r\n" + ui_message : ui_message;

  // This message will be displayed by Omaha meta installer in the error
  // dialog.
  result = key.SetStringValue(L"InstallerResultUIString", message.c_str());
  if (ERROR_SUCCESS != result) {
    return false;
  }
  return true;
}

bool OmahaUtil::ClearChannel() {
  CRegKey key;
  LONG result = OpenClientStateKey(&key, KEY_READ | KEY_WRITE);
  if (ERROR_SUCCESS != result) {
    // The parent key is already deleted. It's OK.
    return true;
  }
  if (ReadChannel().empty()) {
    // The value does not exist. It's OK.
    return true;
  }
  result = key.DeleteValue(kChannelKeyName);
  if (ERROR_SUCCESS != result) {
    return false;
  }
  return true;
}

#else   // !GOOGLE_JAPANESE_INPUT_BUILD

bool OmahaUtil::WriteChannel(const std::wstring &value) {
  return true;
}

// Reads a REG_SZ channel name from "ap" in Mozc's client state key.
std::wstring OmahaUtil::ReadChannel() {
  return L"";
}

bool OmahaUtil::ClearOmahaError() {
  return true;
}

bool OmahaUtil::WriteOmahaError(const std::wstring &ui_message,
                                const std::wstring &header) {
  return true;
}

bool OmahaUtil::ClearChannel() {
  return true;
}

#endif  // GOOGLE_JAPANESE_INPUT_BUILD

}  // namespace win32
}  // namespace mozc
