// Copyright (c) 2009 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// chrome_tab.cc : Implementation of DLL Exports.
#include "base/at_exit.h"
#include "base/command_line.h"
#include "base/file_util.h"
#include "base/file_version_info.h"
#include "base/logging.h"
#include "base/path_service.h"
#include "base/registry.h"
#include "base/string_piece.h"
#include "base/string_util.h"
#include "base/sys_string_conversions.h"
#include "chrome/common/chrome_constants.h"
#include "grit/chrome_frame_resources.h"
#include "chrome_frame/bho.h"
#include "chrome_frame/chrome_frame_automation.h"
#include "chrome_frame/chrome_launcher.h"
#include "chrome_frame/crash_report.h"
#include "chrome_frame/resource.h"
#include "chrome_frame/utils.h"

// Include without path to make GYP build see it.
#include "chrome_tab.h"  // NOLINT

static const wchar_t kBhoRegistryPath[] =
    L"Software\\Microsoft\\Windows\\CurrentVersion\\Explorer"
    L"\\Browser Helper Objects";

const wchar_t kBhoNoLoadExplorerValue[] = L"NoExplorer";

class ChromeTabModule
    : public AtlPerUserModule<CAtlDllModuleT<ChromeTabModule> > {
 public:
  typedef AtlPerUserModule<CAtlDllModuleT<ChromeTabModule> > ParentClass;

  DECLARE_LIBID(LIBID_ChromeTabLib)
  DECLARE_REGISTRY_APPID_RESOURCEID(IDR_CHROMETAB,
                                    "{FD9B1B31-F4D8-436A-8F4F-D3C2E36733D3}")

  // Override to add our SYSTIME binary value to registry scripts.
  // See chrome_frame_activex.rgs for usage.
  virtual HRESULT AddCommonRGSReplacements(IRegistrarBase* registrar) throw() {
    HRESULT hr = ParentClass::AddCommonRGSReplacements(registrar);

    if (SUCCEEDED(hr)) {
      SYSTEMTIME local_time;
      ::GetSystemTime(&local_time);
      std::string hex(HexEncode(&local_time, sizeof(local_time)));
      base::StringPiece sp_hex(hex);
      hr = registrar->AddReplacement(L"SYSTIME",
                                     base::SysNativeMBToWide(sp_hex).c_str());
      DCHECK(SUCCEEDED(hr));
    }

    if (SUCCEEDED(hr)) {
      std::wstring app_path(
          chrome_launcher::GetChromeExecutablePath());
      app_path = file_util::GetDirectoryFromPath(app_path);
      hr = registrar->AddReplacement(L"CHROME_APPPATH", app_path.c_str());
      DCHECK(SUCCEEDED(hr));
    }

    if (SUCCEEDED(hr)) {
      hr = registrar->AddReplacement(L"CHROME_APPNAME",
                                     chrome::kBrowserProcessExecutableName);
      DCHECK(SUCCEEDED(hr));

      // Fill in VERSION from the VERSIONINFO stored in the DLL's resources.
      scoped_ptr<FileVersionInfo> module_version_info(
          FileVersionInfo::CreateFileVersionInfoForCurrentModule());
      DCHECK(module_version_info != NULL);
      std::wstring file_version(module_version_info->file_version());
      hr = registrar->AddReplacement(L"VERSION", file_version.c_str());
      DCHECK(SUCCEEDED(hr));
    }

    if (SUCCEEDED(hr)) {
      // Add the directory of chrome_launcher.exe.  This will be the same
      // as the directory for the current DLL.
      std::wstring module_dir;
      FilePath module_path;
      if (PathService::Get(base::FILE_MODULE, &module_path)) {
        module_dir = module_path.DirName().ToWStringHack();
      } else {
        NOTREACHED();
      }
      hr = registrar->AddReplacement(L"CHROME_LAUNCHER_APPPATH",
                                     module_dir.c_str());
      DCHECK(SUCCEEDED(hr));
    }

    if (SUCCEEDED(hr)) {
      // Add the filename of chrome_launcher.exe
      hr = registrar->AddReplacement(L"CHROME_LAUNCHER_APPNAME",
                                     chrome_launcher::kLauncherExeBaseName);
      DCHECK(SUCCEEDED(hr));
    }

    return hr;
  }
};

ChromeTabModule _AtlModule;

base::AtExitManager* g_exit_manager = NULL;

// DLL Entry Point
extern "C" BOOL WINAPI DllMain(HINSTANCE instance,
                               DWORD reason,
                               LPVOID reserved) {
  UNREFERENCED_PARAMETER(instance);
  if (reason == DLL_PROCESS_ATTACH) {
#ifndef NDEBUG
    // Silence traces from the ATL registrar to reduce the log noise.
    ATL::CTrace::s_trace.ChangeCategory(atlTraceRegistrar, 0,
                                        ATLTRACESTATUS_DISABLED);
#endif
    InitializeCrashReporting(false, false);
    g_exit_manager = new base::AtExitManager();
    CommandLine::Init(0, NULL);
    logging::InitLogging(NULL, logging::LOG_ONLY_TO_SYSTEM_DEBUG_LOG,
                        logging::LOCK_LOG_FILE, logging::DELETE_OLD_LOG_FILE);
  } else if (reason == DLL_PROCESS_DETACH) {
    g_patch_helper.UnpatchIfNeeded();
    delete g_exit_manager;
    g_exit_manager = NULL;
    ShutdownCrashReporting();
  }
  return _AtlModule.DllMain(reason, reserved);
}

#ifdef _MANAGED
#pragma managed(pop)
#endif

const wchar_t kPostPlatformUAKey[] =
    L"Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\"
    L"User Agent\\Post Platform";
const wchar_t kClockUserAgent[] = L"chromeframe";

// To delete the clock user agent, set value to NULL.
HRESULT SetClockUserAgent(const wchar_t* value) {
  HRESULT hr;
  RegKey ua_key;
  if (ua_key.Create(HKEY_CURRENT_USER, kPostPlatformUAKey, KEY_WRITE)) {
    if (value) {
      ua_key.WriteValue(kClockUserAgent, value);
    } else {
      ua_key.DeleteValue(kClockUserAgent);
    }
    hr = S_OK;
  } else {
    DLOG(ERROR) << __FUNCTION__ << ": " << kPostPlatformUAKey;
    hr = E_UNEXPECTED;
  }

  return hr;
}

HRESULT RefreshElevationPolicy() {
  const wchar_t kIEFrameDll[] = L"ieframe.dll";
  const char kIERefreshPolicy[] = "IERefreshElevationPolicy";
  HRESULT hr = E_NOTIMPL;
  HMODULE ieframe_module = LoadLibrary(kIEFrameDll);
  if (ieframe_module) {
    typedef HRESULT (__stdcall *IERefreshPolicy)();
    IERefreshPolicy ie_refresh_policy = reinterpret_cast<IERefreshPolicy>(
        GetProcAddress(ieframe_module, kIERefreshPolicy));

    if (ie_refresh_policy) {
      hr = ie_refresh_policy();
    } else {
      hr = HRESULT_FROM_WIN32(GetLastError());
    }
    
    FreeLibrary(ieframe_module);
  } else {
    hr = HRESULT_FROM_WIN32(GetLastError());
  }

  return hr;
}

HRESULT RegisterChromeTabBHO() {
  RegKey ie_bho_key;
  if (!ie_bho_key.Create(HKEY_LOCAL_MACHINE, kBhoRegistryPath,
                       KEY_CREATE_SUB_KEY)) {
    DLOG(WARNING) << "Failed to open registry key "
                  << kBhoRegistryPath
                  << " for write";
    return E_FAIL;
  }

  wchar_t bho_class_id_as_string[MAX_PATH] = {0};
  StringFromGUID2(CLSID_ChromeFrameBHO, bho_class_id_as_string,
                  arraysize(bho_class_id_as_string));

  if (!ie_bho_key.CreateKey(bho_class_id_as_string, KEY_READ | KEY_WRITE)) {
    DLOG(WARNING) << "Failed to create bho registry key under "
                  << kBhoRegistryPath
                  << " for write";
    return E_FAIL;
  }

  ie_bho_key.WriteValue(kBhoNoLoadExplorerValue, 1);
  DLOG(INFO) << "Registered ChromeTab BHO";

  SetClockUserAgent(L"1");
  RefreshElevationPolicy();
  return S_OK;
}

HRESULT UnregisterChromeTabBHO() {
  SetClockUserAgent(NULL);

  RegKey ie_bho_key;
  if (!ie_bho_key.Open(HKEY_LOCAL_MACHINE, kBhoRegistryPath,
                       KEY_READ | KEY_WRITE)) {
    DLOG(WARNING) << "Failed to open registry key "
                  << kBhoRegistryPath
                  << " for write.";
    return E_FAIL;
  }

  wchar_t bho_class_id_as_string[MAX_PATH] = {0};
  StringFromGUID2(CLSID_ChromeFrameBHO, bho_class_id_as_string,
                  arraysize(bho_class_id_as_string));

  if (!ie_bho_key.DeleteKey(bho_class_id_as_string)) {
    DLOG(WARNING) << "Failed to delete bho registry key "
                  << bho_class_id_as_string
                  << " under "
                  << kBhoRegistryPath;
    return E_FAIL;
  }

  DLOG(INFO) << "Unregistered ChromeTab BHO";
  return S_OK;
}

// Used to determine whether the DLL can be unloaded by OLE
STDAPI DllCanUnloadNow() {
  return _AtlModule.DllCanUnloadNow();
}

// Returns a class factory to create an object of the requested type
STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID* ppv) {
  if (g_patch_helper.state() == PatchHelper::UNKNOWN) {
    g_patch_helper.InitializeAndPatchProtocolsIfNeeded();
    UrlMkSetSessionOption(URLMON_OPTION_USERAGENT_REFRESH, NULL, 0, 0);
  }

  return _AtlModule.DllGetClassObject(rclsid, riid, ppv);
}

// DllRegisterServer - Adds entries to the system registry
STDAPI DllRegisterServer() {
  // registers object, typelib and all interfaces in typelib
  HRESULT hr = _AtlModule.DllRegisterServer(TRUE);

#ifdef GOOGLE_CHROME_BUILD
  // Muck with the Omaha configuration so that we don't get updated by non-CF
  // Google Chrome builds.
  UtilUpdateOmahaConfig(true);
#endif

  if (SUCCEEDED(hr)) {
    // Best effort attempt to register the BHO. At this point we silently
    // ignore any errors during registration. There are some traces emitted
    // to the debug log.
    RegisterChromeTabBHO();
  }

  return hr;
}

// DllUnregisterServer - Removes entries from the system registry
STDAPI DllUnregisterServer() {
  HRESULT hr = _AtlModule.DllUnregisterServer(TRUE);

#ifdef GOOGLE_CHROME_BUILD
  // Undo any prior mucking with the Omaha config.
  UtilUpdateOmahaConfig(false);
#endif

  if (SUCCEEDED(hr)) {
    // Best effort attempt to unregister the BHO. At this point we silently
    // ignore any errors during unregistration. There are some traces emitted
    // to the debug log.
    UnregisterChromeTabBHO();
  }
  return hr;
}

STDAPI RegisterNPAPIPlugin() {
  HRESULT hr = _AtlModule.UpdateRegistryFromResourceS(IDR_CHROMEFRAME_NPAPI,
                                                      TRUE);
  return hr;
}

STDAPI UnregisterNPAPIPlugin() {
  HRESULT hr = _AtlModule.UpdateRegistryFromResourceS(IDR_CHROMEFRAME_NPAPI,
                                                      FALSE);
  return hr;
}