/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <windows.h>
#include "mozwrlbase.h"
#include "nsServiceManagerUtils.h"

#include "WindowsUIUtils.h"

#include "nsIObserverService.h"
#include "nsIBaseWindow.h"
#include "nsIDocShell.h"
#include "nsIAppShellService.h"
#include "nsAppShellCID.h"
#include "nsIXULWindow.h"
#include "mozilla/Services.h"
#include "mozilla/WindowsVersion.h"
#include "nsString.h"
#include "nsIWidget.h"

#include <windows.ui.viewmanagement.h>

#pragma comment(lib, "runtimeobject.lib")

using namespace mozilla;
using namespace ABI::Windows::UI;
using namespace ABI::Windows::UI::ViewManagement;
using namespace Microsoft::WRL;
using namespace Microsoft::WRL::Wrappers;
using namespace ABI::Windows::Foundation;

/* All of this is win10 stuff and we're compiling against win81 headers
 * for now, so we may need to do some legwork: */
#if MOZ_WINSDK_MAXVER < 0x0A000000
namespace ABI {
  namespace Windows {
    namespace UI {
      namespace ViewManagement {
        enum UserInteractionMode {
          UserInteractionMode_Mouse = 0,
          UserInteractionMode_Touch = 1
        };
      }
    }
  }
}

#endif

#ifndef RuntimeClass_Windows_UI_ViewManagement_UIViewSettings
#define RuntimeClass_Windows_UI_ViewManagement_UIViewSettings L"Windows.UI.ViewManagement.UIViewSettings"
#endif

#if MOZ_WINSDK_MAXVER < 0x0A000000
namespace ABI {
  namespace Windows {
    namespace UI {
      namespace ViewManagement {
        interface IUIViewSettings;
        MIDL_INTERFACE("C63657F6-8850-470D-88F8-455E16EA2C26")
          IUIViewSettings : public IInspectable
          {
            public:
              virtual HRESULT STDMETHODCALLTYPE get_UserInteractionMode(UserInteractionMode *value) = 0;
          };

        extern const __declspec(selectany) IID & IID_IUIViewSettings = __uuidof(IUIViewSettings);
      }
    }
  }
}
#endif

#ifndef IUIViewSettingsInterop

typedef interface IUIViewSettingsInterop IUIViewSettingsInterop;

MIDL_INTERFACE("3694dbf9-8f68-44be-8ff5-195c98ede8a6")
IUIViewSettingsInterop : public IInspectable
{
public:
  virtual HRESULT STDMETHODCALLTYPE GetForWindow(HWND hwnd, REFIID riid, void **ppv) = 0;
};
#endif

WindowsUIUtils::WindowsUIUtils() :
  mInTabletMode(eTabletModeUnknown)
{
}

WindowsUIUtils::~WindowsUIUtils()
{
}

/*
 * Implement the nsISupports methods...
 */
NS_IMPL_ISUPPORTS(WindowsUIUtils,
                  nsIWindowsUIUtils)

NS_IMETHODIMP
WindowsUIUtils::GetInTabletMode(bool* aResult)
{
  if (mInTabletMode == eTabletModeUnknown) {
    UpdateTabletModeState();
  }
  *aResult = mInTabletMode == eTabletModeOn;
  return NS_OK;
}

NS_IMETHODIMP
WindowsUIUtils::UpdateTabletModeState()
{
  if (!IsWin10OrLater()) {
    return NS_OK;
  }

  nsCOMPtr<nsIAppShellService> appShell(do_GetService(NS_APPSHELLSERVICE_CONTRACTID));
  nsCOMPtr<nsIXULWindow> hiddenWindow;

  nsresult rv = appShell->GetHiddenWindow(getter_AddRefs(hiddenWindow));
  if (NS_FAILED(rv)) {
    return rv;
  }

  nsCOMPtr<nsIDocShell> docShell;
  rv = hiddenWindow->GetDocShell(getter_AddRefs(docShell));
  if (NS_FAILED(rv) || !docShell) {
    return rv;
  }

  nsCOMPtr<nsIBaseWindow> baseWindow(do_QueryInterface(docShell));

  if (!baseWindow)
    return NS_ERROR_FAILURE;

  nsCOMPtr<nsIWidget> widget;
  baseWindow->GetMainWidget(getter_AddRefs(widget));

  if (!widget)
    return NS_ERROR_FAILURE;

  HWND winPtr = (HWND)widget->GetNativeData(NS_NATIVE_WINDOW);
  ComPtr<IUIViewSettingsInterop> uiViewSettingsInterop;

  HRESULT hr = GetActivationFactory(
      HStringReference(RuntimeClass_Windows_UI_ViewManagement_UIViewSettings).Get(),
      &uiViewSettingsInterop);
  if (SUCCEEDED(hr)) {
    ComPtr<IUIViewSettings> uiViewSettings;
    hr = uiViewSettingsInterop->GetForWindow(winPtr, IID_PPV_ARGS(&uiViewSettings));
    if (SUCCEEDED(hr)) {
      UserInteractionMode mode;
      hr = uiViewSettings->get_UserInteractionMode(&mode);
      if (SUCCEEDED(hr)) {
        TabletModeState oldTabletModeState = mInTabletMode;
        mInTabletMode = (mode == UserInteractionMode_Touch) ? eTabletModeOn : eTabletModeOff;
        if (mInTabletMode != oldTabletModeState) {
          nsCOMPtr<nsIObserverService> observerService =
            mozilla::services::GetObserverService();
          NS_NAMED_LITERAL_STRING(tabletMode, "tablet-mode");
          NS_NAMED_LITERAL_STRING(normalMode, "normal-mode");
          observerService->NotifyObservers(nullptr, "tablet-mode-change",
            ((mInTabletMode == eTabletModeOn) ? tabletMode.get() : normalMode.get()));
        }
      }
    }
  }

  return NS_OK;
}