/* 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 https://mozilla.org/MPL/2.0/. */

#include "pch.h"
#include "logs.h"
#include "ImmersiveView.h"
#include "ImmersiveMain.h"

using namespace winrt::ServoApp;

using namespace concurrency;
using namespace std::placeholders;
using namespace winrt::Windows::ApplicationModel;
using namespace winrt::Windows::ApplicationModel::Activation;
using namespace winrt::Windows::ApplicationModel::Core;
using namespace winrt::Windows::Foundation;
using namespace winrt::Windows::Graphics::Holographic;
using namespace winrt::Windows::UI::Core;

// Immediatly start immersive mode:
// int __stdcall wWinMain(HINSTANCE, HINSTANCE, PWSTR, int)
//{
//  winrt::init_apartment();
//  CoreApplication::Run(ImmersiveViewSource());
//  return 0;
//}

// IFrameworkViewSource methods

IFrameworkView ImmersiveViewSource::CreateView() { return holographicView; }

// IFrameworkView methods

// The first method called when the IFrameworkView is being created.
// Use this method to subscribe for Windows shell events and to initialize your
// app.
void ImmersiveView::Initialize(CoreApplicationView const &applicationView) {
  applicationView.Activated(
      std::bind(&ImmersiveView::OnViewActivated, this, _1, _2));

  // Register event handlers for app lifecycle.
  m_suspendingEventToken = CoreApplication::Suspending(
      bind(&ImmersiveView::OnSuspending, this, _1, _2));
  m_resumingEventToken =
      CoreApplication::Resuming(bind(&ImmersiveView::OnResuming, this, _1, _2));

  // At this point we have access to the device and we can create
  // device-dependent resources.
  m_deviceResources = std::make_shared<DX::DeviceResources>();

  m_main = std::make_unique<Immersive::ImmersiveMain>(m_deviceResources);
}

// Called when the CoreWindow object is created (or re-created).
void ImmersiveView::SetWindow(CoreWindow const &window) {

  if (m_main == nullptr) {
    winrt::hstring message(L"main program not intialized.\n");
    OutputDebugStringW(message.data());
    return;
  }

  // Register for keypress notifications.
  m_keyDownEventToken =
      window.KeyDown(bind(&ImmersiveView::OnKeyPressed, this, _1, _2));

  // Register for pointer pressed notifications.
  m_pointerPressedEventToken = window.PointerPressed(
      bind(&ImmersiveView::OnPointerPressed, this, _1, _2));

  // Register for notification that the app window is being closed.
  m_windowClosedEventToken =
      window.Closed(bind(&ImmersiveView::OnWindowClosed, this, _1, _2));

  // Register for notifications that the app window is losing focus.
  m_visibilityChangedEventToken = window.VisibilityChanged(
      bind(&ImmersiveView::OnVisibilityChanged, this, _1, _2));

  // Create a holographic space for the core window for the current view.
  // Presenting holographic frames that are created by this holographic space
  // will put the app into exclusive mode.
  m_holographicSpace = HolographicSpace::CreateForCoreWindow(window);

  // The DeviceResources class uses the preferred DXGI adapter ID from the
  // holographic space (when available) to create a Direct3D device. The
  // HolographicSpace uses this ID3D11Device to create and manage device-based
  // resources such as swap chains.
  m_deviceResources->SetHolographicSpace(m_holographicSpace);

  // The main class uses the holographic space for updates and rendering.
  m_main->SetHolographicSpace(m_holographicSpace);
}

// The Load method can be used to initialize scene resources or to load a
// previously saved app state.
void ImmersiveView::Load(winrt::hstring const &) {}

// This method is called after the window becomes active. It oversees the
// update, draw, and present loop, and it also oversees window message
// processing.
void ImmersiveView::Run() {

  if (m_main == nullptr) {
    winrt::hstring message(L"main program not intialized.\n");
    OutputDebugStringW(message.data());
    return;
  }

  CoreWindow::GetForCurrentThread().Activate();

  while (!m_windowClosed) {
    if (m_windowVisible && (m_holographicSpace != nullptr)) {
      CoreWindow::GetForCurrentThread().Dispatcher().ProcessEvents(
          CoreProcessEventsOption::ProcessAllIfPresent);

      HolographicFrame holographicFrame = m_main->Update();

      if (m_main->Render(holographicFrame)) {
        // The holographic frame has an API that presents the swap chain for
        // each holographic camera.
        m_deviceResources->Present(holographicFrame);
      }
    } else {
      CoreWindow::GetForCurrentThread().Dispatcher().ProcessEvents(
          CoreProcessEventsOption::ProcessOneAndAllPending);
    }
  }
}

// Terminate events do not cause Uninitialize to be called. It will be called if
// your IFrameworkView class is torn down while the app is in the foreground,
// for example if the Run method exits.
void ImmersiveView::Uninitialize() {
  m_main.reset();
  m_deviceResources.reset();

  CoreApplication::Suspending(m_suspendingEventToken);
  CoreApplication::Resuming(m_resumingEventToken);

  auto const &window = CoreWindow::GetForCurrentThread();
  window.KeyDown(m_keyDownEventToken);
  window.PointerPressed(m_pointerPressedEventToken);
  window.Closed(m_windowClosedEventToken);
  window.VisibilityChanged(m_visibilityChangedEventToken);
}

// Application lifecycle event handlers

// Called when the app is prelaunched. Use this method to load resources ahead
// of time and enable faster launch times.
void ImmersiveView::OnLaunched(LaunchActivatedEventArgs const &args) {
  if (args.PrelaunchActivated()) {
    //
    // TODO: Insert code to preload resources here.
    //
  }
}

// Called when the app view is activated. Activates the app's CoreWindow.
void ImmersiveView::OnViewActivated(CoreApplicationView const &sender,
                                    IActivatedEventArgs const &) {
  // Run() won't start until the CoreWindow is activated.
  sender.CoreWindow().Activate();
}

void ImmersiveView::OnSuspending(
    winrt::Windows::Foundation::IInspectable const &,
    SuspendingEventArgs const &args) {
  // Save app state asynchronously after requesting a deferral. Holding a
  // deferral indicates that the application is busy performing suspending
  // operations. Be aware that a deferral may not be held indefinitely; after
  // about five seconds, the app will be forced to exit.
  SuspendingDeferral deferral = args.SuspendingOperation().GetDeferral();

  create_task([this, deferral]() {
    m_deviceResources->Trim();

    if (m_main != nullptr) {
      m_main->SaveAppState();
    }

    //
    // TODO: Insert code here to save your app state.
    //

    deferral.Complete();
  });
}

void ImmersiveView::OnResuming(
    winrt::Windows::Foundation::IInspectable const &,
    winrt::Windows::Foundation::IInspectable const &) {
  // Restore any data or state that was unloaded on suspend. By default, data
  // and state are persisted when resuming from suspend. Note that this event
  // does not occur if the app was previously terminated.

  if (m_main != nullptr) {
    m_main->LoadAppState();
  }

  //
  // TODO: Insert code here to load your app state.
  //
}

// Window event handlers

void ImmersiveView::OnVisibilityChanged(
    CoreWindow const &, VisibilityChangedEventArgs const &args) {
  m_windowVisible = args.Visible();
}

void ImmersiveView::OnWindowClosed(CoreWindow const &,
                                   CoreWindowEventArgs const &) {
  m_windowClosed = true;
}

// Input event handlers

void ImmersiveView::OnKeyPressed(CoreWindow const &, KeyEventArgs const &) {
  //
  // TODO: Bluetooth keyboards are supported by HoloLens. You can use this
  // method for
  //       keyboard input if you want to support it as an optional input method
  //       for your holographic app.
  //
}

void ImmersiveView::OnPointerPressed(CoreWindow const &,
                                     PointerEventArgs const &) {
  // Allow the user to interact with the holographic world using the mouse.
  if (m_main != nullptr) {
    m_main->OnPointerPressed();
  }
}