/* -*- 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/. */

/* PluginUtilsWin.cpp - top-level Windows plugin management code */

#include <mmdeviceapi.h>
#include "PluginUtilsWin.h"
#include "PluginModuleParent.h"
#include "mozilla/StaticMutex.h"

namespace mozilla {
namespace plugins {
namespace PluginUtilsWin {

class AudioNotification;
typedef nsTHashtable<nsPtrHashKey<PluginModuleParent>> PluginModuleSet;
StaticMutex sMutex;

class AudioDeviceMessageRunnable : public Runnable {
 public:
  explicit AudioDeviceMessageRunnable(
      AudioNotification* aAudioNotification,
      NPAudioDeviceChangeDetailsIPC aChangeDetails);

  explicit AudioDeviceMessageRunnable(
      AudioNotification* aAudioNotification,
      NPAudioDeviceStateChangedIPC aDeviceState);

  NS_IMETHOD Run() override;

 protected:
  // The potential payloads for the message.  Type determined by mMessageType.
  NPAudioDeviceChangeDetailsIPC mChangeDetails;
  NPAudioDeviceStateChangedIPC mDeviceState;
  enum { DEFAULT_DEVICE_CHANGED, DEVICE_STATE_CHANGED } mMessageType;

  AudioNotification* mAudioNotification;
};

class AudioNotification final : public IMMNotificationClient {
 public:
  AudioNotification() : mIsRegistered(false), mRefCt(1) {
    HRESULT hr =
        CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL,
                         CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&mDeviceEnum));
    if (FAILED(hr)) {
      mDeviceEnum = nullptr;
      return;
    }

    hr = mDeviceEnum->RegisterEndpointNotificationCallback(this);
    if (FAILED(hr)) {
      mDeviceEnum->Release();
      mDeviceEnum = nullptr;
      return;
    }

    mIsRegistered = true;
  }

  // IMMNotificationClient Implementation
  HRESULT STDMETHODCALLTYPE OnDefaultDeviceChanged(EDataFlow flow, ERole role,
                                                   LPCWSTR device_id) override {
    NPAudioDeviceChangeDetailsIPC changeDetails;
    changeDetails.flow = (int32_t)flow;
    changeDetails.role = (int32_t)role;
    changeDetails.defaultDevice = device_id ? std::wstring(device_id) : L"";

    // Make sure that plugin is notified on the main thread.
    RefPtr<AudioDeviceMessageRunnable> runnable =
        new AudioDeviceMessageRunnable(this, changeDetails);
    NS_DispatchToMainThread(runnable);
    return S_OK;
  }

  HRESULT STDMETHODCALLTYPE OnDeviceAdded(LPCWSTR device_id) override {
    return S_OK;
  };

  HRESULT STDMETHODCALLTYPE OnDeviceRemoved(LPCWSTR device_id) override {
    return S_OK;
  }

  HRESULT STDMETHODCALLTYPE OnDeviceStateChanged(LPCWSTR device_id,
                                                 DWORD new_state) override {
    NPAudioDeviceStateChangedIPC deviceStateIPC;
    deviceStateIPC.device = device_id ? std::wstring(device_id) : L"";
    deviceStateIPC.state = (uint32_t)new_state;

    // Make sure that plugin is notified on the main thread.
    RefPtr<AudioDeviceMessageRunnable> runnable =
        new AudioDeviceMessageRunnable(this, deviceStateIPC);
    NS_DispatchToMainThread(runnable);
    return S_OK;
  }

  HRESULT STDMETHODCALLTYPE
  OnPropertyValueChanged(LPCWSTR device_id, const PROPERTYKEY key) override {
    return S_OK;
  }

  // IUnknown Implementation
  ULONG STDMETHODCALLTYPE AddRef() override {
    return InterlockedIncrement(&mRefCt);
  }

  ULONG STDMETHODCALLTYPE Release() override {
    ULONG ulRef = InterlockedDecrement(&mRefCt);
    if (0 == ulRef) {
      delete this;
    }
    return ulRef;
  }

  HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid,
                                           VOID** ppvInterface) override {
    if (__uuidof(IUnknown) == riid) {
      AddRef();
      *ppvInterface = (IUnknown*)this;
    } else if (__uuidof(IMMNotificationClient) == riid) {
      AddRef();
      *ppvInterface = (IMMNotificationClient*)this;
    } else {
      *ppvInterface = NULL;
      return E_NOINTERFACE;
    }
    return S_OK;
  }

  /*
   * A Valid instance must be Unregistered before Releasing it.
   */
  void Unregister() {
    if (mDeviceEnum) {
      mDeviceEnum->UnregisterEndpointNotificationCallback(this);
    }
    mIsRegistered = false;
  }

  /*
   * True whenever the notification server is set to report events to this
   * object.
   */
  bool IsRegistered() { return mIsRegistered; }

  void AddModule(PluginModuleParent* aModule) {
    StaticMutexAutoLock lock(sMutex);
    mAudioNotificationSet.PutEntry(aModule);
  }

  void RemoveModule(PluginModuleParent* aModule) {
    StaticMutexAutoLock lock(sMutex);
    mAudioNotificationSet.RemoveEntry(aModule);
  }

  /*
   * Are any modules registered for audio notifications?
   */
  bool HasModules() { return !mAudioNotificationSet.IsEmpty(); }

  const PluginModuleSet* GetModuleSet() const { return &mAudioNotificationSet; }

 private:
  bool mIsRegistered;  // only used to make sure that Unregister is called
                       // before destroying a Valid instance.
  LONG mRefCt;
  IMMDeviceEnumerator* mDeviceEnum;

  // Set of plugin modules that have registered to be notified when the audio
  // device changes.
  PluginModuleSet mAudioNotificationSet;

  ~AudioNotification() {
    MOZ_ASSERT(!mIsRegistered,
               "Destroying AudioNotification without first calling Unregister");
    if (mDeviceEnum) {
      mDeviceEnum->Release();
    }
  }
};  // class AudioNotification

// callback that gets notified of audio device events, or NULL
AudioNotification* sAudioNotification = nullptr;

nsresult RegisterForAudioDeviceChanges(PluginModuleParent* aModuleParent,
                                       bool aShouldRegister) {
  // Hold the AudioNotification singleton iff there are PluginModuleParents
  // that are subscribed to it.
  if (aShouldRegister) {
    if (!sAudioNotification) {
      // We are registering the first module.  Create the singleton.
      sAudioNotification = new AudioNotification();
      if (!sAudioNotification->IsRegistered()) {
        PLUGIN_LOG_DEBUG(
            ("Registered for plugin audio device notification failed."));
        sAudioNotification->Release();
        sAudioNotification = nullptr;
        return NS_ERROR_FAILURE;
      }
      PLUGIN_LOG_DEBUG(("Registered for plugin audio device notification."));
    }
    sAudioNotification->AddModule(aModuleParent);
  } else if (!aShouldRegister && sAudioNotification) {
    sAudioNotification->RemoveModule(aModuleParent);
    if (!sAudioNotification->HasModules()) {
      // We have removed the last module from the notification mechanism
      // so we can destroy the singleton.
      PLUGIN_LOG_DEBUG(("Unregistering for plugin audio device notification."));
      sAudioNotification->Unregister();
      sAudioNotification->Release();
      sAudioNotification = nullptr;
    }
  }
  return NS_OK;
}

AudioDeviceMessageRunnable::AudioDeviceMessageRunnable(
    AudioNotification* aAudioNotification,
    NPAudioDeviceChangeDetailsIPC aChangeDetails)
    : Runnable("AudioDeviceMessageRunnableCD"),
      mChangeDetails(aChangeDetails),
      mMessageType(DEFAULT_DEVICE_CHANGED),
      mAudioNotification(aAudioNotification) {
  // We increment the AudioNotification ref-count here -- the runnable will
  // decrement it when it is done with us.
  mAudioNotification->AddRef();
}

AudioDeviceMessageRunnable::AudioDeviceMessageRunnable(
    AudioNotification* aAudioNotification,
    NPAudioDeviceStateChangedIPC aDeviceState)
    : Runnable("AudioDeviceMessageRunnableSC"),
      mDeviceState(aDeviceState),
      mMessageType(DEVICE_STATE_CHANGED),
      mAudioNotification(aAudioNotification) {
  // We increment the AudioNotification ref-count here -- the runnable will
  // decrement it when it is done with us.
  mAudioNotification->AddRef();
}

NS_IMETHODIMP
AudioDeviceMessageRunnable::Run() {
  StaticMutexAutoLock lock(sMutex);
  PLUGIN_LOG_DEBUG(("Notifying %d plugins of audio device change.",
                    mAudioNotification->GetModuleSet()->Count()));

  bool success = true;
  for (auto iter = mAudioNotification->GetModuleSet()->ConstIter();
       !iter.Done(); iter.Next()) {
    PluginModuleParent* pluginModule = iter.Get()->GetKey();
    switch (mMessageType) {
      case DEFAULT_DEVICE_CHANGED:
        success &= pluginModule->SendNPP_SetValue_NPNVaudioDeviceChangeDetails(
            mChangeDetails);
        break;
      case DEVICE_STATE_CHANGED:
        success &= pluginModule->SendNPP_SetValue_NPNVaudioDeviceStateChanged(
            mDeviceState);
        break;
      default:
        MOZ_ASSERT_UNREACHABLE("bad AudioDeviceMessageRunnable state");
    }
  }
  mAudioNotification->Release();
  return success ? NS_OK : NS_ERROR_FAILURE;
}

}  // namespace PluginUtilsWin
}  // namespace plugins
}  // namespace mozilla