// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/metrics/desktop_session_duration/desktop_session_duration_observer.h"

#include "base/memory/ptr_util.h"
#include "chrome/browser/metrics/desktop_session_duration/desktop_session_duration_tracker.h"
#include "content/public/browser/render_view_host.h"

namespace metrics {

DesktopSessionDurationObserver::DesktopSessionDurationObserver(
    content::WebContents* web_contents,
    DesktopSessionDurationTracker* service)
    : content::WebContentsObserver(web_contents),
      content::WebContentsUserData<DesktopSessionDurationObserver>(
          *web_contents),
      service_(service) {
  RegisterInputEventObserver(web_contents->GetPrimaryMainFrame());
}

DesktopSessionDurationObserver::~DesktopSessionDurationObserver() = default;

// static
DesktopSessionDurationObserver*
DesktopSessionDurationObserver::CreateForWebContents(
    content::WebContents* web_contents) {
  DCHECK(web_contents);

  if (!DesktopSessionDurationTracker::IsInitialized())
    return nullptr;

  DesktopSessionDurationObserver* observer = FromWebContents(web_contents);
  if (!observer) {
    observer = new DesktopSessionDurationObserver(
        web_contents, DesktopSessionDurationTracker::Get());
    web_contents->SetUserData(UserDataKey(), base::WrapUnique(observer));
  }
  return observer;
}

void DesktopSessionDurationObserver::RegisterInputEventObserver(
    content::RenderFrameHost* host) {
  if (host != nullptr)
    host->GetRenderWidgetHost()->AddInputEventObserver(this);
}

void DesktopSessionDurationObserver::UnregisterInputEventObserver(
    content::RenderFrameHost* host) {
  if (host != nullptr)
    host->GetRenderWidgetHost()->RemoveInputEventObserver(this);
}

void DesktopSessionDurationObserver::OnInputEvent(
    const content::RenderWidgetHost& widget,
    const blink::WebInputEvent& event,
    input::InputEventSource source) {
  service_->OnUserEvent(event.GetTypeAsUiEventType());
}

void DesktopSessionDurationObserver::RenderFrameHostChanged(
    content::RenderFrameHost* old_host,
    content::RenderFrameHost* new_host) {
  if (!new_host->IsInPrimaryMainFrame())
    return;

  UnregisterInputEventObserver(old_host);
  RegisterInputEventObserver(new_host);
}

WEB_CONTENTS_USER_DATA_KEY_IMPL(DesktopSessionDurationObserver);

}  // namespace metrics