// Copyright (c) 2012 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.

#include "chrome/browser/media/media_stream_capture_indicator.h"

#include "base/bind.h"
#include "base/i18n/rtl.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/utf_string_conversions.h"
#include "chrome/app/chrome_command_ids.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/extensions/extension_service.h"
#include "chrome/browser/extensions/image_loader.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/status_icons/status_icon.h"
#include "chrome/browser/status_icons/status_tray.h"
#include "chrome/browser/tab_contents/tab_util.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/browser/invalidate_type.h"
#include "content/public/browser/web_contents.h"
#include "content/public/browser/web_contents_delegate.h"
#include "content/public/browser/web_contents_observer.h"
#include "grit/chromium_strings.h"
#include "grit/generated_resources.h"
#include "grit/theme_resources.h"
#include "net/base/net_util.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/resource/resource_bundle.h"
#include "ui/gfx/image/image_skia.h"

using content::BrowserThread;
using content::WebContents;

namespace {

const extensions::Extension* GetExtension(WebContents* web_contents) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  if (!web_contents)
    return NULL;

  Profile* profile =
      Profile::FromBrowserContext(web_contents->GetBrowserContext());
  if (!profile)
    return NULL;

  ExtensionService* extension_service = profile->GetExtensionService();
  if (!extension_service)
    return NULL;

  return extension_service->extensions()->GetExtensionOrAppByURL(
      ExtensionURLInfo(web_contents->GetURL()));
}

// Gets the security originator of the tab. It returns a string with no '/'
// at the end to display in the UI.
string16 GetSecurityOrigin(WebContents* web_contents) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  if (!web_contents)
    return string16();

  std::string security_origin = web_contents->GetURL().GetOrigin().spec();

  // Remove the last character if it is a '/'.
  if (!security_origin.empty()) {
    std::string::iterator it = security_origin.end() - 1;
    if (*it == '/')
      security_origin.erase(it);
  }

  return UTF8ToUTF16(security_origin);
}

string16 GetTitle(WebContents* web_contents) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  if (!web_contents)
    return string16();

  const extensions::Extension* const extension = GetExtension(web_contents);
  if (extension)
    return UTF8ToUTF16(extension->name());

  string16 tab_title = web_contents->GetTitle();

  if (tab_title.empty()) {
    // If the page's title is empty use its security originator.
    tab_title = GetSecurityOrigin(web_contents);
  } else {
    // If the page's title matches its URL, use its security originator.
    std::string languages =
        content::GetContentClient()->browser()->GetAcceptLangs(
            web_contents->GetBrowserContext());
    if (tab_title == net::FormatUrl(web_contents->GetURL(), languages))
      tab_title = GetSecurityOrigin(web_contents);
  }

  return tab_title;
}

}  // namespace

// Stores usage counts for all the capture devices associated with a single
// WebContents instance, and observes for the destruction of the WebContents
// instance.
class MediaStreamCaptureIndicator::WebContentsDeviceUsage
    : protected content::WebContentsObserver {
 public:
  explicit WebContentsDeviceUsage(WebContents* web_contents);

  bool IsWebContentsDestroyed() const { return web_contents() == NULL; }

  bool IsCapturingAudio() const { return audio_ref_count_ > 0; }
  bool IsCapturingVideo() const { return video_ref_count_ > 0; }
  bool IsMirroring() const { return mirroring_ref_count_ > 0; }

  // Updates ref-counts up (|direction| is true) or down by one, based on the
  // type of each device provided.  In the increment-upward case, the return
  // value is the message ID for the balloon body to show, or zero if the
  // balloon should not be shown.
  int TallyUsage(const content::MediaStreamDevices& devices, bool direction);

 private:
  int audio_ref_count_;
  int video_ref_count_;
  int mirroring_ref_count_;

  DISALLOW_COPY_AND_ASSIGN(WebContentsDeviceUsage);
};

MediaStreamCaptureIndicator::WebContentsDeviceUsage::WebContentsDeviceUsage(
    WebContents* web_contents)
    : content::WebContentsObserver(web_contents),
      audio_ref_count_(0), video_ref_count_(0), mirroring_ref_count_(0) {
}

int MediaStreamCaptureIndicator::WebContentsDeviceUsage::TallyUsage(
    const content::MediaStreamDevices& devices, bool direction) {
  const int inc_amount = direction ? +1 : -1;
  bool incremented_audio_count = false;
  bool incremented_video_count = false;
  for (content::MediaStreamDevices::const_iterator it = devices.begin();
       it != devices.end(); ++it) {
    if (it->type == content::MEDIA_TAB_AUDIO_CAPTURE ||
        it->type == content::MEDIA_TAB_VIDEO_CAPTURE) {
      mirroring_ref_count_ += inc_amount;
    } else if (content::IsAudioMediaType(it->type)) {
      audio_ref_count_ += inc_amount;
      incremented_audio_count = (inc_amount > 0);
    } else if (content::IsVideoMediaType(it->type)) {
      video_ref_count_ += inc_amount;
      incremented_video_count = (inc_amount > 0);
    } else {
      NOTIMPLEMENTED();
    }
  }

  DCHECK_LE(0, audio_ref_count_);
  DCHECK_LE(0, video_ref_count_);
  DCHECK_LE(0, mirroring_ref_count_);

  if (incremented_audio_count && incremented_video_count)
    return IDS_MEDIA_STREAM_STATUS_TRAY_BALLOON_BODY_AUDIO_AND_VIDEO;
  else if (incremented_audio_count)
    return IDS_MEDIA_STREAM_STATUS_TRAY_BALLOON_BODY_AUDIO_ONLY;
  else if (incremented_video_count)
    return IDS_MEDIA_STREAM_STATUS_TRAY_BALLOON_BODY_VIDEO_ONLY;
  else
    return 0;
}

MediaStreamCaptureIndicator::MediaStreamCaptureIndicator()
    : status_icon_(NULL),
      mic_image_(NULL),
      camera_image_(NULL),
      balloon_image_(NULL),
      should_show_balloon_(false) {
}

MediaStreamCaptureIndicator::~MediaStreamCaptureIndicator() {
  // The user is responsible for cleaning up by reporting the closure of any
  // opened devices.  However, there exists a race condition at shutdown: The UI
  // thread may be stopped before CaptureDevicesClosed() posts the task to
  // invoke DoDevicesClosedOnUIThread().  In this case, usage_map_ won't be
  // empty like it should.
  DCHECK(usage_map_.empty() ||
         !BrowserThread::IsMessageLoopValid(BrowserThread::UI));

  // Free any WebContentsDeviceUsage objects left over.
  for (UsageMap::const_iterator it = usage_map_.begin(); it != usage_map_.end();
       ++it) {
    delete it->second;
  }
}

bool MediaStreamCaptureIndicator::IsCommandIdChecked(
    int command_id) const {
  NOTIMPLEMENTED() << "There are no checked items in the MediaStream menu.";
  return false;
}

bool MediaStreamCaptureIndicator::IsCommandIdEnabled(
    int command_id) const {
  return command_id != IDC_MinimumLabelValue;
}

bool MediaStreamCaptureIndicator::GetAcceleratorForCommandId(
    int command_id, ui::Accelerator* accelerator) {
  // No accelerators for status icon context menu.
  return false;
}

void MediaStreamCaptureIndicator::ExecuteCommand(int command_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  const int index =
      command_id - IDC_MEDIA_CONTEXT_MEDIA_STREAM_CAPTURE_LIST_FIRST;
  DCHECK_LE(0, index);
  DCHECK_GT(static_cast<int>(command_targets_.size()), index);
  WebContents* const web_contents = command_targets_[index];
  UsageMap::const_iterator it = usage_map_.find(web_contents);
  if (it == usage_map_.end() || it->second->IsWebContentsDestroyed())
    return;
  web_contents->GetDelegate()->ActivateContents(web_contents);
}

void MediaStreamCaptureIndicator::CaptureDevicesOpened(
    int render_process_id,
    int render_view_id,
    const content::MediaStreamDevices& devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK(!devices.empty());

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&MediaStreamCaptureIndicator::DoDevicesOpenedOnUIThread,
                 this, render_process_id, render_view_id, devices));
}

void MediaStreamCaptureIndicator::CaptureDevicesClosed(
    int render_process_id,
    int render_view_id,
    const content::MediaStreamDevices& devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK(!devices.empty());

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&MediaStreamCaptureIndicator::DoDevicesClosedOnUIThread,
                 this, render_process_id, render_view_id, devices));
}

void MediaStreamCaptureIndicator::DoDevicesOpenedOnUIThread(
    int render_process_id,
    int render_view_id,
    const content::MediaStreamDevices& devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  AddCaptureDevices(render_process_id, render_view_id, devices);
}

void MediaStreamCaptureIndicator::DoDevicesClosedOnUIThread(
    int render_process_id,
    int render_view_id,
    const content::MediaStreamDevices& devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  RemoveCaptureDevices(render_process_id, render_view_id, devices);
}

void MediaStreamCaptureIndicator::MaybeCreateStatusTrayIcon() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (status_icon_)
    return;

  // If there is no browser process, we should not create the status tray.
  if (!g_browser_process)
    return;

  StatusTray* status_tray = g_browser_process->status_tray();
  if (!status_tray)
    return;

  status_icon_ = status_tray->CreateStatusIcon();

  EnsureStatusTrayIconResources();
}

void MediaStreamCaptureIndicator::EnsureStatusTrayIconResources() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (!mic_image_) {
    mic_image_ = ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
        IDR_INFOBAR_MEDIA_STREAM_MIC);
  }
  if (!camera_image_) {
    camera_image_ = ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
        IDR_INFOBAR_MEDIA_STREAM_CAMERA);
  }
  if (!balloon_image_) {
    balloon_image_ = ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
        IDR_PRODUCT_LOGO_32);
  }
  DCHECK(mic_image_);
  DCHECK(camera_image_);
  DCHECK(balloon_image_);
}

void MediaStreamCaptureIndicator::ShowBalloon(
    WebContents* web_contents, int balloon_body_message_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK_NE(0, balloon_body_message_id);

  // Only show the balloon for extensions.
  const extensions::Extension* const extension = GetExtension(web_contents);
  if (!extension) {
    DVLOG(1) << "Balloon is shown only for extensions";
    return;
  }

  string16 message =
      l10n_util::GetStringFUTF16(balloon_body_message_id,
                                 UTF8ToUTF16(extension->name()));
  Profile* profile =
      Profile::FromBrowserContext(web_contents->GetBrowserContext());

  should_show_balloon_ = true;
  extensions::ImageLoader::Get(profile)->LoadImageAsync(
      extension,
      extension->GetIconResource(32, ExtensionIconSet::MATCH_BIGGER),
      gfx::Size(32, 32),
      base::Bind(&MediaStreamCaptureIndicator::OnImageLoaded,
                 this, message));
}

void MediaStreamCaptureIndicator::OnImageLoaded(
    const string16& message,
    const gfx::Image& image) {
  if (!should_show_balloon_ || !status_icon_)
    return;

  const gfx::ImageSkia* image_skia = !image.IsEmpty() ? image.ToImageSkia() :
      ui::ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
          IDR_APP_DEFAULT_ICON);
  status_icon_->DisplayBalloon(*image_skia, string16(), message);
}

void MediaStreamCaptureIndicator::MaybeDestroyStatusTrayIcon() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  // Make sure images that finish loading don't cause a balloon to be shown.
  should_show_balloon_ = false;

  if (!status_icon_)
    return;

  // If there is no browser process, we should not do anything.
  if (!g_browser_process)
    return;

  StatusTray* status_tray = g_browser_process->status_tray();
  if (status_tray != NULL) {
    status_tray->RemoveStatusIcon(status_icon_);
    status_icon_ = NULL;
  }
}

void MediaStreamCaptureIndicator::UpdateStatusTrayIconContextMenu() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  scoped_ptr<ui::SimpleMenuModel> menu(new ui::SimpleMenuModel(this));

  bool audio = false;
  bool video = false;
  int command_id = IDC_MEDIA_CONTEXT_MEDIA_STREAM_CAPTURE_LIST_FIRST;
  command_targets_.clear();
  for (UsageMap::const_iterator iter = usage_map_.begin();
       iter != usage_map_.end(); ++iter) {
    // Check if any audio and video devices have been used.
    const WebContentsDeviceUsage& usage = *iter->second;
    if (usage.IsWebContentsDestroyed() ||
        (!usage.IsCapturingAudio() && !usage.IsCapturingVideo())) {
      continue;
    }
    audio = audio || usage.IsCapturingAudio();
    video = video || usage.IsCapturingVideo();

    WebContents* const web_contents = iter->first;
    command_targets_.push_back(web_contents);
    menu->AddItem(command_id, GetTitle(web_contents));

    // If reaching the maximum number, no more item will be added to the menu.
    if (command_id == IDC_MEDIA_CONTEXT_MEDIA_STREAM_CAPTURE_LIST_LAST)
      break;
    ++command_id;
  }

  if (command_targets_.empty()) {
    MaybeDestroyStatusTrayIcon();
    return;
  }

  // The icon will take the ownership of the passed context menu.
  MaybeCreateStatusTrayIcon();
  if (status_icon_) {
    status_icon_->SetContextMenu(menu.release());
    UpdateStatusTrayIconDisplay(audio, video);
  }
}

void MediaStreamCaptureIndicator::UpdateStatusTrayIconDisplay(
    bool audio, bool video) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(audio || video);
  DCHECK(status_icon_);
  int message_id = 0;
  if (audio && video) {
    message_id = IDS_MEDIA_STREAM_STATUS_TRAY_TEXT_AUDIO_AND_VIDEO;
    status_icon_->SetImage(*camera_image_);
  } else if (audio && !video) {
    message_id = IDS_MEDIA_STREAM_STATUS_TRAY_TEXT_AUDIO_ONLY;
    status_icon_->SetImage(*mic_image_);
  } else if (!audio && video) {
    message_id = IDS_MEDIA_STREAM_STATUS_TRAY_TEXT_VIDEO_ONLY;
    status_icon_->SetImage(*camera_image_);
  }

  status_icon_->SetToolTip(l10n_util::GetStringFUTF16(
      message_id, l10n_util::GetStringUTF16(IDS_PRODUCT_NAME)));
}

WebContents* MediaStreamCaptureIndicator::LookUpByKnownAlias(
    int render_process_id, int render_view_id) const {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  WebContents* result =
      tab_util::GetWebContentsByID(render_process_id, render_view_id);
  if (!result) {
    const RenderViewIDs key(render_process_id, render_view_id);
    AliasMap::const_iterator it = aliases_.find(key);
    if (it != aliases_.end())
      result = it->second;
  }
  return result;
}

void MediaStreamCaptureIndicator::AddCaptureDevices(
    int render_process_id,
    int render_view_id,
    const content::MediaStreamDevices& devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  WebContents* const web_contents =
      LookUpByKnownAlias(render_process_id, render_view_id);
  if (!web_contents)
    return;

  // Increase the usage ref-counts.
  WebContentsDeviceUsage*& usage = usage_map_[web_contents];
  if (!usage)
    usage = new WebContentsDeviceUsage(web_contents);
  const int balloon_body_message_id = usage->TallyUsage(devices, true);

  // Keep track of the IDs as a known alias to the WebContents instance.
  const AliasMap::iterator insert_it = aliases_.insert(
      make_pair(RenderViewIDs(render_process_id, render_view_id),
                web_contents)).first;
  DCHECK_EQ(web_contents, insert_it->second)
      << "BUG: IDs refer to two different WebContents instances.";

  web_contents->NotifyNavigationStateChanged(content::INVALIDATE_TYPE_TAB);

  UpdateStatusTrayIconContextMenu();
  if (balloon_body_message_id)
    ShowBalloon(web_contents, balloon_body_message_id);
}

void MediaStreamCaptureIndicator::RemoveCaptureDevices(
    int render_process_id,
    int render_view_id,
    const content::MediaStreamDevices& devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  WebContents* const web_contents =
      LookUpByKnownAlias(render_process_id, render_view_id);
  if (!web_contents)
    return;

  // Decrease the usage ref-counts.
  WebContentsDeviceUsage* const usage = usage_map_[web_contents];
  DCHECK(usage);
  usage->TallyUsage(devices, false);

  if (!usage->IsWebContentsDestroyed())
    web_contents->NotifyNavigationStateChanged(content::INVALIDATE_TYPE_TAB);

  // Remove the usage and alias mappings if all the devices have been closed.
  if (!usage->IsCapturingAudio() && !usage->IsCapturingVideo() &&
      !usage->IsMirroring()) {
    for (AliasMap::iterator alias_it = aliases_.begin();
         alias_it != aliases_.end(); ) {
      if (alias_it->second == web_contents)
        aliases_.erase(alias_it++);
      else
        ++alias_it;
    }
    delete usage;
    usage_map_.erase(web_contents);
  }

  UpdateStatusTrayIconContextMenu();
}

bool MediaStreamCaptureIndicator::IsCapturingUserMedia(
    int render_process_id, int render_view_id) const {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  WebContents* const web_contents =
      LookUpByKnownAlias(render_process_id, render_view_id);
  if (!web_contents)
    return false;

  UsageMap::const_iterator it = usage_map_.find(web_contents);
  return (it != usage_map_.end() &&
          (it->second->IsCapturingAudio() || it->second->IsCapturingVideo()));
}

bool MediaStreamCaptureIndicator::IsBeingMirrored(
    int render_process_id, int render_view_id) const {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  WebContents* const web_contents =
      LookUpByKnownAlias(render_process_id, render_view_id);
  if (!web_contents)
    return false;

  UsageMap::const_iterator it = usage_map_.find(web_contents);
  return it != usage_map_.end() && it->second->IsMirroring();
}