// Copyright (c) 2011 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/ui/webui/active_downloads_ui.h"

#include <algorithm>
#include <string>
#include <vector>

#include "base/callback.h"
#include "base/command_line.h"
#include "base/file_util.h"
#include "base/logging.h"
#include "base/memory/singleton.h"
#include "base/message_loop.h"
#include "base/path_service.h"
#include "base/string_piece.h"
#include "base/string_util.h"
#include "base/threading/thread.h"
#include "base/time.h"
#include "base/utf_string_conversions.h"
#include "base/values.h"
#include "chrome/browser/chromeos/cros/cros_library.h"
#include "chrome/browser/chromeos/login/user_manager.h"
#include "chrome/browser/download/download_item.h"
#include "chrome/browser/download/download_manager.h"
#include "chrome/browser/download/download_util.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/tabs/tab_strip_model.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_list.h"
#include "chrome/browser/ui/browser_window.h"
#include "chrome/browser/ui/webui/favicon_source.h"
#include "chrome/browser/ui/webui/mediaplayer_ui.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/jstemplate_builder.h"
#include "chrome/common/net/url_fetcher.h"
#include "chrome/common/url_constants.h"
#include "content/browser/browser_thread.h"
#include "content/browser/tab_contents/tab_contents.h"
#include "grit/browser_resources.h"
#include "grit/chromium_strings.h"
#include "grit/generated_resources.h"
#include "grit/locale_settings.h"
#include "net/base/escape.h"
#include "net/url_request/url_request_file_job.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/resource/resource_bundle.h"

namespace {

static const int kPopupLeft = 0;
static const int kPopupTop = 0;
static const int kPopupWidth = 250;
// Minimum height of window must be 100, so kPopupHeight has space for
// 2 download rows of 36 px and 'Show All Downloads' which is 29px.
static const int kPopupHeight = 36 * 2 + 29;

static const char kPropertyPath[] = "path";
static const char kPropertyTitle[] = "title";
static const char kPropertyDirectory[] = "isDirectory";

class ActiveDownloadsUIHTMLSource : public ChromeURLDataManager::DataSource {
 public:
  ActiveDownloadsUIHTMLSource();

  // Called when the network layer has requested a resource underneath
  // the path we registered.
  virtual void StartDataRequest(const std::string& path,
                                bool is_incognito,
                                int request_id);
  virtual std::string GetMimeType(const std::string&) const {
    return "text/html";
  }

 private:
  ~ActiveDownloadsUIHTMLSource() {}

  DISALLOW_COPY_AND_ASSIGN(ActiveDownloadsUIHTMLSource);
};

// The handler for Javascript messages related to the "active_downloads" view.
class ActiveDownloadsHandler
    : public WebUIMessageHandler,
      public DownloadManager::Observer,
      public DownloadItem::Observer {
 public:
  ActiveDownloadsHandler();
  virtual ~ActiveDownloadsHandler();

  // Initialization after Attach.
  void Init();

  // WebUIMessageHandler implementation.
  virtual WebUIMessageHandler* Attach(WebUI* web_ui);
  virtual void RegisterMessages();

  // DownloadItem::Observer interface.
  virtual void OnDownloadUpdated(DownloadItem* item);
  virtual void OnDownloadOpened(DownloadItem* item) { }

  // DownloadManager::Observer interface.
  virtual void ModelChanged();

  // WebUI Callbacks.
  void HandleGetDownloads(const ListValue* args);
  void HandlePauseToggleDownload(const ListValue* args);
  void HandleCancelDownload(const ListValue* args);
  void HandleAllowDownload(const ListValue* args);
  void OpenNewPopupWindow(const ListValue* args);
  void OpenNewFullWindow(const ListValue* args);
  void PlayMediaFile(const ListValue* args);

 private:
  // Downloads helpers.
  DownloadItem* GetDownloadById(const ListValue* args);
  void UpdateDownloadList();
  void SendDownloads();
  void AddDownload(DownloadItem* item);

  void OpenNewWindow(const ListValue* args, bool popup);

  Profile* profile_;
  TabContents* tab_contents_;
  DownloadManager* download_manager_;

  typedef std::vector<DownloadItem*> DownloadList;
  DownloadList active_downloads_;
  DownloadList downloads_;

  DISALLOW_COPY_AND_ASSIGN(ActiveDownloadsHandler);
};

////////////////////////////////////////////////////////////////////////////////
//
// ActiveDownloadsUIHTMLSource
//
////////////////////////////////////////////////////////////////////////////////

ActiveDownloadsUIHTMLSource::ActiveDownloadsUIHTMLSource()
    : DataSource(chrome::kChromeUIActiveDownloadsHost, MessageLoop::current()) {
}

void ActiveDownloadsUIHTMLSource::StartDataRequest(const std::string& path,
                                              bool is_incognito,
                                              int request_id) {
  DictionaryValue localized_strings;
  localized_strings.SetString("allowdownload",
      l10n_util::GetStringUTF16(IDS_FILEBROWSER_CONFIRM_DOWNLOAD));
  localized_strings.SetString("cancel",
      l10n_util::GetStringUTF16(IDS_DOWNLOAD_LINK_CANCEL));
  localized_strings.SetString("confirmcancel",
      l10n_util::GetStringUTF16(IDS_FILEBROWSER_CONFIRM_CANCEL));
  localized_strings.SetString("confirmyes",
      l10n_util::GetStringUTF16(IDS_FILEBROWSER_CONFIRM_YES));
  localized_strings.SetString("open",
      l10n_util::GetStringUTF16(IDS_FILEBROWSER_OPEN));
  localized_strings.SetString("pause",
      l10n_util::GetStringUTF16(IDS_DOWNLOAD_LINK_PAUSE));
  localized_strings.SetString("resume",
      l10n_util::GetStringUTF16(IDS_DOWNLOAD_LINK_RESUME));
  localized_strings.SetString("showalldownloads",
      l10n_util::GetStringUTF16(IDS_FILEBROWSER_SHOW_ALL_DOWNLOADS));
  FilePath default_download_path;
  if (!PathService::Get(chrome::DIR_DEFAULT_DOWNLOADS,
                        &default_download_path)) {
    NOTREACHED();
  }
  // TODO(viettrungluu): this is wrong -- FilePath's need not be Unicode.
  localized_strings.SetString("downloadpath", default_download_path.value());
  localized_strings.SetString("error_unknown_file_type",
      l10n_util::GetStringUTF16(IDS_FILEBROWSER_ERROR_UNKNOWN_FILE_TYPE));
  SetFontAndTextDirection(&localized_strings);

  static const base::StringPiece active_downloads_html(
      ResourceBundle::GetSharedInstance().GetRawDataResource(
          IDR_ACTIVE_DOWNLOADS_HTML));
  const std::string full_html = jstemplate_builder::GetI18nTemplateHtml(
      active_downloads_html, &localized_strings);

  scoped_refptr<RefCountedBytes> html_bytes(new RefCountedBytes);
  html_bytes->data.resize(full_html.size());
  std::copy(full_html.begin(), full_html.end(), html_bytes->data.begin());

  SendResponse(request_id, html_bytes);
}

////////////////////////////////////////////////////////////////////////////////
//
// ActiveDownloadsHandler
//
////////////////////////////////////////////////////////////////////////////////

ActiveDownloadsHandler::ActiveDownloadsHandler()
    : profile_(NULL),
      tab_contents_(NULL),
      download_manager_(NULL) {
}

ActiveDownloadsHandler::~ActiveDownloadsHandler() {
  for (size_t i = 0; i < downloads_.size(); ++i) {
    downloads_[i]->RemoveObserver(this);
  }
  download_manager_->RemoveObserver(this);
}

WebUIMessageHandler* ActiveDownloadsHandler::Attach(WebUI* web_ui) {
  // Create our favicon data source.
  profile_ = web_ui->GetProfile();
  profile_->GetChromeURLDataManager()->AddDataSource(
      new FaviconSource(profile_));
  tab_contents_ = web_ui->tab_contents();
  return WebUIMessageHandler::Attach(web_ui);
}

void ActiveDownloadsHandler::Init() {
  download_manager_ = profile_->GetDownloadManager();
  download_manager_->AddObserver(this);
}

void ActiveDownloadsHandler::RegisterMessages() {
  web_ui_->RegisterMessageCallback("getDownloads",
      NewCallback(this, &ActiveDownloadsHandler::HandleGetDownloads));
  web_ui_->RegisterMessageCallback("pauseToggleDownload",
      NewCallback(this, &ActiveDownloadsHandler::HandlePauseToggleDownload));
  web_ui_->RegisterMessageCallback("cancelDownload",
      NewCallback(this, &ActiveDownloadsHandler::HandleCancelDownload));
  web_ui_->RegisterMessageCallback("allowDownload",
      NewCallback(this, &ActiveDownloadsHandler::HandleAllowDownload));
  web_ui_->RegisterMessageCallback("openNewPopupWindow",
      NewCallback(this, &ActiveDownloadsHandler::OpenNewPopupWindow));
  web_ui_->RegisterMessageCallback("openNewFullWindow",
      NewCallback(this, &ActiveDownloadsHandler::OpenNewFullWindow));
  web_ui_->RegisterMessageCallback("playMediaFile",
      NewCallback(this, &ActiveDownloadsHandler::PlayMediaFile));
}

void ActiveDownloadsHandler::PlayMediaFile(const ListValue* args) {
  FilePath file_path(UTF16ToUTF8(ExtractStringValue(args)));

  Browser* browser = Browser::GetBrowserForController(
      &tab_contents_->controller(), NULL);
  MediaPlayer* mediaplayer = MediaPlayer::GetInstance();
  mediaplayer->ForcePlayMediaFile(profile_, file_path, browser);
}

DownloadItem* ActiveDownloadsHandler::GetDownloadById(
    const ListValue* args) {
  int i;
  if (!ExtractIntegerValue(args, &i))
    return NULL;
  size_t id(i);
  return id < downloads_.size() ? downloads_[id] : NULL;
}

void ActiveDownloadsHandler::HandlePauseToggleDownload(const ListValue* args) {
  DownloadItem* item = GetDownloadById(args);
  if (item && item->IsPartialDownload())
    item->TogglePause();
}

void ActiveDownloadsHandler::HandleAllowDownload(const ListValue* args) {
  DownloadItem* item = GetDownloadById(args);
  if (item)
    item->DangerousDownloadValidated();
}

void ActiveDownloadsHandler::HandleCancelDownload(const ListValue* args) {
  DownloadItem* item = GetDownloadById(args);
  if (item) {
    if (item->IsPartialDownload())
      item->Cancel(true);
    item->Delete(DownloadItem::DELETE_DUE_TO_USER_DISCARD);
  }
}

void ActiveDownloadsHandler::OpenNewFullWindow(const ListValue* args) {
  OpenNewWindow(args, false);
}

void ActiveDownloadsHandler::OpenNewPopupWindow(const ListValue* args) {
  OpenNewWindow(args, true);
}

void ActiveDownloadsHandler::OpenNewWindow(const ListValue* args, bool popup) {
  std::string url = UTF16ToUTF8(ExtractStringValue(args));
  Browser* browser = popup ?
      Browser::CreateForType(Browser::TYPE_APP_PANEL, profile_) :
      BrowserList::GetLastActive();
  browser::NavigateParams params(browser, GURL(url), PageTransition::LINK);
  params.disposition = NEW_FOREGROUND_TAB;
  browser::Navigate(&params);
  // TODO(beng): The following two calls should be automatic by Navigate().
  if (popup)
    params.browser->window()->SetBounds(gfx::Rect(0, 0, 400, 300));
  params.browser->window()->Show();
}

void ActiveDownloadsHandler::ModelChanged() {
  UpdateDownloadList();
}

void ActiveDownloadsHandler::HandleGetDownloads(const ListValue* args) {
  UpdateDownloadList();
}

void ActiveDownloadsHandler::UpdateDownloadList() {
  DownloadList downloads;
  download_manager_->GetAllDownloads(FilePath(), &downloads);
  active_downloads_.clear();
  for (size_t i = 0; i < downloads.size(); ++i) {
    AddDownload(downloads[i]);
  }
  SendDownloads();
}

void ActiveDownloadsHandler::AddDownload(DownloadItem* item) {
  // Observe in progress and dangerous downloads.
  if (item->state() == DownloadItem::IN_PROGRESS ||
      item->safety_state() == DownloadItem::DANGEROUS) {
    active_downloads_.push_back(item);

    DownloadList::const_iterator it =
      std::find(downloads_.begin(), downloads_.end(), item);
    if (it == downloads_.end()) {
      downloads_.push_back(item);
      item->AddObserver(this);
    }
  }
}

void ActiveDownloadsHandler::SendDownloads() {
  ListValue results;
  for (size_t i = 0; i < downloads_.size(); ++i) {
    results.Append(download_util::CreateDownloadItemValue(downloads_[i], i));
  }

  web_ui_->CallJavascriptFunction("downloadsList", results);
}

void ActiveDownloadsHandler::OnDownloadUpdated(DownloadItem* item) {
  DownloadList::iterator it =
      find(downloads_.begin(), downloads_.end(), item);

  if (it == downloads_.end()) {
    NOTREACHED() << "Updated item " << item->full_path().value()
      << " not found";
  }

  if (item->state() == DownloadItem::REMOVING) {
    item->RemoveObserver(this);
    downloads_.erase(it);
    DownloadList::iterator ita =
        find(active_downloads_.begin(), active_downloads_.end(), item);
    if (ita != active_downloads_.end())
      active_downloads_.erase(ita);
    SendDownloads();
  } else {
    const size_t id = it - downloads_.begin();
    scoped_ptr<DictionaryValue> result(
        download_util::CreateDownloadItemValue(item, id));
    web_ui_->CallJavascriptFunction("downloadUpdated", *result);
  }
}

}  // namespace

////////////////////////////////////////////////////////////////////////////////
//
// ActiveDownloadsUI
//
////////////////////////////////////////////////////////////////////////////////


ActiveDownloadsUI::ActiveDownloadsUI(TabContents* contents)
    : HtmlDialogUI(contents) {
  ActiveDownloadsHandler* handler = new ActiveDownloadsHandler();
  AddMessageHandler(handler->Attach(this));
  handler->Init();
  ActiveDownloadsUIHTMLSource* html_source = new ActiveDownloadsUIHTMLSource();

  // Set up the chrome://active-downloads/ source.
  contents->profile()->GetChromeURLDataManager()->AddDataSource(html_source);
}

// static
Browser* ActiveDownloadsUI::OpenPopup(Profile* profile) {
  Browser* browser = GetPopup(profile);

  // Create new browser if no matching pop up is found.
  if (browser == NULL) {
    browser = Browser::CreateForType(Browser::TYPE_APP_PANEL, profile);

    browser::NavigateParams params(
        browser,
        GURL(chrome::kChromeUIActiveDownloadsURL),
        PageTransition::LINK);
    params.disposition = NEW_FOREGROUND_TAB;
    browser::Navigate(&params);

    // TODO(beng): The following two calls should be automatic by Navigate().
    params.browser->window()->SetBounds(gfx::Rect(kPopupLeft,
                                                  kPopupTop,
                                                  kPopupWidth,
                                                  kPopupHeight));
    params.browser->window()->Show();
  } else {
    browser->window()->Show();
  }

  return browser;
}

Browser* ActiveDownloadsUI::GetPopup(Profile* profile) {
  for (BrowserList::const_iterator it = BrowserList::begin();
       it != BrowserList::end();
       ++it) {
    if (((*it)->type() == Browser::TYPE_APP_PANEL)) {
      TabContents* tab_contents = (*it)->GetSelectedTabContents();
      DCHECK(tab_contents);
      if (!tab_contents)
        continue;
      const GURL& url = tab_contents->GetURL();

      if (url.SchemeIs(chrome::kChromeUIScheme) &&
          url.host() == chrome::kChromeUIActiveDownloadsHost &&
          (*it)->profile() == profile) {
        return (*it);
      }
    }
  }
  return NULL;
}