// Copyright 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/ui/browser_instant_controller.h"

#include "base/bind.h"
#include "chrome/browser/infobars/infobar_service.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/search/instant_service.h"
#include "chrome/browser/search/instant_service_factory.h"
#include "chrome/browser/search/search.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_window.h"
#include "chrome/browser/ui/location_bar/location_bar.h"
#include "chrome/browser/ui/search/instant_search_prerenderer.h"
#include "chrome/browser/ui/search/search_model.h"
#include "chrome/browser/ui/search/search_tab_helper.h"
#include "chrome/browser/ui/tabs/tab_strip_model.h"
#include "chrome/common/search/instant_types.h"
#include "chrome/common/url_constants.h"
#include "components/omnibox/browser/omnibox_popup_model.h"
#include "components/omnibox/browser/omnibox_view.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/navigation_controller.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/user_metrics.h"
#include "content/public/browser/web_contents.h"
#include "content/public/browser/web_contents_user_data.h"
#include "content/public/common/referrer.h"
#include "ui/base/page_transition_types.h"

// Helpers --------------------------------------------------------------------

namespace {

// Helper class for posting a task to reload a tab, to avoid doing a re-entrant
// navigation, since it can be called when starting a navigation. This class
// makes sure to only execute the reload if the WebContents still exists.
class TabReloader : public content::WebContentsUserData<TabReloader> {
 public:
  static void Reload(content::WebContents* web_contents) {
    TabReloader::CreateForWebContents(web_contents);
  }

 private:
  friend class content::WebContentsUserData<TabReloader>;

  explicit TabReloader(content::WebContents* web_contents)
      : web_contents_(web_contents), weak_ptr_factory_(this) {
    content::BrowserThread::PostTask(
        content::BrowserThread::UI,
        FROM_HERE,
        base::Bind(&TabReloader::ReloadImpl, weak_ptr_factory_.GetWeakPtr()));
  }
  ~TabReloader() override {}

  void ReloadImpl() {
    web_contents_->GetController().Reload(false);

    // As the reload was not triggered by the user we don't want to close any
    // infobars. We have to tell the InfoBarService after the reload,
    // otherwise it would ignore this call when
    // WebContentsObserver::DidStartNavigationToPendingEntry is invoked.
    InfoBarService::FromWebContents(web_contents_)->set_ignore_next_reload();

    web_contents_->RemoveUserData(UserDataKey());
  }

  content::WebContents* web_contents_;
  base::WeakPtrFactory<TabReloader> weak_ptr_factory_;
};

}  // namespace

DEFINE_WEB_CONTENTS_USER_DATA_KEY(TabReloader);


// BrowserInstantController ---------------------------------------------------

BrowserInstantController::BrowserInstantController(Browser* browser)
    : browser_(browser),
      instant_(this) {
  browser_->search_model()->AddObserver(this);

  InstantService* instant_service =
      InstantServiceFactory::GetForProfile(profile());
  instant_service->AddObserver(this);
}

BrowserInstantController::~BrowserInstantController() {
  browser_->search_model()->RemoveObserver(this);

  InstantService* instant_service =
      InstantServiceFactory::GetForProfile(profile());
  instant_service->RemoveObserver(this);
}

void BrowserInstantController::OpenInstant(WindowOpenDisposition disposition,
                                           const GURL& url) {
  // Unsupported dispositions.
  if (disposition == WindowOpenDisposition::NEW_BACKGROUND_TAB ||
      disposition == WindowOpenDisposition::NEW_WINDOW ||
      disposition == WindowOpenDisposition::NEW_FOREGROUND_TAB) {
    return;
  }

  // The omnibox currently doesn't use other dispositions, so we don't attempt
  // to handle them. If you hit this DCHECK file a bug and I'll (sky) add
  // support for the new disposition.
  DCHECK(disposition == WindowOpenDisposition::CURRENT_TAB)
      << static_cast<int>(disposition);

  const base::string16& search_terms =
      search::ExtractSearchTermsFromURL(profile(), url);
  if (search_terms.empty())
    return;

  InstantSearchPrerenderer* prerenderer =
      InstantSearchPrerenderer::GetForProfile(profile());
  if (!prerenderer)
    return;

  if (prerenderer->CanCommitQuery(GetActiveWebContents(), search_terms)) {
    // Submit query to render the prefetched results. Browser will swap the
    // prerendered contents with the active tab contents.
    prerenderer->Commit(search_terms, EmbeddedSearchRequestParams(url));
  } else {
    prerenderer->Cancel();
  }
}

Profile* BrowserInstantController::profile() const {
  return browser_->profile();
}

content::WebContents* BrowserInstantController::GetActiveWebContents() const {
  return browser_->tab_strip_model()->GetActiveWebContents();
}

void BrowserInstantController::ActiveTabChanged() {
  instant_.ActiveTabChanged();
}

void BrowserInstantController::TabDeactivated(content::WebContents* contents) {
  InstantSearchPrerenderer* prerenderer =
      InstantSearchPrerenderer::GetForProfile(profile());
  if (prerenderer)
    prerenderer->Cancel();
}

void BrowserInstantController::ModelChanged(
    const SearchModel::State& old_state,
    const SearchModel::State& new_state) {
  if (old_state.mode != new_state.mode) {
    const SearchMode& new_mode = new_state.mode;

    // Record some actions corresponding to the mode change. Note that to get
    // the full story, it's necessary to look at other UMA actions as well,
    // such as tab switches.
    if (new_mode.is_ntp())
      content::RecordAction(base::UserMetricsAction("InstantExtended.ShowNTP"));

    instant_.SearchModeChanged(old_state.mode, new_mode);
  }

  if (old_state.instant_support != new_state.instant_support)
    instant_.InstantSupportChanged(new_state.instant_support);
}

void BrowserInstantController::DefaultSearchProviderChanged(
    bool google_base_url_domain_changed) {
  InstantService* instant_service =
      InstantServiceFactory::GetForProfile(profile());
  if (!instant_service)
    return;

  TabStripModel* tab_model = browser_->tab_strip_model();
  int count = tab_model->count();
  for (int index = 0; index < count; ++index) {
    content::WebContents* contents = tab_model->GetWebContentsAt(index);
    if (!contents)
      continue;

    // Send new search URLs to the renderer.
    content::RenderProcessHost* rph = contents->GetRenderProcessHost();
    instant_service->SendSearchURLsToRenderer(rph);

    if (!instant_service->IsInstantProcess(rph->GetID()))
      continue;

    SearchModel* model = SearchTabHelper::FromWebContents(contents)->model();
    if (google_base_url_domain_changed && model->mode().is_origin_ntp()) {
      GURL local_ntp_url(chrome::kChromeSearchLocalNtpUrl);
      // Replace the server NTP with the local NTP.
      content::NavigationController::LoadURLParams params(local_ntp_url);
      params.should_replace_current_entry = true;
      params.referrer = content::Referrer();
      params.transition_type = ui::PAGE_TRANSITION_RELOAD;
      contents->GetController().LoadURLWithParams(params);
    } else {
      // Reload the contents to ensure that it gets assigned to a
      // non-privileged renderer.
      TabReloader::Reload(contents);
    }
  }
}