// 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/ui/find_bar/find_bar_controller.h"

#include <algorithm>

#include "base/i18n/rtl.h"
#include "base/logging.h"
#include "base/strings/string_util.h"
#include "build/build_config.h"
#include "chrome/browser/chrome_notification_types.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/ui/find_bar/find_bar.h"
#include "chrome/browser/ui/find_bar/find_bar_state.h"
#include "chrome/browser/ui/find_bar/find_bar_state_factory.h"
#include "chrome/browser/ui/find_bar/find_tab_helper.h"
#include "content/public/browser/navigation_details.h"
#include "content/public/browser/navigation_entry.h"
#include "content/public/browser/notification_details.h"
#include "content/public/browser/notification_source.h"
#include "content/public/browser/web_contents.h"
#include "ui/gfx/geometry/rect.h"

using content::NavigationController;
using content::WebContents;

// The minimum space between the FindInPage window and the search result.
static const int kMinFindWndDistanceFromSelection = 5;

FindBarController::FindBarController(FindBar* find_bar)
    : find_bar_(find_bar),
      web_contents_(NULL),
      last_reported_matchcount_(0) {
}

FindBarController::~FindBarController() {
  DCHECK(!web_contents_);
}

void FindBarController::Show() {
  FindTabHelper* find_tab_helper =
      FindTabHelper::FromWebContents(web_contents_);

  // Only show the animation if we're not already showing a find bar for the
  // selected WebContents.
  if (!find_tab_helper->find_ui_active()) {
    MaybeSetPrepopulateText();

    find_tab_helper->set_find_ui_active(true);
    find_bar_->Show(true);
  }
  find_bar_->SetFocusAndSelection();
}

void FindBarController::EndFindSession(SelectionAction selection_action,
                                       ResultAction result_action) {
  find_bar_->Hide(true);

  // |web_contents_| can be NULL for a number of reasons, for example when the
  // tab is closing. We must guard against that case. See issue 8030.
  if (web_contents_) {
    FindTabHelper* find_tab_helper =
        FindTabHelper::FromWebContents(web_contents_);

    // When we hide the window, we need to notify the renderer that we are done
    // for now, so that we can abort the scoping effort and clear all the
    // tickmarks and highlighting.
    find_tab_helper->StopFinding(selection_action);

    if (result_action == kClearResultsInFindBox)
      find_bar_->ClearResults(find_tab_helper->find_result());

    // When we get dismissed we restore the focus to where it belongs.
    find_bar_->RestoreSavedFocus();
  }
}

void FindBarController::ChangeWebContents(WebContents* contents) {
  if (web_contents_) {
    registrar_.RemoveAll();
    find_bar_->StopAnimation();

    FindTabHelper* find_tab_helper =
        FindTabHelper::FromWebContents(web_contents_);
    if (find_tab_helper)
      find_tab_helper->set_selected_range(find_bar_->GetSelectedRange());
  }

  web_contents_ = contents;
  FindTabHelper* find_tab_helper =
      web_contents_ ? FindTabHelper::FromWebContents(web_contents_)
                    : NULL;

  // Hide any visible find window from the previous tab if a NULL tab contents
  // is passed in or if the find UI is not active in the new tab.
  if (find_bar_->IsFindBarVisible() &&
      (!find_tab_helper || !find_tab_helper->find_ui_active())) {
    find_bar_->Hide(false);
  }

  if (!web_contents_)
    return;

  registrar_.Add(this,
                 chrome::NOTIFICATION_FIND_RESULT_AVAILABLE,
                 content::Source<WebContents>(web_contents_));
  registrar_.Add(
      this,
      content::NOTIFICATION_NAV_ENTRY_COMMITTED,
      content::Source<NavigationController>(&web_contents_->GetController()));

  MaybeSetPrepopulateText();

  if (find_tab_helper && find_tab_helper->find_ui_active()) {
    // A tab with a visible find bar just got selected and we need to show the
    // find bar but without animation since it was already animated into its
    // visible state. We also want to reset the window location so that
    // we don't surprise the user by popping up to the left for no apparent
    // reason.
    find_bar_->Show(false);
  }

  UpdateFindBarForCurrentResult();
  find_bar_->UpdateFindBarForChangedWebContents();
}

////////////////////////////////////////////////////////////////////////////////
// FindBarHost, content::NotificationObserver implementation:

void FindBarController::Observe(int type,
                                const content::NotificationSource& source,
                                const content::NotificationDetails& details) {
  FindTabHelper* find_tab_helper =
      FindTabHelper::FromWebContents(web_contents_);
  if (type == chrome::NOTIFICATION_FIND_RESULT_AVAILABLE) {
    // Don't update for notifications from WebContentses other than the one we
    // are actively tracking.
    if (content::Source<WebContents>(source).ptr() == web_contents_) {
      UpdateFindBarForCurrentResult();
      if (find_tab_helper->find_result().final_update() &&
          find_tab_helper->find_result().number_of_matches() == 0) {
        const base::string16& last_search =
            find_tab_helper->previous_find_text();
        const base::string16& current_search = find_tab_helper->find_text();
        if (!base::StartsWith(last_search, current_search,
                              base::CompareCase::SENSITIVE)) {
          find_bar_->AudibleAlert();
        }
      }
    }
  } else if (type == content::NOTIFICATION_NAV_ENTRY_COMMITTED) {
    NavigationController* source_controller =
        content::Source<NavigationController>(source).ptr();
    if (source_controller == &web_contents_->GetController()) {
      content::LoadCommittedDetails* commit_details =
          content::Details<content::LoadCommittedDetails>(details).ptr();
      ui::PageTransition transition_type =
          commit_details->entry->GetTransitionType();
      // Hide the find bar on reload or navigation.
      if (find_bar_->IsFindBarVisible() && commit_details->is_main_frame &&
          (ui::PageTransitionCoreTypeIs(transition_type,
                                        ui::PAGE_TRANSITION_RELOAD) ||
           commit_details->is_navigation_to_different_page()))
        EndFindSession(kKeepSelectionOnPage, kClearResultsInFindBox);
    }
  }
}

// static
gfx::Rect FindBarController::GetLocationForFindbarView(
    gfx::Rect view_location,
    const gfx::Rect& dialog_bounds,
    const gfx::Rect& avoid_overlapping_rect) {
  if (base::i18n::IsRTL()) {
    int boundary = dialog_bounds.width() - view_location.width();
    view_location.set_x(std::min(view_location.x(), boundary));
  } else {
    view_location.set_x(std::max(view_location.x(), dialog_bounds.x()));
  }

  gfx::Rect new_pos = view_location;

  // If the selection rectangle intersects the current position on screen then
  // we try to move our dialog to the left (right for RTL) of the selection
  // rectangle.
  if (!avoid_overlapping_rect.IsEmpty() &&
      avoid_overlapping_rect.Intersects(new_pos)) {
    if (base::i18n::IsRTL()) {
      new_pos.set_x(avoid_overlapping_rect.x() +
                    avoid_overlapping_rect.width() +
                    (2 * kMinFindWndDistanceFromSelection));

      // If we moved it off-screen to the right, we won't move it at all.
      if (new_pos.x() + new_pos.width() > dialog_bounds.width())
        new_pos = view_location;  // Reset.
    } else {
      new_pos.set_x(avoid_overlapping_rect.x() - new_pos.width() -
        kMinFindWndDistanceFromSelection);

      // If we moved it off-screen to the left, we won't move it at all.
      if (new_pos.x() < 0)
        new_pos = view_location;  // Reset.
    }
  }

  return new_pos;
}

void FindBarController::UpdateFindBarForCurrentResult() {
  FindTabHelper* find_tab_helper =
      FindTabHelper::FromWebContents(web_contents_);
  const FindNotificationDetails& find_result = find_tab_helper->find_result();

  // Avoid bug 894389: When a new search starts (and finds something) it reports
  // an interim match count result of 1 before the scoping effort starts. This
  // is to provide feedback as early as possible that we will find something.
  // As you add letters to the search term, this creates a flashing effect when
  // we briefly show "1 of 1" matches because there is a slight delay until
  // the scoping effort starts updating the match count. We avoid this flash by
  // ignoring interim results of 1 if we already have a positive number.
  if (find_result.number_of_matches() > -1) {
    if (last_reported_matchcount_ > 0 &&
        find_result.number_of_matches() == 1 &&
        !find_result.final_update())
      return;  // Don't let interim result override match count.
    last_reported_matchcount_ = find_result.number_of_matches();
  }

  find_bar_->UpdateUIForFindResult(find_result, find_tab_helper->find_text());
}

void FindBarController::MaybeSetPrepopulateText() {
  // Having a per-tab find_string is not compatible with a global find
  // pasteboard, so we always have the same find text in all find bars. This is
  // done through the find pasteboard mechanism, so don't set the text here.
  if (find_bar_->HasGlobalFindPasteboard())
    return;

  // Find out what we should show in the find text box. Usually, this will be
  // the last search in this tab, but if no search has been issued in this tab
  // we use the last search string (from any tab).
  FindTabHelper* find_tab_helper =
      FindTabHelper::FromWebContents(web_contents_);
  base::string16 find_string = find_tab_helper->find_text();
  if (find_string.empty())
    find_string = find_tab_helper->previous_find_text();
  if (find_string.empty()) {
    Profile* profile =
        Profile::FromBrowserContext(web_contents_->GetBrowserContext());
    find_string = FindBarStateFactory::GetLastPrepopulateText(profile);
  }

  // Update the find bar with existing results and search text, regardless of
  // whether or not the find bar is visible, so that if it's subsequently
  // shown it is showing the right state for this tab. We update the find text
  // _first_ since the FindBarView checks its emptiness to see if it should
  // clear the result count display when there's nothing in the box.
  find_bar_->SetFindTextAndSelectedRange(find_string,
                                         find_tab_helper->selected_range());
}