// 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.

// This file defines helper functions shared by the various implementations
// of OmniboxView.

#include "components/omnibox/browser/omnibox_view.h"

#include <algorithm>
#include <utility>

#include "base/strings/string16.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "build/build_config.h"
#include "components/omnibox/browser/autocomplete_match.h"
#include "components/omnibox/browser/omnibox_edit_controller.h"
#include "components/omnibox/browser/omnibox_edit_model.h"
#include "components/omnibox/browser/omnibox_field_trial.h"
#include "components/toolbar/toolbar_model.h"
#include "extensions/common/constants.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/material_design/material_design_controller.h"

#if !defined(OS_IOS)
#include "ui/gfx/paint_vector_icon.h"
#endif

// static
base::string16 OmniboxView::StripJavascriptSchemas(const base::string16& text) {
  const base::string16 kJsPrefix(
      base::ASCIIToUTF16(url::kJavaScriptScheme) + base::ASCIIToUTF16(":"));

  bool found_JavaScript = false;
  size_t i = 0;
  // Find the index of the first character that isn't whitespace, a control
  // character, or a part of a JavaScript: scheme.
  while (i < text.size()) {
    if (base::IsUnicodeWhitespace(text[i]) || (text[i] < 0x20)) {
      ++i;
    } else {
      if (!base::EqualsCaseInsensitiveASCII(text.substr(i, kJsPrefix.length()),
                                            kJsPrefix))
        break;

      // We've found a JavaScript scheme. Continue searching to ensure that
      // strings like "javascript:javascript:alert()" are fully stripped.
      found_JavaScript = true;
      i += kJsPrefix.length();
    }
  }

  // If we found any "JavaScript:" schemes in the text, return the text starting
  // at the first non-whitespace/control character after the last instance of
  // the scheme.
  if (found_JavaScript)
    return text.substr(i);

  return text;
}

// static
base::string16 OmniboxView::SanitizeTextForPaste(const base::string16& text) {
  // Check for non-newline whitespace; if found, collapse whitespace runs down
  // to single spaces.
  // TODO(shess): It may also make sense to ignore leading or
  // trailing whitespace when making this determination.
  for (size_t i = 0; i < text.size(); ++i) {
    if (base::IsUnicodeWhitespace(text[i]) &&
        text[i] != '\n' && text[i] != '\r') {
      const base::string16 collapsed = base::CollapseWhitespace(text, false);
      // If the user is pasting all-whitespace, paste a single space
      // rather than nothing, since pasting nothing feels broken.
      return collapsed.empty() ?
          base::ASCIIToUTF16(" ") : StripJavascriptSchemas(collapsed);
    }
  }

  // Otherwise, all whitespace is newlines; remove it entirely.
  return StripJavascriptSchemas(base::CollapseWhitespace(text, true));
}

OmniboxView::~OmniboxView() {
}

void OmniboxView::OpenMatch(const AutocompleteMatch& match,
                            WindowOpenDisposition disposition,
                            const GURL& alternate_nav_url,
                            const base::string16& pasted_text,
                            size_t selected_line) {
  // Invalid URLs such as chrome://history can end up here.
  if (!match.destination_url.is_valid() || !model_)
    return;
  model_->OpenMatch(
      match, disposition, alternate_nav_url, pasted_text, selected_line);
}

bool OmniboxView::IsEditingOrEmpty() const {
  return (model_.get() && model_->user_input_in_progress()) ||
      (GetOmniboxTextLength() == 0);
}

gfx::ImageSkia OmniboxView::GetIcon(int dip_size,
                                    SkColor color,
                                    IconFetchedCallback on_icon_fetched) const {
#if defined(OS_IOS)
  // OmniboxViewIOS provides its own icon logic. The iOS build also does not
  // link in the vector icon rendering code.
  return gfx::ImageSkia();
#else   // !defined(OS_IOS)
  if (!IsEditingOrEmpty()) {
    return gfx::CreateVectorIcon(
        controller_->GetToolbarModel()->GetVectorIcon(), dip_size, color);
  }

  // For Material Refresh, display the favicon of the default search engine.
  const auto type = model_ ? model_->CurrentTextType()
                           : AutocompleteMatchType::URL_WHAT_YOU_TYPED;
  if (ui::MaterialDesignController::IsNewerMaterialUi() &&
      AutocompleteMatch::IsSearchType(type)) {
    gfx::Image favicon = model_->client()->GetFaviconForDefaultSearchProvider(
        std::move(on_icon_fetched));
    if (!favicon.IsEmpty())
      return favicon.AsImageSkia();

    // If the client returns an empty favicon, fall through to provide the
    // generic vector icon. |on_icon_fetched| may or may not be called later.
    // If it's never called, the vector icon we provide below should remain.
  }

  const gfx::VectorIcon& vector_icon =
      AutocompleteMatch::TypeToVectorIcon(type,
                                          /*is_bookmark=*/false,
                                          /*is_tab_match=*/false);
  return gfx::CreateVectorIcon(vector_icon, dip_size, color);
#endif  // defined(OS_IOS)
}

void OmniboxView::SetUserText(const base::string16& text) {
  SetUserText(text, true);
}

void OmniboxView::SetUserText(const base::string16& text,
                              bool update_popup) {
  if (model_)
    model_->SetUserText(text);
  SetWindowTextAndCaretPos(text, text.length(), update_popup, true);
}

void OmniboxView::RevertAll() {
  CloseOmniboxPopup();
  if (model_)
    model_->Revert();
  TextChanged();
}

void OmniboxView::CloseOmniboxPopup() {
  if (model_)
    model_->StopAutocomplete();
}

bool OmniboxView::IsImeShowingPopup() const {
  // Default to claiming that the IME is not showing a popup, since hiding the
  // omnibox dropdown is a bad user experience when we don't know for sure that
  // we have to.
  return false;
}

void OmniboxView::ShowImeIfNeeded() {
}

void OmniboxView::HideImeIfNeeded() {}

bool OmniboxView::IsIndicatingQueryRefinement() const {
  // The default implementation always returns false.  Mobile ports can override
  // this method and implement as needed.
  return false;
}

void OmniboxView::GetState(State* state) {
  state->text = GetText();
  state->keyword = model()->keyword();
  state->is_keyword_selected = model()->is_keyword_selected();
  GetSelectionBounds(&state->sel_start, &state->sel_end);
}

OmniboxView::StateChanges OmniboxView::GetStateChanges(const State& before,
                                                     const State& after) {
  OmniboxView::StateChanges state_changes;
  state_changes.old_text = &before.text;
  state_changes.new_text = &after.text;
  state_changes.new_sel_start = after.sel_start;
  state_changes.new_sel_end = after.sel_end;
  const bool old_sel_empty = before.sel_start == before.sel_end;
  const bool new_sel_empty = after.sel_start == after.sel_end;
  const bool sel_same_ignoring_direction =
      std::min(before.sel_start, before.sel_end) ==
          std::min(after.sel_start, after.sel_end) &&
      std::max(before.sel_start, before.sel_end) ==
          std::max(after.sel_start, after.sel_end);
  state_changes.selection_differs =
      (!old_sel_empty || !new_sel_empty) && !sel_same_ignoring_direction;
  state_changes.text_differs = before.text != after.text;
  state_changes.keyword_differs =
      (after.is_keyword_selected != before.is_keyword_selected) ||
      (after.is_keyword_selected && before.is_keyword_selected &&
       after.keyword != before.keyword);

  // When the user has deleted text, we don't allow inline autocomplete.  Make
  // sure to not flag cases like selecting part of the text and then pasting
  // (or typing) the prefix of that selection.  (We detect these by making
  // sure the caret, which should be after any insertion, hasn't moved
  // forward of the old selection start.)
  state_changes.just_deleted_text =
      (before.text.length() > after.text.length()) &&
      (after.sel_start <= std::min(before.sel_start, before.sel_end));

  return state_changes;
}

OmniboxView::OmniboxView(OmniboxEditController* controller,
                         std::unique_ptr<OmniboxClient> client)
    : controller_(controller), shift_key_down_(false) {
  // |client| can be null in tests.
  if (client) {
    model_.reset(new OmniboxEditModel(this, controller, std::move(client)));
  }
}

void OmniboxView::TextChanged() {
  EmphasizeURLComponents();
  if (model_)
    model_->OnChanged();
}

void OmniboxView::UpdateTextStyle(
    const base::string16& display_text,
    const bool text_is_url,
    const AutocompleteSchemeClassifier& classifier) {
  enum DemphasizeComponents {
    EVERYTHING,
    ALL_BUT_SCHEME,
    ALL_BUT_HOST,
    NOTHING,
  } deemphasize = NOTHING;

  url::Component scheme, host;
  AutocompleteInput::ParseForEmphasizeComponents(display_text, classifier,
                                                 &scheme, &host);

  if (text_is_url) {
    const base::string16 url_scheme =
        display_text.substr(scheme.begin, scheme.len);
    // Extension IDs are not human-readable, so deemphasize everything to draw
    // attention to the human-readable name in the location icon text.
    // Data URLs are rarely human-readable and can be used for spoofing, so draw
    // attention to the scheme to emphasize "this is just a bunch of data".
    // For normal URLs, the host is the best proxy for "identity".
    if (url_scheme == base::UTF8ToUTF16(extensions::kExtensionScheme))
      deemphasize = EVERYTHING;
    else if (url_scheme == base::UTF8ToUTF16(url::kDataScheme))
      deemphasize = ALL_BUT_SCHEME;
    else if (host.is_nonempty())
      deemphasize = ALL_BUT_HOST;
  }

  gfx::Range scheme_range = scheme.is_nonempty()
                                ? gfx::Range(scheme.begin, scheme.end())
                                : gfx::Range::InvalidRange();
  switch (deemphasize) {
    case EVERYTHING:
      SetEmphasis(false, gfx::Range::InvalidRange());
      break;
    case NOTHING:
      SetEmphasis(true, gfx::Range::InvalidRange());
      break;
    case ALL_BUT_SCHEME:
      DCHECK(scheme_range.IsValid());
      SetEmphasis(false, gfx::Range::InvalidRange());
      SetEmphasis(true, scheme_range);
      break;
    case ALL_BUT_HOST:
      SetEmphasis(false, gfx::Range::InvalidRange());
      SetEmphasis(true, gfx::Range(host.begin, host.end()));
      break;
  }

  // Emphasize the scheme for security UI display purposes (if necessary).
  if (!model()->user_input_in_progress() && scheme_range.IsValid())
    UpdateSchemeStyle(scheme_range);
}