// Copyright 2015 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/browsing_data/browsing_data_counter_utils.h"

#include "base/command_line.h"
#include "chrome/browser/browsing_data/autofill_counter.h"
#include "chrome/browser/browsing_data/cache_counter.h"
#include "chrome/browser/browsing_data/history_counter.h"
#include "chrome/browser/browsing_data/passwords_counter.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/pref_names.h"
#include "chrome/grit/generated_resources.h"
#include "components/prefs/pref_service.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/text/bytes_formatting.h"

bool AreCountersEnabled() {
  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kEnableClearBrowsingDataCounters)) {
    return true;
  }

  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kDisableClearBrowsingDataCounters)) {
    return false;
  }

  // Enabled by default.
  return true;
}

// A helper function to display the size of cache in units of MB or higher.
// We need this, as 1 MB is the lowest nonzero cache size displayed by the
// counter.
base::string16 FormatBytesMBOrHigher(BrowsingDataCounter::ResultInt bytes) {
  if (ui::GetByteDisplayUnits(bytes) >= ui::DataUnits::DATA_UNITS_MEBIBYTE)
    return ui::FormatBytes(bytes);

  return ui::FormatBytesWithUnits(
      bytes, ui::DataUnits::DATA_UNITS_MEBIBYTE, true);
}

base::string16 GetCounterTextFromResult(
    const BrowsingDataCounter::Result* result) {
  base::string16 text;
  std::string pref_name = result->source()->GetPrefName();

  if (!result->Finished()) {
    // The counter is still counting.
    text = l10n_util::GetStringUTF16(IDS_CLEAR_BROWSING_DATA_CALCULATING);

  } else if (pref_name == prefs::kDeletePasswords) {
    // Passwords counter.
    BrowsingDataCounter::ResultInt passwords_count =
        static_cast<const BrowsingDataCounter::FinishedResult*>(
            result)->Value();
    text = l10n_util::GetPluralStringFUTF16(
        IDS_DEL_PASSWORDS_COUNTER, passwords_count);

  } else if (pref_name == prefs::kDeleteCache) {
    // Cache counter.
    BrowsingDataCounter::ResultInt cache_size_bytes =
        static_cast<const BrowsingDataCounter::FinishedResult*>(
            result)->Value();

    PrefService* prefs = result->source()->GetProfile()->GetPrefs();
    BrowsingDataRemover::TimePeriod time_period =
        static_cast<BrowsingDataRemover::TimePeriod>(
            prefs->GetInteger(prefs::kDeleteTimePeriod));

    // Three cases: Nonzero result for the entire cache, nonzero result for
    // a subset of cache (i.e. a finite time interval), and almost zero (< 1MB).
    static const int kBytesInAMegabyte = 1024 * 1024;
    if (cache_size_bytes >= kBytesInAMegabyte) {
      base::string16 formatted_size = FormatBytesMBOrHigher(cache_size_bytes);
      text = time_period == BrowsingDataRemover::EVERYTHING
          ? formatted_size
          : l10n_util::GetStringFUTF16(IDS_DEL_CACHE_COUNTER_UPPER_ESTIMATE,
                                       formatted_size);
    } else {
      text = l10n_util::GetStringUTF16(IDS_DEL_CACHE_COUNTER_ALMOST_EMPTY);
    }

  } else if (pref_name == prefs::kDeleteBrowsingHistory) {
    // History counter.
    const HistoryCounter::HistoryResult* history_result =
        static_cast<const HistoryCounter::HistoryResult*>(result);
    BrowsingDataCounter::ResultInt local_item_count = history_result->Value();
    bool has_synced_visits = history_result->has_synced_visits();

    text = has_synced_visits
        ? l10n_util::GetPluralStringFUTF16(
              IDS_DEL_BROWSING_HISTORY_COUNTER_SYNCED, local_item_count)
        : l10n_util::GetPluralStringFUTF16(
              IDS_DEL_BROWSING_HISTORY_COUNTER, local_item_count);

  } else if (pref_name == prefs::kDeleteFormData) {
    // Autofill counter.
    const AutofillCounter::AutofillResult* autofill_result =
        static_cast<const AutofillCounter::AutofillResult*>(result);
    AutofillCounter::ResultInt num_suggestions = autofill_result->Value();
    AutofillCounter::ResultInt num_credit_cards =
        autofill_result->num_credit_cards();
    AutofillCounter::ResultInt num_addresses = autofill_result->num_addresses();

    std::vector<base::string16> displayed_strings;

    if (num_credit_cards) {
      displayed_strings.push_back(l10n_util::GetPluralStringFUTF16(
          IDS_DEL_AUTOFILL_COUNTER_CREDIT_CARDS, num_credit_cards));
    }
    if (num_addresses) {
      displayed_strings.push_back(l10n_util::GetPluralStringFUTF16(
          IDS_DEL_AUTOFILL_COUNTER_ADDRESSES, num_addresses));
    }
    if (num_suggestions) {
      // We use a different wording for autocomplete suggestions based on the
      // length of the entire string.
      switch (displayed_strings.size()) {
        case 0:
          displayed_strings.push_back(l10n_util::GetPluralStringFUTF16(
              IDS_DEL_AUTOFILL_COUNTER_SUGGESTIONS, num_suggestions));
          break;
        case 1:
          displayed_strings.push_back(l10n_util::GetPluralStringFUTF16(
              IDS_DEL_AUTOFILL_COUNTER_SUGGESTIONS_LONG, num_suggestions));
          break;
        case 2:
          displayed_strings.push_back(l10n_util::GetPluralStringFUTF16(
              IDS_DEL_AUTOFILL_COUNTER_SUGGESTIONS_SHORT, num_suggestions));
          break;
        default:
          NOTREACHED();
      }
    }

    // Construct the resulting string from the sections in |displayed_strings|.
    switch (displayed_strings.size()) {
      case 0:
        text = l10n_util::GetStringUTF16(IDS_DEL_AUTOFILL_COUNTER_EMPTY);
        break;
      case 1:
        text = displayed_strings[0];
        break;
      case 2:
        text = l10n_util::GetStringFUTF16(IDS_DEL_AUTOFILL_COUNTER_TWO_TYPES,
                                          displayed_strings[0],
                                          displayed_strings[1]);
        break;
      case 3:
        text = l10n_util::GetStringFUTF16(IDS_DEL_AUTOFILL_COUNTER_THREE_TYPES,
                                          displayed_strings[0],
                                          displayed_strings[1],
                                          displayed_strings[2]);
        break;
      default:
        NOTREACHED();
    }
  }

  return text;
}

bool GetDeletionPreferenceFromDataType(
    BrowsingDataType data_type, std::string* out_pref) {
  switch (data_type) {
    case HISTORY:
      *out_pref = prefs::kDeleteBrowsingHistory;
      return true;
    case CACHE:
      *out_pref = prefs::kDeleteCache;
      return true;
    case COOKIES:
      *out_pref = prefs::kDeleteCookies;
      return true;
    case PASSWORDS:
      *out_pref = prefs::kDeletePasswords;
      return true;
    case FORM_DATA:
      *out_pref = prefs::kDeleteFormData;
      return true;
    case BOOKMARKS:
      // Bookmarks are deleted on the Android side. No corresponding deletion
      // preference.
      return false;
    case NUM_TYPES:
      // This is not an actual type.
      NOTREACHED();
      return false;
  }
  NOTREACHED();
  return false;
}

BrowsingDataCounter* CreateCounterForPreference(std::string pref_name) {
  if (!AreCountersEnabled())
    return nullptr;

  if (pref_name == prefs::kDeleteBrowsingHistory)
    return new HistoryCounter();
  if (pref_name == prefs::kDeleteCache)
    return new CacheCounter();
  if (pref_name == prefs::kDeletePasswords)
    return new PasswordsCounter();
  if (pref_name == prefs::kDeleteFormData)
    return new AutofillCounter();

  return nullptr;
}