/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <locale.h>

#include "OSPreferences.h"

#include "dlfcn.h"

#include "glib.h"

#include "gio/gio.h"

using namespace mozilla::intl;

OSPreferences::OSPreferences() {}

OSPreferences::~OSPreferences() {}

bool OSPreferences::ReadSystemLocales(nsTArray<nsCString>& aLocaleList) {

  MOZ_ASSERT(aLocaleList.IsEmpty());

  nsAutoCString defaultLang(uloc_getDefault());

  if (CanonicalizeLanguageTag(defaultLang)) {

    aLocaleList.AppendElement(defaultLang);

    return true;

  }

  return false;

}

bool OSPreferences::ReadRegionalPrefsLocales(nsTArray<nsCString>& aLocaleList) {

  MOZ_ASSERT(aLocaleList.IsEmpty());

  // For now we're just taking the LC_TIME from POSIX environment for all

  // regional preferences.

  nsAutoCString localeStr(setlocale(LC_TIME, nullptr));

  if (CanonicalizeLanguageTag(localeStr)) {

    aLocaleList.AppendElement(localeStr);

    return true;

  }

  return false;

}

/*

 * This looks up into gtk settings for hourCycle format.

 *

 * This works for all GUIs that use gtk settings like Gnome, Elementary etc.

 * Ubuntu does not use those settings so we'll want to support them separately.

 *

 * We're taking the current 12/24h settings irrelevant of the locale, because

 * in the UI user selects this setting for all locales.

 */

typedef GVariant* (*get_value_fn_t)(GSettings*, const gchar*);

static get_value_fn_t FindGetValueFunction() {

  get_value_fn_t fn = reinterpret_cast<get_value_fn_t>(

      dlsym(RTLD_DEFAULT, "g_settings_get_user_value"));

  return fn ? fn : &g_settings_get_value;

}

static int HourCycle() {

  int rval = 0;

  const char* schema;

  const char* key;

  const char* env = getenv("XDG_CURRENT_DESKTOP");

  if (env && strcmp(env, "Unity") == 0) {

    schema = "com.canonical.indicator.datetime";

    key = "time-format";

  } else {

    schema = "org.gnome.desktop.interface";

    key = "clock-format";

  }

  // This is a workaround for old GTK versions.

  // Once we bump the minimum version to 2.40 we should replace

  // this with g_settings_schme_source_lookup.

  // See bug 1356718 for details.

  const char* const* schemas = g_settings_list_schemas();

  GSettings* settings = nullptr;

  for (uint32_t i = 0; schemas[i] != nullptr; i++) {

    if (strcmp(schemas[i], schema) == 0) {

      settings = g_settings_new(schema);

      break;

    }

  }

  if (settings) {

    // We really want to use g_settings_get_user_value which will

    // only want to take it if user manually changed the value.

    // But this requires glib 2.40, and we still support older glib versions,

    // so we have to check whether it's available and fall back to the older

    // g_settings_get_value if not.

    static get_value_fn_t sGetValueFunction = FindGetValueFunction();

    GVariant* value = sGetValueFunction(settings, key);

    if (value) {

      if (g_variant_is_of_type(value, G_VARIANT_TYPE_STRING)) {

        const char* strVal = g_variant_get_string(value, nullptr);

        if (strncmp("12", strVal, 2) == 0) {

          rval = 12;

        } else if (strncmp("24", strVal, 2) == 0) {

          rval = 24;

        }

      }

      g_variant_unref(value);

    }

    g_object_unref(settings);

  }

  return rval;

}

/**

 * Since Gtk does not provide a way to customize or format date/time patterns,

 * we're reusing ICU data here, but we do modify it according to the only

 * setting Gtk gives us - hourCycle.

 *

 * This means that for gtk we will return a pattern from ICU altered to

 * represent h12/h24 hour cycle if the user modified the default value.

 *

 * In short, this should work like this:

 *

 *  * gtk defaults, pl: 24h

 *  * gtk defaults, en: 12h

 *

 *  * gtk 12h, pl: 12h

 *  * gtk 12h, en: 12h

 *

 *  * gtk 24h, pl: 24h

 *  * gtk 12h, en: 12h

 */

bool OSPreferences::ReadDateTimePattern(DateTimeFormatStyle aDateStyle,

                                        DateTimeFormatStyle aTimeStyle,

                                        const nsACString& aLocale,

                                        nsAString& aRetVal) {

  nsAutoString skeleton;

  if (!GetDateTimeSkeletonForStyle(aDateStyle, aTimeStyle, aLocale, skeleton)) {

    return false;

  }

  // Customize the skeleton if necessary to reflect user's 12/24hr pref

  switch (HourCycle()) {

    case 12: {

      // If skeleton contains 'H' or 'k', replace with 'h' or 'K' respectively,

      // and add 'a' unless already present.

      if (skeleton.FindChar('H') == -1 && skeleton.FindChar('k') == -1) {

        break;  // nothing to do

      }

      bool foundA = false;

      for (size_t i = 0; i < skeleton.Length(); ++i) {

        switch (skeleton[i]) {

          case 'a':

            foundA = true;

            break;

          case 'H':

            skeleton.SetCharAt('h', i);

            break;

          case 'k':

            skeleton.SetCharAt('K', i);

            break;

        }

      }

      if (!foundA) {

        skeleton.Append(char16_t('a'));

      }

      break;

    }

    case 24:

      // If skeleton contains 'h' or 'K', replace with 'H' or 'k' respectively,

      // and delete 'a' if present.

      if (skeleton.FindChar('h') == -1 && skeleton.FindChar('K') == -1) {

        break;  // nothing to do

      }

      for (int32_t i = 0; i < int32_t(skeleton.Length()); ++i) {

        switch (skeleton[i]) {

          case 'a':

            skeleton.Cut(i, 1);

            --i;

            break;

          case 'h':

            skeleton.SetCharAt('H', i);

            break;

          case 'K':

            skeleton.SetCharAt('k', i);

            break;

        }

      }

      break;

  }

  if (!GetPatternForSkeleton(skeleton, aLocale, aRetVal)) {

    return false;

  }

  return true;

}