/* -*- 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/. */

#ifndef mozilla_intl_MozLocale_h__
#define mozilla_intl_MozLocale_h__

#include "nsString.h"
#include "nsTArray.h"

namespace mozilla {
namespace intl {

/**
 * Locale class is a core representation of a single locale.
 *
 * A locale is a data object representing a combination of language, script,
 * region, variant and a set of regional extension preferences that may further
 * specify particular user choices like calendar, numbering system, etc.
 *
 * A locale can be expressed as a language tag string, like a simple "fr" for
 * French, or a more specific "sr-Cyrl-RS-u-hc-h12" for Serbian in Russia with a
 * Cyrylic script, and hour cycle selected to be `h12`.
 *
 * The format of the language tag follows BCP47 standard and implements a subset
 * of it. In the future we expect to extend this class to cover more subtags and
 * extensions.
 *
 * BCP47: https://tools.ietf.org/html/bcp47
 *
 * The aim of this class it aid in validation, parsing and canonicalization of
 * the string.
 *
 * It allows the user to input any well-formed BCP47 language tag and operate
 * on its subtags in a canonicalized form.
 *
 * It should be used for all operations on language tags, and together with
 * LocaleService::NegotiateLanguages for language negotiation.
 *
 * Example:
 *
 *     Locale loc = Locale("de-at");
 *
 *     ASSERT_TRUE(loc.GetLanguage().Equals("de"));
 *     ASSERT_TRUE(loc.GetScript().IsEmpty());
 *     ASSERT_TRUE(loc.GetRegion().Equals("AT")); // canonicalized to upper case
 *
 *
 * Note: The file name is `MozLocale` to avoid compilation problems on
 * case-insensitive Windows. The class name is `Locale`.
 */
class Locale {
 public:
  explicit Locale(const nsACString& aLocale);
  explicit Locale(const char* aLocale) : Locale(nsDependentCString(aLocale)){};

  const nsACString& GetLanguage() const;
  const nsACString& GetScript() const;
  const nsACString& GetRegion() const;
  const nsTArray<nsCString>& GetVariants() const;

  bool IsValid() const { return mIsValid; }

  const nsCString AsString() const;

  bool Matches(const Locale& aOther, bool aThisRange, bool aOtherRange) const;
  bool AddLikelySubtags();
  void ClearVariants();
  void ClearRegion();

  // Mark the object as invalid, meaning we shouldn't use it any more.
  void Invalidate() { mIsValid = false; }

  bool operator==(const Locale& aOther) {
    // Note: invalid Locale objects are never treated as equal to anything
    // (even other invalid ones).
    return IsValid() && aOther.IsValid() &&
           mLanguage.Equals(aOther.mLanguage) &&
           mScript.Equals(aOther.mScript) && mRegion.Equals(aOther.mRegion) &&
           mVariants == aOther.mVariants;
  }

 private:
  nsAutoCStringN<3> mLanguage;
  nsAutoCStringN<4> mScript;
  nsAutoCStringN<2> mRegion;
  nsTArray<nsCString> mVariants;
  bool mIsValid = true;
};

}  // namespace intl
}  // namespace mozilla

DECLARE_USE_COPY_CONSTRUCTORS(mozilla::intl::Locale)

#endif /* mozilla_intl_MozLocale_h__ */