[Core] Refactor the base argparser and translation code.

- Move baseargparser out of deluge/ui since it is also used by the
  Daemon and could cause packaging issues if UI code is not available.
  - Renamed baseargparser to argparserbase to follow existing Deluge
    naming.
  - Renamed get_version to distinguish from deluge.common.get_version.
- Translation code is usable by more than just the UIs so also move it
  to Deluge namespace and re-use i18n directory and make it a package.
  - Renamed setup_translations to singular as it felt more correct.
  - Renamed set_dummy_trans to be more descriptive.

Closes: #3081

3 files changed, 265 insertions, 0 deletions

diff --git a/deluge/i18n/__init__.py b/deluge/i18n/__init__.py
new file mode 100644
index 000000000..701d2afa6
--- /dev/null
+++ b/deluge/i18n/__init__.py
@@ -0,0 +1,15 @@
+from .util import (
+    I18N_DOMAIN,
+    get_languages,
+    set_language,
+    setup_mock_translation,
+    setup_translation,
+)
+
+__all__ = [
+    'I18N_DOMAIN',
+    'set_language',
+    'get_languages',
+    'setup_translation',
+    'setup_mock_translation',
+]
diff --git a/deluge/i18n/languages.py b/deluge/i18n/languages.py
new file mode 100644
index 000000000..49dc53026
--- /dev/null
+++ b/deluge/i18n/languages.py
@@ -0,0 +1,117 @@
+# -*- coding: utf-8 -*-
+#
+# This file is public domain.
+#
+
+from __future__ import unicode_literals
+
+# Language code for this installation. All choices can be found here:
+# http://www.i18nguy.com/unicode/language-identifiers.html
+LANGUAGE_CODE = 'en-us'
+
+
+# Deferred translation
+def _(message):
+    return message
+
+
+# Languages we provide translations for, out of the box.
+LANGUAGES = {
+    'af': _('Afrikaans'),
+    'ar': _('Arabic'),
+    'ast': _('Asturian'),
+    'az': _('Azerbaijani'),
+    'bg': _('Bulgarian'),
+    'be': _('Belarusian'),
+    'bn': _('Bengali'),
+    'br': _('Breton'),
+    'bs': _('Bosnian'),
+    'ca': _('Catalan'),
+    'cs': _('Czech'),
+    'cy': _('Welsh'),
+    'da': _('Danish'),
+    'de': _('German'),
+    'el': _('Greek'),
+    'en': _('English'),
+    'en_AU': _('English (Australia)'),
+    'en_CA': _('English (Canada)'),
+    'en_GB': _('English (United Kingdom)'),
+    'eo': _('Esperanto'),
+    'es': _('Spanish'),
+    'es-ar': _('Argentinian Spanish'),
+    'es-mx': _('Mexican Spanish'),
+    'es-ni': _('Nicaraguan Spanish'),
+    'es-ve': _('Venezuelan Spanish'),
+    'et': _('Estonian'),
+    'eu': _('Basque'),
+    'fa': _('Persian'),
+    'fi': _('Finnish'),
+    'fr': _('French'),
+    'fy': _('Frisian'),
+    'ga': _('Irish'),
+    'gl': _('Galician'),
+    'he': _('Hebrew'),
+    'hi': _('Hindi'),
+    'hr': _('Croatian'),
+    'hu': _('Hungarian'),
+    'ia': _('Interlingua'),
+    'id': _('Indonesian'),
+    'is': _('Icelandic'),
+    'it': _('Italian'),
+    'iu': _('Inuktitut'),
+    'ja': _('Japanese'),
+    'ka': _('Georgian'),
+    'kk': _('Kazakh'),
+    'km': _('Khmer'),
+    'kn': _('Kannada'),
+    'ko': _('Korean'),
+    'ku': _('Kurdish'),
+    'la': _('Latin'),
+    'lb': _('Luxembourgish'),
+    'lt': _('Lithuanian'),
+    'lv': _('Latvian'),
+    'mk': _('Macedonian'),
+    'ml': _('Malayalam'),
+    'mn': _('Mongolian'),
+    'ms': _('Mayaly'),
+    'my': _('Burmese'),
+    'nb': _('Norwegian Bokmal'),
+    'ne': _('Nepali'),
+    'nds': _('Low German'),
+    'nl': _('Dutch'),
+    'nn': _('Norwegian Nynorsk'),
+    'os': _('Ossetic'),
+    'pa': _('Punjabi'),
+    'pl': _('Polish'),
+    'pms': _('Piedmontese'),
+    'pt': _('Portuguese'),
+    'pt_BR': _('Brazilian Portuguese'),
+    'ro': _('Romanian'),
+    'ru': _('Russian'),
+    'sk': _('Slovak'),
+    'sl': _('Slovenian'),
+    'si': _('Sinhalese'),
+    'sq': _('Albanian'),
+    'sr': _('Serbian'),
+    'sr-latn': _('Serbian Latin'),
+    'sv': _('Swedish'),
+    'sw': _('Swahili'),
+    'ta': _('Tamil'),
+    'te': _('Telugu'),
+    'th': _('Thai'),
+    'tl': _('Tagalog'),
+    'tlh': _('Klingon'),
+    'tr': _('Turkish'),
+    'tt': _('Tatar'),
+    'udm': _('Udmurt'),
+    'uk': _('Ukrainian'),
+    'ur': _('Urdu'),
+    'vi': _('Vietnamese'),
+    'zh_CN': _('Chinese (Simplified)'),
+    'zh_HK': _('Chinese (Hong Kong)'),
+    'zh-hans': _('Simplified Chinese'),
+    'zh-hant': _('Traditional Chinese'),
+    'zh_TW': _('Chinese (Taiwan)'),
+}
+
+del _
diff --git a/deluge/i18n/util.py b/deluge/i18n/util.py
new file mode 100644
index 000000000..a2f287645
--- /dev/null
+++ b/deluge/i18n/util.py
@@ -0,0 +1,133 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2007,2008 Andrew Resch <andrewresch@gmail.com>
+#
+# This file is part of Deluge and is licensed under GNU General Public License 3.0, or later, with
+# the additional special exception to link portions of this program with the OpenSSL library.
+# See LICENSE for more details.
+#
+
+from __future__ import unicode_literals
+
+import ctypes
+import gettext
+import locale
+import logging
+import os
+import sys
+
+from six.moves import builtins
+
+import deluge.common
+
+from .languages import LANGUAGES
+
+log = logging.getLogger(__name__)
+
+I18N_DOMAIN = 'deluge'
+
+
+def get_translations_path():
+    """Get the absolute path to the directory containing translation files"""
+    return deluge.common.resource_filename('deluge', 'i18n')
+
+
+def get_languages():
+    lang = []
+
+    translations_path = get_translations_path()
+    for root, dirs, files in os.walk(translations_path):
+        # Get the dirs
+        lang_dirs = dirs
+        break
+    else:
+        return lang
+
+    for i, lang_code in enumerate(lang_dirs):
+        name = '%s (Language name missing)' % lang_code
+        if lang_code in LANGUAGES:
+            name = LANGUAGES[lang_code]
+        lang.append([lang_code, _(name)])
+
+    lang = sorted(lang, key=lambda l: l[1])
+    return lang
+
+
+def set_language(lang):
+    """
+    Set the language to use.
+
+    gettext and GtkBuilder will load the translations from the specified
+    language.
+
+    :param lang: the language, e.g. "en", "de" or "en_GB"
+    :type lang: str
+    """
+    # Necessary to set these environment variables for GtkBuilder
+    deluge.common.set_env_variable('LANGUAGE', lang)  # Windows/Linux
+    deluge.common.set_env_variable('LANG', lang)  # For OSX
+
+    translations_path = get_translations_path()
+    try:
+        ro = gettext.translation(
+            'deluge', localedir=translations_path, languages=[lang]
+        )
+        ro.install()
+    except IOError as ex:
+        log.warning('IOError when loading translations: %s', ex)
+
+
+def setup_mock_translation(warn_msg=None):
+    def _func(*txt):
+        if warn_msg:
+            log.warning(
+                '"%s" has been marked for translation, but translation is unavailable.',
+                txt[0],
+            )
+        return txt[0]
+
+    builtins.__dict__['_'] = _func
+    builtins.__dict__['ngettext'] = builtins.__dict__['_n'] = _func
+
+
+# Initialize gettext
+def setup_translation():
+    translations_path = get_translations_path()
+    log.info('Setting up translations from %s', translations_path)
+
+    try:
+        if hasattr(locale, 'bindtextdomain'):
+            locale.bindtextdomain(I18N_DOMAIN, translations_path)
+        if hasattr(locale, 'textdomain'):
+            locale.textdomain(I18N_DOMAIN)
+
+        gettext.bindtextdomain(I18N_DOMAIN, translations_path)
+        gettext.bind_textdomain_codeset(I18N_DOMAIN, 'UTF-8')
+        gettext.textdomain(I18N_DOMAIN)
+
+        # Workaround for Python 2 unicode gettext (keyword removed in Py3).
+        kwargs = {} if not deluge.common.PY2 else {'unicode': True}
+
+        gettext.install(I18N_DOMAIN, translations_path, names='ngettext', **kwargs)
+        builtins.__dict__['_n'] = builtins.__dict__['ngettext']
+
+        libintl = None
+        if deluge.common.windows_check():
+            libintl = ctypes.cdll.LoadLibrary('libintl-8.dll')
+        elif deluge.common.osx_check():
+            libintl = ctypes.cdll.LoadLibrary('libintl.dylib')
+
+        if libintl:
+            libintl.bindtextdomain(
+                I18N_DOMAIN, translations_path.encode(sys.getfilesystemencoding())
+            )
+            libintl.textdomain(I18N_DOMAIN)
+            libintl.bind_textdomain_codeset(I18N_DOMAIN, 'UTF-8')
+            libintl.gettext.restype = ctypes.c_char_p
+
+    except Exception as ex:
+        log.error('Unable to initialize gettext/locale!')
+        log.exception(ex)
+        setup_mock_translation()
+
+    deluge.common.translate_size_units()