[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

18 files changed, 82 insertions, 62 deletions

diff --git a/deluge/ui/baseargparser.py b/deluge/argparserbase.py
index 6024e99d5..3952e1ef3 100644
--- a/deluge/ui/baseargparser.py
+++ b/deluge/argparserbase.py
@@ -86,7 +86,7 @@ argparse.ArgumentParser.find_subcommand = find_subcommand
 argparse.ArgumentParser.set_default_subparser = set_default_subparser
 
 
-def get_version():
+def _get_version_detail():
     version_str = '%s\n' % (common.get_version())
     try:
         from deluge._libtorrent import LT_VERSION
@@ -151,7 +151,7 @@ class HelpAction(argparse._HelpAction):
         parser.exit()
 
 
-class BaseArgParser(argparse.ArgumentParser):
+class ArgParserBase(argparse.ArgumentParser):
     def __init__(self, *args, **kwargs):
         if 'formatter_class' not in kwargs:
             kwargs['formatter_class'] = lambda prog: DelugeTextHelpFormatter(
@@ -165,7 +165,7 @@ class BaseArgParser(argparse.ArgumentParser):
             self.log_stream = kwargs['log_stream']
             del kwargs['log_stream']
 
-        super(BaseArgParser, self).__init__(*args, **kwargs)
+        super(ArgParserBase, self).__init__(*args, **kwargs)
 
         self.common_setup = False
         self.process_arg_group = False
@@ -178,13 +178,13 @@ class BaseArgParser(argparse.ArgumentParser):
             '-V',
             '--version',
             action='version',
-            version='%(prog)s ' + get_version(),
+            version='%(prog)s ' + _get_version_detail(),
             help=_('Print version information'),
         )
         self.group.add_argument(
             '-v',
             action='version',
-            version='%(prog)s ' + get_version(),
+            version='%(prog)s ' + _get_version_detail(),
             help=argparse.SUPPRESS,
         )  # Deprecated arg
         self.group.add_argument(
@@ -246,7 +246,7 @@ class BaseArgParser(argparse.ArgumentParser):
             argparse.Namespace: The parsed arguments.
 
         """
-        options = super(BaseArgParser, self).parse_args(args=args)
+        options = super(ArgParserBase, self).parse_args(args=args)
         return self._handle_ui_options(options)
 
     def parse_known_ui_args(self, args, withhold=None):
@@ -262,7 +262,7 @@ class BaseArgParser(argparse.ArgumentParser):
         """
         if withhold:
             args = [a for a in args if a not in withhold]
-        options, remaining = super(BaseArgParser, self).parse_known_args(args=args)
+        options, remaining = super(ArgParserBase, self).parse_known_args(args=args)
         options.remaining = remaining
         # Hanlde common and process group options
         return self._handle_ui_options(options)
diff --git a/deluge/core/daemon_entry.py b/deluge/core/daemon_entry.py
index d62245c36..0a2261a08 100644
--- a/deluge/core/daemon_entry.py
+++ b/deluge/core/daemon_entry.py
@@ -15,10 +15,10 @@ from logging import DEBUG, FileHandler, getLogger
 
 from twisted.internet.error import CannotListenError
 
+from deluge.argparserbase import ArgParserBase
 from deluge.common import run_profiled
 from deluge.configmanager import get_config_dir
-from deluge.ui.baseargparser import BaseArgParser
-from deluge.ui.translations_util import set_dummy_trans
+from deluge.i18n import setup_mock_translation
 
 
 def add_daemon_options(parser):
@@ -78,10 +78,10 @@ def start_daemon(skip_start=False):
         deluge.core.daemon.Daemon: A new daemon object
 
     """
-    set_dummy_trans(warn_msg=True)
+    setup_mock_translation(warn_msg=True)
 
     # Setup the argument parser
-    parser = BaseArgParser()
+    parser = ArgParserBase()
     add_daemon_options(parser)
 
     options = parser.parse_args()
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/ui/languages.py b/deluge/i18n/languages.py
index ab2df02e7..49dc53026 100644
--- a/deluge/ui/languages.py
+++ b/deluge/i18n/languages.py
@@ -9,6 +9,12 @@ from __future__ import unicode_literals
 # 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'),
@@ -107,3 +113,5 @@ LANGUAGES = {
     'zh-hant': _('Traditional Chinese'),
     'zh_TW': _('Chinese (Taiwan)'),
 }
+
+del _
diff --git a/deluge/ui/translations_util.py b/deluge/i18n/util.py
index cf64c994f..a2f287645 100644
--- a/deluge/ui/translations_util.py
+++ b/deluge/i18n/util.py
@@ -20,35 +20,19 @@ from six.moves import builtins
 
 import deluge.common
 
+from .languages import LANGUAGES
+
 log = logging.getLogger(__name__)
-log.addHandler(
-    logging.NullHandler()
-)  # Silence: No handlers could be found for logger "deluge.util.lang"
 
 I18N_DOMAIN = 'deluge'
 
 
-def set_dummy_trans(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
-
-
 def get_translations_path():
     """Get the absolute path to the directory containing translation files"""
     return deluge.common.resource_filename('deluge', 'i18n')
 
 
 def get_languages():
-    from deluge.ui import languages  # Import here so that gettext has been setup first
-
     lang = []
 
     translations_path = get_translations_path()
@@ -61,9 +45,9 @@ def get_languages():
 
     for i, lang_code in enumerate(lang_dirs):
         name = '%s (Language name missing)' % lang_code
-        if lang_code in languages.LANGUAGES:
-            name = languages.LANGUAGES[lang_code]
-        lang.append([lang_code, name])
+        if lang_code in LANGUAGES:
+            name = LANGUAGES[lang_code]
+        lang.append([lang_code, _(name)])
 
     lang = sorted(lang, key=lambda l: l[1])
     return lang
@@ -93,8 +77,21 @@ def set_language(lang):
         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_translations():
+def setup_translation():
     translations_path = get_translations_path()
     log.info('Setting up translations from %s', translations_path)
 
@@ -131,6 +128,6 @@ def setup_translations():
     except Exception as ex:
         log.error('Unable to initialize gettext/locale!')
         log.exception(ex)
-        set_dummy_trans()
+        setup_mock_translation()
 
     deluge.common.translate_size_units()
diff --git a/deluge/tests/common.py b/deluge/tests/common.py
index 4ca34d400..0fb8d5002 100644
--- a/deluge/tests/common.py
+++ b/deluge/tests/common.py
@@ -23,7 +23,7 @@ import deluge.configmanager
 import deluge.core.preferencesmanager
 import deluge.log
 from deluge.error import DelugeError
-from deluge.ui.translations_util import setup_translations
+from deluge.i18n import setup_translation
 
 # This sets log level to critical, so use log.critical() to debug while running unit tests
 deluge.log.setup_logger('none')
@@ -75,7 +75,7 @@ def add_watchdog(deferred, timeout=0.05, message=None):
 
 
 # Initialize gettext
-setup_translations()
+setup_translation()
 
 
 class ReactorOverride(object):
diff --git a/deluge/tests/test_common.py b/deluge/tests/test_common.py
index 7e90cbc91..3cecb6467 100644
--- a/deluge/tests/test_common.py
+++ b/deluge/tests/test_common.py
@@ -30,7 +30,7 @@ from deluge.common import (
     is_url,
     windows_check,
 )
-from deluge.ui.translations_util import setup_translations
+from deluge.i18n import setup_translation
 
 from .common import get_test_data_file, set_tmp_config_dir
 
@@ -38,7 +38,7 @@ from .common import get_test_data_file, set_tmp_config_dir
 class CommonTestCase(unittest.TestCase):
     def setUp(self):  # NOQA
         self.config_dir = set_tmp_config_dir()
-        setup_translations()
+        setup_translation()
 
     def tearDown(self):  # NOQA
         pass
diff --git a/deluge/tests/test_files_tab.py b/deluge/tests/test_files_tab.py
index 5625010ea..23865d78f 100644
--- a/deluge/tests/test_files_tab.py
+++ b/deluge/tests/test_files_tab.py
@@ -13,7 +13,7 @@ from twisted.trial import unittest
 import deluge.component as component
 from deluge.common import windows_check
 from deluge.configmanager import ConfigManager
-from deluge.ui.translations_util import setup_translations
+from deluge.i18n import setup_translation
 
 from . import common
 from .basetest import BaseTestCase
@@ -27,7 +27,7 @@ try:
 except ImportError:
     libs_available = False
 
-setup_translations()
+setup_translation()
 
 
 @pytest.mark.gtkui
diff --git a/deluge/tests/test_torrentview.py b/deluge/tests/test_torrentview.py
index 6c4350a48..590760d1e 100644
--- a/deluge/tests/test_torrentview.py
+++ b/deluge/tests/test_torrentview.py
@@ -15,7 +15,7 @@ from twisted.trial import unittest
 
 import deluge.component as component
 from deluge.configmanager import ConfigManager
-from deluge.ui.translations_util import setup_translations
+from deluge.i18n import setup_translation
 
 from . import common
 from .basetest import BaseTestCase
@@ -36,7 +36,7 @@ except (ImportError, ValueError):
 else:
     libs_available = True
 
-setup_translations()
+setup_translation()
 
 
 @pytest.mark.gtkui
diff --git a/deluge/ui/console/console.py b/deluge/ui/console/console.py
index 99d6ea72c..58d31d514 100644
--- a/deluge/ui/console/console.py
+++ b/deluge/ui/console/console.py
@@ -15,7 +15,7 @@ import os
 import sys
 
 import deluge.common
-from deluge.ui.baseargparser import BaseArgParser, DelugeTextHelpFormatter
+from deluge.argparserbase import ArgParserBase, DelugeTextHelpFormatter
 from deluge.ui.ui import UI
 
 log = logging.getLogger(__name__)
@@ -143,7 +143,7 @@ class Console(UI):
     def start(self):
         if self.ui_args is None:
             # Started directly by deluge-console script so must find the UI args manually
-            options, remaining = BaseArgParser(common_help=False).parse_known_args()
+            options, remaining = ArgParserBase(common_help=False).parse_known_args()
             self.ui_args = remaining
 
         i = self.console_parser.find_subcommand(args=self.ui_args)
diff --git a/deluge/ui/console/modes/preferences/preference_panes.py b/deluge/ui/console/modes/preferences/preference_panes.py
index 2bdf5a932..62029a6a9 100644
--- a/deluge/ui/console/modes/preferences/preference_panes.py
+++ b/deluge/ui/console/modes/preferences/preference_panes.py
@@ -13,6 +13,7 @@ import logging
 
 from deluge.common import is_ip
 from deluge.decorators import overrides
+from deluge.i18n import get_languages
 from deluge.ui.client import client
 from deluge.ui.common import DISK_CACHE_KEYS
 from deluge.ui.console.widgets import BaseInputPane, BaseWindow
@@ -192,7 +193,6 @@ class InterfacePane(BasePreferencePane):
             _('Move selection when moving torrents in the queue'),
             console_config['torrentview']['move_selection'],
         )
-        from deluge.ui.translations_util import get_languages
 
         langs = get_languages()
         langs.insert(0, ('', 'System Default'))
diff --git a/deluge/ui/console/utils/column.py b/deluge/ui/console/utils/column.py
index 47b0b2433..d93215957 100644
--- a/deluge/ui/console/utils/column.py
+++ b/deluge/ui/console/utils/column.py
@@ -13,11 +13,11 @@ import copy
 import logging
 
 import deluge.common
+from deluge.i18n import setup_translation
 from deluge.ui.common import TORRENT_DATA_FIELD
 from deluge.ui.console.utils import format_utils
-from deluge.ui.translations_util import setup_translations
 
-setup_translations()
+setup_translation()
 
 log = logging.getLogger(__name__)
 
diff --git a/deluge/ui/gtk3/gtkui.py b/deluge/ui/gtk3/gtkui.py
index c30561ecb..8feed0e5c 100644
--- a/deluge/ui/gtk3/gtkui.py
+++ b/deluge/ui/gtk3/gtkui.py
@@ -47,11 +47,11 @@ from deluge.common import (
 )
 from deluge.configmanager import ConfigManager, get_config_dir
 from deluge.error import DaemonRunningError
+from deluge.i18n import I18N_DOMAIN, set_language, setup_translation
 from deluge.ui.client import client
 from deluge.ui.hostlist import LOCALHOST
 from deluge.ui.sessionproxy import SessionProxy
 from deluge.ui.tracker_icons import TrackerIcons
-from deluge.ui.translations_util import I18N_DOMAIN, set_language, setup_translations
 
 # isort:imports-localfolder
 from .addtorrentdialog import AddTorrentDialog
@@ -146,7 +146,7 @@ def windowing(like):
 class GtkUI(object):
     def __init__(self, args):
         # Setup gtkbuilder/glade translation
-        setup_translations()
+        setup_translation()
         Builder().set_translation_domain(I18N_DOMAIN)
 
         # Setup signals
diff --git a/deluge/ui/gtk3/preferences.py b/deluge/ui/gtk3/preferences.py
index c91e7f2ed..b19612891 100644
--- a/deluge/ui/gtk3/preferences.py
+++ b/deluge/ui/gtk3/preferences.py
@@ -22,9 +22,9 @@ import deluge.common
 import deluge.component as component
 from deluge.configmanager import ConfigManager, get_config_dir
 from deluge.error import AuthManagerError, NotAuthorizedError
+from deluge.i18n import get_languages
 from deluge.ui.client import client
 from deluge.ui.common import DISK_CACHE_KEYS, PREFS_CATOG_TRANS
-from deluge.ui.translations_util import get_languages
 
 from .common import associate_magnet_links, get_clipboard_text, get_deluge_icon
 from .dialogs import AccountDialog, ErrorDialog, InformationDialog, YesNoDialog
diff --git a/deluge/ui/ui.py b/deluge/ui/ui.py
index 6b149f72d..0986ec777 100644
--- a/deluge/ui/ui.py
+++ b/deluge/ui/ui.py
@@ -14,8 +14,8 @@ import logging
 import deluge.common
 import deluge.configmanager
 import deluge.log
-from deluge.ui.baseargparser import BaseArgParser
-from deluge.ui.translations_util import setup_translations
+from deluge.argparserbase import ArgParserBase
+from deluge.i18n import setup_translation
 
 log = logging.getLogger(__name__)
 
@@ -38,8 +38,8 @@ class UI(object):
     def __init__(self, name, **kwargs):
         self.__name = name
         self.ui_args = kwargs.pop('ui_args', None)
-        setup_translations()
-        self.__parser = BaseArgParser(**kwargs)
+        setup_translation()
+        self.__parser = ArgParserBase(**kwargs)
 
     def parse_args(self, parser, args=None):
         options = parser.parse_args(args)
diff --git a/deluge/ui/ui_entry.py b/deluge/ui/ui_entry.py
index cefce0db5..71ce83783 100644
--- a/deluge/ui/ui_entry.py
+++ b/deluge/ui/ui_entry.py
@@ -23,8 +23,8 @@ import pkg_resources
 
 import deluge.common
 import deluge.configmanager
-from deluge.ui.baseargparser import BaseArgParser
-from deluge.ui.translations_util import setup_translations
+from deluge.argparserbase import ArgParserBase
+from deluge.i18n import setup_translation
 
 DEFAULT_PREFS = {'default_ui': 'gtk'}
 
@@ -33,7 +33,7 @@ AMBIGUOUS_CMD_ARGS = ('-h', '--help', '-v', '-V', '--version')
 
 def start_ui():
     """Entry point for ui script"""
-    setup_translations()
+    setup_translation()
 
     # Get the registered UI entry points
     ui_entrypoints = {}
@@ -59,7 +59,7 @@ def start_ui():
         return _parser
 
     # Setup parser with Common Options and add UI Options group.
-    parser = add_ui_options_group(BaseArgParser())
+    parser = add_ui_options_group(ArgParserBase())
 
     # Parse and handle common/process group options
     options = parser.parse_known_ui_args(sys.argv, withhold=AMBIGUOUS_CMD_ARGS)
@@ -81,7 +81,7 @@ def start_ui():
     # We have parsed and got the config dir needed to get the default UI
     # Now create a parser for choosing the UI. We reuse the ui option group for
     # parsing to succeed and the text displayed to user, but result is not used.
-    parser = add_ui_options_group(BaseArgParser(common_help=True))
+    parser = add_ui_options_group(ArgParserBase(common_help=True))
 
     # Create subparser for each registered UI. Empty title is used to remove unwanted positional text.
     subparsers = parser.add_subparsers(
diff --git a/deluge/ui/web/json_api.py b/deluge/ui/web/json_api.py
index d06ce1ef6..d760845e6 100644
--- a/deluge/ui/web/json_api.py
+++ b/deluge/ui/web/json_api.py
@@ -26,12 +26,12 @@ from deluge import component, httpdownloader
 from deluge.common import AUTH_LEVEL_DEFAULT, get_magnet_info, is_magnet
 from deluge.configmanager import get_config_dir
 from deluge.error import NotAuthorizedError
+from deluge.i18n import get_languages
 from deluge.ui.client import Client, client
 from deluge.ui.common import FileTree2, TorrentInfo
 from deluge.ui.coreconfig import CoreConfig
 from deluge.ui.hostlist import HostList
 from deluge.ui.sessionproxy import SessionProxy
-from deluge.ui.translations_util import get_languages
 from deluge.ui.web.common import _
 
 log = logging.getLogger(__name__)
diff --git a/deluge/ui/web/server.py b/deluge/ui/web/server.py
index ebb92151a..c8f901a5a 100644
--- a/deluge/ui/web/server.py
+++ b/deluge/ui/web/server.py
@@ -25,8 +25,8 @@ from deluge import common, component, configmanager
 from deluge.common import is_ipv6
 from deluge.core.rpcserver import check_ssl_keys
 from deluge.crypto_utils import get_context_factory
+from deluge.i18n import set_language, setup_translation
 from deluge.ui.tracker_icons import TrackerIcons
-from deluge.ui.translations_util import set_language, setup_translations
 from deluge.ui.web.auth import Auth
 from deluge.ui.web.common import Template
 from deluge.ui.web.json_api import JSON, WebApi, WebUtils
@@ -687,7 +687,7 @@ class DelugeWeb(component.Component):
             # Strip away slashes and serve on the base path as well as root path
             self.top_level.putChild(self.base.strip('/'), self.top_level)
 
-        setup_translations()
+        setup_translation()
 
         # Remove twisted version number from 'server' http-header for security reasons
         server.version = 'TwistedWeb'