mediawiki: Allow setting site language code

Closes: #2137

Signed-off-by: nbenedek <contact@nbenedek.me>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/mediawiki/__init__.py

@@ -14,7 +14,7 @@ from plinth.modules.backups.components import BackupRestore
 from plinth.modules.firewall.components import Firewall
 from plinth.package import Packages
 
-from . import manifest, privileged
+from . import manifest, privileged, forms
 
 _description = [
     _('MediaWiki is the wiki engine that powers Wikipedia and other WikiMedia '
@@ -146,3 +146,14 @@ def set_server_url(domain):
 def get_site_name():
     """Return the value of MediaWiki's site name."""
     return _get_config_value('$wgSitename') or 'Wiki'
+
+
+def get_default_language():
+    """Return the value of MediaWiki's default language"""
+    default_lang_key = _get_config_value('$wgLanguageCode')
+    language_choices = forms.get_languages()
+    for code, name in language_choices:
+        if code == default_lang_key:
+            return code
+
+    return None

plinth/modules/mediawiki/data/etc/mediawiki/FreedomBoxStaticSettings.php

@@ -45,6 +45,9 @@ $wgServer = "https://freedombox.local";
 # Site Name
 $wgSitename = "Wiki";
 
+# Default language
+$wgLanguageCode = "en";
+
 # Enable default extensions
 wfLoadExtension( 'Cite' );
 wfLoadExtension( 'Interwiki' );

plinth/modules/mediawiki/forms.py

@@ -4,6 +4,7 @@ FreedomBox app for configuring MediaWiki.
 """
 
 import pathlib
+import re
 
 from django import forms
 from django.core import validators
@@ -20,6 +21,17 @@ def get_skins():
             if skin.is_dir()]
 
 
+def get_languages():
+    """Return a list of available languages as choice field values."""
+    with open('/var/lib/mediawiki/includes/languages/data/Names.php',
+              'r') as lang_file:
+        content = lang_file.read()
+    matches = re.findall(r"'([a-z_-]+)' => '(.+)', # .+", content)
+    language_choices = [(code, name) for code, name in matches]
+
+    return language_choices
+
+
 class MediaWikiForm(forms.Form):  # pylint: disable=W0232
     """MediaWiki configuration form."""
     password = forms.CharField(
@@ -58,3 +70,10 @@ class MediaWikiForm(forms.Form):  # pylint: disable=W0232
         help_text=_('Choose a default skin for your MediaWiki installation. '
                     'Users have the option to select their preferred skin.'),
         choices=get_skins)
+
+    default_lang = forms.ChoiceField(
+        label=_('Default Language'), required=False,
+        help_text=_('Choose a default language for your MediaWiki '
+                    'installation. Users have the option to select '
+                    'their preferred language.'),
+        choices=get_languages)

plinth/modules/mediawiki/privileged.py

@@ -205,3 +205,18 @@ def set_server_url(server_url: str):
 def set_site_name(site_name: str):
     """Set the value of $wgSitename for this MediaWiki server."""
     _update_setting('$wgSitename', f'$wgSitename = "{site_name}";\n')
+
+
+@privileged
+def set_default_language(language: str):
+    """Set the value of $wgLanguageCode for this MediaWiki server."""
+    _update_setting('$wgLanguageCode ', f'$wgLanguageCode = "{language}";\n')
+    # In MediaWiki 1.8 or older, if you change this after installation, you
+    # should run the maintenance/rebuildmessages.php script to rebuild the
+    # user interface messages (MediaWiki namespace). Otherwise, you will not
+    # see the interface in the new language, or a mix of the old and new
+    # languages.
+    rebuild_messages_script = os.path.join(MAINTENANCE_SCRIPTS_DIR,
+                                           'rebuildmessages.php')
+    subprocess.check_call([
+        _get_php_command(), rebuild_messages_script])

plinth/modules/mediawiki/views.py

@@ -10,7 +10,8 @@ from plinth import app as app_module
 from plinth import views
 from plinth.modules import mediawiki
 
-from . import get_default_skin, get_server_url, get_site_name, privileged
+from . import (get_default_skin,
+               get_server_url, get_site_name, get_default_language, privileged)
 from .forms import MediaWikiForm
 
 logger = logging.getLogger(__name__)
@@ -36,7 +37,9 @@ class MediaWikiAppView(views.AppView):
             'domain':
                 get_server_url(),
             'site_name':
-                get_site_name()
+                get_site_name(),
+            'default_lang':
+                get_default_language()
         })
         return initial
 
@@ -102,4 +105,8 @@ class MediaWikiAppView(views.AppView):
             privileged.set_site_name(new_config['site_name'])
             messages.success(self.request, _('Site name updated'))
 
+        if is_changed('default_lang'):
+            privileged.set_default_language(new_config['default_lang'])
+            messages.success(self.request, _('Default language changed'))
+
         return super().form_valid(form)