Update handling of unsupported translations (#1467)

* Handle unsupported fonts

* Update archinstall/locales/README.md

Co-authored-by: codefiles <11915375+codefiles@users.noreply.github.com>

Co-authored-by: Daniel Girtler <girtler.daniel@gmail.com>
Co-authored-by: codefiles <11915375+codefiles@users.noreply.github.com>

5 files changed, 85 insertions, 27 deletions

diff --git a/archinstall/lib/menu/menu.py b/archinstall/lib/menu/menu.py
index 16153e2c..112bc0ae 100644
--- a/archinstall/lib/menu/menu.py
+++ b/archinstall/lib/menu/menu.py
@@ -1,7 +1,7 @@
 from dataclasses import dataclass
 from enum import Enum, auto
 from os import system
-from typing import Dict, List, Union, Any, TYPE_CHECKING, Optional
+from typing import Dict, List, Union, Any, TYPE_CHECKING, Optional, Callable
 
 from archinstall.lib.menu.simple_menu import TerminalMenu
 
@@ -52,9 +52,9 @@ class Menu(TerminalMenu):
 		sort :bool = True,
 		preset_values :Union[str, List[str]] = None,
 		cursor_index : Optional[int] = None,
-		preview_command=None,
-		preview_size=0.75,
-		preview_title='Info',
+		preview_command: Optional[Callable] = None,
+		preview_size: float = 0.75,
+		preview_title: str = 'Info',
 		header :Union[List[str],str] = None,
 		raise_error_on_interrupt :bool = False,
 		raise_error_warning_msg :str = '',
@@ -152,6 +152,7 @@ class Menu(TerminalMenu):
 		self._multi = multi
 		self._raise_error_on_interrupt = raise_error_on_interrupt
 		self._raise_error_warning_msg = raise_error_warning_msg
+		self._preview_command = preview_command
 
 		menu_title = f'\n{title}\n\n'
 
@@ -198,7 +199,7 @@ class Menu(TerminalMenu):
 			# show_search_hint=True,
 			preselected_entries=self.preset_values,
 			cursor_index=self.cursor_index,
-			preview_command=preview_command,
+			preview_command=lambda x: self._preview_wrapper(preview_command, x),
 			preview_size=preview_size,
 			preview_title=preview_title,
 			raise_error_on_interrupt=self._raise_error_on_interrupt,
@@ -235,6 +236,13 @@ class Menu(TerminalMenu):
 		else:
 			return MenuSelection(type_=MenuSelectionType.Esc)
 
+	def _preview_wrapper(self, preview_command: Optional[Callable], current_selection: str) -> Optional[str]:
+		if preview_command:
+			if self._default_option is not None and f'{self._default_option} {self._default_str}' == current_selection:
+				current_selection = self._default_option
+			return preview_command(current_selection)
+		return None
+
 	def run(self) -> MenuSelection:
 		ret = self._show()
 
diff --git a/archinstall/lib/translationhandler.py b/archinstall/lib/translationhandler.py
index 08deb3e7..ef33b8ec 100644
--- a/archinstall/lib/translationhandler.py
+++ b/archinstall/lib/translationhandler.py
@@ -17,41 +17,55 @@ if TYPE_CHECKING:
 @dataclass
 class Language:
 	abbr: str
-	lang: str
+	name_en: str
 	translation: gettext.NullTranslations
 	translation_percent: int
 	translated_lang: Optional[str]
+	external_dep: Optional[str]
 
 	@property
 	def display_name(self) -> str:
-		if self.translated_lang:
+		if not self.external_dep and self.translated_lang:
 			name = self.translated_lang
 		else:
-			name = self.lang
+			name = self.name_en
+
 		return f'{name} ({self.translation_percent}%)'
 
 	def is_match(self, lang_or_translated_lang: str) -> bool:
-		if self.lang == lang_or_translated_lang:
+		if self.name_en == lang_or_translated_lang:
 			return True
 		elif self.translated_lang == lang_or_translated_lang:
 			return True
 		return False
 
 	def json(self) -> str:
-		return self.lang
+		return self.name_en
 
 
 class TranslationHandler:
-	_base_pot = 'base.pot'
-	_languages = 'languages.json'
-
 	def __init__(self):
-		# to display latin, greek, cyrillic characters
-		self._set_font('LatGrkCyr-8x16')
+		self._base_pot = 'base.pot'
+		self._languages = 'languages.json'
+
+		# check if a custom font was provided, otherwise we'll
+		# use one that can display latin, greek, cyrillic characters
+		if self.is_custom_font_enabled():
+			self._set_font(self.custom_font_path().name)
+		else:
+			self._set_font('LatGrkCyr-8x16')
 
 		self._total_messages = self._get_total_active_messages()
 		self._translated_languages = self._get_translations()
 
+	@classmethod
+	def custom_font_path(cls) -> Path:
+		return Path('/usr/share/kbd/consolefonts/archinstall_font.psfu.gz')
+
+	@classmethod
+	def is_custom_font_enabled(cls) -> bool:
+		return cls.custom_font_path().exists()
+
 	@property
 	def translated_languages(self) -> List[Language]:
 		return self._translated_languages
@@ -70,6 +84,7 @@ class TranslationHandler:
 			abbr = mapping_entry['abbr']
 			lang = mapping_entry['lang']
 			translated_lang = mapping_entry.get('translated_lang', None)
+			external_dep = mapping_entry.get('external_dep', False)
 
 			try:
 				# get a translation for a specific language
@@ -84,7 +99,7 @@ class TranslationHandler:
 					# prevent cases where the .pot file is out of date and the percentage is above 100
 					percent = min(100, percent)
 
-				language = Language(abbr, lang, translation, percent, translated_lang)
+				language = Language(abbr, lang, translation, percent, translated_lang, external_dep)
 				languages.append(language)
 			except FileNotFoundError as error:
 				raise TranslationError(f"Could not locate language file for '{lang}': {error}")
@@ -138,7 +153,7 @@ class TranslationHandler:
 		Get a language object by it's name, e.g. English
 		"""
 		try:
-			return next(filter(lambda x: x.lang == name, self._translated_languages))
+			return next(filter(lambda x: x.name_en == name, self._translated_languages))
 		except Exception:
 			raise ValueError(f'No language with name found: {name}')
 
@@ -175,8 +190,7 @@ class TranslationHandler:
 		translation_files = []
 		for filename in filenames:
 			if len(filename) == 2 or filename == 'pt_BR':
-				if filename not in ['ur', 'ta']:
-					translation_files.append(filename)
+				translation_files.append(filename)
 
 		return translation_files
 
diff --git a/archinstall/lib/user_interaction/general_conf.py b/archinstall/lib/user_interaction/general_conf.py
index 34c80c21..6365014d 100644
--- a/archinstall/lib/user_interaction/general_conf.py
+++ b/archinstall/lib/user_interaction/general_conf.py
@@ -13,7 +13,7 @@ from ..output import log
 from ..profiles import Profile, list_profiles
 from ..mirrors import list_mirrors
 
-from ..translationhandler import Language
+from ..translationhandler import Language, TranslationHandler
 from ..packages.packages import validate_package_list
 
 from ..storage import storage
@@ -125,16 +125,34 @@ def select_archinstall_language(languages: List[Language], preset_value: Languag
 	# name of the language in its own language
 	options = {lang.display_name: lang for lang in languages}
 
+	def dependency_preview(current_selection: str) -> Optional[str]:
+		current_lang = options[current_selection]
+
+		if current_lang.external_dep and not TranslationHandler.is_custom_font_enabled():
+			font_file = TranslationHandler.custom_font_path()
+			text = str(_('To be able to use this translation, please install a font manually that supports the language.')) + '\n'
+			text += str(_('The font should be stored as {}')).format(font_file)
+			return text
+		return None
+
 	choice = Menu(
 		_('Archinstall language'),
 		list(options.keys()),
-		default_option=preset_value.display_name
+		default_option=preset_value.display_name,
+		preview_command=lambda x: dependency_preview(x),
+		preview_size=0.5
 	).run()
 
 	match choice.type_:
-		case MenuSelectionType.Esc: return preset_value
+		case MenuSelectionType.Esc:
+			return preset_value
 		case MenuSelectionType.Selection:
-			return options[choice.value]
+			language: Language = options[choice.value]
+			# we have to make sure that the proper AUR dependency is
+			# present to be able to use this language
+			if not language.external_dep or TranslationHandler.is_custom_font_enabled():
+				return language
+			return select_archinstall_language(languages, preset_value)
 
 
 def select_profile(preset) -> Optional[Profile]:
diff --git a/archinstall/locales/README.md b/archinstall/locales/README.md
index 51662702..37dc32e3 100644
--- a/archinstall/locales/README.md
+++ b/archinstall/locales/README.md
@@ -1,8 +1,26 @@
 # Nationalization
 
-Archinstall supports multiple languages, which depend on translations coming from the community :) 
+Archinstall supports multiple languages, which depend on translations coming from the community :)
 
-New languages can be added simply by creating a new folder with the proper language abbrevation (see list `languages.json` if unsure).  
+## Important Note
+Before starting a new language translation be aware that a font for that language may not be
+available on the ISO. We are using the pre-installed font `/usr/share/kbd/consolefonts/LatGrkCyr-8x16.psfu.gz` in archinstall
+which should cover a fair amount of different languages but unfortunately not all of them.
+
+We have the option to provide a custom font in case the above is not covering a specific language, which can
+be achieved by installing the font yourself on the ISO and saving it to `/usr/share/kbd/consolefonts/archinstall_font.psfu.gz`.
+If this font is present it will be automatically loaded and all languages which are not supported by the default font will
+be enabled (but only some might actually work).
+
+Please make sure that the provided language works with the default font on the ISO, and if not mark it in the `languages.json`
+that it needs an external dependency
+```
+{"abbr": "ur", "lang": "Urdu", "translated_lang": "اردو", "external_dep":  true},
+```
+
+## Adding new languages
+
+New languages can be added simply by creating a new folder with the proper language abbreviation (see list `languages.json` if unsure).  
 Run the following command to create a new template for a language
 ```
 mkdir -p <abbr>/LC_MESSAGES/ && touch <abbr>/LC_MESSAGES/base.po
diff --git a/archinstall/locales/languages.json b/archinstall/locales/languages.json
index 55ddf57e..344d3d51 100644
--- a/archinstall/locales/languages.json
+++ b/archinstall/locales/languages.json
@@ -155,7 +155,7 @@
  {"abbr": "sw", "lang": "Swahili (macrolanguage)"},
  {"abbr": "sv", "lang": "Swedish", "translated_lang":  "Svenska"},
  {"abbr": "ty", "lang": "Tahitian"},
- {"abbr": "ta", "lang": "Tamil", "translated_lang":  "தமிழ்"},
+ {"abbr": "ta", "lang": "Tamil", "translated_lang":  "தமிழ்", "external_dep": true},
  {"abbr": "tt", "lang": "Tatar"},
  {"abbr": "te", "lang": "Telugu"},
  {"abbr": "tg", "lang": "Tajik"},
@@ -170,7 +170,7 @@
  {"abbr": "tw", "lang": "Twi"},
  {"abbr": "ug", "lang": "Uighur"},
  {"abbr": "uk", "lang": "Ukrainian"},
- {"abbr": "ur", "lang": "Urdu", "translated_lang": "اردو"},
+ {"abbr": "ur", "lang": "Urdu", "translated_lang": "اردو", "external_dep":  true},
  {"abbr": "uz", "lang": "Uzbek"},
  {"abbr": "ve", "lang": "Venda"},
  {"abbr": "vi", "lang": "Vietnamese"},