[mod] replace engines_languages.json by engines_traits.json

Implementations of the *traits* of the engines.

Engine's traits are fetched from the origin engine and stored in a JSON file in
the *data folder*.  Most often traits are languages and region codes and their
mapping from SearXNG's representation to the representation in the origin search
engine.

To load traits from the persistence::

    searx.enginelib.traits.EngineTraitsMap.from_data()

For new traits new properties can be added to the class::

    searx.enginelib.traits.EngineTraits

.. hint::

   Implementation is downward compatible to the deprecated *supported_languages
   method* from the vintage implementation.

   The vintage code is tagged as *deprecated* an can be removed when all engines
   has been ported to the *traits method*.

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

.github/workflows/data-update.yml

@@ -17,7 +17,7 @@ jobs:
           - update_currencies.py
           - update_external_bangs.py
           - update_firefox_version.py
-          - update_languages.py
+          - update_engine_traits.py
           - update_wikidata_units.py
           - update_engine_descriptions.py
     steps:

docs/admin/engines/configured_engines.rst

@@ -42,7 +42,7 @@ Explanation of the :ref:`general engine configuration` shown in the table
         - Timeout
         - Weight
         - Paging
-        - Language
+        - Language, Region
         - Safe search
         - Time range
 

docs/admin/engines/settings.rst

@@ -569,10 +569,13 @@ engine is shown.  Most of the options have a default value or even are optional.
   To disable by default the engine, but not deleting it.  It will allow the user
   to manually activate it in the settings.
 
+``inactive``: optional
+  Remove the engine from the settings (*disabled & removed*).
+
 ``language`` : optional
   If you want to use another language for a specific engine, you can define it
-  by using the full ISO code of language and country, like ``fr_FR``, ``en_US``,
-  ``de_DE``.
+  by using the ISO code of language (and region), like ``fr``, ``en-US``,
+  ``de-DE``.
 
 ``tokens`` : optional
   A list of secret tokens to make this engine *private*, more details see

docs/conf.py

@@ -127,6 +127,10 @@ extensions = [
     'notfound.extension',  # https://github.com/readthedocs/sphinx-notfound-page
 ]
 
+autodoc_default_options = {
+    'member-order': 'groupwise',
+}
+
 myst_enable_extensions = [
   "replacements", "smartquotes"
 ]
@@ -135,6 +139,7 @@ suppress_warnings = ['myst.domains']
 
 intersphinx_mapping = {
     "python": ("https://docs.python.org/3/", None),
+    "babel" : ("https://babel.readthedocs.io/en/latest/", None),
     "flask": ("https://flask.palletsprojects.com/", None),
     "flask_babel": ("https://python-babel.github.io/flask-babel/", None),
     # "werkzeug": ("https://werkzeug.palletsprojects.com/", None),

docs/dev/engine_overview.rst

@@ -54,6 +54,7 @@ Engine File
                                        - ``offline`` :ref:`[ref] <offline engines>`
                                        - ``online_dictionary``
                                        - ``online_currency``
+                                       - ``online_url_search``
    ======================= =========== ========================================================
 
 .. _engine settings:
@@ -131,8 +132,10 @@ Passed Arguments (request)
 These arguments can be used to construct the search query.  Furthermore,
 parameters with default value can be redefined for special purposes.
 
+.. _engine request online:
 
-.. table:: If the ``engine_type`` is ``online``
+.. table:: If the ``engine_type`` is :py:obj:`online
+           <searx.search.processors.online.OnlineProcessor.get_params>`
    :width: 100%
 
    ====================== ============== ========================================================================
@@ -149,12 +152,16 @@ parameters with default value can be redefined for special purposes.
    safesearch             int            ``0``, between ``0`` and ``2`` (normal, moderate, strict)
    time_range             Optional[str]  ``None``, can be ``day``, ``week``, ``month``, ``year``
    pageno                 int            current pagenumber
-   language               str            specific language code like ``'en_US'``, or ``'all'`` if unspecified
+   searxng_locale         str            SearXNG's locale selected by user.  Specific language code like
+                                         ``'en'``, ``'en-US'``, or ``'all'`` if unspecified.
    ====================== ============== ========================================================================
 
 
-.. table:: If the ``engine_type`` is ``online_dictionary``, in addition to the
-           ``online`` arguments:
+.. _engine request online_dictionary:
+
+.. table:: If the ``engine_type`` is :py:obj:`online_dictionary
+           <searx.search.processors.online_dictionary.OnlineDictionaryProcessor.get_params>`,
+           in addition to the :ref:`online <engine request online>` arguments:
    :width: 100%
 
    ====================== ============== ========================================================================
@@ -165,8 +172,11 @@ parameters with default value can be redefined for special purposes.
    query                  str            the text query without the languages
    ====================== ============== ========================================================================
 
-.. table:: If the ``engine_type`` is ``online_currency```, in addition to the
-           ``online`` arguments:
+.. _engine request online_currency:
+
+.. table:: If the ``engine_type`` is :py:obj:`online_currency
+           <searx.search.processors.online_currency.OnlineCurrencyProcessor.get_params>`,
+           in addition to the :ref:`online <engine request online>` arguments:
    :width: 100%
 
    ====================== ============== ========================================================================
@@ -179,6 +189,26 @@ parameters with default value can be redefined for special purposes.
    to_name                str            currency name
    ====================== ============== ========================================================================
 
+.. _engine request online_url_search:
+
+.. table:: If the ``engine_type`` is :py:obj:`online_url_search
+           <searx.search.processors.online_url_search.OnlineUrlSearchProcessor.get_params>`,
+           in addition to the :ref:`online <engine request online>` arguments:
+   :width: 100%
+
+   ====================== ============== ========================================================================
+   argument               type           default-value, information
+   ====================== ============== ========================================================================
+   search_url             dict           URLs from the search query:
+
+                                         .. code:: python
+
+                                            {
+                                              'http': str,
+                                              'ftp': str,
+                                              'data:image': str
+                                            }
+   ====================== ============== ========================================================================
 
 Specify Request
 ---------------

docs/dev/searxng_extra/update.rst

@@ -52,12 +52,12 @@ Scripts to update static data in :origin:`searx/data/`
   :members:
 
 
-``update_languages.py``
-=======================
+``update_engine_traits.py``
+===========================
 
-:origin:`[source] <searxng_extra/update/update_languages.py>`
+:origin:`[source] <searxng_extra/update/update_engine_traits.py>`
 
-.. automodule:: searxng_extra.update.update_languages
+.. automodule:: searxng_extra.update.update_engine_traits
   :members:
 
 

docs/src/searx.enginelib.rst

@@ -0,0 +1,17 @@
+.. _searx.enginelib:
+
+============
+Engine model
+============
+
+.. automodule:: searx.enginelib
+  :members:
+
+.. _searx.enginelib.traits:
+
+=============
+Engine traits
+=============
+
+.. automodule:: searx.enginelib.traits
+  :members:

docs/src/searx.engines.rst

@@ -1,8 +1,8 @@
-.. _load_engines:
+.. _searx.engines:
 
-============
-Load Engines
-============
+=================
+SearXNG's engines
+=================
 
 .. automodule:: searx.engines
   :members:

docs/src/searx.search.processors.rst

@@ -0,0 +1,47 @@
+.. _searx.search.processors:
+
+=================
+Search processors
+=================
+
+.. contents:: Contents
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+
+Abstract processor class
+========================
+
+.. automodule:: searx.search.processors.abstract
+  :members:
+
+Offline processor
+=================
+
+.. automodule:: searx.search.processors.offline
+  :members:
+
+Online processor
+================
+
+.. automodule:: searx.search.processors.online
+  :members:
+
+Online currency processor
+=========================
+
+.. automodule:: searx.search.processors.online_currency
+  :members:
+
+Online Dictionary processor
+===========================
+
+.. automodule:: searx.search.processors.online_dictionary
+  :members:
+
+Online URL search processor
+===========================
+
+.. automodule:: searx.search.processors.online_url_search
+  :members:

manage

@@ -63,7 +63,7 @@ PYLINT_SEARXNG_DISABLE_OPTION="\
 I,C,R,\
 W0105,W0212,W0511,W0603,W0613,W0621,W0702,W0703,W1401,\
 E1136"
-PYLINT_ADDITIONAL_BUILTINS_FOR_ENGINES="supported_languages,language_aliases,logger,categories"
+PYLINT_ADDITIONAL_BUILTINS_FOR_ENGINES="traits,supported_languages,language_aliases,logger,categories"
 PYLINT_OPTIONS="-m pylint -j 0 --rcfile .pylintrc"
 
 help() {

searx/autocomplete.py

@@ -12,7 +12,7 @@ from lxml import etree
 from httpx import HTTPError
 
 from searx import settings
-from searx.data import ENGINES_LANGUAGES
+from searx.engines import engines
 from searx.network import get as http_get
 from searx.exceptions import SearxEngineResponseException
 
@@ -111,7 +111,7 @@ def seznam(query, _lang):
 
 def startpage(query, lang):
     # startpage autocompleter
-    lui = ENGINES_LANGUAGES['startpage'].get(lang, 'english')
+    lui = engines['startpage'].supported_languages.get(lang, 'english')  # vintage / deprecated
     url = 'https://startpage.com/suggestions?{query}'
     resp = get(url.format(query=urlencode({'q': query, 'segment': 'startpage.udog', 'lui': lui})))
     data = resp.json()
@@ -177,12 +177,19 @@ backends = {
 }
 
 
-def search_autocomplete(backend_name, query, lang):
+def search_autocomplete(backend_name, query, sxng_locale):
     backend = backends.get(backend_name)
     if backend is None:
         return []
 
+    if engines[backend_name].traits.data_type != "traits_v1":
+        # vintage / deprecated
+        if not sxng_locale or sxng_locale == 'all':
+            sxng_locale = 'en'
+        else:
+            sxng_locale = sxng_locale.split('-')[0]
+
     try:
-        return backend(query, lang)
+        return backend(query, sxng_locale)
     except (HTTPError, SearxEngineResponseException):
         return []

searx/data/__init__.py

@@ -7,7 +7,7 @@
 """
 
 __all__ = [
-    'ENGINES_LANGUAGES',
+    'ENGINE_TRAITS',
     'CURRENCIES',
     'USER_AGENTS',
     'EXTERNAL_URLS',
@@ -42,7 +42,6 @@ def ahmia_blacklist_loader():
         return f.read().split()
 
 
-ENGINES_LANGUAGES = _load('engines_languages.json')
 CURRENCIES = _load('currencies.json')
 USER_AGENTS = _load('useragents.json')
 EXTERNAL_URLS = _load('external_urls.json')
@@ -50,3 +49,4 @@ WIKIDATA_UNITS = _load('wikidata_units.json')
 EXTERNAL_BANGS = _load('external_bangs.json')
 OSM_KEYS_TAGS = _load('osm_keys_tags.json')
 ENGINE_DESCRIPTIONS = _load('engine_descriptions.json')
+ENGINE_TRAITS = _load('engine_traits.json')

searx/enginelib/__init__.py

@@ -0,0 +1,143 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# lint: pylint
+"""Engine related implementations
+
+.. note::
+
+   The long term goal is to modularize all relevant implementations to the
+   engines here in this Python package.  In addition to improved modularization,
+   this will also be necessary in part because the probability of circular
+   imports will increase due to the increased typification of implementations in
+   the future.
+
+   ToDo:
+
+   - move :py:obj:`searx.engines.load_engine` to a new module `searx.enginelib`.
+"""
+
+
+from __future__ import annotations
+from typing import Union, Dict, List, Callable, TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from searx.enginelib import traits
+
+
+class Engine:  # pylint: disable=too-few-public-methods
+    """Class of engine instances build from YAML settings.
+
+    Further documentation see :ref:`general engine configuration`.
+
+    .. hint::
+
+       This class is currently never initialized and only used for type hinting.
+    """
+
+    # Common options in the engine module
+
+    engine_type: str
+    """Type of the engine (:origin:`searx/search/processors`)"""
+
+    paging: bool
+    """Engine supports multiple pages."""
+
+    time_range_support: bool
+    """Engine supports search time range."""
+
+    safesearch: bool
+    """Engine supports SafeSearch"""
+
+    language_support: bool
+    """Engine supports languages (locales) search."""
+
+    language: str
+    """For an engine, when there is ``language: ...`` in the YAML settings the engine
+    does support only this one language:
+
+    .. code:: yaml
+
+      - name: google french
+        engine: google
+        language: fr
+    """
+
+    region: str
+    """For an engine, when there is ``region: ...`` in the YAML settings the engine
+    does support only this one region::
+
+    .. code:: yaml
+
+      - name: google belgium
+        engine: google
+        region: fr-BE
+    """
+
+    fetch_traits: Callable
+    """Function to to fetch engine's traits from origin."""
+
+    traits: traits.EngineTraits
+    """Traits of the engine."""
+
+    # settings.yml
+
+    categories: List[str]
+    """Tabs, in which the engine is working."""
+
+    name: str
+    """Name that will be used across SearXNG to define this engine.  In settings, on
+    the result page .."""
+
+    engine: str
+    """Name of the python file used to handle requests and responses to and from
+    this search engine (file name from :origin:`searx/engines` without
+    ``.py``)."""
+
+    enable_http: bool
+    """Enable HTTP (by default only HTTPS is enabled)."""
+
+    shortcut: str
+    """Code used to execute bang requests (``!foo``)"""
+
+    timeout: float
+    """Specific timeout for search-engine."""
+
+    display_error_messages: bool
+    """Display error messages on the web UI."""
+
+    proxies: dict
+    """Set proxies for a specific engine (YAML):
+
+    .. code:: yaml
+
+       proxies :
+         http:  socks5://proxy:port
+         https: socks5://proxy:port
+    """
+
+    disabled: bool
+    """To disable by default the engine, but not deleting it.  It will allow the
+    user to manually activate it in the settings."""
+
+    inactive: bool
+    """Remove the engine from the settings (*disabled & removed*)."""
+
+    about: dict
+    """Additional fileds describing the engine.
+
+    .. code:: yaml
+
+       about:
+          website: https://example.com
+          wikidata_id: Q306656
+          official_api_documentation: https://example.com/api-doc
+          use_official_api: true
+          require_api_key: true
+          results: HTML
+    """
+
+    # deprecated properties
+
+    _fetch_supported_languages: Callable  # deprecated use fetch_traits
+    supported_languages: Union[List[str], Dict[str, str]]  # deprecated use traits
+    language_aliases: Dict[str, str]  # deprecated not needed when using triats
+    supported_languages_url: str  # deprecated not needed when using triats

searx/enginelib/traits.py

@@ -0,0 +1,387 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# lint: pylint
+"""Engine's traits are fetched from the origin engines and stored in a JSON file
+in the *data folder*.  Most often traits are languages and region codes and
+their mapping from SearXNG's representation to the representation in the origin
+search engine.  For new traits new properties can be added to the class
+:py:class:`EngineTraits`.
+
+To load traits from the persistence :py:obj:`EngineTraitsMap.from_data` can be
+used.
+"""
+
+from __future__ import annotations
+import json
+import dataclasses
+from typing import Dict, Union, List, Callable, Optional, TYPE_CHECKING
+from typing_extensions import Literal, Self
+
+from babel.localedata import locale_identifiers
+
+from searx import locales
+from searx.data import data_dir, ENGINE_TRAITS
+
+if TYPE_CHECKING:
+    from . import Engine
+
+
+class EngineTraitsEncoder(json.JSONEncoder):
+    """Encodes :class:`EngineTraits` to a serializable object, see
+    :class:`json.JSONEncoder`."""
+
+    def default(self, o):
+        """Return dictionary of a :class:`EngineTraits` object."""
+        if isinstance(o, EngineTraits):
+            return o.__dict__
+        return super().default(o)
+
+
+@dataclasses.dataclass
+class EngineTraits:
+    """The class is intended to be instantiated for each engine."""
+
+    regions: Dict[str, str] = dataclasses.field(default_factory=dict)
+    """Maps SearXNG's internal representation of a region to the one of the engine.
+
+    SearXNG's internal representation can be parsed by babel and the value is
+    send to the engine:
+
+    .. code:: python
+
+       regions ={
+           'fr-BE' : <engine's region name>,
+       }
+
+       for key, egnine_region regions.items():
+          searxng_region = babel.Locale.parse(key, sep='-')
+          ...
+    """
+
+    languages: Dict[str, str] = dataclasses.field(default_factory=dict)
+    """Maps SearXNG's internal representation of a language to the one of the engine.
+
+    SearXNG's internal representation can be parsed by babel and the value is
+    send to the engine:
+
+    .. code:: python
+
+       languages = {
+           'ca' : <engine's language name>,
+       }
+
+       for key, egnine_lang in languages.items():
+          searxng_lang = babel.Locale.parse(key)
+          ...
+    """
+
+    all_locale: Optional[str] = None
+    """To which locale value SearXNG's ``all`` language is mapped (shown a "Default
+    language").
+    """
+
+    data_type: Literal['traits_v1', 'supported_languages'] = 'traits_v1'
+    """Data type, default is 'traits_v1' for vintage use 'supported_languages'.
+
+    .. hint::
+
+       For the transition period until the *fetch* functions of all the engines
+       are converted there will be the data_type 'supported_languages', which
+       maps the old logic unchanged 1:1.
+
+       Instances of data_type 'supported_languages' do not implement methods
+       like ``self.get_language(..)`` and ``self.get_region(..)``
+
+    """
+
+    custom: Dict[str, Dict] = dataclasses.field(default_factory=dict)
+    """A place to store engine's custom traits, not related to the SearXNG core
+
+    """
+
+    def get_language(self, searxng_locale: str, default=None):
+        """Return engine's language string that *best fits* to SearXNG's locale.
+
+        :param searxng_locale: SearXNG's internal representation of locale
+          selected by the user.
+
+        :param default: engine's default language
+
+        The *best fits* rules are implemented in
+        :py:obj:`locales.get_engine_locale`.  Except for the special value ``all``
+        which is determined from :py:obj`EngineTraits.all_language`.
+        """
+        if searxng_locale == 'all' and self.all_locale is not None:
+            return self.all_locale
+        return locales.get_engine_locale(searxng_locale, self.languages, default=default)
+
+    def get_region(self, searxng_locale: str, default=None):
+        """Return engine's region string that best fits to SearXNG's locale.
+
+        :param searxng_locale: SearXNG's internal representation of locale
+          selected by the user.
+
+        :param default: engine's default region
+
+        The *best fits* rules are implemented in
+        :py:obj:`locales.get_engine_locale`.  Except for the special value ``all``
+        which is determined from :py:obj`EngineTraits.all_language`.
+        """
+        if searxng_locale == 'all' and self.all_locale is not None:
+            return self.all_locale
+        return locales.get_engine_locale(searxng_locale, self.regions, default=default)
+
+    def is_locale_supported(self, searxng_locale: str) -> bool:
+        """A *locale* (SearXNG's internal representation) is considered to be supported
+        by the engine if the *region* or the *language* is supported by the
+        engine.  For verification the functions :py:func:`self.get_region` and
+        :py:func:`self.get_region` are used.
+        """
+        if self.data_type == 'traits_v1':
+            return bool(self.get_region(searxng_locale) or self.get_language(searxng_locale))
+
+        if self.data_type == 'supported_languages':  # vintage / deprecated
+            # pylint: disable=import-outside-toplevel
+            from searx.utils import match_language
+
+            if searxng_locale == 'all':
+                return True
+            x = match_language(searxng_locale, self.supported_languages, self.language_aliases, None)
+            return bool(x)
+
+            # return bool(self.get_supported_language(searxng_locale))
+        raise TypeError('engine traits of type %s is unknown' % self.data_type)
+
+    def copy(self):
+        """Create a copy of the dataclass object."""
+        return EngineTraits(**dataclasses.asdict(self))
+
+    @classmethod
+    def fetch_traits(cls, engine: Engine) -> Union[Self, None]:
+        """Call a function ``fetch_traits(engine_traits)`` from engines namespace to fetch
+        and set properties from the origin engine in the object ``engine_traits``.  If
+        function does not exists, ``None`` is returned.
+        """
+
+        fetch_traits = getattr(engine, 'fetch_traits', None)
+        engine_traits = None
+
+        if fetch_traits:
+            engine_traits = cls()
+            fetch_traits(engine_traits)
+        return engine_traits
+
+    def set_traits(self, engine: Engine):
+        """Set traits from self object in a :py:obj:`.Engine` namespace.
+
+        :param engine: engine instance build by :py:func:`searx.engines.load_engine`
+        """
+
+        if self.data_type == 'traits_v1':
+            self._set_traits_v1(engine)
+
+        elif self.data_type == 'supported_languages':  # vintage / deprecated
+            self._set_supported_languages(engine)
+
+        else:
+            raise TypeError('engine traits of type %s is unknown' % self.data_type)
+
+    def _set_traits_v1(self, engine: Engine):
+        # For an engine, when there is `language: ...` in the YAML settings the engine
+        # does support only this one language (region)::
+        #
+        #   - name: google italian
+        #     engine: google
+        #     language: it
+        #     region: it-IT
+
+        traits = self.copy()
+
+        _msg = "settings.yml - engine: '%s' / %s: '%s' not supported"
+
+        languages = traits.languages
+        if hasattr(engine, 'language'):
+            if engine.language not in languages:
+                raise ValueError(_msg % (engine.name, 'language', engine.language))
+            traits.languages = {engine.language: languages[engine.language]}
+
+        regions = traits.regions
+        if hasattr(engine, 'region'):
+            if engine.region not in regions:
+                raise ValueError(_msg % (engine.name, 'region', engine.region))
+            traits.regions = {engine.region: regions[engine.region]}
+
+        engine.language_support = bool(traits.languages or traits.regions)
+
+        # set the copied & modified traits in engine's namespace
+        engine.traits = traits
+
+    # -------------------------------------------------------------------------
+    # The code below is deprecated an can hopefully be deleted at one day
+    # -------------------------------------------------------------------------
+
+    supported_languages: Union[List[str], Dict[str, str]] = dataclasses.field(default_factory=dict)
+    """depricated: does not work for engines that do support languages based on a
+    region.  With this type it is not guaranteed that the key values can be
+    parsed by :py:obj:`babel.Locale.parse`!
+    """
+
+    # language_aliases: Dict[str, str] = dataclasses.field(default_factory=dict)
+    # """depricated: does not work for engines that do support languages based on a
+    # region.  With this type it is not guaranteed that the key values can be
+    # parsed by :py:obj:`babel.Locale.parse`!
+    # """
+
+    BABEL_LANGS = [
+        lang_parts[0] + '-' + lang_parts[-1] if len(lang_parts) > 1 else lang_parts[0]
+        for lang_parts in (lang_code.split('_') for lang_code in locale_identifiers())
+    ]
+
+    # def get_supported_language(self, searxng_locale, default=None):  # vintage / deprecated
+    #     """Return engine's language string that *best fits* to SearXNG's locale."""
+    #     if searxng_locale == 'all' and self.all_locale is not None:
+    #         return self.all_locale
+    #     return locales.get_engine_locale(searxng_locale, self.supported_languages, default=default)
+
+    @classmethod  # vintage / deprecated
+    def fetch_supported_languages(cls, engine: Engine) -> Union[Self, None]:
+        """DEPRECATED: Calls a function ``_fetch_supported_languages`` from engine's
+        namespace to fetch languages from the origin engine.  If function does
+        not exists, ``None`` is returned.
+        """
+
+        # pylint: disable=import-outside-toplevel
+        from searx import network
+        from searx.utils import gen_useragent
+
+        fetch_languages = getattr(engine, '_fetch_supported_languages', None)
+        if fetch_languages is None:
+            return None
+
+        # The headers has been moved here from commit 9b6ffed06: Some engines (at
+        # least bing and startpage) return a different result list of supported
+        # languages depending on the IP location where the HTTP request comes from.
+        # The IP based results (from bing) can be avoided by setting a
+        # 'Accept-Language' in the HTTP request.
+
+        headers = {
+            'User-Agent': gen_useragent(),
+            'Accept-Language': "en-US,en;q=0.5",  # bing needs to set the English language
+        }
+        resp = network.get(engine.supported_languages_url, headers=headers)
+        supported_languages = fetch_languages(resp)
+        if isinstance(supported_languages, list):
+            supported_languages.sort()
+
+        engine_traits = cls()
+        engine_traits.data_type = 'supported_languages'
+        engine_traits.supported_languages = supported_languages
+        return engine_traits
+
+    def _set_supported_languages(self, engine: Engine):  # vintage / deprecated
+        traits = self.copy()
+
+        # pylint: disable=import-outside-toplevel
+        from searx.utils import match_language
+
+        _msg = "settings.yml - engine: '%s' / %s: '%s' not supported"
+
+        if hasattr(engine, 'language'):
+            if engine.language not in self.supported_languages:
+                raise ValueError(_msg % (engine.name, 'language', engine.language))
+
+            if isinstance(self.supported_languages, dict):
+                traits.supported_languages = {engine.language: self.supported_languages[engine.language]}
+            else:
+                traits.supported_languages = [engine.language]
+
+        engine.language_support = bool(traits.supported_languages)
+        engine.supported_languages = traits.supported_languages
+
+        # find custom aliases for non standard language codes
+        traits.language_aliases = {}  # pylint: disable=attribute-defined-outside-init
+
+        for engine_lang in getattr(engine, 'language_aliases', {}):
+            iso_lang = match_language(engine_lang, self.BABEL_LANGS, fallback=None)
+            if (
+                iso_lang
+                and iso_lang != engine_lang
+                and not engine_lang.startswith(iso_lang)
+                and iso_lang not in self.supported_languages
+            ):
+                traits.language_aliases[iso_lang] = engine_lang
+
+        engine.language_aliases = traits.language_aliases
+
+        # set the copied & modified traits in engine's namespace
+        engine.traits = traits
+
+
+class EngineTraitsMap(Dict[str, EngineTraits]):
+    """A python dictionary to map :class:`EngineTraits` by engine name."""
+
+    ENGINE_TRAITS_FILE = (data_dir / 'engine_traits.json').resolve()
+    """File with persistence of the :py:obj:`EngineTraitsMap`."""
+
+    def save_data(self):
+        """Store EngineTraitsMap in in file :py:obj:`self.ENGINE_TRAITS_FILE`"""
+        with open(self.ENGINE_TRAITS_FILE, 'w', encoding='utf-8') as f:
+            json.dump(self, f, indent=2, sort_keys=True, cls=EngineTraitsEncoder)
+
+    @classmethod
+    def from_data(cls) -> Self:
+        """Instantiate :class:`EngineTraitsMap` object from :py:obj:`ENGINE_TRAITS`"""
+        obj = cls()
+        for k, v in ENGINE_TRAITS.items():
+            obj[k] = EngineTraits(**v)
+        return obj
+
+    @classmethod
+    def fetch_traits(cls, log: Callable) -> Self:
+        from searx import engines  # pylint: disable=cyclic-import, import-outside-toplevel
+
+        names = list(engines.engines)
+        names.sort()
+        obj = cls()
+
+        for engine_name in names:
+            engine = engines.engines[engine_name]
+
+            traits = EngineTraits.fetch_traits(engine)
+            if traits is not None:
+                log("%-20s: SearXNG languages --> %s " % (engine_name, len(traits.languages)))
+                log("%-20s: SearXNG regions   --> %s" % (engine_name, len(traits.regions)))
+                obj[engine_name] = traits
+
+            # vintage / deprecated
+            _traits = EngineTraits.fetch_supported_languages(engine)
+            if _traits is not None:
+                log("%-20s: %s supported_languages (deprecated)" % (engine_name, len(_traits.supported_languages)))
+                if traits is not None:
+                    traits.supported_languages = _traits.supported_languages
+                    obj[engine_name] = traits
+                else:
+                    obj[engine_name] = _traits
+                continue
+
+        return obj
+
+    def set_traits(self, engine: Engine):
+        """Set traits in a :py:obj:`Engine` namespace.
+
+        :param engine: engine instance build by :py:func:`searx.engines.load_engine`
+        """
+
+        engine_traits = EngineTraits(data_type='traits_v1')
+        if engine.name in self.keys():
+            engine_traits = self[engine.name]
+
+        elif engine.engine in self.keys():
+            # The key of the dictionary traits_map is the *engine name*
+            # configured in settings.xml.  When multiple engines are configured
+            # in settings.yml to use the same origin engine (python module)
+            # these additional engines can use the languages from the origin
+            # engine.  For this use the configured ``engine: ...`` from
+            # settings.yml
+            engine_traits = self[engine.engine]
+
+        engine_traits.set_traits(engine)

searx/engines/__init__.py

@@ -11,24 +11,22 @@ usage::
 
 """
 
+from __future__ import annotations
+
 import sys
 import copy
-from typing import Dict, List, Optional
-
 from os.path import realpath, dirname
-from babel.localedata import locale_identifiers
-from searx import logger, settings
-from searx.data import ENGINES_LANGUAGES
-from searx.network import get
-from searx.utils import load_module, match_language, gen_useragent
 
+from typing import TYPE_CHECKING, Dict, Optional
+
+from searx import logger, settings
+from searx.utils import load_module
+
+if TYPE_CHECKING:
+    from searx.enginelib import Engine
 
 logger = logger.getChild('engines')
 ENGINE_DIR = dirname(realpath(__file__))
-BABEL_LANGS = [
-    lang_parts[0] + '-' + lang_parts[-1] if len(lang_parts) > 1 else lang_parts[0]
-    for lang_parts in (lang_code.split('_') for lang_code in locale_identifiers())
-]
 ENGINE_DEFAULT_ARGS = {
     "engine_type": "online",
     "inactive": False,
@@ -36,8 +34,6 @@ ENGINE_DEFAULT_ARGS = {
     "timeout": settings["outgoing"]["request_timeout"],
     "shortcut": "-",
     "categories": ["general"],
-    "supported_languages": [],
-    "language_aliases": {},
     "paging": False,
     "safesearch": False,
     "time_range_support": False,
@@ -47,29 +43,13 @@ ENGINE_DEFAULT_ARGS = {
     "send_accept_language_header": False,
     "tokens": [],
     "about": {},
+    "supported_languages": [],  # deprecated use traits
+    "language_aliases": {},  # deprecated not needed when using traits
 }
 # set automatically when an engine does not have any tab category
 OTHER_CATEGORY = 'other'
 
 
-class Engine:  # pylint: disable=too-few-public-methods
-    """This class is currently never initialized and only used for type hinting."""
-
-    name: str
-    engine: str
-    shortcut: str
-    categories: List[str]
-    supported_languages: List[str]
-    about: dict
-    inactive: bool
-    disabled: bool
-    language_support: bool
-    paging: bool
-    safesearch: bool
-    time_range_support: bool
-    timeout: float
-
-
 # Defaults for the namespace of an engine module, see :py:func:`load_engine`
 
 categories = {'general': []}
@@ -136,9 +116,15 @@ def load_engine(engine_data: dict) -> Optional[Engine]:
         return None
 
     update_engine_attributes(engine, engine_data)
-    set_language_attributes(engine)
     update_attributes_for_tor(engine)
 
+    # avoid cyclic imports
+    # pylint: disable=import-outside-toplevel
+    from searx.enginelib.traits import EngineTraitsMap
+
+    trait_map = EngineTraitsMap.from_data()
+    trait_map.set_traits(engine)
+
     if not is_engine_active(engine):
         return None
 
@@ -190,60 +176,6 @@ def update_engine_attributes(engine: Engine, engine_data):
             setattr(engine, arg_name, copy.deepcopy(arg_value))
 
 
-def set_language_attributes(engine: Engine):
-    # assign supported languages from json file
-    if engine.name in ENGINES_LANGUAGES:
-        engine.supported_languages = ENGINES_LANGUAGES[engine.name]
-
-    elif engine.engine in ENGINES_LANGUAGES:
-        # The key of the dictionary ENGINES_LANGUAGES is the *engine name*
-        # configured in settings.xml.  When multiple engines are configured in
-        # settings.yml to use the same origin engine (python module) these
-        # additional engines can use the languages from the origin engine.
-        # For this use the configured ``engine: ...`` from settings.yml
-        engine.supported_languages = ENGINES_LANGUAGES[engine.engine]
-
-    if hasattr(engine, 'language'):
-        # For an engine, when there is `language: ...` in the YAML settings, the
-        # engine supports only one language, in this case
-        # engine.supported_languages should contains this value defined in
-        # settings.yml
-        if engine.language not in engine.supported_languages:
-            raise ValueError(
-                "settings.yml - engine: '%s' / language: '%s' not supported" % (engine.name, engine.language)
-            )
-
-        if isinstance(engine.supported_languages, dict):
-            engine.supported_languages = {engine.language: engine.supported_languages[engine.language]}
-        else:
-            engine.supported_languages = [engine.language]
-
-    # find custom aliases for non standard language codes
-    for engine_lang in engine.supported_languages:
-        iso_lang = match_language(engine_lang, BABEL_LANGS, fallback=None)
-        if (
-            iso_lang
-            and iso_lang != engine_lang
-            and not engine_lang.startswith(iso_lang)
-            and iso_lang not in engine.supported_languages
-        ):
-            engine.language_aliases[iso_lang] = engine_lang
-
-    # language_support
-    engine.language_support = len(engine.supported_languages) > 0
-
-    # assign language fetching method if auxiliary method exists
-    if hasattr(engine, '_fetch_supported_languages'):
-        headers = {
-            'User-Agent': gen_useragent(),
-            'Accept-Language': "en-US,en;q=0.5",  # bing needs to set the English language
-        }
-        engine.fetch_supported_languages = (
-            # pylint: disable=protected-access
-            lambda: engine._fetch_supported_languages(get(engine.supported_languages_url, headers=headers))
-        )
-
-
 def update_attributes_for_tor(engine: Engine) -> bool:
     if using_tor_proxy(engine) and hasattr(engine, 'onion_url'):
         engine.search_url = engine.onion_url + getattr(engine, 'search_path', '')

searx/engines/demo_offline.py

@@ -63,7 +63,7 @@ def search(query, request_params):
     for row in result_list:
         entry = {
             'query': query,
-            'language': request_params['language'],
+            'language': request_params['searxng_locale'],
             'value': row.get("value"),
             # choose a result template or comment out to use the *default*
             'template': 'key-value.html',

searx/locales.py

@@ -8,7 +8,7 @@ from typing import Set
 import os
 import pathlib
 
-from babel import Locale
+import babel
 from babel.support import Translations
 import babel.languages
 import babel.core
@@ -134,7 +134,7 @@ def locales_initialize(directory=None):
     flask_babel.get_translations = get_translations
 
     for tag, descr in ADDITIONAL_TRANSLATIONS.items():
-        locale = Locale.parse(LOCALE_BEST_MATCH[tag], sep='-')
+        locale = babel.Locale.parse(LOCALE_BEST_MATCH[tag], sep='-')
         LOCALE_NAMES[tag] = descr
         if locale.text_direction == 'rtl':
             RTL_LOCALES.add(tag)
@@ -142,7 +142,7 @@ def locales_initialize(directory=None):
     for tag in LOCALE_BEST_MATCH:
         descr = LOCALE_NAMES.get(tag)
         if not descr:
-            locale = Locale.parse(tag, sep='-')
+            locale = babel.Locale.parse(tag, sep='-')
             LOCALE_NAMES[tag] = get_locale_descr(locale, tag.replace('-', '_'))
             if locale.text_direction == 'rtl':
                 RTL_LOCALES.add(tag)
@@ -154,12 +154,66 @@ def locales_initialize(directory=None):
         tag = dirname.replace('_', '-')
         descr = LOCALE_NAMES.get(tag)
         if not descr:
-            locale = Locale.parse(dirname)
+            locale = babel.Locale.parse(dirname)
             LOCALE_NAMES[tag] = get_locale_descr(locale, dirname)
             if locale.text_direction == 'rtl':
                 RTL_LOCALES.add(tag)
 
 
+def region_tag(locale: babel.Locale) -> str:
+    """Returns SearXNG's region tag from the locale (e.g. zh-TW , en-US)."""
+    if not locale.territory:
+        raise ValueError('%s missed a territory')
+    return locale.language + '-' + locale.territory
+
+
+def language_tag(locale: babel.Locale) -> str:
+    """Returns SearXNG's language tag from the locale and if exits, the tag
+    includes the script name (e.g. en, zh_Hant).
+    """
+    sxng_lang = locale.language
+    if locale.script:
+        sxng_lang += '_' + locale.script
+    return sxng_lang
+
+
+def get_offical_locales(
+    territory: str, languages=None, regional: bool = False, de_facto: bool = True
+) -> Set[babel.Locale]:
+    """Returns a list of :py:obj:`babel.Locale` with languages from
+    :py:obj:`babel.languages.get_official_languages`.
+
+    :param territory: The territory (country or region) code.
+
+    :param languages: A list of language codes the languages from
+      :py:obj:`babel.languages.get_official_languages` should be in
+      (intersection).  If this argument is ``None``, all official languages in
+      this territory are used.
+
+    :param regional: If the regional flag is set, then languages which are
+      regionally official are also returned.
+
+    :param de_facto: If the de_facto flag is set to `False`, then languages
+      which are “de facto” official are not returned.
+
+    """
+    ret_val = set()
+    o_languages = babel.languages.get_official_languages(territory, regional=regional, de_facto=de_facto)
+
+    if languages:
+        languages = [l.lower() for l in languages]
+        o_languages = set(l for l in o_languages if l.lower() in languages)
+
+    for lang in o_languages:
+        try:
+            locale = babel.Locale.parse(lang + '_' + territory)
+            ret_val.add(locale)
+        except babel.UnknownLocaleError:
+            continue
+
+    return ret_val
+
+
 def get_engine_locale(searxng_locale, engine_locales, default=None):
     """Return engine's language (aka locale) string that best fits to argument
     ``searxng_locale``.
@@ -177,6 +231,10 @@ def get_engine_locale(searxng_locale, engine_locales, default=None):
           ...
           'pl-PL'          : 'pl_PL',
           'pt-PT'          : 'pt_PT'
+          ..
+          'zh'             : 'zh'
+          'zh_Hans'        : 'zh'
+          'zh_Hant'        : 'zh-classical'
       }
 
     .. hint::
@@ -210,13 +268,13 @@ def get_engine_locale(searxng_locale, engine_locales, default=None):
       engine.
 
     """
-    # pylint: disable=too-many-branches
+    # pylint: disable=too-many-branches, too-many-return-statements
 
     engine_locale = engine_locales.get(searxng_locale)
 
     if engine_locale is not None:
-        # There was a 1:1 mapping (e.g. "fr-BE --> fr_BE" or "fr --> fr_FR"), no
-        # need to narrow language nor territory.
+        # There was a 1:1 mapping (e.g. a region "fr-BE --> fr_BE" or a language
+        # "zh --> zh"), no need to narrow language-script nor territory.
         return engine_locale
 
     try:
@@ -227,6 +285,12 @@ def get_engine_locale(searxng_locale, engine_locales, default=None):
         except babel.core.UnknownLocaleError:
             return default
 
+    searxng_lang = language_tag(locale)
+    engine_locale = engine_locales.get(searxng_lang)
+    if engine_locale is not None:
+        # There was a 1:1 mapping (e.g. "zh-HK --> zh_Hant" or "zh-CN --> zh_Hans")
+        return engine_locale
+
     # SearXNG's selected locale is not supported by the engine ..
 
     if locale.territory:
@@ -247,10 +311,6 @@ def get_engine_locale(searxng_locale, engine_locales, default=None):
 
     if locale.language:
 
-        searxng_lang = locale.language
-        if locale.script:
-            searxng_lang += '_' + locale.script
-
         terr_lang_dict = {}
         for territory, langs in babel.core.get_global("territory_languages").items():
             if not langs.get(searxng_lang, {}).get('official_status'):

searx/preferences.py

@@ -13,7 +13,7 @@ from typing import Iterable, Dict, List
 import flask
 
 from searx import settings, autocomplete
-from searx.engines import Engine
+from searx.enginelib import Engine
 from searx.plugins import Plugin
 from searx.locales import LOCALE_NAMES
 from searx.webutils import VALID_LANGUAGE_CODE

searx/search/processors/__init__.py

@@ -30,7 +30,10 @@ from .abstract import EngineProcessor
 
 logger = logger.getChild('search.processors')
 PROCESSORS: Dict[str, EngineProcessor] = {}
-"""Cache request processores, stored by *engine-name* (:py:func:`initialize`)"""
+"""Cache request processores, stored by *engine-name* (:py:func:`initialize`)
+
+:meta hide-value:
+"""
 
 
 def get_processor_class(engine_type):

searx/search/processors/abstract.py

@@ -138,7 +138,8 @@ class EngineProcessor(ABC):
         return False
 
     def get_params(self, search_query, engine_category):
-        """Returns a set of *request params* or ``None`` if request is not supported.
+        """Returns a set of (see :ref:`request params <engine request arguments>`) or
+        ``None`` if request is not supported.
 
         Not supported conditions (``None`` is returned):
 
@@ -159,11 +160,20 @@ class EngineProcessor(ABC):
         params['safesearch'] = search_query.safesearch
         params['time_range'] = search_query.time_range
         params['engine_data'] = search_query.engine_data.get(self.engine_name, {})
+        params['searxng_locale'] = search_query.lang
+
+        # deprecated / vintage --> use params['searxng_locale']
+        #
+        # Conditions related to engine's traits are implemented in engine.traits
+        # module. Don't do 'locale' decissions here in the abstract layer of the
+        # search processor, just pass the value from user's choice unchanged to
+        # the engine request.
 
         if hasattr(self.engine, 'language') and self.engine.language:
             params['language'] = self.engine.language
         else:
             params['language'] = search_query.lang
+
         return params
 
     @abstractmethod

searx/search/processors/online.py

@@ -51,6 +51,9 @@ class OnlineProcessor(EngineProcessor):
         super().initialize()
 
     def get_params(self, search_query, engine_category):
+        """Returns a set of :ref:`request params <engine request online>` or ``None``
+        if request is not supported.
+        """
         params = super().get_params(search_query, engine_category)
         if params is None:
             return None

searx/search/processors/online_currency.py

@@ -38,8 +38,8 @@ class OnlineCurrencyProcessor(OnlineProcessor):
     engine_type = 'online_currency'
 
     def get_params(self, search_query, engine_category):
-        """Returns a set of *request params* or ``None`` if search query does not match
-        to :py:obj:`parser_re`."""
+        """Returns a set of :ref:`request params <engine request online_currency>`
+        or ``None`` if search query does not match to :py:obj:`parser_re`."""
 
         params = super().get_params(search_query, engine_category)
         if params is None:

searx/search/processors/online_dictionary.py

@@ -18,8 +18,9 @@ class OnlineDictionaryProcessor(OnlineProcessor):
     engine_type = 'online_dictionary'
 
     def get_params(self, search_query, engine_category):
-        """Returns a set of *request params* or ``None`` if search query does not match
-        to :py:obj:`parser_re`."""
+        """Returns a set of :ref:`request params <engine request online_dictionary>` or
+        ``None`` if search query does not match to :py:obj:`parser_re`.
+        """
         params = super().get_params(search_query, engine_category)
         if params is None:
             return None

searx/search/processors/online_url_search.py

@@ -20,9 +20,10 @@ class OnlineUrlSearchProcessor(OnlineProcessor):
     engine_type = 'online_url_search'
 
     def get_params(self, search_query, engine_category):
-        """Returns a set of *request params* or ``None`` if search query does not match
-        to at least one of :py:obj:`re_search_urls`.
+        """Returns a set of :ref:`request params <engine request online>` or ``None`` if
+        search query does not match to :py:obj:`re_search_urls`.
         """
+
         params = super().get_params(search_query, engine_category)
         if params is None:
             return None

searx/webapp.py

@@ -907,16 +907,11 @@ def autocompleter():
     # and there is a query part
     if len(raw_text_query.autocomplete_list) == 0 and len(sug_prefix) > 0:
 
-        # get language from cookie
-        language = request.preferences.get_value('language')
-        if not language or language == 'all':
-            language = 'en'
-        else:
-            language = language.split('-')[0]
+        # get SearXNG's locale and autocomplete backend from cookie
+        sxng_locale = request.preferences.get_value('language')
+        backend_name = request.preferences.get_value('autocomplete')
 
-        # run autocompletion
-        raw_results = search_autocomplete(request.preferences.get_value('autocomplete'), sug_prefix, language)
-        for result in raw_results:
+        for result in search_autocomplete(backend_name, sug_prefix, sxng_locale):
             # attention: this loop will change raw_text_query object and this is
             # the reason why the sug_prefix was stored before (see above)
             if result != sug_prefix:
@@ -1001,7 +996,9 @@ def preferences():
             'rate80': rate80,
             'rate95': rate95,
             'warn_timeout': e.timeout > settings['outgoing']['request_timeout'],
-            'supports_selected_language': _is_selected_language_supported(e, request.preferences),
+            'supports_selected_language': e.traits.is_locale_supported(
+                str(request.preferences.get_value('language') or 'all')
+            ),
             'result_count': result_count,
         }
     # end of stats
@@ -1052,7 +1049,9 @@ def preferences():
     # supports
     supports = {}
     for _, e in filtered_engines.items():
-        supports_selected_language = _is_selected_language_supported(e, request.preferences)
+        supports_selected_language = e.traits.is_locale_supported(
+            str(request.preferences.get_value('language') or 'all')
+        )
         safesearch = e.safesearch
         time_range_support = e.time_range_support
         for checker_test_name in checker_results.get(e.name, {}).get('errors', {}):
@@ -1099,16 +1098,6 @@ def preferences():
     )
 
 
-def _is_selected_language_supported(engine, preferences: Preferences):  # pylint: disable=redefined-outer-name
-    language = preferences.get_value('language')
-    if language == 'all':
-        return True
-    x = match_language(
-        language, getattr(engine, 'supported_languages', []), getattr(engine, 'language_aliases', {}), None
-    )
-    return bool(x)
-
-
 @app.route('/image_proxy', methods=['GET'])
 def image_proxy():
     # pylint: disable=too-many-return-statements, too-many-branches
@@ -1327,9 +1316,11 @@ def config():
         if not request.preferences.validate_token(engine):
             continue
 
-        supported_languages = engine.supported_languages
-        if isinstance(engine.supported_languages, dict):
-            supported_languages = list(engine.supported_languages.keys())
+        _languages = engine.traits.languages.keys()
+        if engine.traits.data_type == 'supported_languages':  # vintage / deprecated
+            _languages = engine.traits.supported_languages
+            if isinstance(_languages, dict):
+                _languages = _languages.keys()
 
         _engines.append(
             {
@@ -1339,7 +1330,8 @@ def config():
                 'enabled': not engine.disabled,
                 'paging': engine.paging,
                 'language_support': engine.language_support,
-                'supported_languages': supported_languages,
+                'languages': list(_languages),
+                'regions': list(engine.traits.regions.keys()),
                 'safesearch': engine.safesearch,
                 'time_range_support': engine.time_range_support,
                 'timeout': engine.timeout,

searx/webutils.py

@@ -1,4 +1,6 @@
 # -*- coding: utf-8 -*-
+from __future__ import annotations
+
 import os
 import pathlib
 import csv
@@ -8,7 +10,7 @@ import re
 import inspect
 import itertools
 from datetime import datetime, timedelta
-from typing import Iterable, List, Tuple, Dict
+from typing import Iterable, List, Tuple, Dict, TYPE_CHECKING
 
 from io import StringIO
 from codecs import getincrementalencoder
@@ -16,7 +18,10 @@ from codecs import getincrementalencoder
 from flask_babel import gettext, format_date
 
 from searx import logger, settings
-from searx.engines import Engine, OTHER_CATEGORY
+from searx.engines import OTHER_CATEGORY
+
+if TYPE_CHECKING:
+    from searx.enginelib import Engine
 
 
 VALID_LANGUAGE_CODE = re.compile(r'^[a-z]{2,3}(-[a-zA-Z]{2})?$')

searxng_extra/update/update_engine_traits.py

@@ -1,19 +1,21 @@
 #!/usr/bin/env python
 # lint: pylint
-
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""This script generates languages.py from intersecting each engine's supported
-languages.
+"""Update :py:obj:`searx.enginelib.traits.EngineTraitsMap` and :origin:`searx/languages.py`
 
-Output files: :origin:`searx/data/engines_languages.json` and
-:origin:`searx/languages.py` (:origin:`CI Update data ...
-<.github/workflows/data-update.yml>`).
+:py:obj:`searx.enginelib.traits.EngineTraitsMap.ENGINE_TRAITS_FILE`:
+  Persistence of engines traits, fetched from the engines.
+
+:origin:`searx/languages.py`
+  Is generated  from intersecting each engine's supported traits.
+
+The script :origin:`searxng_extra/update/update_engine_traits.py` is called in
+the :origin:`CI Update data ... <.github/workflows/data-update.yml>`
 
 """
 
 # pylint: disable=invalid-name
 from unicodedata import lookup
-import json
 from pathlib import Path
 from pprint import pformat
 from babel import Locale, UnknownLocaleError
@@ -21,36 +23,26 @@ from babel.languages import get_global
 from babel.core import parse_locale
 
 from searx import settings, searx_dir
+from searx import network
 from searx.engines import load_engines, engines
-from searx.network import set_timeout_for_thread
+from searx.enginelib.traits import EngineTraitsMap
 
 # Output files.
-engines_languages_file = Path(searx_dir) / 'data' / 'engines_languages.json'
 languages_file = Path(searx_dir) / 'languages.py'
 
 
-# Fetches supported languages for each engine and writes json file with those.
-def fetch_supported_languages():
-    set_timeout_for_thread(10.0)
+def fetch_traits_map():
+    """Fetchs supported languages for each engine and writes json file with those."""
+    network.set_timeout_for_thread(10.0)
 
-    engines_languages = {}
-    names = list(engines)
-    names.sort()
+    def log(msg):
+        print(msg)
 
-    for engine_name in names:
-        if hasattr(engines[engine_name], 'fetch_supported_languages'):
-            engines_languages[engine_name] = engines[engine_name].fetch_supported_languages()
-            print("fetched %s languages from engine %s" % (len(engines_languages[engine_name]), engine_name))
-            if type(engines_languages[engine_name]) == list:  # pylint: disable=unidiomatic-typecheck
-                engines_languages[engine_name] = sorted(engines_languages[engine_name])
-
-    print("fetched languages from %s engines" % len(engines_languages))
-
-    # write json file
-    with open(engines_languages_file, 'w', encoding='utf-8') as f:
-        json.dump(engines_languages, f, indent=2, sort_keys=True)
-
-    return engines_languages
+    traits_map = EngineTraitsMap.fetch_traits(log=log)
+    print("fetched properties from %s engines" % len(traits_map))
+    print("write json file: %s" % traits_map.ENGINE_TRAITS_FILE)
+    traits_map.save_data()
+    return traits_map
 
 
 # Get babel Locale object from lang_code if possible.
@@ -124,17 +116,43 @@ def get_territory_name(lang_code):
     return country_name
 
 
-# Join all language lists.
-def join_language_lists(engines_languages):
-    language_list = {}
-    for engine_name in engines_languages:
-        for lang_code in engines_languages[engine_name]:
+def join_language_lists(traits_map: EngineTraitsMap):
+    """Join all languages of the engines into one list.  The returned language list
+    contains language codes (``zh``) and region codes (``zh-TW``).  The codes can
+    be parsed by babel::
 
-            # apply custom fixes if necessary
-            if lang_code in getattr(engines[engine_name], 'language_aliases', {}).values():
-                lang_code = next(
-                    lc for lc, alias in engines[engine_name].language_aliases.items() if lang_code == alias
-                )
+      babel.Locale.parse(language_list[n])
+    """
+    # pylint: disable=too-many-branches
+    language_list = {}
+
+    for eng_name, eng_traits in traits_map.items():
+        eng = engines[eng_name]
+        eng_codes = set()
+
+        if eng_traits.data_type == 'traits_v1':
+            # items of type 'engine_traits' do have regions & languages, the
+            # list of eng_codes should contain both.
+            eng_codes.update(eng_traits.regions.keys())
+            eng_codes.update(eng_traits.languages.keys())
+
+        elif eng_traits.data_type == 'supported_languages':
+            # vintage / deprecated
+            _codes = set()
+            if isinstance(eng_traits.supported_languages, dict):
+                _codes.update(eng_traits.supported_languages.keys())
+            elif isinstance(eng_traits.supported_languages, list):
+                _codes.update(eng_traits.supported_languages)
+            else:
+                raise TypeError('engine.supported_languages type %s is unknown' % type(eng_traits.supported_languages))
+
+            for lang_code in _codes:
+                # apply custom fixes if necessary
+                if lang_code in getattr(eng, 'language_aliases', {}).values():
+                    lang_code = next(lc for lc, alias in eng.language_aliases.items() if lang_code == alias)
+                eng_codes.add(lang_code)
+
+        for lang_code in eng_codes:
 
             locale = get_locale(lang_code)
 
@@ -149,10 +167,10 @@ def join_language_lists(engines_languages):
                     # get language's data from babel's Locale object
                     language_name = locale.get_language_name().title()
                     english_name = locale.english_name.split(' (')[0]
-                elif short_code in engines_languages['wikipedia']:
+                elif short_code in traits_map['wikipedia'].supported_languages:
                     # get language's data from wikipedia if not known by babel
-                    language_name = engines_languages['wikipedia'][short_code]['name']
-                    english_name = engines_languages['wikipedia'][short_code]['english_name']
+                    language_name = traits_map['wikipedia'].supported_languages[short_code]['name']
+                    english_name = traits_map['wikipedia'].supported_languages[short_code]['english_name']
                 else:
                     language_name = None
                     english_name = None
@@ -182,15 +200,15 @@ def join_language_lists(engines_languages):
                 }
 
             # count engine for both language_country combination and language alone
-            language_list[short_code]['counter'].add(engine_name)
+            language_list[short_code]['counter'].add(eng_name)
             if lang_code != short_code:
-                language_list[short_code]['countries'][lang_code]['counter'].add(engine_name)
+                language_list[short_code]['countries'][lang_code]['counter'].add(eng_name)
 
     return language_list
 
 
 # Filter language list so it only includes the most supported languages and countries
-def filter_language_list(all_languages):
+def filter_language_list(joined_languages_map):
     min_engines_per_lang = 12
     min_engines_per_country = 7
     # pylint: disable=consider-using-dict-items, consider-iterating-dictionary
@@ -198,6 +216,7 @@ def filter_language_list(all_languages):
         engine_name
         for engine_name in engines.keys()
         if 'general' in engines[engine_name].categories
+        and hasattr(engines[engine_name], 'supported_languages')
         and engines[engine_name].supported_languages
         and not engines[engine_name].disabled
     ]
@@ -205,7 +224,7 @@ def filter_language_list(all_languages):
     # filter list to include only languages supported by most engines or all default general engines
     filtered_languages = {
         code: lang
-        for code, lang in all_languages.items()
+        for code, lang in joined_languages_map.items()
         if (
             len(lang['counter']) >= min_engines_per_lang
             or all(main_engine in lang['counter'] for main_engine in main_engines)
@@ -214,8 +233,8 @@ def filter_language_list(all_languages):
 
     def _copy_lang_data(lang, country_name=None):
         new_dict = {}
-        new_dict['name'] = all_languages[lang]['name']
-        new_dict['english_name'] = all_languages[lang]['english_name']
+        new_dict['name'] = joined_languages_map[lang]['name']
+        new_dict['english_name'] = joined_languages_map[lang]['english_name']
         if country_name:
             new_dict['country_name'] = country_name
         return new_dict
@@ -305,9 +324,13 @@ def write_languages_file(languages):
         new_file.close()
 
 
-if __name__ == "__main__":
+def main():
     load_engines(settings['engines'])
-    _engines_languages = fetch_supported_languages()
-    _all_languages = join_language_lists(_engines_languages)
-    _filtered_languages = filter_language_list(_all_languages)
-    write_languages_file(_filtered_languages)
+    traits_map = fetch_traits_map()
+    joined_languages_map = join_language_lists(traits_map)
+    filtered_languages = filter_language_list(joined_languages_map)
+    write_languages_file(filtered_languages)
+
+
+if __name__ == "__main__":
+    main()