[enh] settings.yml: add use_default_settings option (2nd version)

3 files changed, 131 insertions, 93 deletions

diff --git a/searx/__init__.py b/searx/__init__.py
index 214e554d4..9bbc7c8c3 100644
--- a/searx/__init__.py
+++ b/searx/__init__.py
@@ -16,7 +16,7 @@ along with searx. If not, see < http://www.gnu.org/licenses/ >.
 '''
 
 import logging
-import searx.settings
+import searx.settings_loader
 from os import environ
 from os.path import realpath, dirname, join, abspath, isfile
 
@@ -24,7 +24,7 @@ from os.path import realpath, dirname, join, abspath, isfile
 searx_dir = abspath(dirname(__file__))
 engine_dir = dirname(realpath(__file__))
 static_path = abspath(join(dirname(__file__), 'static'))
-settings, settings_load_message = searx.settings.load_settings()
+settings, settings_load_message = searx.settings_loader.load_settings()
 
 if settings['ui']['static_path']:
     static_path = settings['ui']['static_path']
diff --git a/searx/settings.py b/searx/settings.py
deleted file mode 100644
index cdddff589..000000000
--- a/searx/settings.py
+++ /dev/null
@@ -1,91 +0,0 @@
-import collections.abc
-
-import yaml
-from searx.exceptions import SearxSettingsException
-from os import environ
-from os.path import dirname, join, abspath, isfile
-
-
-searx_dir = abspath(dirname(__file__))
-
-
-def check_settings_yml(file_name):
-    if isfile(file_name):
-        return file_name
-    else:
-        return None
-
-
-def load_yaml(file_name):
-    try:
-        with open(file_name, 'r', encoding='utf-8') as settings_yaml:
-            settings = yaml.safe_load(settings_yaml)
-            if not isinstance(settings, dict) or len(settings) == 0:
-                raise SearxSettingsException('Empty file', file_name)
-            return settings
-    except IOError as e:
-        raise SearxSettingsException(e, file_name)
-    except yaml.YAMLError as e:
-        raise SearxSettingsException(e, file_name)
-
-
-def get_default_settings_path():
-    return check_settings_yml(join(searx_dir, 'settings.yml'))
-
-
-def get_user_settings_path():
-    # find location of settings.yml
-    if 'SEARX_SETTINGS_PATH' in environ:
-        # if possible set path to settings using the
-        # enviroment variable SEARX_SETTINGS_PATH
-        return check_settings_yml(environ['SEARX_SETTINGS_PATH'])
-    else:
-        # if not, get it from searx code base or last solution from /etc/searx
-        return check_settings_yml('/etc/searx/settings.yml')
-
-
-def update_dict(d, u):
-    for k, v in u.items():
-        if isinstance(v, collections.abc.Mapping):
-            d[k] = update_dict(d.get(k, {}), v)
-        else:
-            d[k] = v
-    return d
-
-
-def update_settings(default_settings, user_settings):
-    for k, v in user_settings.items():
-        if k == 'use_default_settings':
-            continue
-        elif k == 'engines':
-            default_engines = default_settings[k]
-            default_engines_dict = dict((definition['name'], definition) for definition in default_engines)
-            default_settings[k] = [update_dict(default_engines_dict[definition['name']], definition)
-                                   for definition in v]
-        else:
-            update_dict(default_settings[k], v)
-
-    return default_settings
-
-
-def load_settings(load_user_setttings=True):
-    default_settings_path = get_default_settings_path()
-    user_settings_path = get_user_settings_path()
-    if user_settings_path is None or not load_user_setttings:
-        # no user settings
-        return (load_yaml(default_settings_path),
-                'load the default settings from {}'.format(default_settings_path))
-
-    # user settings
-    user_settings = load_yaml(user_settings_path)
-    if user_settings.get('use_default_settings'):
-        # the user settings are merged with the default configuration
-        default_settings = load_yaml(default_settings_path)
-        update_settings(default_settings, user_settings)
-        return (default_settings,
-                'merge the default settings ( {} ) and the user setttings ( {} )'
-                .format(default_settings_path, user_settings_path))
-
-    # the user settings, fully replace the default configuration
-    return (user_settings,
-            'load the user settings from {}'.format(user_settings_path))
diff --git a/searx/settings_loader.py b/searx/settings_loader.py
new file mode 100644
index 000000000..172069bd5
--- /dev/null
+++ b/searx/settings_loader.py
@@ -0,0 +1,129 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+from os import environ
+from os.path import dirname, join, abspath, isfile
+from collections.abc import Mapping
+from itertools import filterfalse
+
+import yaml
+
+from searx.exceptions import SearxSettingsException
+
+
+searx_dir = abspath(dirname(__file__))
+
+
+def check_settings_yml(file_name):
+    if isfile(file_name):
+        return file_name
+    return None
+
+
+def load_yaml(file_name):
+    try:
+        with open(file_name, 'r', encoding='utf-8') as settings_yaml:
+            return yaml.safe_load(settings_yaml)
+    except IOError as e:
+        raise SearxSettingsException(e, file_name)
+    except yaml.YAMLError as e:
+        raise SearxSettingsException(e, file_name)
+
+
+def get_default_settings_path():
+    return check_settings_yml(join(searx_dir, 'settings.yml'))
+
+
+def get_user_settings_path():
+    # find location of settings.yml
+    if 'SEARX_SETTINGS_PATH' in environ:
+        # if possible set path to settings using the
+        # enviroment variable SEARX_SETTINGS_PATH
+        return check_settings_yml(environ['SEARX_SETTINGS_PATH'])
+
+    # if not, get it from searx code base or last solution from /etc/searx
+    return check_settings_yml('/etc/searx/settings.yml')
+
+
+def update_dict(default_dict, user_dict):
+    for k, v in user_dict.items():
+        if isinstance(v, Mapping):
+            default_dict[k] = update_dict(default_dict.get(k, {}), v)
+        else:
+            default_dict[k] = v
+    return default_dict
+
+
+def update_settings(default_settings, user_settings):
+    # merge everything except the engines
+    for k, v in user_settings.items():
+        if k not in ('use_default_settings', 'engines'):
+            update_dict(default_settings[k], v)
+
+    # parse the engines
+    remove_engines = None
+    keep_only_engines = None
+    use_default_settings = user_settings.get('use_default_settings')
+    if isinstance(use_default_settings, dict):
+        remove_engines = use_default_settings.get('engines', {}).get('remove')
+        keep_only_engines = use_default_settings.get('engines', {}).get('keep_only')
+
+    if 'engines' in user_settings or remove_engines is not None or keep_only_engines is not None:
+        engines = default_settings['engines']
+
+        # parse "use_default_settings.engines.remove"
+        if remove_engines is not None:
+            engines = list(filterfalse(lambda engine: (engine.get('name')) in remove_engines, engines))
+
+        # parse "use_default_settings.engines.keep_only"
+        if keep_only_engines is not None:
+            engines = list(filter(lambda engine: (engine.get('name')) in keep_only_engines, engines))
+
+        # parse "engines"
+        user_engines = user_settings.get('engines')
+        if user_engines:
+            engines_dict = dict((definition['name'], definition) for definition in engines)
+            for user_engine in user_engines:
+                default_engine = engines_dict.get(user_engine['name'])
+                if default_engine:
+                    update_dict(default_engine, user_engine)
+                else:
+                    engines.append(user_engine)
+
+        # store the result
+        default_settings['engines'] = engines
+
+    return default_settings
+
+
+def is_use_default_settings(user_settings):
+    use_default_settings = user_settings.get('use_default_settings')
+    if use_default_settings is True:
+        return True
+    if isinstance(use_default_settings, dict):
+        return True
+    if use_default_settings is False or use_default_settings is None:
+        return False
+    raise ValueError('Invalid value for use_default_settings')
+
+
+def load_settings(load_user_setttings=True):
+    default_settings_path = get_default_settings_path()
+    user_settings_path = get_user_settings_path()
+    if user_settings_path is None or not load_user_setttings:
+        # no user settings
+        return (load_yaml(default_settings_path),
+                'load the default settings from {}'.format(default_settings_path))
+
+    # user settings
+    user_settings = load_yaml(user_settings_path)
+    if is_use_default_settings(user_settings):
+        # the user settings are merged with the default configuration
+        default_settings = load_yaml(default_settings_path)
+        update_settings(default_settings, user_settings)
+        return (default_settings,
+                'merge the default settings ( {} ) and the user setttings ( {} )'
+                .format(default_settings_path, user_settings_path))
+
+    # the user settings, fully replace the default configuration
+    return (user_settings,
+            'load the user settings from {}'.format(user_settings_path))