new preferences handling

Preferences class was introduced in order to handle user preferences. Right now
it parses cookies and the form in preferences. Also it can retrieve settings
based on the name of the setting.

ATTENTION
Please note that engine preferences are handled differently from now on. So it
introduces incompatible changes. Every user who has saved preferences should reset and
save his/her settings again.

This change was needed, because everytime a default disabled engine was
added saved user preferences would broke. Now engine setting tracking is
fixed.

1 files changed, 36 insertions, 133 deletions

diff --git a/searx/webapp.py b/searx/webapp.py
index d10f04e21..7f0b56101 100644
--- a/searx/webapp.py
+++ b/searx/webapp.py
@@ -56,7 +56,7 @@ from searx.engines import (
 from searx.utils import (
     UnicodeWriter, highlight_content, html_to_text, get_themes,
     get_static_files, get_result_templates, gen_useragent, dict_subset,
-    prettify_url, get_blocked_engines
+    prettify_url
 )
 from searx.version import VERSION_STRING
 from searx.languages import language_codes
@@ -64,6 +64,7 @@ from searx.search import Search
 from searx.query import Query
 from searx.autocomplete import searx_bang, backends as autocomplete_backends
 from searx.plugins import plugins
+from searx.preferences import Preferences
 
 # check if the pyopenssl, ndg-httpsclient, pyasn1 packages are installed.
 # They are needed for SSL connection without trouble, see #298
@@ -109,8 +110,6 @@ for indice, theme in enumerate(themes):
     for (dirpath, dirnames, filenames) in os.walk(theme_img_path):
         global_favicons[indice].extend(filenames)
 
-cookie_max_age = 60 * 60 * 24 * 365 * 5  # 5 years
-
 _category_names = (gettext('files'),
                    gettext('general'),
                    gettext('music'),
@@ -222,9 +221,7 @@ def get_current_theme_name(override=None):
 
     if override and override in themes:
         return override
-    theme_name = request.args.get('theme',
-                                  request.cookies.get('theme',
-                                                      default_theme))
+    theme_name = request.args.get('theme', request.preferences.get_value('theme'))
     if theme_name not in themes:
         theme_name = default_theme
     return theme_name
@@ -262,12 +259,8 @@ def image_proxify(url):
 
 
 def render(template_name, override_theme=None, **kwargs):
-    blocked_engines = get_blocked_engines(engines, request.cookies)
-
-    autocomplete = request.cookies.get('autocomplete', settings['search']['autocomplete'])
-
-    if autocomplete not in autocomplete_backends:
-        autocomplete = None
+    blocked_engines = request.preferences.engines.get_disabled()
+    autocomplete = request.preferences.get_value('autocomplete')
 
     nonblocked_categories = set(category for engine_name in engines
                                 for category in engines[engine_name].categories
@@ -295,7 +288,7 @@ def render(template_name, override_theme=None, **kwargs):
                     kwargs['selected_categories'].append(c)
 
     if not kwargs['selected_categories']:
-        cookie_categories = request.cookies.get('categories', '').split(',')
+        cookie_categories = request.preferences.get_value('categories')
         for ccateg in cookie_categories:
             if ccateg in categories:
                 kwargs['selected_categories'].append(ccateg)
@@ -311,9 +304,9 @@ def render(template_name, override_theme=None, **kwargs):
 
     kwargs['searx_version'] = VERSION_STRING
 
-    kwargs['method'] = request.cookies.get('method', 'POST')
+    kwargs['method'] = request.preferences.get_value('method')
 
-    kwargs['safesearch'] = request.cookies.get('safesearch', str(settings['search']['safe_search']))
+    kwargs['safesearch'] = str(request.preferences.get_value('safesearch'))
 
     # override url_for function in templates
     kwargs['url_for'] = url_for_theme
@@ -347,14 +340,18 @@ def render(template_name, override_theme=None, **kwargs):
 @app.before_request
 def pre_request():
     # merge GET, POST vars
+    preferences = Preferences(themes, categories.keys(), engines, plugins)
+    preferences.parse_cookies(request.cookies)
+    request.preferences = preferences
+
     request.form = dict(request.form.items())
     for k, v in request.args.items():
         if k not in request.form:
             request.form[k] = v
 
     request.user_plugins = []
-    allowed_plugins = request.cookies.get('allowed_plugins', '').split(',')
-    disabled_plugins = request.cookies.get('disabled_plugins', '').split(',')
+    allowed_plugins = preferences.plugins.get_enabled()
+    disabled_plugins = preferences.plugins.get_disabled()
     for plugin in plugins:
         if ((plugin.default_on and plugin.id not in disabled_plugins)
                 or plugin.id in allowed_plugins):
@@ -486,7 +483,7 @@ def autocompleter():
         request_data = request.args
 
     # set blocked engines
-    blocked_engines = get_blocked_engines(engines, request.cookies)
+    blocked_engines = request.preferences.engines.get_disabled()
 
     # parse query
     query = Query(request_data.get('q', '').encode('utf-8'), blocked_engines)
@@ -496,8 +493,8 @@ def autocompleter():
     if not query.getSearchQuery():
         return '', 400
 
-    # get autocompleter
-    completer = autocomplete_backends.get(request.cookies.get('autocomplete', settings['search']['autocomplete']))
+    # run autocompleter
+    completer = autocomplete_backends.get(request.preferences.get_value('autocomplete'))
 
     # parse searx specific autocompleter results like !bang
     raw_results = searx_bang(query)
@@ -532,117 +529,23 @@ def autocompleter():
 
 @app.route('/preferences', methods=['GET', 'POST'])
 def preferences():
-    """Render preferences page.
-
-    Settings that are going to be saved as cookies."""
-    lang = None
-    image_proxy = request.cookies.get('image_proxy', settings['server'].get('image_proxy'))
-
-    if request.cookies.get('language')\
-       and request.cookies['language'] in (x[0] for x in language_codes):
-        lang = request.cookies['language']
-
-    blocked_engines = []
-
-    resp = make_response(redirect(urljoin(settings['server']['base_url'], url_for('index'))))
-
-    if request.method == 'GET':
-        blocked_engines = get_blocked_engines(engines, request.cookies)
-    else:  # on save
-        selected_categories = []
-        post_disabled_plugins = []
-        locale = None
-        autocomplete = ''
-        method = 'POST'
-        safesearch = settings['search']['safe_search']
-        for pd_name, pd in request.form.items():
-            if pd_name.startswith('category_'):
-                category = pd_name[9:]
-                if category not in categories:
-                    continue
-                selected_categories.append(category)
-            elif pd_name == 'locale' and pd in settings['locales']:
-                locale = pd
-            elif pd_name == 'image_proxy':
-                image_proxy = pd
-            elif pd_name == 'autocomplete':
-                autocomplete = pd
-            elif pd_name == 'language' and (pd == 'all' or
-                                            pd in (x[0] for
-                                                   x in language_codes)):
-                lang = pd
-            elif pd_name == 'method':
-                method = pd
-            elif pd_name == 'safesearch':
-                safesearch = pd
-            elif pd_name.startswith('engine_'):
-                if pd_name.find('__') > -1:
-                    # TODO fix underscore vs space
-                    engine_name, category = [x.replace('_', ' ') for x in
-                                             pd_name.replace('engine_', '', 1).split('__', 1)]
-                    if engine_name in engines and category in engines[engine_name].categories:
-                        blocked_engines.append((engine_name, category))
-            elif pd_name == 'theme':
-                theme = pd if pd in themes else default_theme
-            elif pd_name.startswith('plugin_'):
-                plugin_id = pd_name.replace('plugin_', '', 1)
-                if not any(plugin.id == plugin_id for plugin in plugins):
-                    continue
-                post_disabled_plugins.append(plugin_id)
-            else:
-                resp.set_cookie(pd_name, pd, max_age=cookie_max_age)
-
-        disabled_plugins = []
-        allowed_plugins = []
-        for plugin in plugins:
-            if plugin.default_on:
-                if plugin.id in post_disabled_plugins:
-                    disabled_plugins.append(plugin.id)
-            elif plugin.id not in post_disabled_plugins:
-                allowed_plugins.append(plugin.id)
-
-        resp.set_cookie('disabled_plugins', ','.join(disabled_plugins), max_age=cookie_max_age)
+    """Render preferences page && save user preferences"""
 
-        resp.set_cookie('allowed_plugins', ','.join(allowed_plugins), max_age=cookie_max_age)
-
-        resp.set_cookie(
-            'blocked_engines', ','.join('__'.join(e) for e in blocked_engines),
-            max_age=cookie_max_age
-        )
-
-        if locale:
-            resp.set_cookie(
-                'locale', locale,
-                max_age=cookie_max_age
-            )
-
-        if lang:
-            resp.set_cookie(
-                'language', lang,
-                max_age=cookie_max_age
-            )
-
-        if selected_categories:
-            # cookie max age: 4 weeks
-            resp.set_cookie(
-                'categories', ','.join(selected_categories),
-                max_age=cookie_max_age
-            )
-
-            resp.set_cookie(
-                'autocomplete', autocomplete,
-                max_age=cookie_max_age
-            )
-
-        resp.set_cookie('method', method, max_age=cookie_max_age)
-
-        resp.set_cookie('safesearch', str(safesearch), max_age=cookie_max_age)
-
-        resp.set_cookie('image_proxy', image_proxy, max_age=cookie_max_age)
-
-        resp.set_cookie('theme', theme, max_age=cookie_max_age)
-
-        return resp
+    # save preferences
+    if request.method == 'POST':
+        resp = make_response(redirect(urljoin(settings['server']['base_url'], url_for('index'))))
+        try:
+            request.preferences.parse_form(request.form)
+        except ValidationException:
+            # TODO use flash feature of flask
+            return resp
+        return request.preferences.save(resp)
+
+    # render preferences
+    image_proxy = request.preferences.get_value('image_proxy')
+    lang = request.preferences.get_value('language')
+    blocked_engines = request.preferences.engines.get_disabled()
+    allowed_plugins = request.preferences.plugins.get_enabled()
 
     # stats for preferences page
     stats = {}
@@ -664,7 +567,7 @@ def preferences():
     return render('preferences.html',
                   locales=settings['locales'],
                   current_locale=get_locale(),
-                  current_language=lang or 'all',
+                  current_language=lang,
                   image_proxy=image_proxy,
                   language_codes=language_codes,
                   engines_by_category=categories,
@@ -674,7 +577,7 @@ def preferences():
                   shortcuts={y: x for x, y in engine_shortcuts.items()},
                   themes=themes,
                   plugins=plugins,
-                  allowed_plugins=[plugin.id for plugin in request.user_plugins],
+                  allowed_plugins=allowed_plugins,
                   theme=get_current_theme_name())
 
 
@@ -750,7 +653,7 @@ Disallow: /preferences
 def opensearch():
     method = 'post'
 
-    if request.cookies.get('method', 'POST') == 'GET':
+    if request.preferences.get_value('method') == 'GET':
         method = 'get'
 
     # chrome/chromium only supports HTTP GET....