Merge pull request #2225 from dalf/processors

Processors

20 files changed, 786 insertions, 667 deletions

diff --git a/docs/admin/engines.rst b/docs/admin/engines.rst
index f1ac03699..0ec86a614 100644
--- a/docs/admin/engines.rst
+++ b/docs/admin/engines.rst
@@ -33,7 +33,7 @@ Engine        ..          Paging support       **P**
 ------------------------- -------------------- ------------
 Shortcut      **S**       Language support     **L**
 Timeout       **TO**      Time range support   **TR**
-Disabled      **D**       Offline              **O**
+Disabled      **D**       Engine type          **ET**
 ------------- ----------- -------------------- ------------
 Safe search   **SS**
 ------------- ----------- ---------------------------------
@@ -62,10 +62,10 @@ Show errors   **DE**
         - SS
         - D
         - TR
-        - O
-	- W
-	- D
-	- DE
+        - ET
+        - W
+        - D
+        - DE
 
       {% for name, mod in engines.items() %}
 
@@ -79,7 +79,7 @@ Show errors   **DE**
         - {{(mod.safesearch and "y") or ""}}
         - {{(mod.disabled and "y") or ""}}
         - {{(mod.time_range_support and "y") or ""}}
-        - {{(mod.offline and "y") or ""}}
+        - {{mod.engine_type or ""}}
         - {{mod.weight or 1 }}
         - {{(mod.disabled and "y") or ""}}
         - {{(mod.display_error_messages and "y") or ""}}
diff --git a/docs/dev/engine_overview.rst b/docs/dev/engine_overview.rst
index 3562ca61a..0d2c00e87 100644
--- a/docs/dev/engine_overview.rst
+++ b/docs/dev/engine_overview.rst
@@ -37,15 +37,16 @@ settings.  However, the standard way is the following:
 engine file
 -----------
 
-======================= =========== ===========================================
+======================= =========== ========================================================
 argument                type        information
-======================= =========== ===========================================
+======================= =========== ========================================================
 categories              list        pages, in which the engine is working
 paging                  boolean     support multible pages
 language_support        boolean     support language choosing
 time_range_support      boolean     support search time range
-offline                 boolean     engine runs offline
-======================= =========== ===========================================
+engine_type             str         ``online`` by default, other possibles values are 
+                                    ``offline``, ``online_dictionnary``, ``online_currency``
+======================= =========== ========================================================
 
 .. _engine settings:
 
@@ -111,22 +112,49 @@ passed arguments
 These arguments can be used to construct the search query.  Furthermore,
 parameters with default value can be redefined for special purposes.
 
+If the ``engine_type`` is ``online```:
+
+====================== ============== ========================================================================
+argument               type           default-value, information
+====================== ============== ========================================================================
+url                    str            ``''``
+method                 str            ``'GET'``
+headers                set            ``{}``
+data                   set            ``{}``
+cookies                set            ``{}``
+verify                 bool           ``True``
+headers.User-Agent     str            a random User-Agent
+category               str            current category, like ``'general'``
+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
+====================== ============== ========================================================================
+
+
+If the ``engine_type`` is ``online_dictionnary```, in addition to the ``online`` arguments:
+
 ====================== ============ ========================================================================
 argument               type         default-value, information
 ====================== ============ ========================================================================
-url                    string       ``''``
-method                 string       ``'GET'``
-headers                set          ``{}``
-data                   set          ``{}``
-cookies                set          ``{}``
-verify                 boolean      ``True``
-headers.User-Agent     string       a random User-Agent
-category               string       current category, like ``'general'``
-started                datetime     current date-time
-pageno                 int          current pagenumber
-language               string       specific language code like ``'en_US'``, or ``'all'`` if unspecified
+from_lang              str          specific language code like ``'en_US'``
+to_lang                str          specific language code like ``'en_US'``
+query                  str          the text query without the languages
 ====================== ============ ========================================================================
 
+If the ``engine_type`` is ``online_currency```, in addition to the ``online`` arguments:
+
+====================== ============ ========================================================================
+argument               type         default-value, information
+====================== ============ ========================================================================
+amount                 float        the amount to convert
+from                   str          ISO 4217 code
+to                     str          ISO 4217 code
+from_name              str          currency name
+to_name                str          currency name
+====================== ============ ========================================================================
+
+
 parsed arguments
 ----------------
 
@@ -137,12 +165,12 @@ request:
 =================== =========== ==========================================================================
 argument            type        information
 =================== =========== ==========================================================================
-url                 string      requested url
-method              string      HTTP request method
+url                 str         requested url
+method              str         HTTP request method
 headers             set         HTTP header information
-data                set         HTTP data information (parsed if ``method != 'GET'``)
+data                set         HTTP data information
 cookies             set         HTTP cookies
-verify              boolean     Performing SSL-Validity check
+verify              bool        Performing SSL-Validity check
 max_redirects       int         maximum redirects, hard limit
 soft_max_redirects  int         maximum redirects, soft limit. Record an error but don't stop the engine
 raise_for_httperror bool        True by default: raise an exception if the HTTP code of response is >= 300
diff --git a/searx/engines/__init__.py b/searx/engines/__init__.py
index b2a9b25a4..f2b7c5a84 100644
--- a/searx/engines/__init__.py
+++ b/searx/engines/__init__.py
@@ -53,7 +53,7 @@ engine_default_args = {'paging': False,
                        'suspend_end_time': 0,
                        'continuous_errors': 0,
                        'time_range_support': False,
-                       'offline': False,
+                       'engine_type': 'online',
                        'display_error_messages': True,
                        'tokens': []}
 
@@ -142,7 +142,9 @@ def load_engine(engine_data):
         'errors': 0
     }
 
-    if not engine.offline:
+    engine_type = getattr(engine, 'engine_type', 'online')
+
+    if engine_type != 'offline':
         engine.stats['page_load_time'] = 0
         engine.stats['page_load_count'] = 0
 
@@ -209,7 +211,7 @@ def get_engines_stats(preferences):
         else:
             score = score_per_result = 0.0
 
-        if not engine.offline:
+        if engine.engine_type != 'offline':
             load_times = 0
             if engine.stats['page_load_count'] != 0:
                 load_times = engine.stats['page_load_time'] / float(engine.stats['page_load_count'])  # noqa
@@ -300,7 +302,7 @@ def initialize_engines(engine_list):
 
 def _set_https_support_for_engine(engine):
     # check HTTPS support if it is not disabled
-    if not engine.offline and not hasattr(engine, 'https_support'):
+    if engine.engine_type != 'offline' and not hasattr(engine, 'https_support'):
         params = engine.request('http_test', {
             'method': 'GET',
             'headers': {},
diff --git a/searx/engines/command.py b/searx/engines/command.py
index 0268d52eb..6321e0004 100644
--- a/searx/engines/command.py
+++ b/searx/engines/command.py
@@ -23,7 +23,7 @@ from threading import Thread
 from searx import logger
 
 
-offline = True
+engine_type = 'offline'
 paging = True
 command = []
 delimiter = {}
diff --git a/searx/engines/currency_convert.py b/searx/engines/currency_convert.py
index 87e21d0af..7098dd3c7 100644
--- a/searx/engines/currency_convert.py
+++ b/searx/engines/currency_convert.py
@@ -1,54 +1,16 @@
 import json
-import re
-import unicodedata
-from searx.data import CURRENCIES  # NOQA
 
 
+engine_type = 'online_currency'
 categories = []
 url = 'https://duckduckgo.com/js/spice/currency/1/{0}/{1}'
 weight = 100
 
-parser_re = re.compile('.*?(\\d+(?:\\.\\d+)?) ([^.0-9]+) (?:in|to) ([^.0-9]+)', re.I)
 https_support = True
 
 
-def normalize_name(name):
-    name = name.lower().replace('-', ' ').rstrip('s')
-    name = re.sub(' +', ' ', name)
-    return unicodedata.normalize('NFKD', name).lower()
-
-
-def name_to_iso4217(name):
-    global CURRENCIES
-
-    name = normalize_name(name)
-    currency = CURRENCIES['names'].get(name, [name])
-    return currency[0]
-
-
-def iso4217_to_name(iso4217, language):
-    global CURRENCIES
-
-    return CURRENCIES['iso4217'].get(iso4217, {}).get(language, iso4217)
-
-
 def request(query, params):
-    m = parser_re.match(query)
-    if not m:
-        # wrong query
-        return params
-    amount, from_currency, to_currency = m.groups()
-    amount = float(amount)
-    from_currency = name_to_iso4217(from_currency.strip())
-    to_currency = name_to_iso4217(to_currency.strip())
-
-    params['url'] = url.format(from_currency, to_currency)
-    params['amount'] = amount
-    params['from'] = from_currency
-    params['to'] = to_currency
-    params['from_name'] = iso4217_to_name(from_currency, 'en')
-    params['to_name'] = iso4217_to_name(to_currency, 'en')
-
+    params['url'] = url.format(params['from'], params['to'])
     return params
 
 
diff --git a/searx/engines/dictzone.py b/searx/engines/dictzone.py
index 727eb6598..5e6f688a1 100644
--- a/searx/engines/dictzone.py
+++ b/searx/engines/dictzone.py
@@ -9,36 +9,24 @@
  @parse       url, title, content
 """
 
-import re
 from urllib.parse import urljoin
 from lxml import html
-from searx.utils import is_valid_lang, eval_xpath
+from searx.utils import eval_xpath
 
+
+engine_type = 'online_dictionnary'
 categories = ['general']
 url = 'https://dictzone.com/{from_lang}-{to_lang}-dictionary/{query}'
 weight = 100
 
-parser_re = re.compile('.*?([a-z]+)-([a-z]+) ([^ ]+)$', re.I)
 results_xpath = './/table[@id="r"]/tr'
 https_support = True
 
 
 def request(query, params):
-    m = parser_re.match(query)
-    if not m:
-        return params
-
-    from_lang, to_lang, query = m.groups()
-
-    from_lang = is_valid_lang(from_lang)
-    to_lang = is_valid_lang(to_lang)
-
-    if not from_lang or not to_lang:
-        return params
-
-    params['url'] = url.format(from_lang=from_lang[2],
-                               to_lang=to_lang[2],
-                               query=query)
+    params['url'] = url.format(from_lang=params['from_lang'][2],
+                               to_lang=params['to_lang'][2],
+                               query=params['query'])
 
     return params
 
diff --git a/searx/engines/translated.py b/searx/engines/translated.py
index 75b8b5f42..2706e3617 100644
--- a/searx/engines/translated.py
+++ b/searx/engines/translated.py
@@ -8,44 +8,26 @@
  @stable      yes
  @parse       url, title, content
 """
-import re
-from searx.utils import is_valid_lang
 
+engine_type = 'online_dictionnary'
 categories = ['general']
 url = 'https://api.mymemory.translated.net/get?q={query}&langpair={from_lang}|{to_lang}{key}'
 web_url = 'https://mymemory.translated.net/en/{from_lang}/{to_lang}/{query}'
 weight = 100
 https_support = True
 
-parser_re = re.compile('.*?([a-z]+)-([a-z]+) (.{2,})$', re.I)
 api_key = ''
 
 
 def request(query, params):
-    m = parser_re.match(query)
-    if not m:
-        return params
-
-    from_lang, to_lang, query = m.groups()
-
-    from_lang = is_valid_lang(from_lang)
-    to_lang = is_valid_lang(to_lang)
-
-    if not from_lang or not to_lang:
-        return params
-
     if api_key:
         key_form = '&key=' + api_key
     else:
         key_form = ''
-    params['url'] = url.format(from_lang=from_lang[1],
-                               to_lang=to_lang[1],
-                               query=query,
+    params['url'] = url.format(from_lang=params['from_lang'][1],
+                               to_lang=params['to_lang'][1],
+                               query=params['query'],
                                key=key_form)
-    params['query'] = query
-    params['from_lang'] = from_lang
-    params['to_lang'] = to_lang
-
     return params
 
 
diff --git a/searx/search.py b/searx/search.py
deleted file mode 100644
index 220950803..000000000
--- a/searx/search.py
+++ /dev/null
@@ -1,541 +0,0 @@
-'''
-searx is free software: you can redistribute it and/or modify
-it under the terms of the GNU Affero General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-searx is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU Affero General Public License for more details.
-
-You should have received a copy of the GNU Affero General Public License
-along with searx. If not, see < http://www.gnu.org/licenses/ >.
-
-(C) 2013- by Adam Tauber, <asciimoo@gmail.com>
-'''
-
-import typing
-import gc
-import threading
-from time import time
-from uuid import uuid4
-from urllib.parse import urlparse
-from _thread import start_new_thread
-
-import requests.exceptions
-import searx.poolrequests as requests_lib
-from searx.engines import engines, settings
-from searx.answerers import ask
-from searx.external_bang import get_bang_url
-from searx.utils import gen_useragent
-from searx.results import ResultContainer
-from searx import logger
-from searx.plugins import plugins
-from searx.exceptions import (SearxEngineAccessDeniedException, SearxEngineCaptchaException,
-                              SearxEngineTooManyRequestsException,)
-from searx.metrology.error_recorder import record_exception, record_error
-
-
-logger = logger.getChild('search')
-
-max_request_timeout = settings.get('outgoing', {}).get('max_request_timeout' or None)
-if max_request_timeout is None:
-    logger.info('max_request_timeout={0}'.format(max_request_timeout))
-else:
-    if isinstance(max_request_timeout, float):
-        logger.info('max_request_timeout={0} second(s)'.format(max_request_timeout))
-    else:
-        logger.critical('outgoing.max_request_timeout if defined has to be float')
-        import sys
-        sys.exit(1)
-
-
-class EngineRef:
-
-    __slots__ = 'name', 'category', 'from_bang'
-
-    def __init__(self, name: str, category: str, from_bang: bool=False):
-        self.name = name
-        self.category = category
-        self.from_bang = from_bang
-
-    def __repr__(self):
-        return "EngineRef({!r}, {!r}, {!r})".format(self.name, self.category, self.from_bang)
-
-    def __eq__(self, other):
-        return self.name == other.name and self.category == other.category and self.from_bang == other.from_bang
-
-
-class SearchQuery:
-    """container for all the search parameters (query, language, etc...)"""
-
-    __slots__ = 'query', 'engineref_list', 'categories', 'lang', 'safesearch', 'pageno', 'time_range',\
-                'timeout_limit', 'external_bang'
-
-    def __init__(self,
-                 query: str,
-                 engineref_list: typing.List[EngineRef],
-                 categories: typing.List[str],
-                 lang: str,
-                 safesearch: int,
-                 pageno: int,
-                 time_range: typing.Optional[str],
-                 timeout_limit: typing.Optional[float]=None,
-                 external_bang: typing.Optional[str]=None):
-        self.query = query
-        self.engineref_list = engineref_list
-        self.categories = categories
-        self.lang = lang
-        self.safesearch = safesearch
-        self.pageno = pageno
-        self.time_range = time_range
-        self.timeout_limit = timeout_limit
-        self.external_bang = external_bang
-
-    def __repr__(self):
-        return "SearchQuery({!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r})".\
-               format(self.query, self.engineref_list, self.categories, self.lang, self.safesearch,
-                      self.pageno, self.time_range, self.timeout_limit, self.external_bang)
-
-    def __eq__(self, other):
-        return self.query == other.query\
-            and self.engineref_list == other.engineref_list\
-            and self.categories == self.categories\
-            and self.lang == other.lang\
-            and self.safesearch == other.safesearch\
-            and self.pageno == other.pageno\
-            and self.time_range == other.time_range\
-            and self.timeout_limit == other.timeout_limit\
-            and self.external_bang == other.external_bang
-
-
-def send_http_request(engine, request_params):
-    # create dictionary which contain all
-    # informations about the request
-    request_args = dict(
-        headers=request_params['headers'],
-        cookies=request_params['cookies'],
-        verify=request_params['verify'],
-        auth=request_params['auth']
-    )
-
-    # setting engine based proxies
-    if hasattr(engine, 'proxies'):
-        request_args['proxies'] = requests_lib.get_proxies(engine.proxies)
-
-    # max_redirects
-    max_redirects = request_params.get('max_redirects')
-    if max_redirects:
-        request_args['max_redirects'] = max_redirects
-
-    # soft_max_redirects
-    soft_max_redirects = request_params.get('soft_max_redirects', max_redirects or 0)
-
-    # raise_for_status
-    request_args['raise_for_httperror'] = request_params.get('raise_for_httperror', False)
-
-    # specific type of request (GET or POST)
-    if request_params['method'] == 'GET':
-        req = requests_lib.get
-    else:
-        req = requests_lib.post
-
-    request_args['data'] = request_params['data']
-
-    # send the request
-    response = req(request_params['url'], **request_args)
-
-    # check soft limit of the redirect count
-    if len(response.history) > soft_max_redirects:
-        # unexpected redirect : record an error
-        # but the engine might still return valid results.
-        status_code = str(response.status_code or '')
-        reason = response.reason or ''
-        hostname = str(urlparse(response.url or '').netloc)
-        record_error(engine.name,
-                     '{} redirects, maximum: {}'.format(len(response.history), soft_max_redirects),
-                     (status_code, reason, hostname))
-
-    return response
-
-
-def search_one_http_request(engine, query, request_params):
-    # update request parameters dependent on
-    # search-engine (contained in engines folder)
-    engine.request(query, request_params)
-
-    # ignoring empty urls
-    if request_params['url'] is None:
-        return None
-
-    if not request_params['url']:
-        return None
-
-    # send request
-    response = send_http_request(engine, request_params)
-
-    # parse the response
-    response.search_params = request_params
-    return engine.response(response)
-
-
-def search_one_http_request_safe(engine_name, query, request_params, result_container, start_time, timeout_limit):
-    # set timeout for all HTTP requests
-    requests_lib.set_timeout_for_thread(timeout_limit, start_time=start_time)
-    # reset the HTTP total time
-    requests_lib.reset_time_for_thread()
-
-    #
-    engine = engines[engine_name]
-
-    # suppose everything will be alright
-    requests_exception = False
-    suspended_time = None
-
-    try:
-        # send requests and parse the results
-        search_results = search_one_http_request(engine, query, request_params)
-
-        # check if the engine accepted the request
-        if search_results is not None:
-            # yes, so add results
-            result_container.extend(engine_name, search_results)
-
-            # update engine time when there is no exception
-            engine_time = time() - start_time
-            page_load_time = requests_lib.get_time_for_thread()
-            result_container.add_timing(engine_name, engine_time, page_load_time)
-            with threading.RLock():
-                engine.stats['engine_time'] += engine_time
-                engine.stats['engine_time_count'] += 1
-                # update stats with the total HTTP time
-                engine.stats['page_load_time'] += page_load_time
-                engine.stats['page_load_count'] += 1
-    except Exception as e:
-        record_exception(engine_name, e)
-
-        # Timing
-        engine_time = time() - start_time
-        page_load_time = requests_lib.get_time_for_thread()
-        result_container.add_timing(engine_name, engine_time, page_load_time)
-
-        # Record the errors
-        with threading.RLock():
-            engine.stats['errors'] += 1
-
-        if (issubclass(e.__class__, requests.exceptions.Timeout)):
-            result_container.add_unresponsive_engine(engine_name, 'HTTP timeout')
-            # requests timeout (connect or read)
-            logger.error("engine {0} : HTTP requests timeout"
-                         "(search duration : {1} s, timeout: {2} s) : {3}"
-                         .format(engine_name, engine_time, timeout_limit, e.__class__.__name__))
-            requests_exception = True
-        elif (issubclass(e.__class__, requests.exceptions.RequestException)):
-            result_container.add_unresponsive_engine(engine_name, 'HTTP error')
-            # other requests exception
-            logger.exception("engine {0} : requests exception"
-                             "(search duration : {1} s, timeout: {2} s) : {3}"
-                             .format(engine_name, engine_time, timeout_limit, e))
-            requests_exception = True
-        elif (issubclass(e.__class__, SearxEngineCaptchaException)):
-            result_container.add_unresponsive_engine(engine_name, 'CAPTCHA required')
-            logger.exception('engine {0} : CAPTCHA')
-            suspended_time = e.suspended_time  # pylint: disable=no-member
-        elif (issubclass(e.__class__, SearxEngineTooManyRequestsException)):
-            result_container.add_unresponsive_engine(engine_name, 'too many requests')
-            logger.exception('engine {0} : Too many requests')
-            suspended_time = e.suspended_time  # pylint: disable=no-member
-        elif (issubclass(e.__class__, SearxEngineAccessDeniedException)):
-            result_container.add_unresponsive_engine(engine_name, 'blocked')
-            logger.exception('engine {0} : Searx is blocked')
-            suspended_time = e.suspended_time  # pylint: disable=no-member
-        else:
-            result_container.add_unresponsive_engine(engine_name, 'unexpected crash')
-            # others errors
-            logger.exception('engine {0} : exception : {1}'.format(engine_name, e))
-    else:
-        if getattr(threading.current_thread(), '_timeout', False):
-            record_error(engine_name, 'Timeout')
-
-    # suspend the engine if there is an HTTP error
-    # or suspended_time is defined
-    with threading.RLock():
-        if requests_exception or suspended_time:
-            # update continuous_errors / suspend_end_time
-            engine.continuous_errors += 1
-            if suspended_time is None:
-                suspended_time = min(settings['search']['max_ban_time_on_fail'],
-                                     engine.continuous_errors * settings['search']['ban_time_on_fail'])
-            engine.suspend_end_time = time() + suspended_time
-        else:
-            # reset the suspend variables
-            engine.continuous_errors = 0
-            engine.suspend_end_time = 0
-
-
-def record_offline_engine_stats_on_error(engine, result_container, start_time):
-    engine_time = time() - start_time
-    result_container.add_timing(engine.name, engine_time, engine_time)
-
-    with threading.RLock():
-        engine.stats['errors'] += 1
-
-
-def search_one_offline_request(engine, query, request_params):
-    return engine.search(query, request_params)
-
-
-def search_one_offline_request_safe(engine_name, query, request_params, result_container, start_time, timeout_limit):
-    engine = engines[engine_name]
-
-    try:
-        search_results = search_one_offline_request(engine, query, request_params)
-
-        if search_results:
-            result_container.extend(engine_name, search_results)
-
-            engine_time = time() - start_time
-            result_container.add_timing(engine_name, engine_time, engine_time)
-            with threading.RLock():
-                engine.stats['engine_time'] += engine_time
-                engine.stats['engine_time_count'] += 1
-
-    except ValueError as e:
-        record_exception(engine_name, e)
-        record_offline_engine_stats_on_error(engine, result_container, start_time)
-        logger.exception('engine {0} : invalid input : {1}'.format(engine_name, e))
-    except Exception as e:
-        record_exception(engine_name, e)
-        record_offline_engine_stats_on_error(engine, result_container, start_time)
-        result_container.add_unresponsive_engine(engine_name, 'unexpected crash', str(e))
-        logger.exception('engine {0} : exception : {1}'.format(engine_name, e))
-    else:
-        if getattr(threading.current_thread(), '_timeout', False):
-            record_error(engine_name, 'Timeout')
-
-
-def search_one_request_safe(engine_name, query, request_params, result_container, start_time, timeout_limit):
-    if engines[engine_name].offline:
-        return search_one_offline_request_safe(engine_name, query, request_params, result_container, start_time, timeout_limit)  # noqa
-    return search_one_http_request_safe(engine_name, query, request_params, result_container, start_time, timeout_limit)
-
-
-def search_multiple_requests(requests, result_container, start_time, timeout_limit):
-    search_id = uuid4().__str__()
-
-    for engine_name, query, request_params in requests:
-        th = threading.Thread(
-            target=search_one_request_safe,
-            args=(engine_name, query, request_params, result_container, start_time, timeout_limit),
-            name=search_id,
-        )
-        th._timeout = False
-        th._engine_name = engine_name
-        th.start()
-
-    for th in threading.enumerate():
-        if th.name == search_id:
-            remaining_time = max(0.0, timeout_limit - (time() - start_time))
-            th.join(remaining_time)
-            if th.is_alive():
-                th._timeout = True
-                result_container.add_unresponsive_engine(th._engine_name, 'timeout')
-                logger.warning('engine timeout: {0}'.format(th._engine_name))
-
-
-# get default reqest parameter
-def default_request_params():
-    return {
-        'method': 'GET',
-        'headers': {},
-        'data': {},
-        'url': '',
-        'cookies': {},
-        'verify': True,
-        'auth': None,
-        'raise_for_httperror': True
-    }
-
-
-class Search:
-    """Search information container"""
-
-    __slots__ = "search_query", "result_container", "start_time", "actual_timeout"
-
-    def __init__(self, search_query):
-        # init vars
-        super().__init__()
-        self.search_query = search_query
-        self.result_container = ResultContainer()
-        self.start_time = None
-        self.actual_timeout = None
-
-    def search_external_bang(self):
-        """
-        Check if there is a external bang.
-        If yes, update self.result_container and return True
-        """
-        if self.search_query.external_bang:
-            self.result_container.redirect_url = get_bang_url(self.search_query)
-
-            # This means there was a valid bang and the
-            # rest of the search does not need to be continued
-            if isinstance(self.result_container.redirect_url, str):
-                return True
-        return False
-
-    def search_answerers(self):
-        """
-        Check if an answer return a result.
-        If yes, update self.result_container and return True
-        """
-        answerers_results = ask(self.search_query)
-
-        if answerers_results:
-            for results in answerers_results:
-                self.result_container.extend('answer', results)
-            return True
-        return False
-
-    def _is_accepted(self, engine_name, engine):
-        # skip suspended engines
-        if engine.suspend_end_time >= time():
-            logger.debug('Engine currently suspended: %s', engine_name)
-            return False
-
-        # if paging is not supported, skip
-        if self.search_query.pageno > 1 and not engine.paging:
-            return False
-
-        # if time_range is not supported, skip
-        if self.search_query.time_range and not engine.time_range_support:
-            return False
-
-        return True
-
-    def _get_params(self, engineref, user_agent):
-        if engineref.name not in engines:
-            return None, None
-
-        engine = engines[engineref.name]
-
-        if not self._is_accepted(engineref.name, engine):
-            return None, None
-
-        # set default request parameters
-        request_params = {}
-        if not engine.offline:
-            request_params = default_request_params()
-            request_params['headers']['User-Agent'] = user_agent
-
-            if hasattr(engine, 'language') and engine.language:
-                request_params['language'] = engine.language
-            else:
-                request_params['language'] = self.search_query.lang
-
-            request_params['safesearch'] = self.search_query.safesearch
-            request_params['time_range'] = self.search_query.time_range
-
-        request_params['category'] = engineref.category
-        request_params['pageno'] = self.search_query.pageno
-
-        with threading.RLock():
-            engine.stats['sent_search_count'] += 1
-
-        return request_params, engine.timeout
-
-    # do search-request
-    def _get_requests(self):
-        # init vars
-        requests = []
-
-        # set default useragent
-        # user_agent = request.headers.get('User-Agent', '')
-        user_agent = gen_useragent()
-
-        # max of all selected engine timeout
-        default_timeout = 0
-
-        # start search-reqest for all selected engines
-        for engineref in self.search_query.engineref_list:
-            # set default request parameters
-            request_params, engine_timeout = self._get_params(engineref, user_agent)
-            if request_params is None:
-                continue
-
-            # append request to list
-            requests.append((engineref.name, self.search_query.query, request_params))
-
-            # update default_timeout
-            default_timeout = max(default_timeout, engine_timeout)
-
-        # adjust timeout
-        actual_timeout = default_timeout
-        query_timeout = self.search_query.timeout_limit
-
-        if max_request_timeout is None and query_timeout is None:
-            # No max, no user query: default_timeout
-            pass
-        elif max_request_timeout is None and query_timeout is not None:
-            # No max, but user query: From user query except if above default
-            actual_timeout = min(default_timeout, query_timeout)
-        elif max_request_timeout is not None and query_timeout is None:
-            # Max, no user query: Default except if above max
-            actual_timeout = min(default_timeout, max_request_timeout)
-        elif max_request_timeout is not None and query_timeout is not None:
-            # Max & user query: From user query except if above max
-            actual_timeout = min(query_timeout, max_request_timeout)
-
-        logger.debug("actual_timeout={0} (default_timeout={1}, ?timeout_limit={2}, max_request_timeout={3})"
-                     .format(actual_timeout, default_timeout, query_timeout, max_request_timeout))
-
-        return requests, actual_timeout
-
-    def search_standard(self):
-        """
-        Update self.result_container, self.actual_timeout
-        """
-        requests, self.actual_timeout = self._get_requests()
-
-        # send all search-request
-        if requests:
-            search_multiple_requests(requests, self.result_container, self.start_time, self.actual_timeout)
-            start_new_thread(gc.collect, tuple())
-
-        # return results, suggestions, answers and infoboxes
-        return True
-
-    # do search-request
-    def search(self):
-        self.start_time = time()
-
-        if not self.search_external_bang():
-            if not self.search_answerers():
-                self.search_standard()
-
-        return self.result_container
-
-
-class SearchWithPlugins(Search):
-    """Similar to the Search class but call the plugins."""
-
-    __slots__ = 'ordered_plugin_list', 'request'
-
-    def __init__(self, search_query, ordered_plugin_list, request):
-        super().__init__(search_query)
-        self.ordered_plugin_list = ordered_plugin_list
-        self.request = request
-
-    def search(self):
-        if plugins.call(self.ordered_plugin_list, 'pre_search', self.request, self):
-            super().search()
-
-        plugins.call(self.ordered_plugin_list, 'post_search', self.request, self)
-
-        results = self.result_container.get_ordered_results()
-
-        for result in results:
-            plugins.call(self.ordered_plugin_list, 'on_result', self.request, self, result)
-
-        return self.result_container
diff --git a/searx/search/__init__.py b/searx/search/__init__.py
new file mode 100644
index 000000000..4511463f3
--- /dev/null
+++ b/searx/search/__init__.py
@@ -0,0 +1,265 @@
+'''
+searx is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+searx is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with searx. If not, see < http://www.gnu.org/licenses/ >.
+
+(C) 2013- by Adam Tauber, <asciimoo@gmail.com>
+'''
+
+import typing
+import gc
+import threading
+from time import time
+from uuid import uuid4
+from _thread import start_new_thread
+
+from searx import settings
+from searx.answerers import ask
+from searx.external_bang import get_bang_url
+from searx.results import ResultContainer
+from searx import logger
+from searx.plugins import plugins
+from searx.search.processors import processors, initialize as initialize_processors
+
+
+logger = logger.getChild('search')
+
+max_request_timeout = settings.get('outgoing', {}).get('max_request_timeout' or None)
+if max_request_timeout is None:
+    logger.info('max_request_timeout={0}'.format(max_request_timeout))
+else:
+    if isinstance(max_request_timeout, float):
+        logger.info('max_request_timeout={0} second(s)'.format(max_request_timeout))
+    else:
+        logger.critical('outgoing.max_request_timeout if defined has to be float')
+        import sys
+        sys.exit(1)
+
+
+def initialize(settings_engines=None):
+    settings_engines = settings_engines or settings['engines']
+    initialize_processors(settings_engines)
+
+
+class EngineRef:
+
+    __slots__ = 'name', 'category', 'from_bang'
+
+    def __init__(self, name: str, category: str, from_bang: bool=False):
+        self.name = name
+        self.category = category
+        self.from_bang = from_bang
+
+    def __repr__(self):
+        return "EngineRef({!r}, {!r}, {!r})".format(self.name, self.category, self.from_bang)
+
+    def __eq__(self, other):
+        return self.name == other.name and self.category == other.category and self.from_bang == other.from_bang
+
+
+class SearchQuery:
+    """container for all the search parameters (query, language, etc...)"""
+
+    __slots__ = 'query', 'engineref_list', 'categories', 'lang', 'safesearch', 'pageno', 'time_range',\
+                'timeout_limit', 'external_bang'
+
+    def __init__(self,
+                 query: str,
+                 engineref_list: typing.List[EngineRef],
+                 categories: typing.List[str],
+                 lang: str,
+                 safesearch: int,
+                 pageno: int,
+                 time_range: typing.Optional[str],
+                 timeout_limit: typing.Optional[float]=None,
+                 external_bang: typing.Optional[str]=None):
+        self.query = query
+        self.engineref_list = engineref_list
+        self.categories = categories
+        self.lang = lang
+        self.safesearch = safesearch
+        self.pageno = pageno
+        self.time_range = time_range
+        self.timeout_limit = timeout_limit
+        self.external_bang = external_bang
+
+    def __repr__(self):
+        return "SearchQuery({!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r})".\
+               format(self.query, self.engineref_list, self.categories, self.lang, self.safesearch,
+                      self.pageno, self.time_range, self.timeout_limit, self.external_bang)
+
+    def __eq__(self, other):
+        return self.query == other.query\
+            and self.engineref_list == other.engineref_list\
+            and self.categories == self.categories\
+            and self.lang == other.lang\
+            and self.safesearch == other.safesearch\
+            and self.pageno == other.pageno\
+            and self.time_range == other.time_range\
+            and self.timeout_limit == other.timeout_limit\
+            and self.external_bang == other.external_bang
+
+
+class Search:
+    """Search information container"""
+
+    __slots__ = "search_query", "result_container", "start_time", "actual_timeout"
+
+    def __init__(self, search_query):
+        # init vars
+        super().__init__()
+        self.search_query = search_query
+        self.result_container = ResultContainer()
+        self.start_time = None
+        self.actual_timeout = None
+
+    def search_external_bang(self):
+        """
+        Check if there is a external bang.
+        If yes, update self.result_container and return True
+        """
+        if self.search_query.external_bang:
+            self.result_container.redirect_url = get_bang_url(self.search_query)
+
+            # This means there was a valid bang and the
+            # rest of the search does not need to be continued
+            if isinstance(self.result_container.redirect_url, str):
+                return True
+        return False
+
+    def search_answerers(self):
+        """
+        Check if an answer return a result.
+        If yes, update self.result_container and return True
+        """
+        answerers_results = ask(self.search_query)
+
+        if answerers_results:
+            for results in answerers_results:
+                self.result_container.extend('answer', results)
+            return True
+        return False
+
+    # do search-request
+    def _get_requests(self):
+        # init vars
+        requests = []
+
+        # max of all selected engine timeout
+        default_timeout = 0
+
+        # start search-reqest for all selected engines
+        for engineref in self.search_query.engineref_list:
+            processor = processors[engineref.name]
+
+            # set default request parameters
+            request_params = processor.get_params(self.search_query, engineref.category)
+            if request_params is None:
+                continue
+
+            # append request to list
+            requests.append((engineref.name, self.search_query.query, request_params))
+
+            # update default_timeout
+            default_timeout = max(default_timeout, processor.engine.timeout)
+
+        # adjust timeout
+        actual_timeout = default_timeout
+        query_timeout = self.search_query.timeout_limit
+
+        if max_request_timeout is None and query_timeout is None:
+            # No max, no user query: default_timeout
+            pass
+        elif max_request_timeout is None and query_timeout is not None:
+            # No max, but user query: From user query except if above default
+            actual_timeout = min(default_timeout, query_timeout)
+        elif max_request_timeout is not None and query_timeout is None:
+            # Max, no user query: Default except if above max
+            actual_timeout = min(default_timeout, max_request_timeout)
+        elif max_request_timeout is not None and query_timeout is not None:
+            # Max & user query: From user query except if above max
+            actual_timeout = min(query_timeout, max_request_timeout)
+
+        logger.debug("actual_timeout={0} (default_timeout={1}, ?timeout_limit={2}, max_request_timeout={3})"
+                     .format(actual_timeout, default_timeout, query_timeout, max_request_timeout))
+
+        return requests, actual_timeout
+
+    def search_multiple_requests(self, requests):
+        search_id = uuid4().__str__()
+
+        for engine_name, query, request_params in requests:
+            th = threading.Thread(
+                target=processors[engine_name].search,
+                args=(query, request_params, self.result_container, self.start_time, self.actual_timeout),
+                name=search_id,
+            )
+            th._timeout = False
+            th._engine_name = engine_name
+            th.start()
+
+        for th in threading.enumerate():
+            if th.name == search_id:
+                remaining_time = max(0.0, self.actual_timeout - (time() - self.start_time))
+                th.join(remaining_time)
+                if th.is_alive():
+                    th._timeout = True
+                    self.result_container.add_unresponsive_engine(th._engine_name, 'timeout')
+                    logger.warning('engine timeout: {0}'.format(th._engine_name))
+
+    def search_standard(self):
+        """
+        Update self.result_container, self.actual_timeout
+        """
+        requests, self.actual_timeout = self._get_requests()
+
+        # send all search-request
+        if requests:
+            self.search_multiple_requests(requests)
+            start_new_thread(gc.collect, tuple())
+
+        # return results, suggestions, answers and infoboxes
+        return True
+
+    # do search-request
+    def search(self):
+        self.start_time = time()
+
+        if not self.search_external_bang():
+            if not self.search_answerers():
+                self.search_standard()
+
+        return self.result_container
+
+
+class SearchWithPlugins(Search):
+    """Similar to the Search class but call the plugins."""
+
+    __slots__ = 'ordered_plugin_list', 'request'
+
+    def __init__(self, search_query, ordered_plugin_list, request):
+        super().__init__(search_query)
+        self.ordered_plugin_list = ordered_plugin_list
+        self.request = request
+
+    def search(self):
+        if plugins.call(self.ordered_plugin_list, 'pre_search', self.request, self):
+            super().search()
+
+        plugins.call(self.ordered_plugin_list, 'post_search', self.request, self)
+
+        results = self.result_container.get_ordered_results()
+
+        for result in results:
+            plugins.call(self.ordered_plugin_list, 'on_result', self.request, self, result)
+
+        return self.result_container
diff --git a/searx/search/processors/__init__.py b/searx/search/processors/__init__.py
new file mode 100644
index 000000000..4cae3cd0f
--- /dev/null
+++ b/searx/search/processors/__init__.py
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+from .online import OnlineProcessor
+from .offline import OfflineProcessor
+from .online_dictionary import OnlineDictionaryProcessor
+from .online_currency import OnlineCurrencyProcessor
+from .abstract import EngineProcessor
+from searx import logger
+import searx.engines as engines
+
+
+__all__ = ['EngineProcessor', 'OfflineProcessor', 'OnlineProcessor',
+           'OnlineDictionaryProcessor', 'OnlineCurrencyProcessor', 'processors']
+logger = logger.getChild('search.processors')
+processors = {}
+
+
+def get_processor_class(engine_type):
+    for c in [OnlineProcessor, OfflineProcessor, OnlineDictionaryProcessor, OnlineCurrencyProcessor]:
+        if c.engine_type == engine_type:
+            return c
+    return None
+
+
+def get_processor(engine, engine_name):
+    engine_type = getattr(engine, 'engine_type', 'online')
+    processor_class = get_processor_class(engine_type)
+    if processor_class:
+        return processor_class(engine, engine_name)
+    else:
+        return None
+
+
+def initialize(engine_list):
+    engines.initialize_engines(engine_list)
+    for engine_name, engine in engines.engines.items():
+        processor = get_processor(engine, engine_name)
+        if processor is None:
+            logger.error('Error get processor for engine %s', engine_name)
+        else:
+            processors[engine_name] = processor
diff --git a/searx/search/processors/abstract.py b/searx/search/processors/abstract.py
new file mode 100644
index 000000000..cf3fd7236
--- /dev/null
+++ b/searx/search/processors/abstract.py
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+from abc import abstractmethod
+from searx import logger
+
+
+logger = logger.getChild('searx.search.processor')
+
+
+class EngineProcessor:
+
+    def __init__(self, engine, engine_name):
+        self.engine = engine
+        self.engine_name = engine_name
+
+    def get_params(self, search_query, engine_category):
+        # if paging is not supported, skip
+        if search_query.pageno > 1 and not self.engine.paging:
+            return None
+
+        # if time_range is not supported, skip
+        if search_query.time_range and not self.engine.time_range_support:
+            return None
+
+        params = {}
+        params['category'] = engine_category
+        params['pageno'] = search_query.pageno
+        params['safesearch'] = search_query.safesearch
+        params['time_range'] = search_query.time_range
+
+        if hasattr(self.engine, 'language') and self.engine.language:
+            params['language'] = self.engine.language
+        else:
+            params['language'] = search_query.lang
+        return params
+
+    @abstractmethod
+    def search(self, query, params, result_container, start_time, timeout_limit):
+        pass
diff --git a/searx/search/processors/offline.py b/searx/search/processors/offline.py
new file mode 100644
index 000000000..ede8eb5e1
--- /dev/null
+++ b/searx/search/processors/offline.py
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+import threading
+from time import time
+from searx import logger
+from searx.metrology.error_recorder import record_exception, record_error
+from searx.search.processors.abstract import EngineProcessor
+
+
+logger = logger.getChild('search.processor.offline')
+
+
+class OfflineProcessor(EngineProcessor):
+
+    engine_type = 'offline'
+
+    def _record_stats_on_error(self, result_container, start_time):
+        engine_time = time() - start_time
+        result_container.add_timing(self.engine_name, engine_time, engine_time)
+
+        with threading.RLock():
+            self.engine.stats['errors'] += 1
+
+    def _search_basic(self, query, params):
+        return self.engine.search(query, params)
+
+    def search(self, query, params, result_container, start_time, timeout_limit):
+        try:
+            search_results = self._search_basic(query, params)
+
+            if search_results:
+                result_container.extend(self.engine_name, search_results)
+
+                engine_time = time() - start_time
+                result_container.add_timing(self.engine_name, engine_time, engine_time)
+                with threading.RLock():
+                    self.engine.stats['engine_time'] += engine_time
+                    self.engine.stats['engine_time_count'] += 1
+
+        except ValueError as e:
+            record_exception(self.engine_name, e)
+            self._record_stats_on_error(result_container, start_time)
+            logger.exception('engine {0} : invalid input : {1}'.format(self.engine_name, e))
+        except Exception as e:
+            record_exception(self.engine_name, e)
+            self._record_stats_on_error(result_container, start_time)
+            result_container.add_unresponsive_engine(self.engine_name, 'unexpected crash', str(e))
+            logger.exception('engine {0} : exception : {1}'.format(self.engine_name, e))
+        else:
+            if getattr(threading.current_thread(), '_timeout', False):
+                record_error(self.engine_name, 'Timeout')
diff --git a/searx/search/processors/online.py b/searx/search/processors/online.py
new file mode 100644
index 000000000..17bbfef0f
--- /dev/null
+++ b/searx/search/processors/online.py
@@ -0,0 +1,211 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+from urllib.parse import urlparse
+from time import time
+import threading
+
+import requests.exceptions
+
+import searx.poolrequests as poolrequests
+from searx.engines import settings
+from searx import logger
+from searx.utils import gen_useragent
+from searx.exceptions import (SearxEngineAccessDeniedException, SearxEngineCaptchaException,
+                              SearxEngineTooManyRequestsException,)
+from searx.metrology.error_recorder import record_exception, record_error
+
+from searx.search.processors.abstract import EngineProcessor
+
+
+logger = logger.getChild('search.processor.online')
+
+DEFAULT_PARAMS = {
+    'method': 'GET',
+    'headers': {},
+    'data': {},
+    'url': '',
+    'cookies': {},
+    'verify': True,
+    'auth': None
+}
+
+
+class OnlineProcessor(EngineProcessor):
+
+    engine_type = 'online'
+
+    def get_params(self, search_query, engine_category):
+        params = super().get_params(search_query, engine_category)
+        if params is None:
+            return None
+
+        # skip suspended engines
+        if self.engine.suspend_end_time >= time():
+            logger.debug('Engine currently suspended: %s', self.engine_name)
+            return None
+
+        # add default params
+        params.update(DEFAULT_PARAMS)
+
+        # add an user agent
+        params['headers']['User-Agent'] = gen_useragent()
+
+        return params
+
+    def _send_http_request(self, params):
+        # create dictionary which contain all
+        # informations about the request
+        request_args = dict(
+            headers=params['headers'],
+            cookies=params['cookies'],
+            verify=params['verify'],
+            auth=params['auth']
+        )
+
+        # setting engine based proxies
+        if hasattr(self.engine, 'proxies'):
+            request_args['proxies'] = poolrequests.get_proxies(self.engine.proxies)
+
+        # max_redirects
+        max_redirects = params.get('max_redirects')
+        if max_redirects:
+            request_args['max_redirects'] = max_redirects
+
+        # soft_max_redirects
+        soft_max_redirects = params.get('soft_max_redirects', max_redirects or 0)
+
+        # raise_for_status
+        request_args['raise_for_httperror'] = params.get('raise_for_httperror', False)
+
+        # specific type of request (GET or POST)
+        if params['method'] == 'GET':
+            req = poolrequests.get
+        else:
+            req = poolrequests.post
+
+        request_args['data'] = params['data']
+
+        # send the request
+        response = req(params['url'], **request_args)
+
+        # check soft limit of the redirect count
+        if len(response.history) > soft_max_redirects:
+            # unexpected redirect : record an error
+            # but the engine might still return valid results.
+            status_code = str(response.status_code or '')
+            reason = response.reason or ''
+            hostname = str(urlparse(response.url or '').netloc)
+            record_error(self.engine_name,
+                         '{} redirects, maximum: {}'.format(len(response.history), soft_max_redirects),
+                         (status_code, reason, hostname))
+
+        return response
+
+    def _search_basic(self, query, params):
+        # update request parameters dependent on
+        # search-engine (contained in engines folder)
+        self.engine.request(query, params)
+
+        # ignoring empty urls
+        if params['url'] is None:
+            return None
+
+        if not params['url']:
+            return None
+
+        # send request
+        response = self._send_http_request(params)
+
+        # parse the response
+        response.search_params = params
+        return self.engine.response(response)
+
+    def search(self, query, params, result_container, start_time, timeout_limit):
+        # set timeout for all HTTP requests
+        poolrequests.set_timeout_for_thread(timeout_limit, start_time=start_time)
+        # reset the HTTP total time
+        poolrequests.reset_time_for_thread()
+
+        # suppose everything will be alright
+        requests_exception = False
+        suspended_time = None
+
+        try:
+            # send requests and parse the results
+            search_results = self._search_basic(query, params)
+
+            # check if the engine accepted the request
+            if search_results is not None:
+                # yes, so add results
+                result_container.extend(self.engine_name, search_results)
+
+                # update engine time when there is no exception
+                engine_time = time() - start_time
+                page_load_time = poolrequests.get_time_for_thread()
+                result_container.add_timing(self.engine_name, engine_time, page_load_time)
+                with threading.RLock():
+                    self.engine.stats['engine_time'] += engine_time
+                    self.engine.stats['engine_time_count'] += 1
+                    # update stats with the total HTTP time
+                    self.engine.stats['page_load_time'] += page_load_time
+                    self.engine.stats['page_load_count'] += 1
+        except Exception as e:
+            record_exception(self.engine_name, e)
+
+            # Timing
+            engine_time = time() - start_time
+            page_load_time = poolrequests.get_time_for_thread()
+            result_container.add_timing(self.engine_name, engine_time, page_load_time)
+
+            # Record the errors
+            with threading.RLock():
+                self.engine.stats['errors'] += 1
+
+            if (issubclass(e.__class__, requests.exceptions.Timeout)):
+                result_container.add_unresponsive_engine(self.engine_name, 'HTTP timeout')
+                # requests timeout (connect or read)
+                logger.error("engine {0} : HTTP requests timeout"
+                             "(search duration : {1} s, timeout: {2} s) : {3}"
+                             .format(self.engine_name, engine_time, timeout_limit, e.__class__.__name__))
+                requests_exception = True
+            elif (issubclass(e.__class__, requests.exceptions.RequestException)):
+                result_container.add_unresponsive_engine(self.engine_name, 'HTTP error')
+                # other requests exception
+                logger.exception("engine {0} : requests exception"
+                                 "(search duration : {1} s, timeout: {2} s) : {3}"
+                                 .format(self.engine_name, engine_time, timeout_limit, e))
+                requests_exception = True
+            elif (issubclass(e.__class__, SearxEngineCaptchaException)):
+                result_container.add_unresponsive_engine(self.engine_name, 'CAPTCHA required')
+                logger.exception('engine {0} : CAPTCHA')
+                suspended_time = e.suspended_time  # pylint: disable=no-member
+            elif (issubclass(e.__class__, SearxEngineTooManyRequestsException)):
+                result_container.add_unresponsive_engine(self.engine_name, 'too many requests')
+                logger.exception('engine {0} : Too many requests')
+                suspended_time = e.suspended_time  # pylint: disable=no-member
+            elif (issubclass(e.__class__, SearxEngineAccessDeniedException)):
+                result_container.add_unresponsive_engine(self.engine_name, 'blocked')
+                logger.exception('engine {0} : Searx is blocked')
+                suspended_time = e.suspended_time  # pylint: disable=no-member
+            else:
+                result_container.add_unresponsive_engine(self.engine_name, 'unexpected crash')
+                # others errors
+                logger.exception('engine {0} : exception : {1}'.format(self.engine_name, e))
+        else:
+            if getattr(threading.current_thread(), '_timeout', False):
+                record_error(self.engine_name, 'Timeout')
+
+        # suspend the engine if there is an HTTP error
+        # or suspended_time is defined
+        with threading.RLock():
+            if requests_exception or suspended_time:
+                # update continuous_errors / suspend_end_time
+                self.engine.continuous_errors += 1
+                if suspended_time is None:
+                    suspended_time = min(settings['search']['max_ban_time_on_fail'],
+                                         self.engine.continuous_errors * settings['search']['ban_time_on_fail'])
+                self.engine.suspend_end_time = time() + suspended_time
+            else:
+                # reset the suspend variables
+                self.engine.continuous_errors = 0
+                self.engine.suspend_end_time = 0
diff --git a/searx/search/processors/online_currency.py b/searx/search/processors/online_currency.py
new file mode 100644
index 000000000..f0e919c03
--- /dev/null
+++ b/searx/search/processors/online_currency.py
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+import unicodedata
+import re
+
+from searx.data import CURRENCIES
+from .online import OnlineProcessor
+
+
+parser_re = re.compile('.*?(\\d+(?:\\.\\d+)?) ([^.0-9]+) (?:in|to) ([^.0-9]+)', re.I)
+
+
+def normalize_name(name):
+    name = name.lower().replace('-', ' ').rstrip('s')
+    name = re.sub(' +', ' ', name)
+    return unicodedata.normalize('NFKD', name).lower()
+
+
+def name_to_iso4217(name):
+    global CURRENCIES
+    name = normalize_name(name)
+    currency = CURRENCIES['names'].get(name, [name])
+    return currency[0]
+
+
+def iso4217_to_name(iso4217, language):
+    global CURRENCIES
+    return CURRENCIES['iso4217'].get(iso4217, {}).get(language, iso4217)
+
+
+class OnlineCurrencyProcessor(OnlineProcessor):
+
+    engine_type = 'online_currency'
+
+    def get_params(self, search_query, engine_category):
+        params = super().get_params(search_query, engine_category)
+        if params is None:
+            return None
+
+        m = parser_re.match(search_query.query)
+        if not m:
+            return None
+
+        amount_str, from_currency, to_currency = m.groups()
+        try:
+            amount = float(amount_str)
+        except ValueError:
+            return None
+        from_currency = name_to_iso4217(from_currency.strip())
+        to_currency = name_to_iso4217(to_currency.strip())
+
+        params['amount'] = amount
+        params['from'] = from_currency
+        params['to'] = to_currency
+        params['from_name'] = iso4217_to_name(from_currency, 'en')
+        params['to_name'] = iso4217_to_name(to_currency, 'en')
+        return params
diff --git a/searx/search/processors/online_dictionary.py b/searx/search/processors/online_dictionary.py
new file mode 100644
index 000000000..8e9ef1620
--- /dev/null
+++ b/searx/search/processors/online_dictionary.py
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+import re
+
+from searx.utils import is_valid_lang
+from .online import OnlineProcessor
+
+
+parser_re = re.compile('.*?([a-z]+)-([a-z]+) ([^ ]+)$', re.I)
+
+
+class OnlineDictionaryProcessor(OnlineProcessor):
+
+    engine_type = 'online_dictionnary'
+
+    def get_params(self, search_query, engine_category):
+        params = super().get_params(search_query, engine_category)
+        if params is None:
+            return None
+
+        m = parser_re.match(search_query.query)
+        if not m:
+            return None
+
+        from_lang, to_lang, query = m.groups()
+
+        from_lang = is_valid_lang(from_lang)
+        to_lang = is_valid_lang(to_lang)
+
+        if not from_lang or not to_lang:
+            return None
+
+        params['from_lang'] = from_lang
+        params['to_lang'] = to_lang
+        params['query'] = query
+
+        return params
diff --git a/searx/webapp.py b/searx/webapp.py
index ace5a12dc..5076355d0 100755
--- a/searx/webapp.py
+++ b/searx/webapp.py
@@ -60,7 +60,7 @@ from searx import brand, static_path
 from searx import settings, searx_dir, searx_debug
 from searx.exceptions import SearxParameterException
 from searx.engines import (
-    categories, engines, engine_shortcuts, get_engines_stats, initialize_engines
+    categories, engines, engine_shortcuts, get_engines_stats
 )
 from searx.webutils import (
     UnicodeWriter, highlight_content, get_resources_directory,
@@ -71,7 +71,7 @@ from searx.webadapter import get_search_query_from_webapp, get_selected_categori
 from searx.utils import html_to_text, gen_useragent, dict_subset, match_language
 from searx.version import VERSION_STRING
 from searx.languages import language_codes as languages
-from searx.search import SearchWithPlugins
+from searx.search import SearchWithPlugins, initialize
 from searx.query import RawTextQuery
 from searx.autocomplete import searx_bang, backends as autocomplete_backends
 from searx.plugins import plugins
@@ -131,7 +131,7 @@ werkzeug_reloader = flask_run_development or (searx_debug and __name__ == "__mai
 # initialize the engines except on the first run of the werkzeug server.
 if not werkzeug_reloader\
    or (werkzeug_reloader and os.environ.get("WERKZEUG_RUN_MAIN") == "true"):
-    initialize_engines(settings['engines'])
+    initialize()
 
 babel = Babel(app)
 
diff --git a/tests/unit/test_search.py b/tests/unit/test_search.py
index 464a9b37d..9938a43a5 100644
--- a/tests/unit/test_search.py
+++ b/tests/unit/test_search.py
@@ -3,7 +3,6 @@
 from searx.testing import SearxTestCase
 from searx.search import SearchQuery, EngineRef
 import searx.search
-import searx.engines
 
 
 SAFESEARCH = 0
@@ -39,7 +38,7 @@ class SearchTestCase(SearxTestCase):
 
     @classmethod
     def setUpClass(cls):
-        searx.engines.initialize_engines(TEST_ENGINES)
+        searx.search.initialize(TEST_ENGINES)
 
     def test_timeout_simple(self):
         searx.search.max_request_timeout = None
diff --git a/tests/unit/test_standalone_searx.py b/tests/unit/test_standalone_searx.py
index 74e31369f..06d70246a 100644
--- a/tests/unit/test_standalone_searx.py
+++ b/tests/unit/test_standalone_searx.py
@@ -8,8 +8,7 @@ import sys
 from mock import Mock, patch
 from nose2.tools import params
 
-from searx.search import SearchQuery, EngineRef
-from searx.engines import initialize_engines
+from searx.search import SearchQuery, EngineRef, initialize
 from searx.testing import SearxTestCase
 
 
@@ -30,7 +29,7 @@ class StandaloneSearx(SearxTestCase):
     def setUpClass(cls):
         engine_list = [{'engine': 'dummy', 'name': 'engine1', 'shortcut': 'e1'}]
 
-        initialize_engines(engine_list)
+        initialize(engine_list)
 
     def test_parse_argument_no_args(self):
         """Test parse argument without args."""
diff --git a/tests/unit/test_webadapter.py b/tests/unit/test_webadapter.py
index f620cf300..32417f019 100644
--- a/tests/unit/test_webadapter.py
+++ b/tests/unit/test_webadapter.py
@@ -17,7 +17,7 @@ TEST_ENGINES = [
         'categories': 'general',
         'shortcut': 'do',
         'timeout': 3.0,
-        'offline': True,
+        'engine_type': 'offline',
         'tokens': ['my-token'],
     },
 ]
@@ -28,7 +28,7 @@ class ValidateQueryCase(SearxTestCase):
 
     @classmethod
     def setUpClass(cls):
-        searx.engines.initialize_engines(TEST_ENGINES)
+        searx.search.initialize(TEST_ENGINES)
 
     def test_query_private_engine_without_token(self):
         preferences = Preferences(['oscar'], ['general'], engines, [])
diff --git a/utils/standalone_searx.py b/utils/standalone_searx.py
index 0a35cc4a2..c52035fb9 100755
--- a/utils/standalone_searx.py
+++ b/utils/standalone_searx.py
@@ -6,8 +6,8 @@ Getting categories without initiate the engine will only return `['general']`
 >>> import searx.engines
 ... list(searx.engines.categories.keys())
 ['general']
->>> import searx
-... searx.engines.initialize_engines(searx.settings['engines'])
+>>> import searx.search
+... searx.search.initialize()
 ... list(searx.engines.categories.keys())
 ['general', 'it', 'science', 'images', 'news', 'videos', 'music', 'files', 'social media', 'map']
 
@@ -22,11 +22,11 @@ Example to run it from python:
 >>> import importlib
 ... import json
 ... import sys
-... import searx
 ... import searx.engines
+... import searx.search
 ... search_query = 'rain'
 ... # initialize engines
-... searx.engines.initialize_engines(searx.settings['engines'])
+... searx.search.initialize()
 ... # load engines categories once instead of each time the function called
 ... engine_cs = list(searx.engines.categories.keys())
 ... # load module
@@ -82,7 +82,6 @@ from json import dumps
 from typing import Any, Dict, List, Optional
 
 import searx
-import searx.engines
 import searx.preferences
 import searx.query
 import searx.search
@@ -208,7 +207,7 @@ def parse_argument(
 
 
 if __name__ == '__main__':
-    searx.engines.initialize_engines(searx.settings['engines'])
+    searx.search.initialize()
     engine_cs = list(searx.engines.categories.keys())
     prog_args = parse_argument(category_choices=engine_cs)
     search_q = get_search_query(prog_args, engine_categories=engine_cs)